ABSTRACT
Objective To investigate the expression of IL-6/STAT3 signal pathway induced by lipopolysaccharide (LPS) on human intrahepatic biliary epithelial cells (HiBECs) in vitro.Methods The HiBECs were cultured in vitro.The cells were stimulated by LPS at different concentrations (0,0.1,1,2,4,8 μg/ml) and different time (24,48,72 h).The expression of IL-6 was measured by ELISA to determine the best concentration and time of LPS.Then we chose the best concentration and time of LPS to intervene the cells in the further experiments.The levels of mRNA expression of c-Myc and Mcl-1 were detected by fluorescence quantitative reverse transcrption PCR (RT-qRCR).The proportion of p-STAT3/STAT3 protein and the expression of c-Myc and Mcl-1 protein in HiBECs were analyzed by Western blot.Results LPS upregulated the expression of IL-6, and reached its peak at 4 μg/ml and 24 h(F=16.492,17.763,P<0.001,P<0.01).LPS increased the mRNA expression of c-Myc and Mcl-1(P<0.01).Meanwhile, The ratio of p-STAT3/STAT3 (P<0.05) protein and the expression of c-Myc (P<0.001) and Mcl-1 (P<0.05) protein were upregulated after stimulating with LPS.Conclusion The IL-6/STAT3 signal pathway can be activated by LPS in HiBECs, and LPS may promote the expression of c-Myc and Mcl-1 through this signal pathway.
ABSTRACT
Objective To investigate the effect of equol on ERK mediated signal transduction pathway and to clarify its mechanism of proliferation inhibition on human ovarian carcinoma cell line SKOV-3. Method SKOV-3 cells were treated with 10-8,10-7,10-6,10-5,5?10-5,10-4 mol/L equol for 24,48 and 72h. After pretreatment with 10 ?mol/L U0126 an ERK signaling pathway inhibitor or ICI182,780,estrogen receptor inhibitors for 1h,then treatment with 50 ?mol/L equol for 2h,the cell viability was examined and the expressions of ERK and p-ERK protein were determined using Western blotting. Results Equol was demonstrated to inhibit SKOV-3,proliferation time-and dose-dependently. The expression of p-ERK protein was decreased in dose-dependent manner,while the expression of total ERK was unchanged. Both the single use of U0126,or ICI182,780,and combined with equol could decrease the expression of p-ERK protein. Conclusion Equol could inhibit proliferation in ovarian carcinoma cell lines SKOV-3. Its inhibitory effect appears to be due to down-regulation of p-ERK protein.