Research About The Effect Of MicroRNA-28 On The Regulation Of MGC-803 In Gastric Cancer Cells

Objective:It is known that high expression of LSD1 is an important cause of inducing various cancers such as gastric cancer.However,microRNAs that significantly down-regulate the expression of LSD1 in other tumor cells are ineffective in gastric cancer cells.The purpose of this project is to find a microRNA that can down-regulate the expression of LSD1 protein in gastric cancer cells,and to study its effects on gastric cancer cells.For the treatment of gastric cancer to find a realistic way.Methods:The 3?UTR region of the mRNA of LSD1 gene in 4 gastric cancer cells was detected to find the mutation site.The open site software was used to predict the microRNA that may down-regulate the expression of human LSD1 protein.After finding the target microRNAs,the gastric cancer cells MGC-803 were transiently transfected with microRNA and their corresponding inhibitors,and then the total protein was extracted for Western Blot experiments to find the best microRNA to continue the experiment.In four gastric cancer cells and gastric epithelial mucosal cells,the best-selected microRNAs were screened previously.The qPCR assay detected whether the content of this microRNA in gastric cancer cells was significantly smaller than that of gastric epithelial mucosa cells,and which is the lowest type in these four gastric cancer cells.This gastric cancer cells continue to undergo proliferation,migration,invasion,cloning,and cell cycle experiments.The relationship between this microRNA and LSD1 expression can also be verified by confirming the patient's tissue immunohistochemistry experiments.Results:The T281 G and G283 T mutations were found in the 3?UTR region of the LSD1 gene mRNAs in gastric cancer cells of BGC-823,HGC-27,MGC-803 and SGC-7901.This mutation changes the secondary structure of the 3?UTR region of the LSD1 gene,which in turn affects the stability of the microRNA binding to it.The finded 10 microRNAs,were detected by Western Blot to search for microRNA-28.And microRNA-28 is one of the best microRNA to down-regulate the expression of LSD1 protein.In addition,from clinical patient samples,the content of microRNA-28 in adjacent tissues was significantly higher than that in cancer tissues,and the expression of LSD1 was reversed.At the same time,the content of microRNA-28 in four types of gastric cancer cells and gastric mucosal epithelial cells was detected.The content of micro RNA-28 in gastric cancer cells was significantly lower than that in gastric epithelial mucosa cells.Coincidentally,the content of microRNA-28 in MGC-803 cells was detected.MGC-803 cells also have the lowest content of microRNA-28 in four gastric cancer cells.The microRNA-28 and its inhibitors were transfected into MGC-803 cells and it was found that microRNA-28 can effectively inhibit the proliferation,migration,invasion,and colony formation of gastric cancer cells,but the effect of microRNA-28 inhibitors are not ideal enough.In cell cycle experiments,the effects of transient transfection of microRNA-28 and microRNA-28 inhibitor gastric cancer cell MGC-803 on cell cycle were similar,but they were significantly different from that of gastric cancer cell MGC-803 that was not transfected.Western Blot analysis of Usp28 also revealed that microRNA-28 and microRNA-28 inhibitors were similar to LSD1 in gastric cancer cell MGC-803.Conclusion:The mutations in the 3?UTR region of the LSD1 gene in gastric cancer cells alter the secondary structure of the 3?UTR region,thereby affecting the stability of miRNA binding.The Western Blot experiment was used to examine 10 kinds of microRNAs predicted by open source softwar Through a series of experiments,there has been demonstrated that microRNA-28 indeed plays a role in inhibiting gastric cancer cells.And it has played an important practical significance for the study of gastric cancer treatment.