癌相关成纤维细胞通过IL-6诱导的“上皮-间质”转换促进宫颈癌细胞的迁移和侵袭

Cancer-associated fibroblasts promotes migration and invasion of cervical epithelial cancer cells through IL-6-induced “epithelial-mesenchymal” transition

背景与目的：癌相关成纤维细胞（cancer-associated fibroblasts，CAFs）能促进上皮肿瘤的侵袭和转移，细胞因子IL-6在肿瘤间质微环境中可能介导间质和上皮的相互作用，促进肿瘤的侵袭和转移，但其具体机制尚不十分清楚。方法：以宫颈癌细胞HeLa为研究模型，用ELISA测定宫颈癌CAFs和正常宫颈组织成纤维细胞（normal fibroblasts，NFs）条件培养基中IL-6的表达；用条件培养基或IL-6分别处理宫颈癌细胞系HeLa；用Western blot测定样品处理前后上皮-间质转化（epithelial-mesenchymal transition，EMT）标志物（如N-Cadherin和Vimentin等）的变化，同时用划痕和transwell小室测定细胞迁移和侵袭能力的变化。结果：CAF中IL-6表达比NF高4～5倍；与对照组相比，用CAF条件培养基或IL-6处理的HeLa细胞间充质细胞标志物Vimentin和N-Cadherin升高，而上皮细胞标志物E-Cadherin和Cytokeratin下降，表明IL-6可以促进细胞的EMT发生；进一步研究发现过量IL-6处理的HeLa细胞中干细胞转录因子Snail 1随STAT3的激活而上升；同时发现过量IL-6处理的HeLa细胞的迁移和侵袭能力大幅增加。结论：CAF在肿瘤微环境中可能通过IL-6/STAT3/Snail通路诱导宫颈癌上皮细胞的EMT转化，从而促进宫颈癌的侵袭和转移能力。

Background and purpose： Cancer-associated fibroblasts （CAFs） are known to promote the invasion and metastasis of epithelial cancers. The cytokine IL-6 may mediate the interaction between stromal cells and epithelia in tumor microenvironment to facilitate the invasiveness and metastasis of cancer, however, such mechanism has not been fully covered yet.Methods：We used cervical cancer cell line HeLa as a model for this study. ELISA was used to measure the levels of IL-6 in CAFs and normal ifbroblasts （NFs） isolated from squamous cervical cancer or normal cervical tissues. CAFs conditioned medium or IL-6 was used to treat cervical cancer HeLa cell line. The epithelial-mesenchymal transition （EMT） markers such as N-Cadherin and Vimentin were detected by Western blot in cells before and after treatment. Scratches and transwell chambers were used to test the abilities of cell migration and invasion. Results：The levels of IL-6 were 4-5 folds higher in CAFs than in NFs. Treatment of HeLa cells with CAF conditioned medium or IL-6 upregulated N-Cadherin and Vimentin, but down-regulated E-Cadherin and cytokeratin, compared with control cells, indicating that IL-6 may stimulate HeLa cells to EMT. Further study found that Snail 1, the featured transcription factor for stem cells, was increased along with the enhanced phosphorylation of STAT3. Meanwhile, the migration and invasion of HeLa cells treated with IL-6 or CAF conditioned medium were markedly increased. Conclusion：CAF induces the EMT of cervical epithelial cancer cells through IL-6/STAT3/Snail pathway, which thereby promotes the invasiveness and metastasis cervical epithelial cancer.