MACC1基因沉默对裸鼠人胃癌细胞移植瘤生长及E－cadherin、N－cadherin蛋白表达的影响

摘要

目的：干扰结肠癌转移相关基因－1（MACC1）的表达，观察MACC1基因沉默后对裸鼠人胃癌细胞移植瘤生长及E－钙黏蛋白（ E－cadherin）、N－钙黏蛋白（ N－cadherin）表达的影响。方法将18只雌鼠随机分为3组，每组6只，将对数生长期的人胃癌 MKN45细胞株、MKN45空质粒细胞株以及干扰MACC1基因表达的MKN45稳定细胞株分别种植于裸鼠背部皮下，分别标记为MKN45 Control组、MKN45－pGPU6组及MKN45－shMACC1组，建立裸鼠移植瘤模型；直至荷瘤实验终止，定期测量皮下瘤体大小，绘制生长曲线；通过免疫组化法、实时定量PCR技术检测3组瘤体MACC1蛋白及mRNA表达水平， Western Blot法检测E－cadherin和N－cadherin蛋白表达的变化。结果与MKN45 Control组相比，MKN45－shMACC1组平均瘤体体积明显缩小（ P＜0．01），MACC1、间质标志物N－cadherin表达明显下调（P＜0．01），上皮标志物E－cadherin表达上调（P＜0．01）。结论 MACC1低表达可以抑制胃癌细胞的增殖，可能通过调节E－cadherin、N－cadherin蛋白表达影响胃癌的上皮间质转化（ EMT）过程。%s:Objective To investigate the effects of MACC1 gene silencing on the growth and expression of E-cad-herin and N-cadherin of human gastric cancer xenografts in nude mice.Methods Eighteen nude mice were randomly divided into three groups ( 6 in each group ) , which were then injected at the subcutaneous tissue on the back with MKN45 gastric cancer cells, MKN45 cells transfected with vector alone and MKN45 cells after MACC1 gene silencing. These mice were marked as Group MKN45 control, Group MKN45-pGPU6 and Group MKN45-shMACC1, correspond-ingly.Then, the volume of tumors were measured to draw growth curves periodically until the end of the experiments. Meanwhile, the quantities of MACC1 within the xenografts of each group were examined at protein and mRNA levels by immunohistochemistry and real-time qPCR.The amounts of E-cadherin and N-cadherin were detected by Western blotting.Results Compared with Group MKN45 control, nude mice in Group MKN45-shMACC1 produced tumors with substantially smaller volume and presented obviously down-regulated levels of MACCA (P<0.01).The injection of MACCA siRNA resulted in reduced amounts of N-cadherin, but increased quantities of E-cadherin (P<0.01).Con-clusion MACC1 gene silencing can block the proliferation of MKN45 cells and mediate the process of EMT by regulating the expression of E-cadherin and N-cadherin.