Study On Expression And Clinical Significance Of MicroRNA-214 And Its Effect On Tumor Immune Escape In Gastric Adenocarcinoma

Objetive: To investigate the expression of microRNA-214 in gastric cancer tissues and adjacent normal tissues,and analyze the correlation between the expression level and the clinic-characteristics of gastric cancer;to clear expression of microRNA-214 in plasma in patients with gastric cancer,and verify the possibility of microRNA-214 being a serological marker of gastric cancer;to explore the fuction of microRNA-214 in immune escape of gastric cancer and the related mechanisms.Method:(1)Expression of microRNA-214 was tested by qRT-PCR in 47 cases of primary gastric cancer tissues and adjacent normal tissues.The correlation between microRNA-214 expression level and clinic-characteristics of gastric cancer were analyzed by Pearson correlation test.(2)Expression of microRNA-214 in plasma was tested by qRT-PCR in 47 cases of primary gastric cancer and 30 cases of healthy people.The correlation between microRNA-214 expression level in cancer tissues and plasma was analyzed by Pearson correlation test.(3)The expression of PTEN,AKT,Foxp3 in gastric cancer tissues and adjacent normal tissues in mRNA and protein level was measured by QRT-PCR,immunohistochemistry and Western blot respectively.(4)The expression of microRNA-214,PTEN,AKT,Foxp3 in SGC7901 in mRNA level after transfected with microRNA-214-inhibitor was measured by QRT-PCR,while the expression of PTEN,AKT,Foxp3 in protein level was measured by Western blot.Results:(1)microRNA-214 was up-regulated in gastric cancer tissues.The Pearson correlation test showed that the expression of microRNA-214 was associated with the tumor size(r=0.620)and lymph node metastasis(r=0.775)(P(27)0.05).(2)microRNA-214 was up-regulated in gastric cancer plasma,and the expression of microRNA-214 in gastric cancer plasma was associated with itsexpression in gastric cancer tissues(r=0.986,P(27)0.001).(3)After transfected with microRNA-214-inhibitor,PTEN was up-regulated while AKT and Foxp3 were down-regulated whether in mRNA level or in protein level(P(27)0.05).Conclusion:Our results demonstrated that microRNA-214 is a potential molecular marker in gastric cancer.We proved that microRNA-214 was able to regulate Foxp3 by targeting PTEN.Our data highlight a possible role of microRNA-214 in tumor immune escape.