PARP inhibition sensitizes endometrial cancer cells to paclitaxel-induced apoptosis.

PARP inhibitors are used in the treatment of gynecological malignancies and it has been demonstrated in preclinical studies that PARP inhibition sensitizes cancer cells to cytotoxic agents. In the present study, PARP expression was detected in different endometrial cancer cell lines by western blot analysis, and PARP activity was measured using an enzymatic assay. In addition, the endometrial cancer cell lines were treated with paclitaxel or carboplatin in combination with the PARP inhibitor PJ34 prior to a cell viability assay and apoptotic nuclei measurement. PARP protein was detected in all four cell lines examined, although its activity varied between the cell lines. Treatment with PJ34 in combination with paclitaxel decreased endometrial cancer cell viability compared with treatment with paclitaxel alone. These results indicate that the inhibition of PARP with PJ34 sensitizes endometrial cancer cells to cytotoxic treatment with paclitaxel.