Preliminary Study On The Effect And Mechanism Of MEP1A On Biological Behavior Of Colorectal Cancer

Background:The mechanism of colorectal cancer(CRC)has not been fully elucidated,and many colorectal cancer related genes need to be found and studied.Has not yet been extensively studied metalloprotease meprin ?(MEP1A)is a secretory transmembrane protein,it can shed or cleave a variety of protein and peptide which in extracellular matrix or on the membrane of surrounding cells.Some studies have reported that MEP1 A has a potential role in promoting cell proliferation and migration.But there is no specific research on the role and mechanism of MEP1 A in the occurrence and development of colorectal cancer.To fill this gap,we conducted a system research to explore the role and the mechanism of MEP1 A in colorectal cancer proliferation,apoptosis,invasion,and the possibility of become new colorectal cancer prognostic factor and therapeutic target.Methods:1.We first detected the expression levels of MEP1 A mRNA and protein in human colorectal cancer and adjacent normal mucosa tissues by Real-time PCR and Western Blot.2.The expression of MEP1 A in tissue microarray containing 88 cases of human colon carcinoma tissue was detected by immunohistochemistry,and the correlation analysis was carried out with the clinical pathological factors and the overall survival time of patients.3.Next we knocked down MEP1 A in the human colorectal cancer cell line Caco2 and LoVo,and these cells were used for cell function assay to detect cell proliferation,apoptosis,and invasion.4.In order to study the relationship between MEP1 A and EGFR-PI3K-Akt pathway or tumor suppressor E-cadherin,we detected the expression level of EGF,phosphorylated Akt and E-cadherin at the cellular level.5.Finally,we used the nude mice subcutaneous and caudal vein injection tumor experiment to detect the effect of MEP1 A on the biological behavior of colorectal cancer in vivo.Results:1.The expression of MEP1 A in colorectal cancer tissues was significantly higher than that in normal mucosa adjacent to cancer.2.MEP1 A expression is associated with a number of clinical and pathological factors of colon cancer,and is an independent prognostic factor for colon cancer.3.The expression of MEP1 A was related to the proliferation,apoptosis and invasion of colorectal cancer cell line.The inhibition of MEP1 A expression could effectively inhibit the proliferation and invasion of colorectal cancer cells and promote its apoptosis.4.Inhibition of MEP1 A can effectively reduce the proliferation and invasion of colorectal cancer cells in nude mice.5.MEP1 A can activate the EGFR-PI3K-Akt pathway indirectly by stimulating EGF shedding,which is likely to be the mechanism by which MEP1 A participates in the development of colorectal cancer.6.The expression of MEP1 A was negatively correlated with the expression of E-cadherin,and there is a possibility that E-cadherin could be cleaved by MEP1 A.Conclusions:In this study,a number of in vitro and in vivo experiments confirmed that MEP1 A played a key role in the development of colorectal cancer,and its mechanism was also preliminary studied.MEP1 A was not only found to be functionally important,but it might also serve as an important and unique indicator of patient prognosis and therapeutic targeting in CRC.