Apoptosis Induction Of Human Hepatocellular Carcinoma Cell Strain HepG2 By Mycoplasma Genitalium Lipid-Associated Membrane Proteins And Mechanism

Object: To observe the effect of mycoplasma genitalium lipid-associated membrane proteins (Mg LAMPs) on apoptosis of human hepatocellular carcinoma cells strain HepG2 in vitro and to explore the mechanism.Method: The inhibitory effects of Mg LAMPs on proliferation of HepG2 cells was assessed by MTT assay. Morphologic changes were observed under inverted microscope. AO/EB double fluorescent labeling was used to display the different phase of cell apoptosis. The activity of caspase-3 was measured by colorimetry. Flow cytometry (FCM) was employed to analysis the cell cycle distribution and apoptosis, and to detect the expression of bcl-2 and bax.Result: Mg LAMPs (12.5-62.5μg/ml) initiated growth inhibition of HepG2 cells in a dose- and time-dependent manner. Morphological study showed that,with the increase of the concentration of Mg LAMPs,the cell adhesion ability decreased,many cells shed from the culture bottle wall and floating in culture medium. The different phase of cell apoptosis could be observed by AO/EB staining under fluorescence microscope. After being treated with 37.5μg/ml Mg LAMPs for 48h, the activity of caspase-3 in cells was significantly higher than that in control. FCM analysis demonstrated that the cell cycle was arrested at G1,G2/M phases.When treated with 0~62.5μg/ml Mg LAMPs for 48h, the apoptosis rate of HepG2 cells showed a dose-dependent manner. Compared with the control group, the Mg LAMPs could induce the expression of bax,while the expression of bcl-2 was decreased significantly.Conclusion: Mg LAMPs could inhibit proliferation and induce apoptosis of HepG2 cells though arresting cell cycle,up-regulating the activity of caspase-3 in cells and influencing the expression of bcl-2 and bax.