The Effect Of ELMOD2 On The Biological Characteristics Of Gastric Cancer Cell Line MGC803 And The Related Mechanisms

Objective: Gastric cancer is a common malignant tumor,and the molecular mechanism of its progression is still not very clear.In-depth study for it will help to identify new molecular targets,which is of great significance for the diagnosis and treatment of gastric cancer.Previous studies in our group indicated that S100A4 could affect the proliferation,migration,apoptosis and anoikis of gastric cancer cells.We also screened the differentially expressed gene profile downstream of S100A4 using gene chip,and ELMOD2 is one of the differentially expressed genes.ELMOD2(ELMO domain containing 2)is a member of human ELMO protein family,and there are few reports on the function of ELMOD2.One study showed that ELMOD2 was associated with familial idiopathic pulmonary fibrosis.Other studies indicated ELMOD2 could affect the lipid metabolism and mouse oocyte meiosis.But the effect of ELMOD2 on the biological characteristics of tumor cells has not been reported yet.Since S100A4 affects the biological characteristics of tumor cells,we speculate that as a downstream gene of S100A4,ELMOD2 might affect the biological characteristics of gastric cancer cells and mediate the effects of S100A4.Studies have shown that ELMOD2 interacts with ARL2 and is a GTPase activating protein of ARL2.It has also been reported that ARL2 affects the biological characteristics of tumor cells,such as colorectal cancer and cervical cancer cells.We further speculate that ELMOD2 might affect the biological characteristics of gastric cancer cells via ARL2.To verify our speculation,we first studied the effects of ELMOD2 on the proliferation,migration and apoptosis of gastric cancer cell line MGC803.In order to explore the underlying molecular mechanisms,we also detected the expression of proliferation,migration and apoptosis related proteins in the cells.Then we further investigated whether ELMOD2 mediated the effect of S100A4 on the migration of MGC803 cells,and whether ELMOD2 affected the migration of MGC803 cells via ARL2.It will deepen the understanding for the molecular mechanism regarding the carcinogenesis and progression of gastric cancer,and provide new clues for molecular targeted therapy of gastric cancer.Methods: Human gastric cancer cells MGC803 were cultured.The cells were transfected with S100A4 specific si RNA.Then real-time quantitative PCR and Western blot were performed to detect the expression of S100A4 and ELMOD2,respectively.The cells were transfected with ELMOD2 expression vector,followed by the detection of ELMOD2 expression using the same methods as described above.After transfection with ELMOD2 expression vector,CCK-8 assay was used to detect cell proliferation,flow cytometry was used to detect apoptosis rate,Transwell assay was used to detect cell migration ability,and Western blot was used to detect PCNA,BAX,BCL-2 and VIMENTIN protein expression.Furthermore,S100A4-si RNA was co-transfected with ELMOD2 expression vector or empty vector into the cells,ELMOD2 expression vector was co-transfected with ARL2-si RNA or NC-si RNA into the cells,and cell migration ability was detected by Transwell assay.Result: 1.The results of real-time quantitative PCR and Western blot showed that silencing S100A4 expression by RNA interference led to significantly decreased expression of ELMOD2 m RNA and protein in MGC803 cells,suggesting that ELMOD2 is a downstream gene of S100A4.2.Real-time quantitative PCR and Western blot showed that after transfection of GV141-ELMOD2 expression vector,the expression of ELMOD2 m RNA and protein were significantly increased in MGC803 cells,suggesting that the transfection led to the overexpression of ELMOD2 in the cells.3.The results of CCK8 assay showed that overexpression of ELMOD2 significantly increased the proliferation of MGC803 cells.4.The results of flow cytometry showed that overexpression of ELMOD2 significantly reduced the apoptotic rate of MGC803 cells.5.The results of Transwell assay showed that overexpression of ELMOD2 significantly increased the migration ability of MGC803 cells.6.Western blot results showed that after transfection of GV141-ELMOD2 expression vector,the expression of proliferation related protein PCNA,apoptosis related protein BCL-2 and migration related protein VIMENTIN increased,while apoptosis related protein BAX decreased.7.Overexpression of ELMOD2 effectively rescued the inhibitory effects of S100A4 silencing on the migration of MGC803 cells,indicating that ELMOD2 could mediate the effect of S100A4 on the migration of the cells.8.ARL2 silencing effectively rescued the promoting effect of ELMOD2 overexpression on the migration of MGC803 cells,indicating that ELMOD2 affected the migration of gastric cancer cells via ARL2.Conclusion: 1.ELMOD2 is an important downstream gene of S100A4.2.ELMOD2 promotes the proliferation and migration of MGC803 cells,and inhibits the apoptosis of the cells.3.ELMOD2 affects the expression of PCNA,BAX,BCL-2 and VIMENTIN protein.4.ELMOD2 mediates the effect of S100A4 on the migration of MGC803 cells.5.ELMOD2 affects the migration of MGC803 cells via ARL2.