The Study Of MAP1LC3B Expression Is Associated With Invasion And Metastasis Of Colorectal Cancer

Backgroud:Colorectal Cancer (Colorectal cancer, CRC) is a common of the digestive tract tumor, and its incidence has recently increased each years, and prone to liver metastasis. Thus, CRC is the current research focus and priorities. Autophagy is one of very important molecular mechanism for the development of colorectal cancer generation. The recently study suggests that the the MAP1LC family gene (MAP1LC3A and MAP1LC3C) were involved in autophagy of breast cancer cells. So far no clinical prognostic studies of MAP1LC3B in colorectal cancer samples have been reported. Therefore, we carried out the present study to investigate the expression of MAP1LC3B in human colorectal cancer tissues and to explore the correlations between MAP1LC3B expression and the clinicopathological features of colorectal cancer. Furthermore, the effects of MAP1LC3B on colorectal cancer cell invasion and metastasis were elucidated using in vitro models.Aim:To detect the expression of MAP1LC3B in colorectal cancer (CRC), analyze the patterns of expression and evaluate its clinical significance, to explore the mechanism of invasion and metastasis and autophagy in CRCMethod:Totally92colorectal cancer samples with clinicopathologic and follow-up data were collected, MAP1LC3B expression were detect by immunohistochemical methods. In vitro Construction of lentiviral pLKO.1-MAP1LC3B-siRNA interference plasmids, HCT-116cell lines transfected with the control group transfected with empty plasmid; by MTT and invasion chamber experiments to detect cell proliferation and invasion capacity. Immunofluorescence cell morphology was observed. Quantitative RT-PCR and Western blot analysis MAP1LC3B and mTOR, ATG5and of HIF-la protein expression levels. Result:The high expression of MAP1LC3B happened in76of92cases (82.6%), and it was closely correlated with hepatic metastasis, TNM stage and poor survival time (P<0.05). And univariate and multivariate analysis approved its prognostic significance (P<0.05). Knockdown of MAP1LC3B expression in HCT-116cell, the invasion ability of cell is reduced, and promote cell autophagy formation;in addtion to, the expression levels of mTOR, ATG5and HIF-1α protein was decreased significant (P<0.05).Conclusion:(1) MAP1LC3B is highly expressed in CRC tissues and expression in CRC cells, the high expression of MAP1LC3B was closely correlated with hepatic metastasis, TNM stage and poor survival time. High expression of this gene suggests the possibility of postoperative metastasis and shortening of survival.(2) The molecular mechanisms of MAP1LC3B regulation of mTOR, ATG5and HIF-1α expression mediated autophagy plays an important role in CRC invasion and metastasis.