VDR agonists increase sensitivity of MCF-7 and BT-474 breast cancer cells to 5 FU

Abstract

Background/Aim: The study aimed to test the potential for increasing the antiproliferative activity of 5-fluorouracil against breast cancer cells of various molecular subtypes by Vitamin D receptor (VDR) agonists, calcitriol and tacalcitol, used at a low concentration of 10 nM. Materials and Methods: Calcitriol and tacalcitol were used to increase the antiproliferative effect of 5-fluorouracil against the following human breast cancer cell lines: MCF- 7, T47D, BT-474 (luminal); JIMT-1, SKBR-3 (HER2- enriched); MDA-MB-231 (triple-negative/basal-B), and nonmalignant MCF-10A breast epithelial cells. Results: Both calcitriol and tacalcitol significantly increased the sensitivity of MCF-7 and BT-474 cells to the antiproliferative effect of 5-fluorouracil, while no increase in the sensitivity of MDAMB- 231 cells to 5-fluorouracil treatment was observed. Conclusion: The VDR agonist used at the relatively low concentration of 10 nM may increase the sensitivity of breast cancer cells, at least of the luminal subtype, to the antiproliferative effect of 5-fluorouracil.