Stat3信号通路参与结肠癌细胞中AngⅡ对MMPs表达的诱导

Role of Stat3 signaling pathway in induction of MMPs expression by angiotensin Ⅱ in human colon cancer cell lines

目的探讨转录因子Stat3在血管紧张素Ⅱ(AngⅡ)诱导结肠癌细胞株表达基质金属蛋白酶-2(MMP-2)和MMP-9中的作用。方法以AngⅡ受体(AT1R)高表达的人结肠癌细胞Lovo为研究对象,观察经AngⅡ处理不同时间后Stat3、MMP-2和MMP-9mRNA及其编码蛋白、磷酸化Stat3(Phospho-Stat3)蛋白的表达变化;研究AngⅡ受体1(AT1R)拮抗剂和JAK激酶抑制剂AG490对上述蛋白表达的影响;并观察转染Stat3反义寡核苷酸后,Lovo细胞中上述蛋白的表达变化。采用实时定量RT-PCR检测Stat3、MMP-2和MMP-9mRNA的表达;Westernblotting法检测Phospho-Stat3、Stat3、MMP-2和MMP-9的蛋白表达。结果Lovo细胞经10-7mol/LAngⅡ处理后,Stat3和MMP-9mRNA均在刺激后30min达最高峰,MMP-2mRNA在刺激后1h达最高峰;Phospho-Stat3蛋白在刺激后12h表达最强,MMP-2和MMP-9蛋白在刺激后48h表达最强;AT1R拮抗剂和AG490分别能显著抑制上述蛋白的表达上调;转染Stat3反义寡核苷酸后,Phospho-Stat3、MMP-2和MMP-9的蛋白表达均有明显减少。结论Stat3信号通路参与了AngⅡ对MMP-2和MMP-9表达的诱导,可能在结肠肿瘤的侵袭转移过程中具有一定的作用。

Objective To investigate the role of Stat3 in the induction of MMPs expression by angiotensin Ⅱ （Ang Ⅱ ）in human colon cancer cell lines. Methods Lovo, a colon cancer cell line with much higher level of Ang Ⅱ receptor （ATIR） , was selected to be studied. Lovo cells were treated with Ang Ⅱ （ 10 ^-7 mol/L） at indicated time. The expression of Stat3, MMP-2, MMP-9 mRNA and its coding protein and Phospho-Stat3 were detected at different time of treatment. The effects of ATIR antagonist and AG490 were also studied. Stat3 antisense oligodexynucleotide（as-ODN）was transfected into Lovo cells mediated by liposomal reagent. The expression of Star3, MMP-2 and MMP-9 mRNA were analysed by real-tlme PCR. The expression of Phospho-Stat3, Stat3, MMP-2 and MMP-9 protein were detected by Western blotting. Results After treatment with Ang Ⅱ （ 10^-7 mol/L） , the peak levels of Stat3 and MMP-9 mRNA were present at 30 min, and MMP-2 mRNA at 1 h as well. The highest level of Phospho-Stat3 protein emerged at 12 h, while those of MMP-2 and MMP-9 protein at 48 h. ATIR antagonist and AG490 could significantly inhibit the up-regulation of all these proteins. Stat3 as-ODN could obviously inhibit the expression of Phospho-Stat3, MMP-2 and MMP-9 protein. Conclusion Stat3 participates in the induction of MMP-2 and MMP-9 expression by Ang Ⅱ , which may play an important role in the metastasis of colon cancer.