MAPKAP kinase-2 as a specific target for blocking proliferation of P53-defective

1. A method of sensitizing cells to chemotherapy comprising

administering to the cells an effective amount of a MAPKAP kinase-2 polypeptide inhibitor to sensitize p53-deficient cells to a DNA damaging chemotherapeutic agent,

then administering an effective amount of a chemotherapeutic to the sensitized p53-deficient cells to kill the cells wherein the chemotherapeutic agent is administered after and within twenty-eight days of administering the MAPKAP kinase-2 polypeptide inhibitor.

2. The method of claim 1 , wherein the chemotherapeutic agent is selected from the group consisting of altretamine,-amsacrine, azacitidine, bleomycin,-busulfan, capecitabine, carboplatin, carmustine, chlorambucil, 2-chlorodeoxyadenosine, cisplatin, cyclophosphamide, cytarabine, Cytoxan, dacarbazine, daunorubicin, docetaxel, doxorubicin, epirubicin, etoposide, floxuridine, fludarabine, 5-fluorouracil, gemcitabine, hexamethylmelamine, hydroxyurea,-ifosfamid, irinotecan, letrozole, lomustine, mechlorethamine, melphalen, mercaptopurine, 6-mercaptopurine, methotrexate, mitomycin, mitoxantrone, paclitaxel, pentostatin, procarbazine, raltitrexed, streptozocin, temozolomide, 6-thioguanine, topotecan, toremofine, trastuzumab, vinblastine, vincristine, vindesine, and vinorelbine.

3. The method of claim 1 , further comprising administering radiation therapy simultaneously or within twenty-eight days of administering the inhibitor.

4. The method of claim 1 , wherein the p53-deficient cells are cancer cells selected from the group consisting of acoustic neuroma, acute leukemia, acute lymphocytic leukemia, acute monocytic leukemia, acute myeloblastic leukemia, acute myelocytic leukemia, acute myelomonocytic leukemia, acute promyelocytic leukemia, acute erythroleukemia, adenocarcinoma, angiosarcoma, astrocytoma, basal cell carcinoma, bile duct carcinoma, bladder carcinoma, brain cancer, breast cancer, bronchogenic carcinoma, cervical cancer, chondrosarcoma, chordoma, choriocarcinoma, chronic leukemia, chronic lymphocytic leukemia, chronic myelocytic leukemia, colon cancer, colon carcinoma, craniopharyngioma, cystadenocarcinoma, embryonal carcinoma, endotheliosarcoma, ependymoma, epithelial carcinoma, Ewing's tumor, glioma, heavy chain disease, hemangioblastoma, hepatoma, Hodgkin's disease, large cell carcinoma, leiomyosarcoma, liposarcoma, lung cancer, lung carcinoma, lymphangioendotheliosarcoma, lymphangiosarcoma, macroglobulinemia, medullary carcinoma, medulloblastoma, melanoma, meningioma, mesothelioma, myxosarcoma, neuroblastoma, non-Hodgkin's disease, oligodendroglioma, osteogenic sarcoma, ovarian cancer, pancreatic cancer, papillary adenocarcinomas, papillary carcinoma, pinealoma, polycythemia vera, prostate cancer, rhabdomyosarcoma, renal cell carcinoma, retinoblastoma, schwannoma, sebaceous gland carcinoma, seminoma, small cell lung carcinoma, squamous cell carcinoma, sweat gland carcinoma, synovioma, testicular cancer, uterine cancer, Waldenstrom's fibrosarcoma, and Wilm's tumor.

5. The method of claim 1 , wherein the inhibitor alters a DNA damage-responsive cell cycle checkpoint of the p53-deficient cell.

6. The method of claim 5 , wherein the DNA damage-responsive cell cycle checkpoint is G 1 /S phase arrest.

7. The method of claim 6 , wherein Cdc25a degradation in the p53-deficient cells is impaired.

8. The method of claim 5 , wherein the DNA damage-responsive cell cycle checkpoint is G 2 /M phase arrest.

9. The method of claim 8 , wherein the interaction between Cdc25b and a 14-3-3 protein is reduced in comparison to a p53-deficient control cell.

10. The method of claim 1 , wherein cell death is by apoptosis.

11. The method of claim 10 , wherein apoptosis is at least partially dependent on caspase-3 activation.

12. The method of claim 1 , wherein the MAPKAP kinase-2polypeptide inhibitor is selected from the group consisting of a nucleic acid, a peptide and a small molecule.

13. The method of claim 1 , wherein the effective amount of a chemotherapeutic to the cells to kill the cells is lower than the effective amount of the chemotherapeutic to kill cells in the absence of the MAPKAP kinase-2 polypeptide inhibitor.

14. The method of claim 1 , wherein the chemotherapeutic agent is administered subsequent to administering the MAPKAP kinase-2 polypeptide inhibitor.