A Preliminary Function Study Of LncRNA GC240 In Gastric Cancer About Clinical Phenotype And Progrosis

Background: Gastric cancer is a common malignancy worldwide and the ratio of men to women that develop gastric cancer is approximately 3:1. A large number of new cases diagnosed annually around the world. In China, the incidence of gastric cancer ranked only second to lung cancer and the mortality rate ranked third, become a threat to the health of our main lethal tumors. Gastric cancer is a multi-factor and multi-stage process. A growing number of studies have shown that long non-coding RNA(lnc RNA) play an important role in the development and prognosis of gastric cancer. Lnc RNA is defined as RNA molecules(>200nt) without the ability of coding protein. While lnc RNA can’t encode proteins, but studies show that lnc RNA can regulate gene expression at the transcriptional level, post-transcriptional level and other levels. In recent years, studies have shown that lnc RNA expression in gastric cancer is disorder, and their abnormal expression associated gastric cancer carcinogenesis, metastasis and prognosis. However, the mechanism of lnc RNA function in human gastric cancer also need further study.Methods: The Arraystar microarray was used to screen differentially expressed lnc RNA in five pairs of gastric cancer and adjacent normal tissue. By RT-PCR method, with largest Fold-change, GC240 was verified low-expression in gastric cancer tissue which is consistent with the results of microarray. RT-PCR was used to detect the expression level GC240 in gastric tissue and cells and we found that the expression of GC240 is correlated significantly with gastric cancer stage and prognosis, by analyzing epidemiological data. The experiments of over-expression and down-expression of GC240 in gastric cancer cell was used to explore the function of GC240 in proliferation, metastasis and invasion of cells.Results: In 75 gastric cancer and adjacent normal tissues, GC240 were 58 cases of gastric cancer tissues with low expression and 17 cases of high expression showed that the down-expression of GC240 in gastric cancer, results were consistent with the results of the microarray. The expression of GC240 in gastric cancer cell lines is also showing a significant low. Epidemiological data analysis found significant correlation between GC240 expression and gastric cancer stage and depth of invasion. In gastric cancer cells MGC-803 and BGC-823, we transfected over-expression plasmid of GC240, found that the ability of proliferation, migration and invasion of gastric cancer cell was significantly inhibited, while MGC-803 and BGC-823 transfected GC240-si RNA, migration and invasion of gastric cancer cells was significantly improved. In the analysis of the expression level of GC240 and patient survival found that patients with high expression GC240 have a better prognosis.Conclusion: Low-expression in gastric cancer, long non-coding RNA GC240 in gastric cancer can inhibited cell proliferation, migration and invasion of gastric cancer cells significantly. Patients with GC240 highly expressed have a better prognosis. So, we concluded that high-expression GC240 is a protective effect for gastric cancer, especially in the early gastric cancer. The results of this study may provide clues to further investigate the mechanism and clinical application of lnc RNA in gastric cancer.