| ObjectiveGastric cancer is a widely seen malignant tumor with a high incidence in our country.It is difficult to diagnose the early gastric cancer and the postoperative survival rate is lower,only using operation treatment is poor,and it is often necessary to combine radiotherapy and chemotherapy in order to achieve a cure.Although some effects of radiotherapy and chemotherapy for gastric cancer have been achieved,the therapeutic effects of chemotherapeutic drugs have not yet reached the expected results and the toxic side effects are more serious.Therefore,it is necessary to develop a novel antitumor drug that can kill tumor cells and have low toxicity.At present,the more popular method is to extract effective active substances from natural products.chaetocin is a small molecule natural product produced from the genus chaetocin and has good results in the clinical treatment of hematological tumors.At the same time,chaetocin has broad prospects for the treatment of solid tumors.This study aims to explore that chaetocin promotes autophagy in gastric cancer SGC-7901 cells and inhibits tumor cell proliferation,and to explore the mechanism how the autophagy was induced by chaetocin,which is used to increase the theoretical support for clinical therapy in gastric cancer.MethodsThe viability was detected by CCK8 assay in gastric cancer SGC-7901 cells;the apoptosis of gastric cancer SGC-7901 cells induced by chaetocin was detected by flow cytometry Annexin-V-FITC/PI double staining method.Using light microscopy observed the morphological diversification which was induced by chaetocin ingastric cancer SGC-7901 cells,and using fluorescence microscope observed the autophagosomes which were stained by MDC.By western blotting detecting molecular markers of autophagy and expression levels of LC3 protein autophagy substrate p62 protein,the reaction autophagy changes in levels of molecular biology.Finally,western blotting was used to detect the expression level of PI3K/Akt/mTOR-related molecules on the autophagy regulatory pathway and to investigate whether it involved in chaetocin-induced autophagy.ResultsIt is the viability that could be restrainted by chaetocin in gastric cancer SGC-7901 cells,and the cell viability would decrease by the increasing of chaetocin concentration.The result of Annexin-V-FITC/PI dual staining tests showed that,contrasted with the control,when treated by 0.25,0.5 and 1.0 mmol/L chaetocin in the SGC-7901 cells,the early apoptotic rate was 2.37%,2.73% and 5.17%;the rates of late apoptosis and necrosis were 9.47%,13.67%,and 18.63%.The results of light microscopy showed that the morphological changes of gastric cancer cell line SGC-7901 were markedly affected by chaetocin.When the consistence of chaetocin was increased,the cells gradually went round and narrowed,and finally they could not adhere to the wall and were suspended in the culture medium.Stained by MDC the results of fluorescent microscopy after showed that,When the consistence of chaetocin was increased,the observed fluorescence spots increased.The result of Western blotting showed that the expression level of LC3-II protein in gastric cancer SGC-7901 cells increased with the increase of administration time and concentration of chaetocin.The results of the final Western blotting showed that the relative expression levels of p-Akt and p-mTOR protein decreased with increasing concentration of chaetocin.ConclusionsIt was the proliferation that could be restrainted by chaetocin in gastric cancer SGC-7901 cells.When the death was induced by chaetocin in gastric cancer SGC-7901 cells,autophagy and apoptosis were activated,and apoptosis is mainly due to late apoptosis and necrosis.The autophagy might be regulated by chaetocinthrough the PI3K/Akt/mTOR pathway. |
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