Studies On The Anti-Proliferation And Mechanism Of The Killing Effect Of Lignans On MCF-7 Breast Cancer Cell Line

Objective:To investigate the effect of Lignans on MCF-7 breast cancer cells about anti-proliferation and to explore its mechanism.Methods:The experiments were divided into two groups, including control group and drug treated group. The treated group was added by different concentration of lignans, and incubated for 24,48,72h, respectively. Inverted microscope was used for observing the growth condition of MCF-7, MTT assay was used for determining the cell survival rate of all the treated groups and control group. Also, the positive expression ratio of Bax, Bcl-2, p21,p27 and c-myc were detected by immunocytochemistry (ICC).Flow cytometry was used for studying the cell cycle and apoptosis rate.Results:(1)Inverted microscope showed more reproductive activity of MCF-7 breast cancer cell lines in control group than the experimental groups, and the growth inhibition and apopstosis of treated group cells occurred more frequently. (2)MTT assay showed that the survival rate in experimental groups is significant lower. It indicated that the inhibitory effect of lignans in experimental groups was dose and time dependent, and there is the significant difference when compared with the control group (P<0.001). (3)Immunocytochemical staining demonstrated that the cells of control group at 24,48, and 72 hours showed strongly positive of Bcl-2, c-Myc protein, weakly positive of Bax, p21 and p27 protein, while weakly positive of Bcl-2, c-myc protein, strongly positive of Bax, p21 and p27 protein in experimental groups. There is significant difference when compared with the control group (P<0.001). (4)The detection of flow cytometry showed that the apoptotic rate was 0.01% in control group, and 23.55% and 29.03% in experimental groups at 48 and 72 hours, respectively. There is significant difference when compared with the control group (P<0.001). Cell cycle test showed that the percentage of G1, G2, S were 55.6%,16.17% and 28.23% in in control group, while 66.63%,9.67%,23.69% and 64.25%,11.13%,24.62% in experimental groups at 48 and 72 hours.Conclusions:Lignans have obvious anti-proliferation effect on MCF-7 breast cancer cells. The mechanism maybe related to the up-regulation of Bax, down-regulation of Bcl-2 to promote apoptosis, meanwhile to inhibit the expression of c-myc protein by increaseing p21 and p27, concroling cell cycle to inhibit MCF-7 cells from G1 phase entering to the S phase and to prevent DNA synthesis of tumor cells.