Effect Of Methionine Enkephalin On Proliferation And Apoptosis Of Human Gastric Cancer Cell Lines BGC823 And MGC803

Objective: In malignant tumors,gastric cancer is a common disease,and the effect of chemotherapy should be improved.Therefore,it is necessary to explore and study the tumor immunity for improving the treatment of gastric cancer at this stage.Immunotherapy has been used more and more widely in tumor therapy,aiming at stimulating the immune system response,enhancing tumor microenvironment and anti-tumor ability,and achieving tumor cell death.In recent years,it has been found that MENK not only regulates neuroendocrine activity,but also is an important immune regulatory factor.Therefore,MENK,as an endogenous neuropeptide linking the immune system with the neuroendocrine system,has attracted wide attention.In this experiment,methionine enkephalin(MENK)with different concentrations of methionine was used to investigate the effect of BGC823 on the proliferation and apoptosis of human gastric cancer cells in vitro,and to provide a theoretical basis for the immunotherapy of gastric cancer.Methods: Human gastric cancer cell lines BGC82 3 and MGC803 were cultured in vitro and treated with different concentrations(1,2,3,4 mg/ml)of ENK in vitro for 24,48,72 and 96 hours.MTS was used to detect the effect of MENK on the proliferation of BGC82 3 and MGC803 cell lines.Flow cytometry and Annexin V-FITC/PI double staining were used to detect the apoptosis of BGC823 and MGC803 cells treated with 4 mg/ml MENK for 48 hours in vitro.The expression of opioid receptor OGFr was detected by agarose gel electrophoresis and cellular immunofluorescence.;RT-PCR and Western Blot assay were used to detect the effects of MENK on the proliferation of BGC823 and MGC803 cells.The expression of opioid receptors in BGC823 and MGC803 cells was measured after MENK treatment.Results: 1.MENK can inhibit the differentiation of BGC823 and MGC803 cells.The higher the dose and the longer the time,the more obvious the effect is(P<0.05).2.The apoptosis rate of 4mg/ml MENK 48 h treated group was significantly higher than that of blank group by flow cytometry.(P<0.05).3.Agarose gel electrophoresis results showed that there was an obvious band at 132 BP in BGC823 and MGC803 cells,and the expression of opioid receptor OGFr was observed.Similarly,the expression of OGFr in the nuclear membrane and cytoplasm of gastric cancer cells BGC823 and MGC803 was detected by immunofluorescence assay.4.Real time quantitative PCR and Western Blot detection,compared with the blank group,the expression of OGFr in the 4mg/ml MENK 48 h treatment group was increased(P<0.05).Conclusion: In this study,MENK inhibited the proliferation of human gastric cancer cells BGC823 and MGC803 in a dose-and time-dependent manner;MENK can inhibit the proliferation of human gastric cancer cells BGC823 and MGC803 by inducing apoptosis by acting on opioid receptors;The expression of opioid receptor OGFr was observed in gastric cancer cells BGC823 and MGC803,and the expression of OGFr was enhanced after MENK treatment.