Research On The Expression Of MiR-17-5p And MiR-200c In Plasma Exocrine In Patients With Advanced Gastric Cancer

Objective:To investigate the expression of plasma exosome miR-17-5p and miR-200c in patients with advanced gastric cancer and the changes of plasma exosome miR-17-5p and miR-200c in patients with advanced gastric cancer before and after chemotherapy and disease progression,and to determine whether this expression can be a predictor of chemotherapy and disease progression of advanced gastric cancer,so as to provide an important experimental basis for developing individualized treatment strategies for patients with gastric cancer in Qinghai area.Methods:Forty patients with advanced gastric cancer diagnosed by pathology in the Affiliated Hospital of Qinghai University from November 2016 to December 2018 were selected as experimental group,and 20 healthy people were collected as control group.The experimental group was given XELOX regimen chemotherapy,and the short-term efficacy was evaluated after chemotherapy,and the progress of the disease was observed.The expression levels of miR-17-5p and miR-200c in plasma exosomes of control group and experimental group before and after chemotherapy and after disease progression were extracted.The expression differences of miR-17-5p and miR-200c in control group and experimental group were observed.The progress of disease and the expression changes of miRNA in plasma exosomes before and after chemotherapy were observed.The expression changes of miR-17-5p and miR-200c in plasma exosomes before and after chemotherapy and disease progression were analyzed.The correlation between the rate and the time of disease progression.Results:1.comparing with healthy people,The relative expression of plasma exosome miR-17-5p was up-regulated in patients of advanced carcinoma of stomach（P=0.007）.while the relative expression of miR-200c in patients with advanced gastric cancer was lower than that in healthy people（P=0.030）.The results showed that the expression of secretorymiR-17-5p was up-regulated and the expression of miR-200c was down-regulated in patients of advanced carcinoma of stomach.2.The relative expression of plasma exosome miR-17-5p after chemotherapy was lower than that before chemotherapy（P=0.022）,while the relative expression of miR-200c was higher than that before chemotherapy（P=0.032）,The results showed that the expression of miR-17-5p was down-regulated and the expression of miR-200c was up-regulated in patients with advanced carcinoma of stomach after chemotherapy.3.The relative expression of plasma exosome miR-17-5p in the chemotherapy-ineffective group was higher than that in the chemotherapy-effective group（P=0.014）,and the relative expression of miR-200c was lower than that in the effective group（P=0.029）,indicating that the patients with advanced gastric cancer were outside the plasma.The expression levels of miR-17-5p and miR-200c in the body were related to the efficacy of chemotherapy.The chemotherapy effect of high expression of plasma exosomemiR-17-5p before chemotherapy was worse than that of low expression,while miR-200c suggested the opposite result.4.The relative expression of miR-17-5p in plasma exosome after chemotherapy in the effective group was lower than that before chemotherapy（P=0.044）,and the relative expression of miR-200c was higher than that before chemotherapy（P=0.049）,which indicated that chemotherapy was effective in advanced gastric cancer.The expression of miR-17-5p was down-regulated and the expression of miR-200c was up-regulated compared with that before chemotherapy.5.There was no significant difference in the relative expression of miR-17-5p and miR-200c in plasma exosomes after chemotherapy in the chemotherapy-ineffective group compared with that before chemotherapy（P=0.084;P=0.903）,indicating that the chemotherapy of advanced gastric cancer was ineffective,and the expression of miR-17-5p and miR-200c did not change significantly compared with that before chemotherapy.6.After the disease has progressed in the chemotherapy-effective group,The relativeexpression of miR-17-5p in plasma exosome was higher than pre-chemotherapy（P=0.031）,and higher than post-chemotherapy（P=0.004）,while the relative expression of miR-200c was lower than pre-chemotherapy（P=0.045）,lower than post-chemotherapy（P=0.036）.It is suggested that the expression levels of plasma exosome miR-17-5p and miR-200c are related to disease progression.7.After the disease progression in the chemotherapy-ineffective group,The relative expression of miR-17-5p in plasma exosome was higher than that pre-chemotherapy（P=0.044）,and higher than post-chemotherapy（P=0.007）,while the relative expression of miR-200c was not significantly different between pre-chemotherapy and post-chemotherapy（P=0.468,P=0.130）,but 2^-ΔΔCt showed a downward trend,Suggesting that the expression of miR-17-5p and miR-200c in plasma exosome might be related to disease progression.Conclusions:1.The expression of exosome miR-17-5p in the plasma of patients with advanced carcinoma of stomach was significantly up-regulated,and the high expression of exosome miR-17-5p predicted worse chemotherapeutic efficacy.Moreover,the expression of exosome miR-17-5p was related to disease progression.2.The expression of exosome miR-200c in plasma of patients with gastric cancer is down-regulated,it is up-regulated when chemotherapy is effective,and down-regulated when disease progresses.