Flavonoid calycopterin triggers apoptosis in triple-negative and ER-positive human breast cancer cells through activating different patterns of gene expression.

Breast cancer is the most common cause of death related to cancer in women, and several studies proved that flavonoids could induce apoptosis in this cancer through different pathways. Calycopterin is a flavonoid which was shown to induce preferential antiproliferative effects on some cancers; however, no information is available on its effect on breast cancer. Therefore, in this paper, the apoptotic effect of calycopterin and its underlying mechanism in two different breast cancer cells, MDA-MB-231 and MCF7 cell lines were investigated. MTT assay showed that calycopterin reduced the proliferation of both cancer lines with no adverse effect on normal cells. The clonogenic assay showed that calycopterin treatments decreased the colony numbers and sizes, and wound healing assay demonstrated the inhibition of migration in both cancer cells. Cell cycle and annexin/PI analyses indicated that calycopterin augmented sub-G1 population and annexin/PI-positive cells. Gene expression revealed that Bax/Bcl2 increased in the MDA-MB-231 cell line, while no change was observed in that of the MCF7 line. Expression of gene caspase-8 was augmented in both lines, although increased expression of caspase-3 was found just in MDA-MB-231 cells. Our results validated the apoptotic effect of calycopterin on both breast cancer lines with more potency on triple-negative ones.