Tamoxifen enhances apoptotic effect of cisplatin on primary endometrial cell cultures

Background: Cisplatin (CDDP) dose-limited by its side-effects is, in some instances, synergistically amplified when combined with tamoxifen (TAM). TAM has been shown to modulate apoptotic pathways of normal endometrial cells, whereas CDDP induces apoptosis in malignant endometrial cells. Their combined effect on normal or malignant endometrium is as yet unknown. This study aimed to evaluate the combined CDDP and TAM's apoptotic effect on normal endometrial tissue in the context of hormonal milieu. Materials and Methods: Primary endometrial cell cultures were established and maintained both in the presence and absence of steroidal hormones. The cultures were treated for 24 hours with 20μM TAM and 50μM CDDP as single drugs and in combination. Apoptosis was determined by evaluation of pre G1 cell populations in the cell cycle analysis with flow cytometer. Results and Conclusion: CDDP induced apoptosis in all cultures regardless of hormonal environment, while TAM significantly enhanced CDDP-induced apoptosis in steroidal deficient media in an additive manner. These are novel findings depicting CDDP's effect on normal endometrium, singularly and combined with TAM.