MAP1LC3B表达促进结直肠癌侵袭转移的体外研究  

Study on Promotion of Invasion and Metastasis of Colorectal Cancer by MAP1LC3B Expression

作　　者：李蓉蓉[1] 殷先利[2] 李俊军[2] 钟美佐[1] 

机构地区：[1]中南大学湘雅医院,湖南长沙410008 [2]湖南省肿瘤医院病理科

出　　处：《实用预防医学》2013年第2期152-156,共5页Practical Preventive Medicine

摘　　要：目的探讨MAP1LC3B在结直肠癌(CRC)中的表达与侵袭转移及自噬的作用机制。方法采用免疫组织化学方法检测92例结直肠癌组织中MAP1LC3B的表达情况,结合临床病理及随访资料进行分析。体外构建慢病毒pLKO.1-MAP1LC3B-siRNA干扰质粒,转染HCT-116细胞株,对照组转染空质粒;采用MTT和侵袭小室实验检测细胞增殖侵袭能力。免疫荧光观察细胞形态。定量RT-PCR和Western blot方法检测MAP1LC3B、mTOR、ATG5和HIF-1α蛋白表达水平。结果 MAP1LC3B高表达存在于82.6%(76/92)癌组织,高于癌旁组织中的阳性率11.95%(11/92),差异有统计学意义(P<0.05);MAP1LC3B蛋白高表达与肝转移、TNM分期和不良预后具有显著相关性(P<0.05);抑制MAP1LC3B表达降低HCT-116细胞侵袭能力;并促进细胞发生自吞噬;下调mTOR、ATG5和HIF-1α蛋白表达水平,差异有统计学意义(P<0.05)。结论 MAP1LC3B是CRC新的预后指标;MAP1LC3B调控mTOR、ATG5和HIF-1α表达介导自吞噬的作用分子机制在CRC侵袭转移中起重要作用。Objective To detect the expression of MAP1LC3B in colorectal cancer （CRC） and to analyze its expression pattern, and to explore the mechanism of invasion, metastasis and autophagy in CRC. Methods Totally, 92 colorectal cancer samples with clinicopathologic and follow- up data were collected. MAP1LC3B expression was detected by immunohistochemical method. Lentivirus pLKO. 1 - MAP1LC3B - siRNA interference plasmid was constructed in vitro and was transfected into HCT - 116 cell lines. HCT- 116 cells transfected with empty plasmid served as the control. Cell proliferation and invasion capacity were detected by MTT and invasion chamber experiment. Cell morphology was observed by immunofluorescence. The expression of MAP1LC3B, mTOR, ATG5 and HIF - la protein was quantitatively measured by RT- PCR and Western blot. Results MAP1LC3B was highly expressed in the cancer tissue , with a positive rate of 82.6% （76/92）, which was significantly higher than that in the tumor-adjacent tissue （11.95%, 11/92, P〈0.05）. High expression of MAP1LC3B was closely correlated with hepatic metastasis, TNM stage and poor prognosis （P〈0.05）. Knockdown of MAP1LC3B expression in HCT- 116 cell could reduce its invasive ability and promote cell autophagy. Besides, it could markedly decrease the expression of mTOR, ATG5 and HIF- 1a protein （P 〈 0.05）. Conclusions MAP1LC3B is a novel and significant prognostic indicator of patients with CRC. The molecular mechanism of autophagy mediated by regulation of roTOR, ATG5 and HIF - 1a expression by MAP1LC3B plays an important role in CRC invasion and metastasis.

关 键 词：结直肠癌 MAP1LC3B 自吞噬 肝转移 

分 类 号：R735.3[医药卫生—肿瘤]