Paclitaxel, Carboplatin and 1,25-D3 Inhibit Proliferation of Endometrial Cancer Cells In Vitro

Abstract

Background/aim: Endometrial cancer cells are known to be sensitive to carboplatin and paclitaxel. Furthermore, vitamin D (1,25-D3) has been reported to inhibit endometrial cancer cell growth both as a single agent and combined with carboplatin. However, there are no studies comparing the effect of paclitaxel and carboplatin as single agents vs. in combination in endometrial cancer cell lines. Neither has the effect of 1,25-D3 been studied with paclitaxel. The present study investigated the effect of paclitaxel, carboplatin and 1,25-D3 on the growth of endometrial cancer cells in vitro.

Materials and methods: Two endometrial adenocarcinoma cell lines (UT-EC-1 and UT-EC-3) were cultured with different doses of paclitaxel, carboplatin and 1,25-D3. The cellular VDR (vitamin D receptor) mRNA levels were measured and the expression of estrogen (ER) and progesterone (PR) receptors by the cells was determined.

Results: In the UT-EC-1 cell line the growth inhibition was 72% with paclitaxel, 54% with carboplatin and 73% with the combination of these compounds. The corresponding numbers in UT-EC-3 were 70%, 33% and 65%, respectively. 1,25-D3 suppressed cell growth 88% with paclitaxel, 63% with carboplatin and 87% with their combination in the UT-EC-1 cell line.

Conclusion: In both cell lines, single-agent paclitaxel was as effective as the combination of the compounds and more effective than single carboplatin. 1,25-D3 may further contribute to the cytotoxic effect of these agents.

Keywords: 1,25-D3; VDR; Vitamin D; carboplatin; endometrial cancer in vitro; growth inhibition; paclitaxel.