Stat5b信号通路调控bcl-2成员表达抑制结肠癌细胞凋亡的作用及其机制

Molecular mechanism of Stat5b signaling pathway in regulating the expression of bcl-2 family members and promoting survival of human colon cancer cells

目的探讨转录信号转导子与激活子5b(Stat5b)反义寡核苷酸诱导结肠癌细胞凋亡的作用及其机制。方法用阳离子脂质体介导Stat5b反义寡核苷酸(20μmol/L)转染人结肠癌HCT116细胞,MTT法检测细胞增殖状态;流式细胞术检测细胞周期与凋亡;Westernblot检测Stat5、pStat5及凋亡家族成员bcl2、bclxL、Mcl1、Caspase3的表达。结果转染Stat5b反义寡核苷酸72h后HCT116细胞增殖受抑制,G1期细胞比率由68.9%上升至85.6%,S期细胞比率由15.4%下降至7.6%,凋亡细胞比率由5.6%增加至27.5%,Stat5,pStat5与bcl2家族成员表达水平下降。结论Stat5信号转导通路活性增高可能与结肠癌发生发展有关,阻断Stat5通路可以诱导结肠癌细胞凋亡。

Objective To explore the role and mechanism of Stat5b antisense oligonucleotide inducing apoptosis of colon cancer cell lines. Methods Protein lysates were extracted from colon cancer cells. Human colon cancer cell line HCT116 was transfected with Stat5b antisense oligonucleotide mediated by liposome, MTT assay was used to measure the proliferation, and flow cytometry to analyze the cell cycle and apoptosis, The expression ot 5tatb, p-Stat5, bcl-2, bcl-xL, Mcl-1 and Caspase-3 was detected by Western blot. Results Stat5 antisense oligonucleotide （20 μmol/L） inhibited the cells proliferation and induced apoptosis in colon cancer cell lines, the ratio of cells in G1 phase was increased from 68.9 % to 85.6 %, and the ratio of cells in S phase was decreased from 15.4 % to 7.6 %. Star5 antisense ollgonucleotlde also diminished the expression of Star5, p-Star5 and bcl-2 family members. Conclasion Constitutive activation of Star5 is associated with the carcinogenesis of colon cancer cells. Blocking of Star5 signaling could ifiduce apoptosis of colon cancer cells.