| Objective: Gastric cancer(GC)is a common malignant tumor worldwide.In our country,the incidence and mortality of gastric cancer are still very high,which seriously threatens people’s lives and health.For this reason,research on biomarkers used for definitive diagnosis of gastric cancer and effective treatment targets has become a hot spot that needs to be solved urgently.miR-1271-5p is abnormally expressed in a variety of tumors,and the expression varies between tumors in different parts of the digestive system.The purpose of this study was to investigate the expression and clinical significance of miR-1271-5p in gastric cancer,its impact on the biological behavior of gastric cancer cells and its mechanism of action.Methods:1.q RT-PCR was used to detect the expression of miR-1271-5p in 90 cases of gastric cancer and corresponding adjacent tissues and gastric cell lines.The relationship between miR-1271-5p and the clinicopathology and survival time of patients was analyzed in combination with the clinical information of patients.2.Transfected with miR-1271-5p-mimics or miR-1271-5p-inhibitor in gastric cancer cell lines SGC-7901,MGC-803 and AGS,respectively,to overexpress or inhibit their expression,and by q RT-PCR Technology to verify its overexpression or inhibition effect.Flow cytometry was used to detect cell cycle apoptosis and distribution;The CCK8 method was used to detect cell proliferation activity;scratch healing test and Transwell migration test were used to detect cell migration ability;and Transwell invasion test was used to detect cell invasion ability to clarify the effect of miR-1271-5p on the biological behavior of gastric cancer cells.3.Transfection of miR-1271-5p mimics or miR-1271-5p inhibitor in gastric cancer cell lines SGC-7901,MGC-803 and AGS overexpression or knockdown of miR-1271-5p.Used the Targetscan online website(http://www.targetscan.org)to predict the miR-1271-5p target gene,and screen out the proteins whose expression is negatively regulated by miR-1271-5p,and used q RT-PCR,Western blot and cellular immunity Fluorescence method to verify.The correlation between miR-1271-5p and target gene expression was verified in 30 pairs of gastric cancer patients’ tumors and corresponding paracancerous samples.It is clear that miR-1271-5p exerts cancer suppressing effects through target genes.Results:1.Compared with normal gastric epithelial cells GES1,the expression of miR-1271-5p in gastric cancer cell lines SGC-7901,MGC-803,and AGS were all reduced(GES1: 1.001±0.002 vs SGC7901: 0.323±0.003,MGC803:0.124±0.007,AGS: 0.102±0.010,both P<0.001);the expression of miR-1271-5p in gastric cancer tissue was significantly lower than that in the matched adjacent tissues(2.544±0.209 vs 4.427±0.339,P<0.001).The expression level of miR-1271-5p in gastric cancer tissue was significantly negatively correlated with the TNM stage(P=0.028)and the survival time of those with high expression of miR-1271-5p was prolonged,and the survival time of those with low expression was shortened(42 months vs 36 months,P<0.05).2.After transfection with miR-1271-5p mimics,cell proliferation activity,scratch healing rate of SGC-7901,MGC-803 and AGS cells(P<0.001,P<0.001,P=0.001)and Transwell migration(P=0.003,P<0.001,P<0.001)and the number of invasive cells(P=0.001,P<0.001,P<0.001)were remarkably cut down than the cells transfected with mimics.NC;on the contrary,transfected with miR-1271-5p inhibitor inhibited it After expression,cell proliferation activity,scratch healing rate(P<0.001,P=0.002,P<0.001)and Transwell migration(P<0.001,P<0.001,P<0.001)and number of invasive cells(P<0.001,P<0.001,P<0.001)was significantly higher than cells transfected with inhibitor.NC.Percentage of apoptotic cells(P=0.015,P=0.047,P=0.020)and percentage of cells in G2/M phase transfected with SGC-7901,MGC-803 and AGS cells transfected with miR-1271-5p mimics(P=0.004,P=0.004,P=0.022),significantly higher than the cells transfected with mimics.NC;on the contrary,after transfected with miR-1271-5p inhibitor,compared with the control group transfected with inhibitor.NC,the cells The percentage of apoptotic cells(P=0.002,P=0.006,P=0.018)and the percentage of cells in G2/M phase(P=0.025,P=0.033,P=0.085)decreased significantly.After transfection of miR-1271-5p mimics,the epithelial-mesenchymal transformation ability of SGC-7901,MGC-803 and AGS cells was significantly lower than that of cells transfected with mimics.NC.Compared with the control group transfected with inhibitor.NC,the epithelial-mesenchymal transformation ability was significantly improved.3.After transfection of miR-1271-5p-mimics in gastric cancer cell lines SGC-7901,MGC-803 and AGS,AVIL and TGFBR1 m RNA(AVIL,P<0.001,P<0.001,P<0.001;TGFBR1,P<0.001,P<0.001,P<0.001)and protein levels were significantly reduced.On the contrary,after transfection with miR-1271-5p inhibitor,the expression levels of both proteins were significantly increased(AVIL,P<0.001,P<0.001,P<0.001;TGFBR1,P<0.001,P<0.001,P<0.001),indicating that AVIL and TGFBR1 may be the target genes of miR-1271-5p in gastric cancer cells.The expression levels of AVIL and TGFBR1 in gastric cancer tissues were significantly higher than their corresponding adjacent tissues,and the expression levels of AVIL and TGFBR1 in gastric cancer tissues were negatively correlated with the expression levels of miR-1271-5p(P=0.025,r=0.235;P =0.014,r=0.197).Summary:1.The expression of miR-1271-5p in gastric cancer tissues and cell lines are both down-regulated and negatively correlated with the patient’s TNM stage,and positively correlated with the patient’s survival time.2.Overexpression of miR-1271-5p can suppress the proliferation,migration and invasion ability of gastric cancer cells.Mi R-1271-5p may play a role in cancer suppression in the occurrence and development of gastric cancer.3.miR-1271-5p inhibits its expression by binding the target gene AVIL and the 3’UTR region of TGFBR1 m RNA,and exerts its antitumor effect in the development of gastric cancer.Conclusions: miR-1271-5p is down-regulated in gastric cancer tissues and cells,and its low expression is associated with gastric cancer TNM stage;miR-1271-5p inhibits its expression by binding to its target genes AVIL and TGFBR1 m RNA 3’UTR region,thereby supressing the ability of gastric cancer cells to proliferate,migrate and invade. |
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