Fos-like antigen 2 (FOSL2) promotes metastasis in colon cancer
Fos-like antigen 2 (FOSL2) promotes metastasis in colon cancer
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DOI：
10.1016/j.yexcr.2018.08.016
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发表时间：
2018-12-15
影响因子：
3.7
通讯作者：
Fei, Bing-Yuan
中科院分区：
文献类型：
--
作者：
Li, Shuo;Fang, Xue-dong;Fei, Bing-Yuan
在各种癌症中，结直肠癌是发病率和死亡率最高的癌症之一。KRAS突变是结直肠癌发病机制的基本特征之一，与野生型KRAS相比，携带突变KRAS的结直肠癌表现出更强的侵袭性。我们早些时候已经证明，microRNA-143(miR-143)的补充不仅能增敏突变的KRAS而不是野生型KRAS基因的CRC细胞，对紫杉醇介导的细胞毒作用，而且还能抑制细胞的迁移和侵袭能力。因此，这项研究旨在确定miR-143的补充如何抑制带有突变KRAS的CRC细胞的转移前行为。采用定量逆转录聚合酶链式反应(qRT-PCR)对模拟转染组和模拟转染组的LoVo细胞中miR-143基因的前10个信使核糖核酸靶点进行检测。用免疫印迹法检测30例结直肠癌组织、癌旁正常组织和LoVo细胞中同源信使核糖核酸靶点(S)的变化。在LoVo细胞和正常结肠上皮细胞系FHC中，通过Western blotting、体外细胞增殖和跨孔迁移/侵袭实验相结合的获得和丧失功能的研究，分析了信使核糖核酸靶向对促转移行为的影响。异种移植实验检测同源基因靶点在体内对结直肠癌转移的影响。在10个预测的mRNA靶点中，FOSL2(P<；0.05)和Igfbp5(P>；0.05)在转染miR-143模拟物的LoVo细胞中下调。与癌旁正常组织相比，结直肠癌组织中FOSL2基因表达水平显著下调(P<；0.05)。免疫印迹分析显示，经miR-143模拟转染后，LoVo细胞中FOSL2蛋白表达下调，而Igfbp5蛋白表达下调。FOSL2在正常结肠上皮细胞系FHC中过表达或在LoVo细胞中siRNA介导的沉默分别诱导和抑制了亲间充质细胞的功能。而操纵FOSL2的表达对细胞的增殖率没有任何影响，沉默其表达可抑制细胞的体外迁移和侵袭能力。此外，在LoVo细胞中沉默FOSL2的表达可以显著抑制肝脏的侵袭，而对成瘤潜能没有影响。我们的结果提示FOSL2是结直肠癌转移的关键调节因子，可能是判断结直肠癌患者预后的重要标志。
Among different cancers, incidence and mortality of colorectal cancer (CRC) is one of the highest. KRAS mutation is one of the underlying features in the pathogenesis of CRC with CRC tumors harboring mutant KRAS exhibiting a more aggressive behavior compared to CRC tumors with wild type KRAS. We had earlier shown that the microRNA-143 (miR-143) replenishment not only chemosensitizers CRC cell line with mutant KRAS instead of wild-type KRAS gene, to paclitaxel-mediated cytotoxicity, but also inhibits cell migration and invasion ability. Hence, the study aimed to determine how miR-143 replenishment is inhibiting pre-metastatic behavior in CRC cells with mutant KRAS. Top ten mRNA targets of miR-143 as predicted by TargetScan were evaluated by qRT-PCR in LoVo cells which were performed mock transfection or miR-143 mimic transfection. Evaluation of the changes in cognate mRNA target(s) was done in 30 paired CRC tissue and tumor adjacent normal tissue specimens and in LoVo cells by western blot. Effect of the mRNA target on pro-metastatic behavior was assayed by gain- and loss-of-function studies using a combination of western blotting and in vitro cell proliferation and transwell migration/invasion assay in LoVo cells and in the normal colonic epithelium cell line FHC. In vivo effect of the cognate mRNA target on CRC metastasis was assayed by xenograft assay. Of the 10 predicted mRNA targets, FOSL2 (P < 0.05) and IGFBP5 (P > 0.05) was down regulated in LoVo cells transfected with the miR-143 mimic. FOSL2 mRNA levels were significantly downregulated in CRC tissue specimens compared with adjacent normal tissue (P < 0.05). Immunoblot analysis showed that FOSL2, but not IGFBP5, protein expression is down regulated in LoVo cells after the miR-143 mimic transfection. FOSL2 overexpression in the normal colonic epithelial cell line FHC or siRNA-mediated silencing in LoVo cells induced and repressed, respectively, pro-mesenchymal cell features. Whereas manipulation of FOSL2 expression did not have any effect on cell proliferation rates, silencing its expression inhibited cell migration and invasion ability in vitro. In addition, silencing of FOSL2 expression in the LoVo cells can significantly inhibited invasion of hepatic, while no effect was found for tumorigenic potential. Our results suggest that FOSL2 is a critical regulator of CRC metastasis and might be an important marker for prognostic in CRC patients.