TGF-β/Smad3信号参与介导TRB3的促肿瘤作用

摘要

目的 研究TRB3介导的促肿瘤作用与TGF-β/Smad3信号通路的关系.方法 利用PCR扩增具有组成活性的Smad3突变体Smad3D,并将其构建至pcDNA3.1/Myc-His(-)B真核表达载体中.在稳定沉默TRB3的HepG2细胞中转染Smad3D-Myc表达质粒,利用G418筛选稳定表达Smad3D-Myc的细胞株.利用双荧光素酶报告基因系统检测3TP-lux转录活性.利用Transwell实验观察细胞侵袭能力变化.结果 成功构建Smad3D突变体真核表达质粒.成功建立稳定沉默TRB3,同时稳定表达Smad3D突变体的HepG2细胞株.过表达Smad3D能明显增强3TP-lux转录活性,并在一定程度上逆转沉默TRB3后对肿瘤侵袭的抑制作用.结论 TGF-β/Smad3信号通路参与了TRB3促进肿瘤的作用.%Aim To investigate the relationship between TGF-β/Smad3 signaling and TRB3 mediated tumor progression. Methods Constitutively active Smad3 mutant ( Smad3D ) was amplified by PCR and constructed into pcDNA3. 1/Myc-His( -)B expression vector. The qualified recombinant plasmid was trans-fected into HepG2 cells with TRB3 knocking down. Then the cells were selected by G418 to establish cell line with Smad3D-Myc stably expressed. The 3TP-lux reporter activity was detected by the Dual-Luciferase Reporter Assay System. The invasion ability of cells was detected by transwell invasion assay. Results The Smad3D mutant expressing plasmid was constructed successfully. HepG2 cells with TRB3 knocking down and Smad3D overexpressing simultaneously had been established successfully. Overexpression of Smad3D increased the activity of 3TP-lux significantly, and partially reversed the inhibitory effect of tumor invasion caused by TRB3 knocking down. Conclusion TGF-β/Smad3 signaling participates in TRB3 mediated tumor invasion.