RESUMO
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 platinum-sensitive and platinum-resistant ones, and studied tamoxifen-, cisplatin-sensitivity and expression of ERalpha and beta. RESULTS: We observed: no correlation between TAM-sensitivity and ERalpha and ERbeta expressions, no correlation between TAM influence on cisplatin-sensitivity and ERalpha and ERbeta expressions, increase of ERbeta expression after TAM-exposure in 3 cell lines; decrease in the 1 line, no TAM-exposure influence on ERalpha expression and increase of 1050 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.