The Impact Of ELMO3 In Invasion And Metastasis Of Colorectal Cancer

Background:Colorectal cancer(CRC)is one of the most common human digestive tract malignancies and remains the leading cause of malignancy-related mortality in the global.The high fatality rate of CRC is closely related to the high recurrence and metastasis after surgery.In recent years,it has been reported that engulfment and cell motility(ELMO)proteins family plays a crucial role in tumor cell migration and invasion.Therefore,in order to further explore the molecular mechanism of recurrence and metastasis and to find the key molecular markers of CRC,that has important clinical significance for early diagnosis,the prognosis monitoring and the target therapy of CRC.Objective:This study was designed to detect the expression of ELMO3 in CRC tissues and to explore its association with the clinicopathological characteristics.In in-vitro experiments,we aimed to study whether silencing ELMO3 had impacts on cell proliferation,invasion,metastasis,F-actin polymerization,as well as alterations of cell cycle.Methods:1.The real-time quantitative PCR(RT-q PCR)and Western-blot were used to detect the ELMO3 m RNA and protein expression level in 45 cores of CRC and 45 cores of normal colorectal tissues matched to tumor sections.The immunohistochemical(IHC)assay was used to detect the expression of ELMO3 protein in the CRC tissues.The correlationship between the expression level of ELMO3 and clinical pathological parameters of CRC was analyzed.2.In in-vitro experiment,we used a technique called RNA interference to suppress ELMO3 expression level of colon cancer cells,and then by wound healing assay,transwell experiment,the MTS experiment,flow cytometry and fluorescent microscope staining are used to respectively detect colon cancer cell migration,cell proliferation,cell cycle and cell skeleton F-actin polymerization.Results:1.The result of RT-q PCR,Western-blot and IHC analysis revealed that the m RNA and protein levels of ELMO3 in CRC tissues were significantly higher than that in adjacent normal tissues.Moreover,the m RNA and protein levels of ELMO3 in CRC tissues with lymph node metastasis were markedly higher than that in CRC tissues from patients without lymph node metastasis.2.The correlations between the expression of ELMO3 and the clinicopathological parameters of CRC were further analyzed.The positive immunostaining of ELMO3 was significantly correlated with tumor size,pathologic differentiation degree,depth of invasion,lymph node metastasis,distant metastasis and TNM stage.Nevertheless,no significant correlation was found between ELMO3 expression and gender or age.3.In in-vitro experiments,the silencing of ELMO3 inhibited cell proliferation,invasion,metastasis,and F-actin polymerization,and induced Gap 1(G1)phase cell cycle arrest.Conclusion: 1.The ELMO3 expression is up-regulated in CRC tissues,and it is significantly correlated with tumor size,pathologic differentiation degree,depth of invasion,lymph node metastasis,distant metastasis and TNM stage.2.The ELMO3 can promote colon cancer cell proliferation,invasion,metastasis,F-actin polymerization and so on.