| Objective:Gastric cancer is one of the most common malignant tumors in China and even in the world,and the incidence is increasing year by year.The 5-year survival rate of early gastric cancer after treatment is as high as 90%,but the onset of gastric cancer is hidden,patients are often in advanced or even late stage,and the prognosis is poor.Therefore,we urgently need to improve the efficiency of early diagnosis of gastric cancer and find new methods for the treatment of gastric cancer.Circular RNA(circRNA)plays a significant role in the occurrence and development of tumors.It has been reported that the expression of circITGA7 is decreased in colorectal cancer and can inhibit the progression of colorectal cancer,but its expression and mechanism in gastric cancer are not known.The purpose of this study is to explore the expression of circITGA7 in gastric cancer and its possible mechanism,so as to provide novel insights into early diagnosis and treatment of gastric cancer.Materials and Methods:(1)The expression of circITGA7 in gastric cancer and gastric cancer cells was detected by qRT-PCR,and the correlation between circITGA7 and gastric cancer cells was analyzed by combining the clinicopathological data of patients to explore the potential value of circITGA7 as a diagnostic marker of gastric cancer.(2)The over-expression and knockdown plasmids of circITGA7 and the corresponding control plasmids were transfected into human gastric cancer cells MGC-803 and MGC-823,respectively.The changes of apoptosis were detected by flow cytometry.The proliferation ability of gastric cancer cells after over-expression and knockdown of circITGA7 was detected by cloning cell and drawing growth curve.Finally,qRT-PCR and western blot were used to detect the effect of circITGA7 on apoptosis and proliferation-related genes,as well as the protein expression of these genes.(3)The changes of GC cells metastasis in vitro and invasion ability of gastric cancer cells after over-expression and knockdown of circITGA7 were detected by Transwellmigration and invasion assay.By means of qRT-PCR and western blot,the over-expression and the expression changes of genes and proteins related to epithelial-mesenchymal transformation(epithelial-mesenchymal transition,EMT)after knockdown of circITGA7 can be detected,so as to explore the possible mechanism of circITGA7 in the progression of gastric cancer.Results:(1)The results of qRT-PCR detection showed that in terms of the expression level,the control group has an edge over circITGA7 in gastric cancer tissues and gastric cancer cells.That is to say,the expression level of the latter was dramatically lower.Furthermore,the relevant clinicopathological data showed that there was a close connection between the expression level of circITGA7 in gastric cancer and tumor size,lymphatic metastasis and TNM stage.(2)Over-expression of circITGA7 could inhibit the proliferation of gastric cancer cells and promote the apoptosis of gastric cancer cells,while the proliferation ability of gastric cancer cells was enhanced and apoptosis was inhibited after knockdown of circITGA7.The over-expression of circITGA7 could promote the expression of PARP,caspase-3 and P21 protein,but inhibit the expression of Bcl-2 protein.The opposite result was obtained after knockdown of circITGA7.(3)The results of Transwell migration and invasion assay showed that the ability of migration and invasion of gastric cancer cells can be weakened due to the over-expression of circITGA7 while it can be significantly enhanced after knockdown of circITGA7.QRT-PCR and western blot experiments showed that circITGA7 could regulate TGF-? and Wnt signal pathways to inhibit the progression of EMT in gastric cancer cells.Conclusion:The expression of circITGA7 was decreased in gastric cancer tissues and gastric cancer cells,and there was a close connection between the expression level and tumor size,lymphatic metastasis and TNM stage.CircITGA7 can prevent gastric cancer cells from the proliferation,migration and invasion,promote the apoptosis of gastriccancer cells,and reverse the EMT process of gastric cancer cells by regulating TGF-?and Wnt signaling pathways,thus stopping gastric cancer from occurring and developing.Therefore,circITGA7 has the potential to become a diagnostic biomarker and therapeutic target for gastric cancer. |
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