Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Centre Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
Anticancer Res. 2014 Dec;34(12):7061-9.
The epithelial-mesenchymal transition (EMT) is suggested to be a crucial factor for the development of an invasive and metastatic cell phenotype, which is characterized by down-regulation of epithelial adhesive proteins (e.g. E-cadherin) and induction of mesenchymal proteins (e.g. vimentin). Therefore, there is a great clinical interest to specify this phenotype. Different growth factors induce EMT, such as epithelial growth factor (EGF) and transforming growth factor beta 1 (TGFβ1). The role of EMT in human papilloma virus (HPV)-positive squamous cell carcinoma (SCC) is still not understood. The aim of this study was to investigate the expression pattern in p16-positive and -negative SCC cells of vimentin, β-catenin and E-cadherin after stimulation with growth factors.
We incubated the p16-positive CERV196 and p16-negative HNSCC22B SCC cell lines with EGF and EGF/TGFβ1 (10 ng/ml) and detected E-cadherin, vimentin and β-catenin by immunocytochemistry and enzyme-linked immunosorbent assay after 5, 24 and 96 h.
We found a low expression of vimentin in all studied tumor cell lines. The negative control of HNSCC22B cells showed a higher intrinsic level of membranous E-cadherin and β-catenin. We found statistically significant EGF/TGFβ1-induced expression of vimentin dependent on incubation time in p16-negative HNSCC22B cells. Particularly in the presence of EGF, we detected an increase of β-catenin and vimentin expression in p16-positive SCC tumor cell lines in addition to induced cell scattering and unexpected expression of E-cadherin.
In conclusion, E-cadherin, β-catenin and vimentin expression are important features to characterize EMT-like events. We were able to show incomplete EGF-induced EMT with β-catenin expression in p16-positive SCC. Extended studies are required to investigate the mechanistic role of EMT markers, especially in p16-positive SCC, in order to develop new anti-SCC therapies to block EMT progression.
上皮-间充质转化（EMT）被认为是形成侵袭性和转移性细胞表型的关键因素，其特征是上皮黏附蛋白（如 E-钙黏蛋白）下调和间充质蛋白（如波形蛋白）诱导。因此，明确这种表型具有重要的临床意义。不同的生长因子如上皮生长因子（EGF）和转化生长因子β 1（TGFβ1）可诱导 EMT。EMT 在人乳头瘤病毒（HPV）阳性鳞状细胞癌（SCC）中的作用尚不清楚。本研究旨在探讨生长因子刺激后 p16 阳性和阴性 SCC 细胞中波形蛋白、β-连环蛋白和 E-钙黏蛋白的表达模式。
我们用 EGF 和 EGF/TGFβ1（10ng/ml）孵育 p16 阳性的 CERV196 和 p16 阴性的 HNSCC22B SCC 细胞系，并用免疫细胞化学和酶联免疫吸附试验检测 5、24 和 96 小时后 E-钙黏蛋白、波形蛋白和β-连环蛋白的表达。
我们发现所有研究的肿瘤细胞系中波形蛋白的表达水平均较低。HNSCC22B 细胞的阴性对照显示出较高的固有膜 E-钙黏蛋白和β-连环蛋白水平。我们发现，p16 阴性的 HNSCC22B 细胞中 EGF/TGFβ1 诱导的波形蛋白表达依赖于孵育时间，且具有统计学意义。特别是在 EGF 存在的情况下，我们检测到 p16 阳性 SCC 肿瘤细胞系中β-连环蛋白和波形蛋白表达增加，同时伴有细胞散射和意想不到的 E-钙黏蛋白表达。
综上所述，E-钙黏蛋白、β-连环蛋白和波形蛋白的表达是表征 EMT 样事件的重要特征。我们能够显示 p16 阳性 SCC 中 EGF 诱导的不完全 EMT 伴有β-连环蛋白表达。需要进一步研究 EMT 标志物的机制作用，特别是在 p16 阳性 SCC 中，以开发阻止 EMT 进展的新型抗 SCC 治疗方法。
