Study On The Biological Effect And The Clinical Significance Of MiR-650on Gastric Cancer Cells

Objective:Gastric Cancer is one of a communis malignant tumor with high morbidity and mortality, its five-year survival rate is still only at30%-40%. However, there is limited information about the microRNA molecular abnormalities involved in gastric cancer pathogenesis. We investigate the relation between the expression of miR-650and the proliferation and apoptosis activity of the gastric cancer cells, explore the regulatory effect of miR-650in the development and prognosis of gastric cancer and its clinical significance.Methods:RT-PCR was used to examine miR-650expression levels in all five gastric cancer cell lines and the gastric cancer tissues, the internal relation was analysed between patients’postoperative survival period and the clinical factors, which included gender, tumor size, miR-650expression levels and so on. After transfected into gastric cancer cells the mature sequence of miR-650and LNA inhibitor, the cellular growth activity was estimated by CCK-8kit, the apoptosis activity was tested by flow cytometry, using the LC-MS/MS-based techniques quantitatively analysed the candidate targets of miR-650, western blot was used to test the expression levels of RGS7which acted as a target of miR-650in gastric cancer cells, nude mouse xenograft model was used to perform the biological effect of miR-650on gastric cancer cells and the biotherapy of miR-650inhibitor.Results:The expression levels of miR-650were different in all gastric cancer tissues,while there was no relationship between miR-650expression levels and gender, tumor size or TNM stage,there was a significant association between miR-650expression levels and patients’postoperative survival period.KATO III, NUGC4and SGC-7901 gastric cancer cells played high levels of miR-650, while NCI-N87and MKN-45gastric cancer cells only displayed low expression of miR-650in all above gastric cancer cell lines. When transfected into LNA inhibitor, gastric cancer cell lines proliferation significantly decreased, however, the cells apoptosis evidently increased. We considered that RGS7was one of the functional downstream targets of miR-650, the expression levels of RGS7was inversely correlated with miR-650expression levels.Animal experiment results in vivo proved that miR-650inhibitor significantly suppressed tumor growth activity.Conclusion:The up-regulation of miR-650promotes gastric cancer cells growth and inhibits apoptosis, its possible mechanism maybe suppress the expression of the target protein RGS7.MiR-650can modulate the proliferation and apoptosis biological processes of gastric cancer cells in gastric cancer formation processes, and its different expression levels significantly correlates with patients’survival period.So as a new type of specific tumor markers, miR-650may have significant potential clinical value to comprehend the pathogenesis of gastric cancer,to search its diagnosis and treatment targets and to monitor patients’prognosis.