组织蛋白酶B在口腔黏膜上皮癌变过程中的表达及意义

Increased expression of Cathepsin B and its significance in carcinogenesis process of oral squamous cell carcinoma

目的:探讨组织蛋白酶B(Cathepsin B,CB)在口腔鳞状细胞癌中的表达及临床意义。方法:以口腔黏膜上皮永生化细胞系(human immortalized oral epithelia cell line,HIOEC)及经过苯丙芘[benzo(a)pyrene,B(a)P]诱导产生鳞状细胞癌细胞(HB)而形成的口腔鳞癌体外癌变模型为研究对象,通过双向凝胶电泳(2-DE)和质谱分析(LC-MS/MS)筛选和鉴定出差异蛋白质CB。采用实时定量PCR、Western印迹和免疫组化方法,检测口腔鳞癌细胞和30例原发口腔鳞癌标本中的mRNA及蛋白质表达水平。采用SPSS10.0软件包对数据进行非参数检验。结果:与永生化HIOEC相比,HB和CAL27细胞中CB的mRNA水平显著升高,HB、Tca8113、TSCC、CAL27和OSC细胞中CB蛋白表达水平明显升高。30例口腔鳞癌患者癌组织中CB的mRNA和蛋白表达水平均较癌旁组织升高(P<0.01)。CB的表达水平与肿瘤大小、淋巴结转移、临床分期、病理分化程度无显著相关性。结论:CB在口腔鳞癌中的表达明显升高,提示其与肿瘤的发生、发展具有一定关系。

PURPOSE： To investigate the expression of Cathepsin B （CB） in oral squamous cell carcinoma （OSCC） as well as its clinical significance. METHODS： The differentially expressed proteins （including CB） in the in vitro cellular carcinogenesis model of OSCC （including a human immortalized oral epithelia cell （HIOEC） line and a cancerous cell line of HB induced by benzo（a）pyren for 6 months from HIOEC） were acquired by 2-DE and LC-MS/MS. Detection of the mRNA level and protein expression of CB in some OSCC cell lines and tissue specimens from 30 primary OSCC patients was performed using real-time PCR, Western blotting and immunohistochemistry, respectively. All data was analyzed by SPSS10.0 software package for non-parametric analysis. RESULTS： Increased CB mRNA level was observed in the HB and CAL27 cell lines compared with the HIOEC using real-time PCR technique. Western blotting showed increased CB protein expression in the HB, Tca8113, TSCC, CAL27, and OSC cell lines compared with the HIOEC. Increased CB mRNA and immunoreaction levels were also observed in the cancerous tissue specimens from OSCC patients compared with normal adjacent tissues （P〈0.001）. No significant correlation was found between the CB expression and clinical status, such as T stage, N stage, clinical stage, and pathological differential degree. CONCLUSIONS： These results suggest that increased CB expression in OSCC cell lines and tissue specimens could contribute to carcinogenesis process of OSCC, which provides some basis for further study on the carcinogenesis mechanism of OSCC.