Objective To evaluate the role and mechanism of TUG1,a long noncoding RNA(lncRNA)in the development and progression of gastric cancer.Methods Tumor tissue and paracancerous tissue specimens of 60 gastric cancer patients who underwent radical gastrectomy from October 2018 to September 2020 in Jiading District Central Hospital affiliated to Shanghai University of Medicine & Health Sciences were collected.Tissue samples from three of these patients with lymph node metastasis were selected for lncRNA microarray detection to screen for differentially expressed lncRNAs in gastric cancer and paracancerous tissue samples.The expression level of TUG1 in gastric cancer tissues and cells were detected by using real-time fluorescence quantitative polymerase chain reaction.The relationship between the expression level and clinicopathological factors was investigated.The lentiviruses Lenti-TUG1 and Lenti-TUG 1-shRNA were used to transfect gastric cancer cells NCI-N87 and MGC-803.Gastric cancer cells were divided into the Lenti-TUG 1-treated group and the Lenti-TUG1-shRNA-treated group according to lentiviruses transfection.Cells designed without lentivirus were the control group.CCK-8 and animal model experiments were carried out to determine the effects of TUG1 gene on the proliferation of NCI-N87 and MGC-803 in vitro and in vivo.Transwell assay was performed to determine the effects of TUG1 gene on the migration and invasion of NCI-N87 and MGC-803.Annexin V/PI staining assay was performed to determine the effects of TUG1 gene on the apoptosis of NCI-N87 and MGC-803.Western blotting was performed to determine the effects of TUG 1 gene on the expression of apoptosis-and epithelial-mesenchymal transition(EMT)-related proteins.Results The results of lncRNA microarray showed that there were 11 lncRNAs with up-regulated expression and 7 lncRNAs with down-regulated expression in gastric cancer tissues compared with paracancerous tissues.Based on the median relative expression of TUG1 in the gastric cancer tissues,the patients were divided into a high expression group(n=30)and a low expression group(n=30).The proportions of patients with tumor volume ≥5 cm3,lymph node metastasis,distant metastasis,and TNM stage Ⅲ in the high expression group were significantly higher than those in the low expression group(all P＜0.05).The results of cell proliferation assay showed that the optical density of NCI-N87 and MGC-803 cells in the Lenti-TUG 1-treated group was significantly higher than that in the control group,and the optical density of NCI-N87 and MGC-803 cells in the Lenti-TUG1-shRNA-treated group was significantly lower than that in the control group(all P＜0.01).The results of cell migration and invasion assays showed that compared with the control group,the number of migrating and invading NCI-N87 and MGC-803 cells in the Lenti-TUG1-treated group were significantly increased,and the number of migrating and invading NCI-N87 and MGC-803 cells in the Lenti-TUG1-shRNA-treated group were significantly decreased(all P＜0.01).The results of apoptosis assay showed that compared with the control group,the apoptosis rates of NCI-N87 and MGC-803 cells in the Lenti-TUG1-treated group were significantly reduced,and the apoptosis rates of NCI-N87 and MGC-803 cells in the Lenti-TUG1-shRNA-treated group were significantly elevated(all P＜0.01).The results of small animal in vivo imaging experiments showed that compared with the control group,the relative fluorescence intensity of NCI-N87 and MGC-803 cells in the Lenti-TUG1-treated group was significantly increased,and the relative fluorescence intensity of NCI-N87 and MGC-803 cells in the Lenti-TUG1-shRNA-treated group was significantly reduced(all P＜0.01).The results of Western blotting showed that the relative protein expression of Bax,caspase-3 and E-cadherin was significantly decreased,and the relative protein expression of RAB2A,MMP-14 and Bcl-2 was significantly increased in NCI-N87 and MGC-803 cells in the Lenti-TUG1-treated group as compared with those in the control group;the opposite results were obtained in the Lenti-TUG1-shRNA-treated group(all P＜0.01).In 229 gastric cancer tissues,TUG 1 was positively correlated with the expression of RAB2A gene(r=0.180,P=0.006),and miR-186 was negatively correlated with the expression of RAB2 A gene(r=-0.147,P=0.026).Conclusion TUG1 gene may regulate the development and progression of gastric cancer through apoptosis-and EMT-related signaling pathway,which may be a potential target for the treatment of gastric cancer.
维普
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