Influence of tamoxifen on cisplatin-sensitivity and estrogen receptors expression in ovarian carcinoma cell lines

Abstract

Abstract Background: Tamoxifen, used in breast cancer treatment, competitively inhibits estrogen receptor (ER) and also demonstrates direct antiproliferative effect on cancer cells even in ER lacking cancer tissue. However, its molecular mechanism of action is still unclear. Material and methods: We exposed on tamoxifen 11 ovarian cancer cell lines, including well-documented platinumsensitive and platinum-resistant ones, and studied tamoxifen-, cisplatin-sensitivity and expression of ERα and s. Results: We observed: no correlation between TAM-sensitivity and ERα and ERs expressions, no correlation between TAM influence on cisplatin-sensitivity and ERα and ERs expressions, increase of ERs expression after TAM-exposure in 3 cell lines; decrease in the 1 line, no TAM-exposure influence on ERα expression and increase of IC50 for cisplatin after TAM-exposure in 5 (45%) cell lines. These results show ovarian cancer cells being affected by TAM have different platinum sensitivity. Conclusions: Our data suggests that ovarian cancer cells platinum-sensitivity are not linked with ER expressions. We claim the necessity of seeking some TAM predicting factors, using DNA microarrays.