Smad7蛋白在口腔鳞癌组织中的表达及其对口腔鳞癌细胞增殖和迁移能力的影响

目的：检测Smad7蛋白在口腔鳞状细胞癌（oral squamous cell carcinoma, OSCC）中的表达及临床意义，探讨其在口腔鳞癌细胞增殖和迁移中的作用。方法：利用免疫组织化学染色，检测31例原发性口腔鳞癌患者肿瘤组织及癌旁标本中Smad7的表达，并分析其与淋巴结转移之间的关系；利用CCK-8及细胞划痕实验检测Smad7基因沉默对肿瘤细胞增殖及迁移能力的影响；通过Smad7 siRNA干扰HN4细胞，影响Smad7蛋白的表达，利用免疫印迹及qRT-PCR检测其对上皮-间充质转化（epithelial- mesenchymal transition，EMT）相关指标蛋白及RNA表达的影响。采用SPSS18.0软件包对数据进行统计学分析。结果：在口腔鳞癌肿瘤组织中，Smad7蛋白在细胞核和细胞质的表达均显著高于对应的癌旁组织。Smad7的表达与患者颈淋巴结转移显著相关。Smad7 siRNA干扰HN4细胞后，细胞的增殖能力减弱，迁移能力增强。Smad7 siRNA干扰使得HN4细胞神经钙黏附素（N-cadherin）蛋白的表达量升高，而上皮钙黏蛋白（E-cadherin）的表达量下降，N-cadherin蛋白及波形蛋白（Vimentin）RNA表达量显著升高，与对照组相比有显著差异。结论：Smad7的表达与口腔鳞癌患者颈淋巴结转移相关，且Smad7在口腔鳞癌肿瘤细胞的增殖及侵袭转移中发挥重要作用。

Expression of Smad7 protein in oral squamous cell carcinoma and the impact on cell proliferation and migration of oral squamous cell carcinoma

PURPOSE: To investigate the expression of Smad7 in oral squamous cell carcinoma (OSCC) and determine if Smad7 was associated with tumor cell proliferation and migration. METHODS: Thirty-one primary OSCC patients were enrolled in this study. Smad7 expression in tissue specimens were investigated by using immunohistochemistry staining, CCK-8, cell scratch assay, western blotting and qRT- PCR were performed after Smad7 siRNA interference in HN4 cells. Paired t test was used for analysis with SPSS18.0 software package. RESULTS: Nuclear and cytoplasmic expression of Smad7 was increased in primary OSCC tissue samples. Expression of Smad7 was associated with cervical lymph node metastasis. Smad7 knockdown significantly suppressed cell proliferation but promoted tumor cell migration in HN4 cells. Smad7 knockdown promoted N-cadherin and Vimentin expression. CONCLUSIONS: Smad7 expression in OSCC was associated with cervical lymph nodal metastasis and Smad7 might play an essential role in the proliferation and migration of OSCC cells.