TGF-β1通过介导上皮-间叶转化促进甲状腺乳头状癌的侵袭和淋巴结转移

TGF-β1 promotes the progression and lymph node metastasis of papillary thyroid carcinoma by mediating epithelial-mesenchymal transition

目的 探讨TGF-β1对甲状腺乳头状癌(papillary thyroid carcinoma, PTC)侵袭和淋巴结转移的影响及其机制。方法 收集PTC的石蜡包埋标本,运用免疫组化染色对上皮-间叶转化(epithelial-mesenchymal transition, EMT)相关标志物及TGF-β/Smad信号通路蛋白进行检测。体外培养PTC细胞株BCPAP,添加诱导因子进行处理,分别通过CCK-8法和Transwell法检测细胞增殖和侵袭能力,采用qRT-PCR和Western blot法检测TGF-β/Smad信号通路和EMT标志物的表达。结果 PTC和淋巴结转移癌中上皮标志物E-cadherin表达减弱,间叶标志物vimentin表达增强(79.5%vs 81%)(P<0.05);PTC和淋巴结转移癌中TGF-β1(70.5%、76.9%)和Smad2/3(65.9%、69.2%)的阳性率升高(P<0.01)。体外细胞实验发现添加TGF-β1组与其余两组相比,Smad2(1.229±0.016)、Smad3(2.208±0.084)和p-Smad2/3(0.551±0.032)高表达(P<0.05);上皮标志物E-cadherin(0.525±0.029、0.254±0.009)表达降低;间叶标志物N-cadherin(1.590±0.166、0.404±0.018)和vimentin(1.974±0.194、0.473±0.062)表达升高(P<0.05)。添加抑制剂BMP7组,抑制型蛋白Smad7(1.729±0.084、1.106±0.088)表达升高(P<0.05)。结论 PTC及其淋巴结转移标本发生EMT,且TGF-β1和Smad2/3高表达;TGF-β1可通过TGF-β/Smad信号通路介导EMT,促进PTC的侵袭和淋巴结转移。

Purpose To investigate the effect of transforming growth factor TGF-β1 on the invasion and lymph node metastasis of papillary thyroid carcinoma and its mechanism. Methods Paraffin-embedded specimens of papillary thyroid carcinomas were collected, and immunohistochemical staining was used to detect epithelial-mesenchymal transition-related markers and TGF-β/Smad signaling pathway proteins. The papillary thyroid cancer cell line BCPAP was cultured in vitro and treated with inducing factors. The cell proliferation and invasion abilities were detected by CCK-8 method and Transwell method, respectively. The expression of TGF-β/Smad signaling pathway and epithelial-mesenchymal transition markers was detected by qRT-PCR and Western blot. Results The expression of immunohistochemical epithelial marker E-cadherin was decreased in papillary thyroid carcinoma and lymph node metastases, while the expression of mesenchymal marker vimentin was increased(79.5% vs 81%)(P<0.05) respectively, and the positive expression rates of TGF-β1(70.5%, 76.9%) and Smad2/3(65.9%, 69.2%) were increased(P<0.01). The vitro cell experiments showed that Smad2(1.229±0.016), Smad3(2.208±0.084) and p-Smad2/3(0.551±0.032) were highly expressed(P<0.05), the epithelial marker E-cadherin(0.525±0.029, 0.254±0.009) was decreased, and the mesenchymal markers N-cadherin(1.590±0.166, 0.404±0.018) and vimentin(1.974±0.194, 0.473±0.062) were increased(P<0.05) in the TGF-β1 group compared with the other two groups. In the group of adding inhibitor BMP7, the expression of inhibitory protein Smad7(1.729±0.084, 1.106±0.088) increased(P<0.05). Conclusion Epithelial-mesenchymal transition can occurred in papillary thyroid carcinoma and its lymph node metastases, and TGF-β1 and Smad2/3 are highly expressed. TGF-β1 can promote the invasion and lymph node metastasis of papillary thyroid carcinoma by mediating epithelial-mesenchymal transition through the TGF-β/Smad signaling pathway.