Effects Of Parkin On Aerobic Glycolysis,Proliferation And Apoptosis Of Breast Cancer MDA-MB-231 Cells

Objective: The purpose of this study was to analyze the effect of Parkin on aerobic glycolysis,proliferation and apoptosis of breast cancer MDA-MB-231 cel s.Methods: Firstly,taking breast cancer MDA-MB-231 cells as the research object and normal breast epithelial cells MCF-10 A as the control,the mitochondrial morphology and membrane potential were analyzed by mitochondrial fluorescence probe.The expression of apoptosis-related proteins C ytochrome c,Bcl-2 and Bax was examined by Western blot.Glucose consumption,lactic acid and ATP production of the two groups were detected by glucose,lactic acid and ATP detection kit,respectively.The expression of glycolysis related proteins GLUT1,PKM2 and LDHA in the two groups was explored by Western blot.Then,Western blot was used to detect the expression of Parkin in normal breast epithelial cells MCF-10 A and breast cancer cells MDA-MB-231.The MDA-MB-231 cells transfected with Parkin overexpression plasmids were used as the experimental group(Parkin group),and the MDA-MB-231 cells transfected with empty vectors were used as the control group.Mitochondrial morphology,membrane potential and glycolysis were compared between the two groups.Cell growth,colony formation and wound examind healing migration assays were used to evaluate the ability of cell proliferation and migration.The expression of apoptosis-related proteins Bax,Bcl-2 and cleaved Caspase-3 and PI3K/AKT pathway related proteins PTEN and p-AKT were examined by Western blot.Results: Compared with normal breast cells,the morphology of mitochondria in MDA-MB-231 cells changed,the membrane potential decreased and glucose uptake and lactic acid production increased,while ATP production decreased.Western blot showed that the expression of anti-apoptosis protein Bcl-2 and glycolysis-related proteins GLUT1,PKM2 and LDHA in MDA-MB-231 cells increased,and the expression of Parkin protein in MDA-MB-231 cells decreased significantly(P < 0.01).In order to test whether Parkin protein is involved in the regulation of breast carcinogenesis,we constructed breast cancer MDA-MB-231 cells with high expression of Parkin.The overexpression of Parkin protein was verified by Western blot and immunofluorescence detection.The results showed that high expression of Parkin led to restoration of mitochondrial morphology and membrane potential,decreased production of glucose uptake and lactic acid production and increased level of ATP(P< 0.05).O verexpression of Parkin in MDA-MB-231 cells reduced the cell proliferation and migration.Compared to the control group,t he expression of glycolysis-related proteins GLUT1,PKM2 and LDHA decreased in the Parkin group(P < 0.05).Moreover,the expression of anti-apoptotic protein Bcl-2 decreased and the expression of cleaved Caspase-3,PTEN and p-AKT increased(P < 0.05).Conclusions: In breast cancer MDA-MB-231 cells,aerobic glycolysis is the main pathway of glucose metabolism.In the MDA-MB-231 cells successfully transfected with Parkin overexpression plasmids,the aerobic glycolysis pathway was inhibited,the ability of cell proliferation and migration decreased and apoptosis occurred.Parkin may regulate the expression of glycolysis-related enzymes through the PI3K/AKT pathway.