The Treatment of Clear Cell Ovarian Cancer with the Poly(ADP- Ribose) Polymerase (PARP1) Inhibitors (AG14361,Veliparib,Olaparib) as Chemosensitizers

Introduction Most of those who get ovarian cancer will die from this cancer. Of the major types of ovarian cancer clear cell carcinoma is the most aggressive and chemoresistant type of epithelial ovarian cancer. Here the sensitivity of clear cell ovarian carcinoma to poly adenosine diphosphate [ADP-ribose] polymerase (PARP) inhibitors is tested. Methodology Ovarian cancer cell lines were treated with the PARP inhibitors AG14361, Veliparib, or Olaparib alone or in combination with cisplatin, carboplatinum, doxorubicin, 5-fluorouracil (5-FU), gemcitabine and paclitaxel for 72 hours. The IC50 concentrations were calculated. Each experiment was replicated 10 times. Results As single agents the PARP inhibition of ovarian cancer among serous, endometroid and clear cell ovarian cancer cell lines was similar. Clear cell ovarian cancer seemed particularly susceptible to chemo-sensitization by PARP inhibitors with paclitaxel, 5-FU, carboplatin, doxorubicin and/or cisplatin. Antagonism was seen with gemcitabine. Conclusion PARP inhibitors are exceptional chemosensitizers of clear cell ovarian cancer to treatment with most standard chemotherapy agents.