Zheng Yong-Bin, Luo Hai-Ping, Shi Qiang, Hao Zhi-Nan, Ding Yu, Wang Qiu-Shuang, Li Sheng-Bo, Xiao Gao-Chun, Tong Shi-Lun
Yong-Bin Zheng, Hai-Ping Luo, Qiang Shi, Zhi-Nan Hao, Yu Ding, Qiu-Shuang Wang, Sheng-Bo Li, Gao-Chun Xiao, Shi-Lun Tong, Department of Gastrointestinal Surgery, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
World J Gastroenterol. 2014 Jun 7;20(21):6515-22. doi: 10.3748/wjg.v20.i21.6515.
To investigate the biological role and underlying mechanism of miR-132 in colorectal cancer (CRC) progression and invasion.
Quantitative RT-PCR analysis was used to examine the expression levels of miR-132 in five CRC cell lines (SW480, SW620, HCT116, HT29 and LoVo) and a normal colonic cell line NCM460, as well as in tumor tissues with or without metastases. The Kaplan-Meier method was used to analyze the prognostic significance of miR-132 in CRC patients. The biological effects of miR-132 were assessed in CRC cell lines using the transwell assay. Quantitative RT-PCR and western blot analyses were employed to evaluate the expression of miR-132 targets. The regulation of ZEB2 by miR-132 was confirmed using the luciferase activity assay.
miR-132 was significantly down-regulated in the CRC cell lines compared with the normal colonic cell line (P < 0.05), as well as in the CRC tissues with distant metastases compared with the tissues without metastases (10.52 ± 4.69 vs 23.11 ± 7.84) (P < 0.001). Down-regulation of miR-132 was associated with tumor size (P = 0.016), distant metastasis (P = 0.002), and TNM stage (P = 0.020) in CRC patients. Kaplan-Meier survival curve analysis indicated that patients with low expression of miR-132 tended to have worse disease-free survival than patients with high expression of miR-132 (P < 0.001). Moreover, ectopic expression of miR-132 markedly inhibited cell invasion (P < 0.05) and the epithelial-mesenchymal transition (EMT) in CRC cell lines. Further investigation revealed ZEB2, an EMT regulator, was a downstream target of miR-132.
Our study indicated that miR-132 plays an important role in the invasion and metastasis of CRC.
探讨miR-132在结直肠癌（CRC）进展和侵袭中的生物学作用及潜在机制。
采用定量逆转录聚合酶链反应（qRT-PCR）分析检测miR-132在五种CRC细胞系（SW480、SW620、HCT116、HT29和LoVo）、一种正常结肠细胞系NCM460以及有无转移的肿瘤组织中的表达水平。采用Kaplan-Meier法分析miR-132在CRC患者中的预后意义。使用Transwell实验评估miR-132在CRC细胞系中的生物学效应。采用qRT-PCR和蛋白质免疫印迹分析评估miR-132靶标的表达。使用荧光素酶活性测定法证实miR-132对锌指E盒结合蛋白2（ZEB2）的调控作用。
与正常结肠细胞系相比，miR-132在CRC细胞系中显著下调（P<0.05），与无转移的组织相比，在有远处转移的CRC组织中也显著下调（10.52±4.69对23.11±7.84）（P<0.001）。miR-132的下调与CRC患者的肿瘤大小（P=0.016）、远处转移（P=0.002）和TNM分期（P=0.020）相关。Kaplan-Meier生存曲线分析表明，miR-132低表达的患者无病生存期往往比miR-132高表达的患者更差（P<0.001）。此外，miR-132的异位表达显著抑制了CRC细胞系中的细胞侵袭（P<0.05）和上皮-间质转化（EMT）。进一步研究发现，EMT调节因子ZEB2是miR-132的下游靶标。
我们的研究表明，miR-132在CRC的侵袭和转移中起重要作用。
