Radiation sensitization agents for prostate cancer

This application is a 35 U.S.C. §371 U.S. national stage entry of International Application PCT/US2011/044997 (WO 2012/012710) having an International filing date of Jul. 22, 2011 which claims the benefit of the following U.S. Provisional Application No. 61/366,734, filed Jul. 22, 2010, the entire contents of which are incorporated herein by reference.

This work was supported by the following grant from the National Institutes of Health, Grant No: 5P50CA058236-15. The government has certain rights in the invention.

An estimated 1 in 6 men will be diagnosed with prostate cancer (PCa). Although the majority of these men can be successfully treated with surgery or radiation therapy, approximately 20%-40% will biochemically recur within 10 years of treatment. This risk of recurrence is elevated to approximately 50% for men with locally advanced disease, a condition that is primarily managed by radiation therapy. Thus, there is a need for new technologies that improve the therapeutic index of radiation therapy for local disease because these will significantly decrease the morbidity and mortality of PCa.

As described below, the present invention features aptamer-inhibitory nucleic acid molecules that radiosensitize neoplastic cells expressing tumor antigens that bind the aptamer and methods of using aptamer-inhibitory nucleic acid molecules to radiosensitize neoplastic cells.

In one aspect, the invention generally features a method of sensitizing a neoplastic cell to ionizing radiation, the method involving contacting the neoplastic cell with an effective amount of an aptamer-inhibitory nucleic acid chimera.

In another aspect, the invention generally features a method of inducing cell death or terminal differentiation in a neoplastic cell, the method involving contacting the neoplastic cell with an effective amount of an aptamer-inhibitory nucleic acid chimera, and exposing the neoplastic cell to ionizing radiation.

In another aspect, the invention features a method of reducing the growth, proliferation or survival of a neoplastic cell, the method involving contacting the neoplastic cell with an effective amount of an aptamer-inhibitory nucleic acid chimera, and exposing the neoplastic cell to ionizing radiation.

In yet another aspect, the invention features a method of treating neoplasia in a subject involving administering an aptamer-inhibitory nucleic acid chimera to the subject; and exposing the neoplasia to ionizing radiation, thereby treating neoplasia in the subject.

In yet another aspect, the invention features a method of treating prostate cancer in a subject in need thereof involving administering an aptamer-shRNA chimera to the subject, wherein the aptamer-shRNA chimera specifically binds prostate-specific membrane antigen (PSMA), and wherein the shRNA decreases the expression of ACLY, BRCA2, DNMT1, LDHA, MAD2L2, NBN, NONO, DNAPK, RAD23B, or RAD54L; and exposing the subject to ionizing radiation, thereby treating prostate cancer in the subject.

In yet another aspect, the invention features a method of inhibiting angiogenesis in a neoplasia, the method involving contacting neovascular endothelia cells with an effective amount of an aptamer-inhibitory nucleic acid chimera, and exposing the neovascular endothelia cells to ionizing radiation.

In yet another aspect, the invention generally features an oligonucleotide containing an aptamer covalently linked to an shRNA.

In various embodiments of any of the above aspects or any other aspect of the invention delinated herein, the neoplastic cell is in a subject. In another embodiment the inhibitory nucleic acid is selected from the group consisting of shRNA, siRNA, and ribozyme. In further embodiments the inhibitory nucleic acid is siRNA. In other embodiments the aptamer-inhibitory nucleic acid chimera decreases the expression of a target gene. In another embodiment the target gene encodes a DNA repair protein. In yet another embodiment the target gene is selected from the group consisting of ACLY, BRCA2, DNMT1, LDHA, MAD2L2, NBN, NONO, DNAPK, RAD23B, and RAD54L. In further embodiments decreasing the expression of the target gene sensitizes the neoplastic cell to ionizing radiation. In other embodiments the aptamer-inhibitory nucleic acid chimera specifically binds a cell surface molecule. In another embodiment the cell surface molecule is a tumor antigen. In yet another embodiment the tumor antigen is selected from Muc1, HER2, TGFbeta-receptor, Guanylyl Cyclase C (GC-C), PCSA, or prostate-specific membrane antigen (PSMA). In further embodiments the tumor antigen is prostate-specific membrane antigen (PSMA). In other embodiments the aptamer-inhibitory nucleic acid chimera comprises A10-3. In another embodiment the aptamer-inhibitory nucleic acid chimera comprises modified nucleotides. In further embodiments the modified nucleotides are selected from 2′-fluoro-modified pyrimidines, locked-nucleic acids (LNAs), 2′-O-methyl-modified nucleotides, and 2′-amino-modified nucleotides. In other embodiments the modified nucleotides comprise 2′-fluoro-modified pyrimidines. In another embodiment the method is carried out in vivo. In yet another embodiment the aptamer-inhibitory nucleic acid chimera is selected from any of the aptamer-inhibitory nucleic acid chimeras of Table 4. In further embodiments the neoplastic cell is in a subject diagnosed as having a neoplasia selected from the group consisting of prostate cancer, breast cancer, colon cancer, pancreatic cancer, and lung cancer. In other embodiments the method sensitizes the neoplasia to ionizing radiation. In another embodiment the subject is a mammal. In another embodiment the subject is a human.

Compositions and articles defined by the invention were isolated or otherwise manufactured in connection with the examples provided below. Other features and advantages of the invention will be apparent from the detailed description, and from the claims.

By “aptamer” is meant an oligonucleotide that is capable of forming a complex with an intended target substance. The complexation is target-specific in the sense that other materials which may accompany the target do not complex to the aptamer. It is recognized that complexation and affinity are a matter of degree; however, in this context, “target-specific” means that the aptamer binds to target with a much higher degree of affinity than it binds to contaminating materials. The meaning of specificity in this context is thus similar to the meaning of specificity as applied to antibodies, for example.

By “small hairpin RNA” or “shRNA” is meant an oligonucleotide that consists of a stem-loop structure with optional 3′ UU-overhangs. While there may be variation, stems can range from 19 to 31 bp (desirably 25 to 29 bp), and the loops can range from 4 to 30 bp (desirably 4 to 23 bp).

By “aptamer-shRNA chimera” is meant an oligonucleotide that comprises an aptamer covalently linked to an shRNA such that the aptamer retains its ability to bind to its cognate target molecule, and the shRNA is properly processed by the cell to act as an siRNA that inhibits the expression of a target protein.

By “ACLY” is meant a gene that transcribes an RNA having at least 85% nucleotide sequence identity to NM — 001096 or NM — 198830. An exemplary ACLY sequence is provided below:

By “BRCA2” is meant a gene that transcribes an RNA having at least 85% nucleotide sequence identity to NM — 000059. An exemplary BRCA2 sequence is provided below:

By “DNMT1” is meant a gene that transcribes an RNA having at least 85% nucleotide sequence identity to NM — 001130823 NM — 001379. An exemplary DNMT1 sequence is provided below:

By “LDHA” is meant a gene that transcribes an RNA having at least 85% nucleotide sequence identity to NM — 005566, NM — 001135239, NM — 001165414, NM — 001165415, NM — 001165416, or NR — 028500. An exemplary LDHA sequence is provided below:

By “MAD2L2” is meant a gene that transcribes an RNA having at least 85% nucleotide sequence identity to NM — 001127325, NM — 006341, or BC015244.

By “NBN” is meant a gene that transcribes an RNA having at least 85% nucleotide sequence identity to NM — 002485. An exemplary NBN sequence is provided below:

By “NONO” is meant a gene that transcribes an RNA having at least 85% nucleotide sequence identity to NM — 001145408, NM — 007363, NM — 001145409, or NM — 001145410. An exemplary NONO sequence is provided below:

By “DNAPK” is meant a gene that transcribes an RNA having at least 85% nucleotide sequence identity to NM — 006904 or NM — 001081640. DNAPK is also refered to as PRKDC. An exemplary DNAPK sequence is provided below:

By “RAD23B” is meant a gene that transcribes an RNA having at least 85% nucleotide sequence identity to NM — 002874. An exemplary RAD23B sequence is provided below:

By “RAD54L” is meant a gene that transcribes an RNA having at least 85% nucleotide sequence identity to NM — 003579 or NM — 001142548. An exemplary RAD54L sequence is provided below:

By “PSMA” is meant prostate-specific membrane antigen, a polypeptide having at least 85% amino acid sequence identity to NP — 004467, NP00104986, NP — 001180400, NP — 001180401, or NP — 001180402.

By “A10-3” is meant an aptamer as shown in FIG. 13 .

By “agent” is meant any small molecule chemical compound, antibody, nucleic acid molecule, or polypeptide, or fragments thereof.

By “ameliorate” is meant to decrease, suppress, attenuate, diminish, arrest, or stabilize the development or progression of a disease.

By “alteration” is meant a change (increase or decrease) in the expression levels or activity of a gene or polypeptide as detected by standard art known methods such as those described herein. As used herein, an alteration includes a 10% change in expression levels, preferably a 25% change, more preferably a 40% change, and most preferably a 50% or greater change in expression levels.

By “analog” is meant a molecule that is not identical, but has analogous functional or structural features. For example, a polypeptide analog retains the biological activity of a corresponding naturally-occurring polypeptide, while having certain biochemical modifications that enhance the analog's function relative to a naturally occurring polypeptide. Such biochemical modifications could increase the analog's protease resistance, membrane permeability, or half-life, without altering, for example, ligand binding. An analog may include an unnatural amino acid.

The term “cancer” refers to a malignant tumor of potentially unlimited growth that expands locally by invasion and systemically by metastasis.

The term “carcinoma” is art recognized and refers to malignancies of epithelial or endocrine tissues including respiratory system carcinomas, gastrointestinal system carcinomas, genitourinary system carcinomas, testicular carcinomas, breast carcinomas, prostatic carcinomas, endocrine system carcinomas, and melanomas. Exemplary carcinomas include those forming from tissue of the cervix, lung, prostate, breast, head and neck, colon, pancreas and ovary. The term also includes carcinosarcomas, e.g., which include malignant tumors composed of carcinomatous and sarcomatous tissues. An “adenocarcinoma” refers to a carcinoma derived from glandular tissue or in which the tumor cells form recognizable glandular structures.

In this disclosure, “comprises,” “comprising,” “containing” and “having” and the like can have the meaning ascribed to them in U.S. Patent law and can mean “includes,” “including,” and the like; “consisting essentially of” or “consists essentially” likewise has the meaning ascribed in U.S. Patent law and the term is open-ended, allowing for the presence of more than that which is recited so long as basic or novel characteristics of that which is recited is not changed by the presence of more than that which is recited, but excludes prior art embodiments.

“Detect” refers to identifying the presence, absence or amount of the analyte to be detected.

By “detectable label” is meant a composition that when linked to a molecule of interest renders the latter detectable, via spectroscopic, photochemical, biochemical, immunochemical, or chemical means. For example, useful labels include radioactive isotopes, magnetic beads, metallic beads, colloidal particles, fluorescent dyes, electron-dense reagents, enzymes (for example, as commonly used in an ELISA), biotin, digoxigenin, or haptens.

By “disease” is meant any condition or disorder that damages or interferes with the normal function of a cell, tissue, or organ. Examples of diseases include cancer, in particular, any cancer that is amenable to treatment with ionizing radiation. Specific, non-limiting, examples of disease include prostate cancer, colon cancer, breast cancer, pancreatic cancer, and lung cancer.

By “effective amount” is meant the amount required to ameliorate the symptoms of a disease relative to an untreated patient. The effective amount of active compound(s) used to practice the present invention for therapeutic treatment of a disease varies depending upon the manner of administration, the age, body weight, and general health of the subject. Therapeutic treatment can be achieved upon single or multiple dose administration to a subject. Ultimately, the attending physician or veterinarian will decide the appropriate amount and dosage regimen. Such amount is referred to as an “effective” amount.

The invention provides a number of targets that are useful for the development of highly specific drugs to treat or a disorder characterized by the methods delineated herein. In addition, the methods of the invention provide a facile means to identify therapies that are safe for use in subjects. In addition, the methods of the invention provide a route for analyzing virtually any number of compounds for effects on a disease described herein with high-volume throughput, high sensitivity, and low complexity.

By “fragment” is meant a portion of a polypeptide or nucleic acid molecule. This portion contains, preferably, at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of the entire length of the reference nucleic acid molecule or polypeptide. A fragment may contain 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100, 200, 300, 400, 500, 600, 700, 800, 900, or 1000 nucleotides or amino acids.

“Hybridization” means hydrogen bonding, which may be Watson-Crick, Hoogsteen or reversed Hoogsteen hydrogen bonding, between complementary nucleobases. For example, adenine and thymine are complementary nucleobases that pair through the formation of hydrogen bonds.

By “inhibitory nucleic acid” is meant a double-stranded RNA, siRNA, shRNA, or antisense RNA, or a portion thereof, or a mimetic thereof, that when administered to a mammalian cell results in a decrease (e.g., by 10%, 25%, 50%, 75%, or even 90-100%) in the expression of a target gene. Typically, a nucleic acid inhibitor comprises at least a portion of a target nucleic acid molecule, or an ortholog thereof, or comprises at least a portion of the complementary strand of a target nucleic acid molecule. For example, an inhibitory nucleic acid molecule comprises at least a portion of any or all of the nucleic acids delineated herein.

By “isolated polynucleotide” is meant a nucleic acid (e.g., a DNA) that is free of the genes which, in the naturally-occurring genome of the organism from which the nucleic acid molecule of the invention is derived, flank the gene. The term therefore includes, for example, a recombinant DNA that is incorporated into a vector; into an autonomously replicating plasmid or virus; or into the genomic DNA of a prokaryote or eukaryote; or that exists as a separate molecule (for example, a cDNA or a genomic or cDNA fragment produced by PCR or restriction endonuclease digestion) independent of other sequences. In addition, the term includes an RNA molecule that is transcribed from a DNA molecule, as well as a recombinant DNA that is part of a hybrid gene encoding additional polypeptide sequence.

By an “isolated polypeptide” is meant a polypeptide of the invention that has been separated from components that naturally accompany it. Typically, the polypeptide is isolated when it is at least 60%, by weight, free from the proteins and naturally-occurring organic molecules with which it is naturally associated. Preferably, the preparation is at least 75%, more preferably at least 90%, and most preferably at least 99%, by weight, a polypeptide of the invention. An isolated polypeptide of the invention may be obtained, for example, by extraction from a natural source, by expression of a recombinant nucleic acid encoding such a polypeptide; or by chemically synthesizing the protein. Purity can be measured by any appropriate method, for example, column chromatography, polyacrylamide gel electrophoresis, or by HPLC analysis.

The term “neoplastic” refers to those cells having the capacity for autonomous growth, e.g., an abnormal state or condition characterized by rapidly proliferating cell growth. A neoplastic disease state may be categorized as pathologic, e.g., characterizing or constituting a disease state, or may be categorized as non-pathologic, e.g., a deviation from normal but not associated with a disease state. The term is meant to include all types of cancerous growths or oncogenic processes, metastatic tissues or malignantly transformed cells, tissues, or organs, irrespective of histopathologic type or stage of invasiveness. “Pathologic hyperproliferative” cells occur in disease states characterized by malignant tumor growth. Examples of non-pathologic hyperproliferative cells include proliferation of cells associated with wound repair.

The language “inhibiting the growth” of the neoplasm includes the slowing, interrupting, arresting or stopping its growth and metastases and does not necessarily indicate a total elimination of the neoplastic growth.

The common medical meaning of the term “neoplasia” refers to “new cell growth” that results as a loss of responsiveness to normal growth controls, e.g. to neoplastic cell growth. A “hyperplasia” refers to cells undergoing an abnormally high rate of growth. However, as used herein, the term neoplasia generally refers to cells experiencing abnormal cell growth rates. Neoplasias include “tumors,” which may be either benign, premalignant or malignant.

As used herein, “obtaining” as in “obtaining an agent” includes synthesizing, purchasing, or otherwise acquiring the agent.

“Primer set” means a set of oligonucleotides that may be used, for example, for PCR. A primer set would consist of at least 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 30, 40, 50, 60, 80, 100, 200, 250, 300, 400, 500, 600, or more primers.

By “reduces” is meant a negative alteration of at least 10%, 25%, 50%, 75%, or 100%.

By “reference” is meant a standard or control.

A “reference sequence” is a defined sequence used as a basis for sequence comparison. A reference sequence may be a subset of or the entirety of a specified sequence; for example, a segment of a full-length cDNA or gene sequence, or the complete cDNA or gene sequence. For polypeptides, the length of the reference polypeptide sequence can be at least about 16 amino acids, at least about 20 amino acids, at least about 25 amino acids, or about 35 amino acids, about 50 amino acids, or about 100 amino acids. For nucleic acids, the length of the reference nucleic acid sequence can be at least about 50 nucleotides, at least about 60 nucleotides, at least about 75 nucleotides, or about 100 nucleotides or about 300 nucleotides or any integer thereabout or therebetween.

By “siRNA” is meant a double stranded RNA. Optimally, an siRNA is 18, 19, 20, 21, 22, 23 or 24 nucleotides in length and has a 2 base overhang at its 3′ end. These dsRNAs can be introduced to an individual cell or to a whole animal; for example, they may be introduced systemically via the bloodstream. Such siRNAs are used to downregulate mRNA levels or promoter activity.

By “specifically binds” is meant a compound or antibody that recognizes and binds a polypeptide of the invention, but which does not substantially recognize and bind other molecules in a sample, for example, a biological sample, which naturally includes a polypeptide of the invention.

Nucleic acid molecules useful in the methods of the invention include any nucleic acid molecule that encodes a polypeptide of the invention or a fragment thereof. Such nucleic acid molecules need not be 100% identical with an endogenous nucleic acid sequence, but will typically exhibit substantial identity. Polynucleotides having “substantial identity” to an endogenous sequence are typically capable of hybridizing with at least one strand of a double-stranded nucleic acid molecule. Nucleic acid molecules useful in the methods of the invention include any nucleic acid molecule that encodes a polypeptide of the invention or a fragment thereof. Such nucleic acid molecules need not be 100% identical with an endogenous nucleic acid sequence, but will typically exhibit substantial identity. Polynucleotides having “substantial identity” to an endogenous sequence are typically capable of hybridizing with at least one strand of a double-stranded nucleic acid molecule. By “hybridize” is meant a pair to form a double-stranded molecule between complementary polynucleotide sequences (e.g., a gene described herein), or portions thereof, under various conditions of stringency. (See, e.g., Wahl, G. M. and S. L. Berger (1987) Methods Enzymol. 152:399; Kimmel, A. R. (1987) Methods Enzymol. 152:507).

For example, stringent salt concentration will ordinarily be less than about 750 mM NaCl and 75 mM trisodium citrate, preferably less than about 500 mM NaCl and 50 mM trisodium citrate, and more preferably less than about 250 mM NaCl and 25 mM trisodium citrate. Low stringency hybridization can be obtained in the absence of organic solvent, e.g., formamide, while high stringency hybridization can be obtained in the presence of at least about 35% formamide, and more preferably at least about 50% formamide. Stringent temperature conditions can include temperatures of at least about 30° C., of at least about 37° C., or at least about 42° C. Varying additional parameters, such as hybridization time, the concentration of detergent, e.g., sodium dodecyl sulfate (SDS), and the inclusion or exclusion of carrier DNA, are well known to those skilled in the art. Various levels of stringency are accomplished by combining these various conditions as needed. In embodiments, hybridization will occur at 30° C. in 750 mM NaCl, 75 mM trisodium citrate, and 1% SDS. In other embodiments, hybridization will occur at 37° C. in 500 mM NaCl, 50 mM trisodium citrate, 1% SDS, 35% formamide, and 100 μg/ml denatured salmon sperm DNA (ssDNA). In embodiments, hybridization will occur at 42° C. in 250 mM NaCl, 25 mM trisodium citrate, 1% SDS, 50% formamide, and 200 μg/ml ssDNA. Useful variations on these conditions will be readily apparent to those skilled in the art.

For most applications, washing steps that follow hybridization will also vary in stringency. Wash stringency conditions can be defined by salt concentration and by temperature. As above, wash stringency can be increased by decreasing salt concentration or by increasing temperature. For example, stringent salt concentration for the wash steps can be less than about 30 mM NaCl and 3 mM trisodium citrate, or less than about 15 mM NaCl and 1.5 mM trisodium citrate. Stringent temperature conditions for the wash steps can include a temperature of at least about 25° C., of at least about 42° C., or of at least about 68° C. In embodiments, wash steps will occur at 25° C. in 30 mM NaCl, 3 mM trisodium citrate, and 0.1% SDS. In other embodiments, wash steps will occur at 42° C. in 15 mM NaCl, 1.5 mM trisodium citrate, and 0.1% SDS. In related embodiments, wash steps will occur at 68° C. in 15 mM NaCl, 1.5 mM trisodium citrate, and 0.1% SDS. Additional variations on these conditions will be readily apparent to those skilled in the art. Hybridization techniques are well known to those skilled in the art and are described, for example, in Benton and Davis (Science 196:180, 1977); Grunstein and Hogness (Proc. Natl. Acad. Sci., USA 72:3961, 1975); Ausubel et al. (Current Protocols in Molecular Biology, Wiley Interscience, New York, 2001); Berger and Kimmel (Guide to Molecular Cloning Techniques, 1987, Academic Press, New York); and Sambrook et al. (Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, New York).

By “substantially identical” is meant a polypeptide or nucleic acid molecule exhibiting at least 50% identity to a reference amino acid sequence (for example, any one of the amino acid sequences described herein) or nucleic acid sequence (for example, any one of the nucleic acid sequences described herein). Such a sequence can be at least 60%, 80% or 85%, 90%, 95% or even 99% identical at the amino acid level or nucleic acid to the sequence used for comparison.

Sequence identity is typically measured using sequence analysis software (for example, Sequence Analysis Software Package of the Genetics Computer Group, University of Wisconsin Biotechnology Center, 1710 University Avenue, Madison, Wis. 53705, BLAST, BESTFIT, GAP, or PILEUP/PRETTYBOX programs). Such software matches identical or similar sequences by assigning degrees of homology to various substitutions, deletions, and/or other modifications. Conservative substitutions typically include substitutions within the following groups: glycine, alanine; valine, isoleucine, leucine; aspartic acid, glutamic acid, asparagine, glutamine; serine, threonine; lysine, arginine; and phenylalanine, tyrosine. In an exemplary approach to determining the degree of identity, a BLAST program may be used, with a probability score between e −3 and e −100 indicating a closely related sequence.

By “subject” is meant a mammal, including, but not limited to, a human or non-human mammal, such as a bovine, equine, canine, ovine, or feline.

Ranges provided herein are understood to be shorthand for all of the values within the range. For example, a range of 1 to 50 is understood to include any number, combination of numbers, or sub-range from the group consisting 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50.

As used herein, the terms “treat,” treating,” “treatment,” and the like refer to reducing or ameliorating a disorder and/or symptoms associated therewith. It will be appreciated that, although not precluded, treating a disorder or condition does not require that the disorder, condition or symptoms associated therewith be completely eliminated.

Unless specifically stated or obvious from context, as used herein, the term “or” is understood to be inclusive. Unless specifically stated or obvious from context, as used herein, the terms “a”, “an”, and “the” are understood to be singular or plural.

Unless specifically stated or obvious from context, as used herein, the term “about” is understood as within a range of normal tolerance in the art, for example within 2 standard deviations of the mean. About can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clear from context, all numerical values provided herein are modified by the term about.

The recitation of a listing of chemical groups in any definition of a variable herein includes definitions of that variable as any single group or combination of listed groups. The recitation of an embodiment for a variable or aspect herein includes that embodiment as any single embodiment or in combination with any other embodiments or portions thereof.

Any compositions or methods provided herein can be combined with one or more of any of the other compositions and methods provided herein.

FIG. 1 is a plot showing the results of a screen for radiosensitization target genes and their cognate siRNAs. An siRNA library screen for candidate radiosensitization targets was carried out in DU145 cells. Cells were transfected with library siRNAs or controls. Transfected cells were untreated or irradiated (6 Gy) 72 hours later. Radiosensitization was calculated as percent increased cell death associated with a gene-specific siRNA after radiation therapy compared with irradiated cells transfected with a control siRNA. Each diamond represents an siRNA (triplicate, average) organized alphabetically. Mean library radiosensitization and SD are shown by solid and dashed lines, respectively.

FIGS. 2A-2F are graphs showing the confirmation of siRNA mediated radiosensitization using clonogenic survival assays. Radiosensitization was confirmed by clonogenic survival assays (n=3). DU145 cells were reverse transfected with 5 nM control siRNA or ( FIG. 2A ) DNAPK, ( FIG. 2B ) MAD2L2, ( FIG. 2C ) BRCA2, ( FIG. 2D ) NBN, ( FIG. 2E ) RAD23B, or ( FIG. 2F ) RAD54L siRNA 72 hours prior to irradiation. DMF0.1 values are shown for each. Open diamonds, control siRNA; closed squares, candidate siRNA. SF, surviving fraction.

FIGS. 3A-3F are graphs showing the siRNA-mediated knock-down of radiosensitization target genes. DU145 cells were transfected with Candidate siRNAs (5 nM), 48 hours later the mRNA level of target genes were evaluated by qRTPCR. Data are normalized to GAPDH mRNA. ( FIG. 3A ) DNA-PK, ( FIG. 3B ) MAD2L2, ( FIG. 3C ) BRCA2, ( FIG. 3D ) NBN, ( FIG. 3E ) Rad23B, and ( FIG. 3F ) RAD54L. Columns represent mean±S.E.M, n=3.

FIG. 4 is a graph showing the results of siRNA-mediated radiation sensitization of a panel of radiosensitization target genes. LNCaP cells were seeded in 6-well plates at 2×10 5 cells per well. After 24 hours, cells were either transfected with 100 nM of DNA-PK, BRCA2, NBN, MAD2L2, RAD23B, RAD54L siRNAs or control siRNAs separately using HiPerfectTransfection Reagent. 48 hours later, cells were seeded in 96 well plate at 2000 cells per well. 24 hours later, cells were then irradiated with Gy IR using a Gammacell 40 (Nordion, Ottawa, ONT, Canada) 137Cs radiator at approximately 0.6 Gy/min. Cell viability was assessed after 12 days by MTS. means±S.E.M, n=3.

FIGS. 5A -5F demonstrate the ability of aptamer-shRNA chimeras to mediate target gene knock-down in PSMA expressing cells. FIGS. 5A and 5B include structures of illustrative examples of aptamer-shRNA chimeras, including the secondary structure of ( FIG. 5A ) A10-3-DNAPK (SEQ ID NO: 44) and ( FIG. 5B ) Neg-DNAPK (SEQ ID NO: 47). Aptamer and shRNA portions are shown by brackets. FIGS. 5C-5C are graphs showing the results of aptamer-shRNA chimera-mediated RNAi in the absence of transfection reagents. ( FIG. 5C ) LNCaP cells were treated with 0, 4, 40, or 400 nM A10-3-DNAPK for 48 hours, and DNAPK mRNA levels were quantified by qRT-PCR. LNCaP cells were treated with 400 nM of ( FIG. 5D ) A10-3-DNAPK, ( FIG. 5E ) A10-3-BRCA2, or ( FIG. 5F ) A10-3-ATM for 48 hours. Respective target gene mRNA levels were quantified by qRT-PCR. Appropriate siRNAs were transfected (100 nM) as positive controls. Expression was normalized to GAPDH. Mean±SEM (n=3). *P<0.05.

FIG. 6 is a graph showing that aptamer-shRNA chimeras do not illicit an interferon response. 2×10 5 LNCaP cells were either transfected with DNA-PK siRNA or incubated with 400 nM A10-3-Con, A10-3-DNA-PK or NegDNA-PK for 48 hours before interferon β secretion into the cell culture supernatant was analyzed. Cells were separately treated with 5 μg/ml Poly(I:C) (Invitrogen, Carlsbad, Calif.) as a positive control. Detection of interferon β was accomplished by using a commercially available sandwich interferon β ELISA kit (PBL) following manufacturer's recommendations. 25-2,000 pg/ml of interferon-beta standard was used as a positive control for assay integrity. means±S.E.M, n=3.

FIGS. 7A-7H show the PSMA selectivity of the aptamer-shRNA chimeras. FIGS. 7A and 7B include graphs depicting PSMA selectivity. ( FIG. 7A ) PC3-PIP or ( FIG. 7B ) PC3-Flu cells were treated with 400 nM aptamer-shRNA chimeras for 48 hours, and DNAPK expression was quantified by qRT-PCR. siRNA DNAPK (100 nM transfected) was included as a positive control. Expression is normalized to GAPDH. Mean±SEM (n=3). *P<0.05. FIG. 7C is a gel showing aptamer-shRNA chimera processing by Dicer in vitro. Cleavage products were analyzed by denaturing PAGE and ethidium bromide staining. Image was inverted for clarity. FIG. 7D includes a gel showing the results from a cell-based RNAi processing assay. LNCaP cells were treated with 400 nM aptamer-shRNA chimeras, and RNA was extracted 48 hours later for Northern blot assay. Probes are specific to corresponding antisense siRNAs. ds, double-stranded; ss, single-stranded. FIGS. 7E and 7F show the results from targeted in vivo knockdown. Subcutaneous LNCaP tumors were injected with aptamer-shRNA chimeras (200 pmol/injection) on days −3 and −2 and harvested on day 0, and DNAPK expression was determined. FIG. 7E is a graph showing qRT-PCR results. Mean±SEM. *P<0.05. FIG. 7F includes immunohistochemistry results. Original magnification, x400. FIGS. 7G and 7H include gels showing results from 5′-RACE PCR analysis to assess siRNA-mediated cleavage of DNAPK. LNCaP cells transfected with DNAPK siRNA or with A10-3-DNAPK chimeras produced a specific DNAPK cleavage product ( FIG. 7G ). In vivo treatment of LNCaP xenografts with A10-3-DNAPK chimera resulted in siRNA-mediated DNAPK cleavage ( FIG. 7H ).

FIGS. 8A and 8B include flow cytometry results showing the cell surface expression of PSMA. PSMA positive PC3-PIP cells and PSMA negative PC3-Flu cells were incubated with anti-PSMA (J591) antibody and stained with secondary antibody conjugated with Alexa488. PSMA expression was then determined by flow cytometry. 48.2% of PC3-PIP ( FIG. 8A ) cells expressed PSMA when compared to PC3-Flu ( FIG. 8B ) cells.

FIGS. 9A-9D are graphs showing aptamer-shRNA mediated radiosensitization in vitro and in vivo PCa models. FIG. 9A shows in vitro radiosensitization results. LNCaP cells treated with 400 nM A10-3-DNAPK or A10-3-Con or transfected with control siRNA were irradiated 48 hours later with 6 Gy IR, and cell viability was assessed 12 days later by MTS. Percent cell death is relative to nonirradiated cells. FIGS. 9B-9D show in vivo radiosensitization. Established tumors were treated with aptamer-shRNA chimeras (days −3 and −2) and either 6 Gy IR or no radiation (day 0). FIG. 9B shows results for the PC3 tumor model (n=3 per group). A10-3-DNAPK provided no significant therapeutic benefit to nonirradiated or irradiated PC3 tumors. Radiation similarly affected growth in all treatment groups. Mean±SEM. FIG. 9C shows results for the LNCaP tumor model (n≧6 per group). Radiation similarly affected growth in all treatment groups except irradiated A10-3-DNAPK. *P<0.05, *** P<0.001, A10-3-DNAPK IR vs. A 10-3-Con IR and A10-3-DNAPK IR vs. Neg-DNAPK IR; 2-way ANOVA. Mean±SEM. FIG. 9D shows the extension of tumor quadrupling for LNCaP tumor model. Events (animals whose tumor volume was not yet 4-fold the size at injection) were plotted by Kaplan-Meier curve. P<0.01, A10-3-Con IR vs. A10-3-Con and Neg-DNAPK IR vs. Neg-DNAPK; P<0.0001, A10-3-DNAPK IR vs. A10-3-Con IR and A10-3-DNAPK IR vs. Neg-DNAPK IR; log-rank (Mantel-Cox) test.

FIGS. 10A-10G are graphs showing aptamer-shRNA chimera mediated radiosensitization in individual LNCaP tumors in vivo. Established LNCaP tumors were intratumorally injected with 200 pmol aptamer-shRNAs on days −3 and day −2. On day 0, animals were divided into groups that received either 6 Gy radiation (+R) or no radiation (−R). Tumors were measured every other day until reaching four times the volume at time of radiation. FIG. 10A : PBS(−R) (n=6); FIG. 10B : A10-3-Con (−R) (n=6); FIG. 10C : A10-3-DNA-PK(−R) (n=6); FIG. 10D: NegDNA-PK(−R) (n=6); FIG. 10E : A10-3-Con(+R) (n=6); FIG. 10F : Neg-DNA-PK(+R) (n=6); FIG. 10G : A10-3-DNAPK(+R) (n=8).

FIG. 11 shows the result of ex vivo treatment of human prostate tissue with aptamer-shRNA chimeras. Sections of normal human prostate tissue were obtained from fresh radical prostatectomy specimens and maintained ex vivo. These were treated with 200 nM aptamer-shRNA chimeras, and DNAPK levels were detected by immunohistochemistry 48 hours after treatment. Quantitative image analysis determined a 25% reduction in DNAPK Staining for A10-3-DNAPK-treated samples. Original magnification, ×400.

FIGS. 12A-12C illustrate an the design of an aptamer-siRNA chimera. FIG. 12A is a table showing the sequences of the three oligonculeotides (SEQ ID NOS 63-65, respectively, in order of appearance) that comprise the aptamer-siRNA chimera. FIG. 12B shows the structure of the aptamer-siRNA chimera. To generate the aptamer-siRNA molecule the aptamer olignucleotide, sense strand-siRNA olignucleotide, and the antisense strand-siRNA are mixed and annealed. FIG. 12C is a graph showing the ability of the aptamer-siRNA chimera to knock-down expression of the target gene DNAPK.

FIG. 13 shows the structure of the A10-3 aptamer.

The invention features compositions comprising aptamer-inhibitory nucleic acid (e.g., shRNA) chimeras and methods of using the composition to sensitize a cancer cell to radiation.

The invention is based, at least in part, on the discovery that an aptamer that binds to prostate-specific membrane antigen (PSMA) is able to target an attached shRNA to prostate cancer cells and silence the gene that the shRNA targets. In addition, the invention is further based, at least in part, on the discovery of a set of genes, the inhibition of which results in the cancer cell becoming sensitized to ionizing radiation treatment. As described in more detail below, the discovery of these compositions and target genes demonstrates that the therapeutic index for local treatment of prostate cancer (PCa) can be improved by selectively sensitizing PCa cells to IR. The therapeutic strategy to deliver dose-escalated radiation therapy to the prostate, historically considered as more than approximately 70 Gy, has been constrained by the limited tolerance of the urinary tract and rectum (Leibel S A, Hanks G E, Kramer S. Patterns of care outcome studies: results of the national practice in adenocarcinoma of the prostate. Int J Radiat Oncol Biol Phys. 1984; 10(3):401-409; Smit W G, Helle P A, van Putten W L, Wijnmaalen A J, Seldenrath J J, van der Werf-Messing B H. Late radiation damage in prostate cancer patients treated by high dose external radiotherapy in relation to rectal dose. Int J Radiat Oncol Biol Phys. 1990; 18(1):23-29). Thus, the invention provides the benefits of dose-escalated radiation without the associated risks to normal tissue, the concomitant expensive high-tech infrastructure, and/or the added use of androgen suppression. Accordingly, the invention will have a significant impact on PCa morbidity and mortality.

The present invention provides methods of treating a disease or disorder or symptoms thereof which comprise administering a therapeutically effective amount of a pharmaceutical composition comprising an aptamer-inhibitory nucleic acid (e.g., shRNA) chimera to a subject (e.g., a mammal such as a human). Thus, one embodiment is a method of treating a subject suffering from cancer or symptom thereof. The method includes the step of administering to the mammal a therapeutic amount of an aptamer-inhibitory nucleic acid (e.g., shRNA) chimera followed by treating the mammal with ionizing radiation to treat the cancer or symptom thereof, under conditions such that the disease or disorder is treated. In certain embodiments the mammal is suffering from prostate cancer.

The methods herein include administering to the subject (including a subject identified as in need of such treatment) an effective amount of an aptamer-inhibitory nucleic acid (e.g., shRNA) chimera wherein the aptamer binds to a cell surface molecule on the cancer cell and the shRNA inhibits the expression of a target gene wherein the knock-down of the target gene product results in the cancer cell becoming radiosensitized. Following treatment with an aptamer-inhibitory nucleic acid (e.g., shRNA) chimera the cancer is further treated with ionizing radiation. Identifying a subject in need of such treatment can be in the judgment of a subject or a health care professional and can be subjective (e.g. opinion) or objective (e.g. measurable by a test or diagnostic method).

As used herein, the terms “treat,” treating,” “treatment,” and the like refer to reducing or ameliorating a disorder and/or symptoms associated therewith. It will be appreciated that, although not precluded, treating a disorder or condition does not require that the disorder, condition or symptoms associated therewith be completely eliminated.

As used herein, the terms “prevent,” “preventing,” “prevention,” “prophylactic treatment” and the like refer to reducing the probability of developing a disorder or condition in a subject, who does not have, but is at risk of or susceptible to developing a disorder or condition.

The therapeutic methods of the invention in general comprise administration of therapeutically effective amount of the compounds herein, such as a compound of the formulae herein to a subject (e.g., animal, human) in need thereof, including a mammal, particularly a human. Such treatment will be suitably administered to subjects, particularly humans, suffering from, having, susceptible to, or at risk for a disease, disorder, or symptom thereof. Determination of those subjects “at risk” can be made by any objective or subjective determination by a diagnostic test or opinion of a subject or health care provider (e.g., genetic test, enzyme or protein marker, Marker (as defined herein), family history, and the like).

In one embodiment, the invention provides a method of monitoring treatment progress. The method includes the step of determining a level of diagnostic marker (Marker) (e.g., any target delineated herein modulated by a compound herein, a protein or indicator thereof, etc.) or diagnostic measurement (e.g., screen, assay) in a subject suffering from or susceptible to a disorder or symptoms thereof, in which the subject has been administered a therapeutic amount of a compound herein sufficient to treat the disease or symptoms thereof. The level of Marker determined in the method can be compared to known levels of Marker in either healthy normal controls or in other afflicted patients to establish the subject's disease status. In preferred embodiments, a second level of Marker in the subject is determined at a time point later than the determination of the first level, and the two levels are compared to monitor the course of disease or the efficacy of the therapy. In certain preferred embodiments, a pre-treatment level of Marker in the subject is determined prior to beginning treatment according to this invention; this pre-treatment level of Marker can then be compared to the level of Marker in the subject after the treatment commences, to determine the efficacy of the treatment.

Localized Cancer Cells

As used herein, “localized cancer cell” and “localized neoplastic cell” are used interchangeably and refer to a cancer/neoplastic cell present at the site of a tumor/cancer.

The aptamer-inhibitory nucleic acid chimeras are suitable for use to target any localized cancer cell. Cancers can affect a variety of cell types, tissues, or organs, including but not limited to bladder, bone, brain, breast, cartilage, glia, esophagus, fallopian tube, gallbladder, heart, intestines, kidney, liver, lung, lymph node, nervous tissue, ovaries, pancreas, prostate, skeletal muscle, skin, spinal cord, spleen, stomach, testes, thymus, thyroid, trachea, urogenital tract, ureter, urethra, uterus, and vagina, or a tissue or cell type thereof. Examples of such include, but are not limited to, melanoma, renal cancer, prostate cancer, breast cancer, colon cancer and lung cancer, bone cancer, pancreatic cancer, skin cancer, cancer of the head or neck, cutaneous or intraocular malignant melanoma, uterine cancer, ovarian cancer, rectal cancer, cancer of the anal region, stomach cancer, testicular cancer, uterine cancer, carcinoma of the fallopian tubes, carcinoma of the endometrium, carcinoma of the cervix, carcinoma of the vagina, carcinoma of the vulva, Hodgkin's Disease, non-Hodgkin's lymphoma, cancer of the esophagus, cancer of the small intestine, cancer of the endocrine system, cancer of the thyroid gland, cancer of the parathyroid gland, cancer of the adrenal gland, sarcoma of soft tissue, cancer of the urethra, cancer of the penis, chronic or acute leukemias including acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, chronic lymphocytic leukemia, solid tumours of childhood, lymphocytic lymphoma, cancer of the bladder, cancer of the kidney or ureter, carcinoma of the renal pelvis, neoplasm of the central nervous system (CNS), primary CNS lymphoma, tumour angiogenesis, spinal axis tumour, brain stein glioma, pituitary adenoma, Kaposi's sarcoma, epidermoid cancer, squamous cell cancer, T-cell lymphoma, environmentally induced cancers including those induced by asbestos, and combinations of said cancers.

In embodiments, the localized cancer cell is a prostate cancer cell.

An estimated 1 in 6 men will be diagnosed with prostate cancer (PCa). Although the majority of these men can be successfully treated with surgery or radiation therapy, approximately 20%-40% will biochemically recur within 10 years of treatment (Ward J F, Moul J W. Rising prostate-specific antigen after primary prostate cancer therapy. Nat Clin Pract Urol. 2005; 2(4):174-182). This risk of recurrence is elevated to approximately 50% for men with locally advanced disease, a condition that is primarily managed by radiation therapy (Bolla M, et al. Long-term results with immediate androgen suppression and external irradiation in patients with locally advanced prostate cancer (an EORTC study): a phase III randomised trial. Lancet. 2002; 360(9327):103-106; Walz J, et al. A nomogram predicting 10-year life expectancy in candidates for radical prostatectomy or radiotherapy for prostate cancer. J Clin Oncol. 2007; 25(24):3576-3581). Thus, new technologies that improve the therapeutic index of radiation therapy for local disease will significantly affect the morbidity and mortality of PCa.

Ionizing radiation (IR) causes multiple types of cellular injury, of which DNA double-strand breaks (DSBs) are considered the most cytotoxic (Smith G C, Jackson S P. The DNA-dependent protein kinase. Genes Dev. 1999; 13(8):916-934). Naturally occurring mutations in genes that sense or repair DNA damage are associated with increased sensitivity to IR (Helleday T, Lo J, van Gent D C, Engelward B P. DNA double-strand break repair: from mechanistic understanding to cancer treatment. DNA Repair ( Amst ). 2007; 6(7):923-935; Pollard J M, Gatti R A. Clinical radiation sensitivity with DNA repair disorders: an overview. Int J Radiat Oncol Biol Phys. 2009; 74(5):1323-1331). Chemical or siRNA inhibition of DNA repair proteins, such as ataxia telangiectasia mutated (ATM) or NBS1, also results in cellular hypersensitivity to IR (Chalmers A J, Bentzen S M, Buffa F M, A general framework for quantifying the effects of DNA repair inhibitors on radiation sensitivity as a function of dose. Theor Biol Med. Model. 2007; 4:25; Collis S J, Swartz M J, Nelson W G, DeWeese T L. Enhanced radiation and chemotherapy-mediated cell killing of human cancer cells by small inhibitory RNA silencing of DNA repair factors. Cancer Res. 2003; 63(7):1550-1554; Ohnishi K, Scuric Z, Schiestl R H, Okamoto N, Takahashi A, Ohnishi T. siRNA targeting NBS1 or XIAP increases radiation sensitivity of human cancer cells independent of TP53 status. Radiat Res. 2006; 166(3):454-462). Although these approaches have potential, they lack a means to selectively target cancer cells or specific tissues. Prostate-targeted radiosensitization approaches will both increase the therapeutic effect of IR and reduce radiation-associated damage to other pelvic tissues. RNAi is a promising new therapeutic approach. The challenge for translating RNAi therapy is delivery, particularly for specific cell types.

A prostate-specific membrane antigen-targeted (PSMA-targeted) RNA aptamers was previously developed (Lupold S E, Hicke B J, Lin Y, Coffey D S. Identification and characterization of nuclease-stabilized RNA molecules that bind human prostate cancer cells via the prostate-specific membrane antigen. Cancer Res. 2002; 62(14):4029-4033), which are capable of targeting drugs, nanoparticles, and toxins to PSMA-expressing PCa cells and tumors (Cheng J, et al. Formulation of functionalized PLGA-PEG nanoparticles for in vivo targeted drug delivery. Biomaterials. 2007; 28(5):869-876; Chu T C, et al. Aptamer:toxin conjugates that specifically target prostate tumor cells. Cancer Res. 2006; 66(12):5989-5992; Chu T C, et al. Labeling tumor cells with fluorescent nanocrystal-aptamer bioconjugates. Biosens Bioelectron. 2006; 21(10):1859-1866; Farokhzad O C, et al. Targeted nanoparticle aptamer bioconjugates for cancer chemotherapy in vivo. Proc Natl Acad Sci USA. 2006; 103(16):6315-6320; Farokhzad O C, Jon S, Khademhosseini A, Tran T N, Lavan D A, Langer R. Nanoparticle-aptamer bioconjugates: a new approach for targeting prostate cancer cells. Cancer Res. 2004; 64(21):7668-7672). When conjugated to siRNAs and shRNAs, these PSMA aptamers are also capable of delivering cell-selective gene knockdown (Chu T C, Twu K Y, Ellington A D, Levy M. Aptamer mediated siRNA delivery. Nucleic Acids Res. 2006; 34(10):e73; Dassie J P, et al. Systemic administration of optimized aptamer-siRNA chimeras promotes regression of PSMA-expressing tumors. Nat. Biotechnol. 2009; 27(9):839-849; McNamara J O 2nd, et al. Cell type-specific delivery of siRNAs with aptamer-siRNA chimeras. Nat Biotechnol. 2006; 24(8):1005-1015; Pastor F, Kolonias D, Giangrande P H, Gilboa E. Induction of tumour immunity by targeted inhibition of nonsense-mediated mRNA decay. Nature. 2010; 465(7295):227-230; Wullner U, Neef I, Eller A, Kleines M, Tur M K, Barth S. Cell-specific induction of apoptosis by rationally designed bivalent aptamer-siRNA transcripts silencing eukaryotic elongation factor 2 . Curr Cancer Drug Targets. 2008; 8(7):554-565). Because PSMA is highly expressed in PCa, targeted aptamer-inhibitory nucleic acid (e.g., shRNA) chimeras could be used to inhibit DNA repair pathways in prostatic cells for enhanced radiation therapy of locally advanced PCa.

Dose-escalated radiation therapy for localized prostate cancer (PCa) has a clear therapeutic benefit; however, escalated doses may also increase injury to noncancerous tissues. Radiosensitizing agents can improve ionizing radiation (IR) potency, but without targeted delivery, these agents will also sensitize surrounding normal tissues. The prostate-targeted RNAi agents of the invention selectively sensitized prostate-specific membrane antigen-positive (PSMA-positive) cells to IR. siRNA library screens identified DNA-activated protein kinase, catalytic polypeptide (DNAPK) as a preferred radiosensitization target. As described herein, DNAPK shRNAs, delivered by PSMA-targeting RNA aptamers, selectively reduced DNAPK in PCa cells, xenografts, and human prostate tissues. Aptamer-targeted DNAPK shRNAs, combined with IR, dramatically and specifically enhanced PSMA-positive tumor response to IR.

Cancer cells on which the claimed chimeric aptamer-inhibitory nucleic acid (e.g., shRNA) molecules exert a therapeutic effect are not particularly limited. The results described herein demonstrate that the chimeric aptamers are effective in treating any localized cancer cells (e.g., prostate cancer cells). Therefore, in aspects of the invention, the chimeric aptamers are used in combination with radiotherapy, and in embodiments, use of the chimeric aptamers enhances the efficacy of the radiotherapy. It is readily within the skill of the ordinary artisan to choose the appropriate aptamer and shRNA for use with a particular type of cancer cell.

Use of the chimeric aptamers reduces the dosage of radiotherapy, and can suppress the side effects that accompany radiotherapy.

Aptamers

The aptamers of the invention may be prepared by any known method, including synthetic, recombinant, and purification methods, and may be used alone or in combination with other aptamers specific for the same target. Illustrative methods of preparing aptamers are disclosed in U.S. Pat. Nos. 5,582,981 and 5,840,867, both of which are incorporated by reference in their entirety. Further, as described more fully herein, the term “aptamer” specifically includes “secondary aptamers” containing a consensus sequence derived from comparing two or more known aptamers to a given target.

As used herein, the term “binding” refers to an interaction or complexation between a target and an oligonucleotide or aptamer, resulting in a sufficiently stable complex so as to permit separation of oligonucleotide:target complexes from uncomplexed oligonucleotides under given binding complexation or reaction conditions. Binding is mediated through hydrogen bonding or other molecular forces. As used herein, the term “binding” specifically excludes the normal “Watson-Crick”-type binding interactions (i.e., adenine-thymine and guanine-cytosine base-pairing) traditionally associated with the DNA double helix.

In general, a minimum of approximately 3 nucleotides, at least 5 nucleotides, and the like, are necessary to effect specific binding. The only apparent limitations on the binding specificity of the target/oligonucleotide complexes of the invention concern sufficient sequence to be distinctive in the binding oligonucleotide and sufficient binding capacity of the target substance to obtain the necessary interaction. Oligonucleotides of sequences shorter than 10 can be used when the appropriate interaction can be obtained in the context of the environment in which the target is placed. Although the oligonucleotides generally described herein are single-stranded or double-stranded, it is contemplated that aptamers may sometimes assume triple-stranded or quadruple-stranded structures.

As further explained below, the specifically binding oligonucleotides need to contain the sequence-conferring specificity, but may be extended with flanking regions and otherwise derivatized.

The aptamers found to bind to the targets may be isolated, sequenced, and then resynthesized as conventional DNA or RNA moieties, or may be “modified” oligomers which are those conventionally recognized in the art. As the resulting aptamers of the invention include intermediates in their synthesis, any of the hydroxyl groups ordinarily present may be replaced by phosphonate groups, phosphate groups, protected by a standard protecting group, or activated to prepare additional linkages to additional nucleotides, or may be conjugated to solid supports. The 5′ terminal OH is conventionally free but may be phosphorylated; OH substituents at the 3′ terminus may also be phosphorylated. The hydroxyls may also be derivatized to standard protecting groups. One or more phosphodiester linkages may be replaced by alternative linking groups. These alternative linking groups include, but are not limited to embodiments wherein P(O)O is replaced by P(O)S, P(O)NR 2 , P(O)R, P(O)OR′, CO, or CNR 2 , wherein R is H or alkyl (1-20C) and R′ is alkyl (1-20C); in addition, this group may be attached to adjacent nucleotide through O or S, Not all linkages in an oligomer need to be identical.

“Analogous” forms of purines and pyrimidines are those generally known in the art, many of which are used as chemotherapeutic agents. An exemplary but not exhaustive list includes 2′-fluoro-modified pyrimidine, aziridinylcytosine, 4-acetylcytosine, 5-fluorouracil, 5-bromouracil, 5-carboxymethylaminomethyl-2-thiouracil, 5-carboxymethylaminomethyluracil, inosine, N6-isopentenyladenine, 1-methyladenine, 1-methylpseudouracil, 1-methylguanine, 1-methylinosine, 2,2-dimethylguanine, 2-methyladenine, 2-methylguanine, 3-methylcytosine, 5-methylcytosine, N6-methyladenine, 7-methylguanine, 5-methylaminomethyluracil, 5-methoxyaminomethyl-2-thiouracil, beta-D-mannosylqueosine, 5-methoxyuracil, 2-methylthio-N-6-isopentenyladenine, uracil-5-oxyacetic acid methylester, pseudouracil, queosine, 2-thiocytosine, 5-methyl-2-thiouracil, 2-thiouracil, 4-thiouracil, 5-methyluracil, uracil-5-oxyacetic acid, and 2,6-diaminopurine.

Aptamer oligonucleotides may contain analogous forms of ribose or deoxyribose that are generally known in the art. An exemplary, but not exhaustive list includes locked-nucleic acids (LNA), 2′ substituted sugars such as 2′-O-methyl-, 2′-fluoro- or 2′-azido-ribose, carbocyclic sugar analogs, α-anomeric sugars, epimeric sugars such as arabinose, xyloses or lyxoses, pyranose sugars, sedoheptuloses, acyclic analogs and abasic nucleoside analogs such as methyl riboside.

In most instances, the conventional sugars and bases will be used in applying the method of the invention; substitution of analogous forms of sugars, purines and pyrimidines may be advantageous in designing the final product.

Aptamers containing the specific binding sequences discerned through the method of the invention can also be derivatized in various ways. For example, if the aptamer is to be used for separation of the target substance, conventionally the oligonucleotide will be derivatized to a solid support to permit chromatographic separation. If the oligonucleotide is to be used to label cellular components or otherwise for attaching a detectable moiety to target, the oligonucleotide will be derivatized to include a radionuclide, a fluorescent molecule, a chromophore or the like. If the oligonucleotide is to be used in specific binding assays, coupling to solid support or detectable label is also desirable. If it is to be used therapeutically, the oligonucleotide may be derivatized to include ligands which permit easier transit of cellular barriers, toxic moieties which aid in the therapeutic effect, or enzymatic activities which perform desired functions at the targeted site. The aptamer may also be included in a suitable expression system to provide for in situ generation of the desired sequence.

The oligonucleotides used as starting materials in the process of the invention to determine specific binding sequences may be single-stranded or double-stranded DNA or RNA. In embodiments of this invention, the sequences are single-stranded RNA.

In aspects of the invention, the aptamer specifically targets antigens specific to cancer cells, which are also known as cancer antigens or tumor antigens. Such antigens are well known in the art, and it is within the skill of the ordinary artisan to select the appropriate cancer antigen for use with a specific cancer. For example, as described in detail herein, the aptamer in an aptamer-inhibitory nucleic acid chimera can be specific to PSMA. Other illustrative non-limiting examples of aptamer targeted cancer cell antigens includes Muc1, HER2, TGFbeta-receptor, Guanylyl cyclase C (GC-C), and PSCA.

Inhibitory Nucleic Acids

Inhibitory nucleic acid molecules are those oligonucleotides that inhibit the expression or activity of a target gene in a cancer cell, wherein such inhibition results in the cancer cell becoming radiosensitized. Such oligonucleotides include single and double stranded nucleic acid molecules (e.g., DNA, RNA, and analogs thereof) that bind a nucleic acid molecule that encodes a target radiosensitivity protein (e.g., antisense molecules, siRNA, shRNA) as well as nucleic acid molecules that bind directly to a radiosensitivity protein and thereby modulate its biological activity.

shRNA

Small hairpin RNAs consist of a stem-loop structure with optional 3′ UU-overhangs. A “stem-loop structure” refers to a nucleic acid having a secondary structure that includes a region of nucleotides which are known or predicted to form a double strand or duplex (stem portion) that is linked on one side by a region of predominantly single-stranded nucleotides (loop portion). The term “hairpin” is also used herein to refer to stem-loop structures. Such structures are well known in the art and the term is used consistently with its known meaning in the art. As is known in the art, the secondary structure does not require exact base-pairing. Thus, the stem can include one or more base mismatches or bulges. Alternatively, the base-pairing can be exact, i.e. not include any mismatches. The multiple stem-loop structures can be linked to one another through a linker, such as, for example, a nucleic acid linker, a miRNA flanking sequence, other molecule, or some combination thereof.

While there may be variation, stems can range from 21 to 31 bp (e.g., 25 to 29 bp), and the loops can range from 4 to 30 bp (desirably 4 to 23 bp). For expression of shRNAs within cells, any method well known in the art for introducing a nucleic acid construct into cells can be employed. A non-limiting example includes use of plasmid vectors containing either the polymerase III H1-RNA or U6 promoter, a cloning site for the stem-looped RNA insert, and a 4-5-thymidine transcription termination signal can be employed. The Polymerase III promoters generally have well-defined initiation and stop sites and their transcripts lack poly(A) tails. The termination signal for these promoters is defined by the polythymidine tract, and the transcript is typically cleaved after the second uridine. Cleavage at this position generates a 3′ UU overhang in the expressed shRNA, which is similar to the 3′ overhangs of synthetic siRNAs. Furthermore, as described herein, shRNAs may be covalently linked to aptamers to generate the aptamer-shRNA chimeras of the invention.

shRNA also includes micro-RNA embedded shRNAs (miRNA-based shRNAs), wherein the guide strand and the passenger strand of the miRNA duplex are incorporated into an existing (or natural) miRNA or into a modified or synthetic (designed) miRNA. In some instances the precursor miRNA molecule can include more than one stem-loop structure. MicroRNAs are endogenously encoded RNA molecules that are about 22-nucleotides long and generally expressed in a highly tissue- or developmental-stage-specific fashion and that post-transcriptionally regulate target genes. More than 200 distinct miRNAs have been identified in plants and animals. These small regulatory RNAs are believed to serve important biological functions by two prevailing modes of action: (1) by repressing the translation of target mRNAs, and (2) through RNA interference (RNAi), that is, cleavage and degradation of mRNAs. In the latter case, miRNAs function analogously to small interfering RNAs (siRNAs). Thus, one of ordinary skill in the art can readily design and express artificial miRNAs based on the features of existing miRNA genes.

siRNA

Short twenty-one to twenty-five nucleotide double-stranded RNAs are effective at down-regulating gene expression (Zamore et al., Cell 101: 25-33; Elbashir et al., Nature 411: 494-498, 2001, each of which is hereby incorporated by reference). The therapeutic effectiveness of an siRNA in vivo is well known in the art (see McCaffrey et al, (Nature 418: 38-39.2002), which is hereby incorporated by reference). Given the sequence of a target gene, siRNAs may be designed to inactivate that gene. Such siRNAs, for example, could be administered directly to an affected tissue, or administered systemically. The nucleic acid sequence of a gene can be used to design small interfering RNAs (siRNAs) for that gene. The 21 to 25 nucleotide siRNAs may be used, for example, when screening for additional target genes the inhibition of which would radiosensitize a cancer cell. Further, as described herein, siRNA may be coupled with an aptamer to deliver the siRNA to a cancer cell.

Ribozymes

Catalytic RNA molecules or ribozymes that target an antisense target sequence of the present invention can be used to inhibit expression of a target gene nucleic acid molecule in vivo, wherein inhibition of the target gene sensitizes the cancer cell to radiation. The inclusion of ribozyme sequences within antisense RNAs confers RNA-cleaving activity upon them, thereby increasing the activity of the constructs. The design and use of target RNA-specific ribozymes is described in Haseloff et al., Nature 334:585-591. 1988, and U.S. Patent Application Publication No. 2003/0003469 A1, each of which is incorporated by reference.

Accordingly, the invention also features a catalytic RNA molecule that includes, in the binding arm, an antisense RNA having between eight and nineteen consecutive nucleobases. In embodiments of this invention, the catalytic nucleic acid molecule is formed in a hammerhead or hairpin motif. Examples of such hammerhead motifs are well known in the art (see Rossi et al., Aids Research and Human Retroviruses, 8:183, 1992, which is hereby incorporate by reference). Example of hairpin motifs are also well known in the art (see Hampel et al., “RNA Catalyst for Cleaving Specific RNA Sequences,” filed Sep. 20, 1989, which is a continuation-in-part of U.S. Ser. No. 07/247,100 filed Sep. 20, 1988, Hampel and Tritz, Biochemistry, 28:4929, 1989, and Hampel et al., Nucleic Acids Research, 18: 299, 1990, each of which is hereby incorporated by reference). These specific motifs are not limiting in the invention and those skilled in the art will recognize that all that is important in an enzymatic nucleic acid molecule of this invention is that it has a specific substrate binding site which is complementary to one or more of the target gene RNA regions, and that it have nucleotide sequences within or surrounding that substrate binding site which impart an RNA cleaving activity to the molecule. Further, catalytic RNAs of the invention may be covalently linked to an aptamer wherein the aptamer delivers the catalytic RNA to a cancer cell and the catalytic RNA inhibits the production of a target protein and thereby radiosensitizes the cancer cell.

The inhibitory nucleic acid molecules of the present invention may be employed as double-stranded RNAs for RNA interference (RNAi)-mediated knock-down of the expression of a target radiosensitivity protein. In one embodiment, DNAPK expression is reduced in a prostate cancer cell. RNAi is a method for decreasing the cellular expression of specific proteins of interest (reviewed in Tuschl, Chembiochem 2:239-245, 2001; Sharp, Genes & Devel, 15:485-490, 2000; Hutvagner and Zamore, Curr. Opin. Genet. Devel. 12:225-232, 2002; and Hannon, Nature 418:244-251, 2002).

In one embodiment of the invention, a double-stranded RNA (dsRNA) molecule is made that includes between eight and nineteen consecutive nucleobases of a nucleobase oligomer of the invention. The dsRNA can be two distinct strands of RNA that have duplexed, or a single RNA strand that has self-duplexed (small hairpin (sh)RNA). Typically, dsRNAs are about 21 or 22 base pairs, but may be shorter or longer (up to about 29 nucleobases) if desired. dsRNA can be made using standard techniques (e.g., chemical synthesis or in vitro transcription). Kits are available, for example, from Ambion (Austin, Tex.) and Epicentre (Madison, Wis.). Methods for expressing dsRNA in mammalian cells are described in Brummelkamp et al. Science 296:550-553, 2002; Paddison et al. Genes & Devel. 16:948-958, 2002. Paul et al. Nature Biotechnol. 20:505-508, 2002; Sui et al. Proc. Natl. Acad. Sci. USA 99:5515-5520, 2002; Yu et al. Proc. Natl. Acad. Sci. USA 99:6047-6052, 2002; Miyagishi et al. Nature Biotechnol. 20:497-500, 2002; and Lee et al. Nature Biotechnol. 20:500-505 2002, each of which is hereby incorporated by reference.

In aspects of the invention, shRNA are coupled with an aptamer to deliver the shRNA to a cancer cell.

Pharmaceutical Compositions

For therapeutic uses, the compositions or agents identified using the methods disclosed herein may be administered systemically, for example, formulated in a pharmaceutically-acceptable carrier. Preferable routes of administration include, for example, subcutaneous, intravenous, interperitoneally, intramuscular, or intradermal injections that provide continuous, sustained levels of the drug in the patient. Treatment of human patients or other animals will be carried out using a therapeutically effective amount of a radiosensitizing aptamer-inhibitory nucleic acid (e.g., shRNA) chimeric therapeutic in a physiologically-acceptable carrier. Suitable carriers and their formulation are described, for example, in Remington's Pharmaceutical Sciences by E. W. Martin. The amount of the therapeutic aptamer-inhibitory nucleic acid (e.g., shRNA) chimera to be administered varies depending upon the manner of administration, the age and body weight of the patient, and the clinical symptoms of the cancer. Generally, amounts will be in the range of those used for other agents used in the treatment of cancer, although in certain instances lower amounts will be needed because of the increased specificity of the compound. A compound is administered at a dosage that radiosenitizes a cancer cell as determined by a diagnostic method known to one skilled in the art, or using any assay that measures sensitivity to ionizing radiation (e.g., induction of apoptosis).

Formulation of Pharmaceutical Compositions

The administration of an agent of the invention or analog thereof for the treatment of cancer may be by any suitable means that results in a concentration of the therapeutic that, combined with ionizing radiation, is effective in ameliorating, reducing, or stabilizing cancer or a symptom thereof. In one embodiment, administration of the agent and ionizing radiation results in an increase in apoptosis of the cancer cells. In another embodiment, the agent and ionizing radiation results in an increase in the average survival time or quality of life of the subject.

Methods of administering such agents are known in the art. The invention provides for the therapeutic administration of an agent by any means known in the art. The compound may be contained in any appropriate amount in any suitable carrier substance, and is generally present in an amount of 1-95% by weight of the total weight of the composition. The composition may be provided in a dosage form that is suitable for parenteral (e.g., subcutaneously, intravenously, intramuscularly, or intraperitoneally) administration route. In embodiments, the therapeutic composition is administered directly to the cancer mass. In related embodiments, the therapeutic composition is administered directly to the prostate of a subject. The pharmaceutical compositions may be formulated according to conventional pharmaceutical practice (see, e.g., Remington: The Science and Practice of Pharmacy (20th ed.), ed. A. R, Gennaro, Lippincott Williams & Wilkins, 2000 and Encyclopedia of Pharmaceutical Technology, eds. J. Swarbrick and J. C. Boylan, 1988-1999, Marcel Dekker, New York). Suitable formulations include forms for oral administration, depot formulations, formulations for delivery by a patch, semisolid dosage forms to be topically or transdermally delivered.

Pharmaceutical compositions according to the invention may be formulated to release the active compound substantially immediately upon administration or at any predetermined time or time period after administration. The latter types of compositions are generally known as controlled release formulations, which include (i) formulations that create a substantially constant concentration of the drug within the body over an extended period of time; (ii) formulations that after a predetermined lag time create a substantially constant concentration of the drug within the body over an extended period of time; (iii) formulations that sustain action during a predetermined time period by maintaining a relatively, constant, effective level in the body with concomitant minimization of undesirable side effects associated with fluctuations in the plasma level of the active substance (sawtooth kinetic pattern); (iv) formulations that localize action by, e.g., spatial placement of a controlled release composition adjacent to or in the central nervous system or cerebrospinal fluid; (v) formulations that allow for convenient dosing, such that doses are administered, for example, once every one or two weeks; and (vi) formulations that target cancer by using carriers or chemical derivatives to deliver the therapeutic agent to a particular cell type (e.g., prostate cancer cell). For some applications, controlled release formulations obviate the need for frequent dosing during the day to sustain the plasma level at a therapeutic level.

Any of a number of strategies can be pursued in order to obtain controlled release in which the rate of release outweighs the rate of metabolism of the compound in question. In one example, controlled release is obtained by appropriate selection of various formulation parameters and ingredients, including, e.g., various types of controlled release compositions and coatings. Thus, the therapeutic is formulated with appropriate excipients into a pharmaceutical composition that, upon administration, releases the therapeutic in a controlled manner. Examples include single or multiple unit tablet or capsule compositions, oil solutions, suspensions, emulsions, microcapsules, microspheres, molecular complexes, nanoparticles, patches, and liposomes.

Parenteral Compositions

The pharmaceutical composition may be administered parenterally by injection, infusion or implantation (subcutaneous, intravenous, intramuscular, intraperitoneal, or the like) in dosage forms, formulations, or via suitable delivery devices or implants containing conventional, non-toxic pharmaceutically acceptable carriers and adjuvants. The formulation and preparation of such compositions are well known to those skilled in the art of pharmaceutical formulation. Formulations can be found in Remington: The Science and Practice of Pharmacy, supra. Compositions for parenteral use may be provided in unit dosage forms (e.g., in single-dose ampoules), or in vials containing several doses and in which a suitable preservative may be added (see below). The composition may be in the form of a solution, a suspension, an emulsion, an infusion device, or a delivery device for implantation, or it may be presented as a dry powder to be reconstituted with water or another suitable vehicle before use. Apart from the active therapeutic (s), the composition may include suitable parenterally acceptable carriers and/or excipients. The active therapeutic (s) may be incorporated into microspheres, microcapsules, nanoparticles, liposomes, or the like for controlled release. Furthermore, the composition may include suspending, solubilizing, stabilizing, pH-adjusting agents, tonicity adjusting agents, and/or dispersing, agents.

As indicated above, the pharmaceutical compositions according to the invention may be in the form suitable for sterile injection. To prepare such a composition, the suitable active therapeutic(s) are dissolved or suspended in a parenterally acceptable liquid vehicle.

Dosage

Human dosage amounts can initially be determined by extrapolating from the amount of compound used in mice, as a skilled artisan recognizes it is routine in the art to modify the dosage for humans compared to animal models. In certain embodiments it is envisioned that the dosage may vary from between about 1 mg compound/Kg body weight to about 5000 mg compound/Kg body weight; or from about 5 mg/Kg body weight to about 4000 mg/Kg body weight or from about 10 mg/Kg body weight to about 3000 mg/Kg body weight; or from about 50 mg/Kg body weight to about 2000 mg/Kg body weight; or from about 100 mg/Kg body weight to about 1000 mg/Kg body weight; or from about 150 mg/Kg body weight to about 500 mg/Kg body weight. In other embodiments this dose may be about 1, 5, 10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1600, 1700, 1800, 1900, 2000, 2500, 3000, 3500, 4000, 4500, 5000 mg/Kg body weight. In other embodiments, it is envisaged that higher does may be used, such doses may be in the range of about 5 mg compound/Kg body to about 20 mg compound/Kg body. In other embodiments the doses may be about 8, 10, 12, 14, 16 or 18 mg/Kg body weight. Of course, this dosage amount may be adjusted upward or downward, as is routinely done in such treatment protocols, depending on the results of the initial clinical trials and the needs of a particular patient.

Therapeutic Methods

The present invention provides methods of treating cancer by increasing the cancer's sensitivity to ionizing radiation, and exposing the cancer to ionizing radiation when the cancer is in the sensitive state. The methods comprise administering a therapeutically effective amount of a pharmaceutical composition comprising an aptamer-inhibitory nucleic acid (e.g., shRNA) chimera. Not wishing to be bound by any theory, it is believed that the aptamer portion delivers the aptamer-inhibitory nucleic acid (e.g., shRNA) chimera to a cancer cell; the shRNA portion enters the cell, is processed to an siRNA that knocks-down the levels of a target protein; and knock-down of the target protein results in the sentization of the cancer cell to ionizing radiation. Once the cancer cell has been sensitized to ionizing radiation the cancer is exposed to therapeutic amounts of ionizing radiation.

The methods herein include administering to the subject (including a subject identified as in need of such treatment) an effective amount of a compound described herein, or a composition described herein to produce such effect. Identifying a subject in need of such treatment can be in the judgment of a subject or a health care professional and can be subjective (e.g., opinion) or objective (e.g., measurable by a test or diagnostic method).

The therapeutic methods of the invention, which include prophylactic treatment, in general comprise administration of a therapeutically effective amount of the agent herein to a subject (e.g., animal, human) in need thereof, including a mammal, e.g., a human.

Combination Therapies

The present invention also provides combination therapies. The chimeric aptamers of the present invention are suitable for use in combination with other chemotherapeutics, including, but not limited to, an alkylation agent, nitrosourea agent, antimetabolite, anticancer antibiotics, vegetable-origin alkaloid, topoisomerase inhibitor, hormone drug, hormone antagonist, aromatase inhibitor, P-glycoprotein inhibitor, platinum complex derivative, other immunotherapeutic drugs and other anticancer drugs well known in the art. Further, the chimeric aptamers can be used with a cancer treatment adjunct, such as a leucopenia (neutrophenia) treatment drug, thrombocytopenia treatment drug, antiemetic and cancer pain intervention drug, or combinations thereof.

In aspects, the chimeric aptamers can be used with other immunomodulators. Immunomodulators are well known in the art. Examples of the immunomodulator include, but are not limited to, various cytokines that stimulate immune responses such as GM-CSF, M-CSF, G-CSF, interferon-α, β, or γ, IL-1, IL-2, IL-3 and IL-12.

In other aspects, the chimeric aptamers can be used with targeted radiation-therapeutics such as radio-labeled antibodies (e.g., I 131 , Bi 213 , or Y 90 ) or radioactive substances that are taken up by bone (e.g., MDP). In addition, the chimeric aptamers can be used in combination with radiation mimetic drugs such as bleomycin or neocarzinostatin.

Kits

The invention provides kits for the treatment or amelioration of cancer or its symptoms. In one embodiment, the kit includes a therapeutic or prophylactic composition containing an effective amount of an agent of the invention (e.g., aptamer-inhibitory nucleic acid chimera) in unit dosage form. In embodiments, the kit comprises a container which contains a therapeutic or prophylactic compound; such containers can be sterile, and such containers can be in the form of boxes, ampoules, bottles, vials, tubes, bags, pouches, blister-packs, and the like. Such containers can be made of plastic, glass, laminated paper, metal foil, or other materials suitable for holding medicaments.

If desired, an agent of the invention is provided together with instructions for administering it to a subject having cancer. The instructions will generally include information about the use of the composition for the treatment of cancer. In other embodiments, the instructions include at least one of the following: description of the compound; dosage schedule and administration for treatment of cancer or symptoms thereof; precautions; warnings; indications; counter-indications; overdosage information; adverse reactions; animal pharmacology; clinical studies; and/or references. The instructions may be printed directly on the container (when present), or as a label applied to the container, or as a separate sheet, pamphlet, card, or folder supplied in or with the container.

Neovascularization

Angiogenesis is the growth of new blood vessels from pre-existing vessels. Angiogenesis plays a critical role in tumor formation and is essential for growth of tumors beyond 1 mm in diameter. Tumor-associated neovascular endothelial cells express antigens that can serve as targets for the claimed aptamer-inhibitory nucleic acid chimeras. For example, tumor-associate neovascular endothelia cells express prostate-specific membrane antigen (PSMA). (Chang et al., Five different anti-prostate-specific membrane antigen (PSMA) antibodies cofirm PSMA expression in tumor-associated neovasculature, Cancer Res ., vol. 59, pages 3192-3198). In one aspect of the invention, methods are provided for targeting neoplasia associated neovascularization by contacting neovascular endothelia cells with aptamer-inhibitory nucleic acid chimeras and exposing neovascular endothelia cells to ionizing radiation.

The practice of the present invention employs, unless otherwise indicated, conventional techniques of molecular biology (including recombinant techniques), microbiology, cell biology, biochemistry and immunology, which are well within the purview of the skilled artisan. Such techniques are explained fully in the literature, such as, “Molecular Cloning: A Laboratory Manual”, second edition (Sambrook, 1989); “Oligonucleotide Synthesis” (Gait, 1984); “Animal Cell Culture” (Freshney, 1987); “Methods in Enzymology” “Handbook of Experimental Immunology” (Weir, 1996); “Gene Transfer Vectors for Mammalian Cells” (Miller and Calos, 1987); “Current Protocols in Molecular Biology” (Ausubel, 1987); “PCR: The Polymerase Chain Reaction”, (Mullis, 1994); “Current Protocols in Immunology” (Coligan, 1991). These techniques are applicable to the production of the polynucleotides and polypeptides of the invention, and, as such, may be considered in making and practicing the invention. Particularly useful techniques for particular embodiments will be discussed in the sections that follow.

The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the agents and therapeutic methods of the invention, and are not intended to limit the scope of what the inventors regard as their invention.

It should be appreciated that the invention should not be construed to be limited to the examples that are now described; rather, the invention should be construed to include any and all applications provided herein and all equivalent variations within the skill of the ordinary artisan.