Effect Of Monascus Pigments On Breast Cancer Cell Line MDA-MB-231

Monascus pigments are secondary metabolites produced by Monascus purpureus. Monascus pigments have many functions, such as hypolipidemic, anti-oxidation, anti-inflammatory, anti-cancer, and so on. The mechanism of the anti-cancer ability of Monascus pigments on MDA-MB-231 cell has not been investigated. In this work, the effects of Monascus pigments on proliferation and migration of MDA-MB-231 cells were investigated with MTS assay, flow cytometry, Hoechst staining, HE staining, cell invasion and scratch-wound assay. Protein chip technology and RT-qPCR were employed to study the potential molecular mechanisms of Monascus pigments on MDA-MB-231. The following results were obtained from the present study.1. Monascus pigments inhibited viability and induced apoptosis of the MDA-MB-231 cells. When MDA-MB-231 cells were incubated with different concentrations (0,100,200,300μg/mL) of Monascus pigments for different time (12, 24,48h), the pigments inhibited cell growth as assessed by MTS assay, Hoechst assay, and Flow cytometry. The inhibition of Monascus pigments on MDA-MB-231 depended on dosage and incubation time. When the MDA-MB-231 cells were incubated with 300μg/mL Monascus pigment for 24h, the cell viability was 50%.2. Monascus pigments caused cell morphology change. When MDA-MB-231 cells were treated with Monascus pigments (0,100,200,300μg/mL) for 24hrs, the cell shapes changed from typical spindle cells to irregular polygon cells, and the sizes of the cells were much smaller and rounder than regular cells. The cell nucleus and cytoplasm became merged together and could not be distinguished clearly.3. Monascus pigments inhibited the movement ability of MDA-MB-231 cells. In this work, MDA-MB-231 cells were incubated with different concentration of monascus pigments (0,100,200,300μg/mL). The movement abilities upon treatments of various periods of times (12,24,48h) were determined by scratch healing assay. The result implied that with the increase of monascus pigments concentration and the treatment time, the inhibitory effect of monascus pigments on movement abilities of MDA-MB-231 cells became much stronger. With the transwell assy, the number of cells pass through the membrane was reduced obviously with the increase of concentration of monascus pigments. Thus, monascus pigments could inhibit the invasion ability of MDA-MB-231 in vitro.Our results demonstrated that monascus pigments could inhibit MDA-MB-231 cell proliferation, promote cell apoposis, change cell morphology and inhibit the movement ability of MDA-MB-231 cells. To elucidate the molecular mechanisms of monascus pigments on MDA-MB-231, protein antibody microarray and RT-qPCR were used. The results of protein antibody microarray showed that compared with control, monascus pigments treatment resulted in significant changes of 98 proteins. Seven proteins were up-regulated (fold change≥2.0) and 91 were down-regulated (fold change≤0.5) by monascus pigments treatment. KEGG analysis revealed that the biological functions of these proteins were related to cell mitosis, cell adhesion, stress response, and signal transduction. To validate the result of microarray, RT-qPCR was employed to analyze the mRNA level of cell adhesion related proteins:KRT19 (up-regulated), TYMP (up-regulated) and CD44 (down-regulated). The results were consistent with that of the high-throughput protein antibody microarray. The related signaling pathways of 98 proteins were also analyzed by KEGG. The results revealed that the effect of monascus pigments on MDA-MB-231 cell was mainly depended on the PI3K-Akt signaling pathway.In conclusion, this study found out that monascus pigments inhibited proliferation and migration of MDA-MB-231 cells. The potential mechanisms of monascus pigments on MDA-MB-231 were to induce apoptosis and to down-regulate gene expression related to cell migration. PI3K-AKT signaling transduction pathway was identified to be the major pathway involved in effect of monascus pigments on MDA-MB-231. To my knowledgy, this is the first time to report the effect of monascus pigments on MDA-MB-231 cells and will provide basis for treatment of breast cancer by using monascus pigments.