ZNF365/ZFP365 biomarker predictive of anti-cancer response

1. A method of inhibiting the proliferation of breast cancer cells having less than a diploid copy number of ZNF365 in a human subject, the method comprising administering an inhibitor of PARP-1 and/or PARP-2 to a human subject determined to have less than a diploid copy number of ZNF365 n breast cancer cells, wherein the determination is achieved by:

a) measuring the copy number of ZNF365 in a test sample comprising breast cancer cells; and

b) determining that a less than diploid copy number of ZNF365 is present in the breast cancer cells in the test sample.

2. The method of claim 1 , wherein ZNF365 encodes a protein that reduces DNA repair activity.

3. The method of claim 2 , wherein the DNA repair activity is selected from the group consisting of non-homologous end joining, homologous recombination, and DNA single-strand break repair.

4. The method of claim 2 , wherein the protein encoded by ZNF365 interacts with a protein selected from the group consisting of PARP-1, PARP-2, DNA-PK, Ku70, MRE11, RPA, CHEK1, and a topoisomerase.

5. The method of claim 1 , wherein ZNF365 encodes a protein having an amino acid sequence selected from the group consisting of SEQ ID NOs: 2, 4, 6, and 8.

6. The method of claim 1 , wherein the breast cancer cells harbor defects in genes encoding proteins mediating non-homologous end joining, homologous recombination, or DNA single-strand break repair.

7. The method of claim 6 , wherein the breast cancer cells harbor defects in BRCA1, BRCA2, and/or Fanconi anemia (FANC) genes.

8. The method of claim 1 , further administering chemotherapy, radiation therapy, or a combination of chemotherapy and radiation therapy, wherein said chemotherapy does not target PARP-1 and/or PARP-2.

9. The method of claim 8 , wherein the chemotherapy comprises inhibitors selected from the group consisting of inhibitors of DNA-PK, Ku70, MRE11, RPA, CHEK1, and topoisomerases.