Changes Of Autophagy Level In Gastric Cancer SGC7901 Cells Under Acidic Microenvironment And Its Effect On Cell Proliferation

Objective: To investigate the changes of autophagy level of gastric cancer SGC7901 cells and the effect of the change on cell proliferation in acidic environment,which can provide a new strategy of therapy targeting the autophagy in acid environment in gastric cancer.Methods: The human gastric cancer cell line SGC7901 was selected as the study cell.The acid environment’s effect on the formation of autophagosome in gastric cancer cell line SGC7901 was detected by transmission electron microscopy and confocal laser scanning microscopy.The expression of LC3 and p62 in SGC7901 cells that were exposed to acidic condition for different time were detected by Western-Blot to investigate whether long-term exposure to acidic conditions could influence the autophagy levels in SGC7901 cells.To explore the changes of autophagy flux,cells were treated with bafilomycin A1 then detected the expression of LC3-II and p62 by Western-Blot as well.CCK8 were carried out to determine the effect of inhibition of acid-induced autophagy on cell proliferation.Results: 1.Compared with the SGC7901 cells cultured in the neutral environment,the number of autophagosomes in the SGC7901 cells under acidic stress were significantly increased.Under the laser confocal microscope,there were more LC3 puntas in cells cultured under acidic condition than those cultured in neutral environment.The intracellular LC3 fluorescence distribution of SGC7901 cells cultured in neutral environment was scattered.2.Compared with SGC7901 cells cultured in neutral environment,the expression of LC3-II in those cultured under acidic condition was increased while the expression of p62 was decreased.This phenomenon exists in a long time incubation under acidic condition.3.Autophagy flow is upregulated under acidic environment.4.Inhibition of acidic environment induced autophagy can cause cell proliferation inhibition.Conclusion: Autophagy is upregulated in SGC7901 cells incubated under acidic environment,and this autophagy persisted and stabilized for a long time without increasing or decreasing with time.Cell proliferation of SGC7901 cells in the acidicenvironment is slower than in the normal environment;both in acidic environment and normal environment inhibition of autophagy can cause proliferation inhibition of SGC7901 cells,acidic environment of autophagy on gastric cancer SGC7901 has a protective effect.