Investigation of antiproliferative, anti-inflammatory, antitumoral and proapoptotic effects of calcitriol on MCF-7 and MCF-10A cell lines

Abstract

Calcitriol, a biologically active metabolite of vitamin D, regulates signaling pathways related to proliferation, malignant transformation, invasion, metastasis, angiogenesis, and inflammation in human cells. In that context, it is crucial to determine anticancer effects of calcitriol in terms of preventing the development of breast cancer, which is the most common malignancy in women, and improving its prognosis. Here, we investigated possible anti-inflammatory, antitumoral, antiproliferative, and proapoptotic effects of various doses of calcitriol that we applied in vitro conditions on breast adenocarcinoma (MCF-7) and healthy breast epithelial cell lines (MCF-10A). We treated cell lines with 0.5, 1, 10, 25, 50, 100, 200, 500, 1000 and 10000 nM doses of calcitriol for 24 and 48 h. After exposure of 100 nM calcitriol to MCF-7 cell line for 24 h, a significant decrease in cell viability, a significant increase in apoptosis rate, a 13-fold increase in the vitamin D receptor (VDR), a 3-fold decrease in NF-kB, an 8-fold decrease in PGE₂, and a 1.5-fold decrease in COX-2 expression levels were detected compared to the control group. Further, it was determined that a 100 nM dose of calcitriol had antiproliferative, anti-inflammatory, apoptosis-inducing and tumor suppressive effects on MCF-7 breast adenocarcinoma cell line.