PT - JOURNAL ARTICLE AU - DAGMARA KLOPOTOWSKA AU - JANUSZ MATUSZYK TI - VDR Agonists Increase Sensitivity of MCF-7 and BT-474 Breast Cancer Cells to 5 FU AID - 10.21873/anticanres.14015 DP - 2020 Feb 01 TA - Anticancer Research PG - 837--840 VI - 40 IP - 2 4099 - http://ar.iiarjournals.org/content/40/2/837.short 4100 - http://ar.iiarjournals.org/content/40/2/837.full SO - Anticancer Res2020 Feb 01; 40 AB - 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 non-malignant 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 MDA-MB-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.