Department of Pathology, School of Medicine, Southeast University, Nanjing 210009, Jiangsu Province, Peoples Republic of China.
Cell Biol Int. 2011 Nov;35(11):1121-9. doi: 10.1042/CBI20100876.
Altered expression of MUC2 (mucin 2) is related to tumour development in colorectal cancer. Colorectal mucinous carcinomas are positive for MUC2 expression, whereas MUC2 is down-regulated in non-mucinous adenocarcinomas. In the present study, we down-regulated MUC2 expression by RNAi (RNA interference) and investigated the in vitro and in vivo effects on the proliferation and invasion/migration potential of the LS174T human colorectal cancer cells. The LS174T cell line is a goblet-cell-like colorectal cancer cell line that continuously produces high levels of MUC2. Inhibition of MUC2 expression in vitro by transfection of LS174T cells with the recombinant plasmid pcDNA6.2-GW/EmGFP-miR-MUC2 led to the production of a stably transfected MUC2-RNAi LS174T cell line. The proliferation and invasion/migration of MUC2-RNAi cells in vitro were significantly higher than those in control cells, as assessed by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide], colony formation and transwell assays. Subcutaneous injection of MUC2-RNAi LS174T cells into nude mice resulted in the development of subcutaneous tumours visible to the naked eye after 1 week. The growth rate of tumours derived from MUC2-RNAi LS174T cells was greater than that of tumours derived from control cells. Ki67 and matrix metalloproteinase-9 proteins were detected by immunohistochemistry in the xenografts. The expression levels of these proteins were higher in the MUC2-RNAi-derived xenografts than in xenografts derived from control cells. Although the role of MUC2 in colorectal tumorigenesis is not fully understood, these results strongly suggest a relationship between the proliferation and invasion of LS174T cells and the expression of MUC2.
黏蛋白 2（MUC2）的表达改变与结直肠癌的肿瘤发生有关。结直肠黏液腺癌 MUC2 表达阳性，而 MUC2 在非黏液性腺癌中下调。在本研究中，我们通过 RNAi（RNA 干扰）下调 MUC2 的表达，并研究了其对 LS174T 人结肠癌细胞体外和体内增殖和侵袭/迁移能力的影响。LS174T 细胞系是一种具有杯状细胞样特征的结直肠癌细胞系，持续产生高水平的 MUC2。通过用重组质粒 pcDNA6.2-GW/EmGFP-miR-MUC2 转染 LS174T 细胞，抑制 MUC2 在体外的表达，导致产生稳定转染的 MUC2-RNAi LS174T 细胞系。MTT [3-(4,5-二甲基噻唑-2-基)-2,5-二苯基-2H-四唑溴盐]、集落形成和 Transwell 分析评估显示，MUC2-RNAi 细胞的体外增殖和侵袭/迁移能力明显高于对照细胞。将 MUC2-RNAi LS174T 细胞皮下注射到裸鼠中，1 周后可观察到肉眼可见的皮下肿瘤。源自 MUC2-RNAi LS174T 细胞的肿瘤的生长速度大于源自对照细胞的肿瘤。免疫组化检测异种移植瘤中的 Ki67 和基质金属蛋白酶-9 蛋白。MUC2-RNAi 衍生的异种移植物中的这些蛋白的表达水平高于源自对照细胞的异种移植物。尽管 MUC2 在结直肠肿瘤发生中的作用尚未完全阐明，但这些结果强烈表明 LS174T 细胞的增殖和侵袭与 MUC2 的表达之间存在关系。
