肿瘤坏死因子-α通过诱导上皮间质转化促进乳头状甲状腺癌细胞的侵袭转移

Tumor Necrosis Factor-α Induces Malignant Progression through Epithelial Mesenchymal Transition in Papillary Thyroid Cancer Cell Line

目的观察肿瘤坏死因子-α(TNF-α)对乳头状甲状腺癌(PTC)细胞株TPC-1侵袭转移的影响,并探讨上皮间质转化(EMT)在其中的作用。方法采用划痕愈合实验和transwell侵袭实验检测TNF-α对TPC-1侵袭转移能力的影响;实时定量PCR和免疫印记检测EMT标志物E-cadherin、N-cadherin、Vimentin的m RNA及蛋白水平变化。采用免疫荧光检测上述标志物的定位表达。结果划痕愈合实验和transwell侵袭实验结果显示,在TNF-α诱导下,TPC-1的侵袭转移能力明显增强(P <0.05);实时定量PCR结果显示,EMT的上皮标志物E-cadherin mRNA表达水平明显下降,间质标志物N-cadherin mRNA表达上调,而Vimentin mRNA上调不明显。免疫印记结果表明,E-cadherin蛋白表达水平下降,N-cadherin和Vimentin蛋白表达水平上升(P <0.05)。免疫荧光结果显示,E-cadherin和Vimenin定位于细胞质,N-cadherin定位于细胞膜,且在TNF-α作用下,E-cadherin表达水平明显下降,N-cadherin和Vimenin表达水平上调。结论 TNF-α可以通过诱导EMT促进TPC-1侵袭转移,提示TNF-α在人PTC的侵袭转移中发挥重要作用。

Objective To investigate the effects of tumor necrosis factor alpha(TNF-α) on the migration and invasion of the papillary thyroid cancer(PTC) cell line,TPC-1,and to confirm the involvement of epithelial-mesenchymal transition(EMT) mechanism in these progressions. Methods The effect of TNF-α on cell migration and invasion was assessed by wound-healing and transwell assays. The expression levels of mRNAs and EMT marker proteins,E-cadherin,N-cadherin,and Vimentin,were analyzed using RT-PCR and Western blotting. Their distributions were detected by immunofluorescence. Results The wound-healing and transwell assays revealed increased migratory and invasive abilities of PTC cells treated with TNF-α(P < 0.05). RT-PCR displayed a decrease in E-cadherin mRNA level,whereas mRNA level of N-cadherin showed an increase;no apparent increase was observed in mRNA of Vimentin. Western blotting demonstrated a decrease in E-cadherin expression and an increase in N-cadherin and Vimentin expression(P < 0.05). The results were further confirmed by immunofluorescence analysis. Conclusion EMT may be involved in the malignant tumor progression induced by TNF-α in PTC cell line. The inflammation may participate in the invasion and metastasis of human papillary thyroid cancer.