薑黃素及其結構類似物誘導人類乳癌細胞(MCF-7和MDA-MB-231)計畫性死亡之相關研究

Abstract

Curcumin is the primary bioactive constituent of turmeric, which is an herbal medicine used in Asia for a long time. It has been shown to possess anti-inflammatory, antioxidant, anti-metastatic, and apoptosis- induced properties. In this study, curcumin and 23 different kinds of curcumin analogs were evaluated for cytotoxicity effects on two breast cancer cell lines—MCF-7 and MDA-MB-231. According to the results of cell viability assay, analog 2, 6 and 85 showed stronger growth inhibition activities in both MCF-7 and MDA-MB-231 cell lines than curcumin under concentration of 5 μM and were selected as test candidates. The analog 2, 6, and 85 together with negative control of analog 9 with four to six methoxyl substituents in the phenyl groups were chosen to compare structure-activity relationships. Apoptosis activity was examined by Annexin-V-FITC fluorescence stain by a confocal microscopy under 5 μM treatments. Among them, analog 6 was demonstrated to effectively induce apoptosis activity. By flow cytometry analysis for Annexin-V-FITC/PI fluorescence under concentration of 15 μM treatment for 24 hours, analog 6 showed almost 100% apoptosis in both MCF-7 and MDA-MB-231 cell lines; analog 2 induced 80% apoptosis in MDA-MB-231 cell line; analog 85 exhibited 80% apoptosis in MCF-7 cell line. Cell cycle distribution was arrested by curcumin, analog 2, 6, and 85 in G2/M phase in MCF-7 cells. In MDA-MB-231 cells, curcumin, analog 2, and 85 caused cell cycle arrest in G2/M phase; analog 6 caused cell cycle arrest in G0/G1 phase. Analog 9 showed no influence on cell cycle distribution in both cell lines. To study the mechanism of apoptosis induction by analog 6 and curcumin, cellular reactive oxygen species (ROS) produced levels were detected. It was found that curcumin and analog 6 elevated ROS levels in MDA-MB-231 cells after being treated with 30 minutes. Furthermore, curcumin and analog 6 for 24-h treatments induced heme oxygenase-1 (HO-1) protein expressions in both cell lines. Analog 6 increased MDA-MB-231 cells caspase-9 and caspase-3 actived form expression. We concluded that analog 6 induce MDA-MB-231 cells undergo apoptosis through intrinsic pathway. In addition, according to gelatin zymograhy and wound healing assay, analog 6 inhibits MDA-MB-231 cells migration through suppressing MMP-9 activity.