中国地鼠口腔颊囊黏膜癌变过程凋亡相关基因caspase-3、caspase-9、Bax、Bcl-2的表达

目的 探讨凋亡相关基因caspase-3、caspase-9、Bax、Bcl-2在中国地鼠口腔正常黏膜、上皮单纯增生、上皮异常增生和鳞状细胞癌组织中的表达及其意义。方法 采用免疫组织化学法、RT-PCR检测正常中国地鼠口腔黏膜上皮、单纯增生上皮、异常增生上皮和鳞癌组织中caspase-3、caspase-9、Bax、Bcl-2蛋白及mRNA的表达。结果 在口腔黏膜癌变过程中，鳞癌组织中抑制凋亡蛋白Bcl-2表达明显高于口腔正常黏膜、上皮单纯增生、上皮异常增生（P<0.05）；异常增生上皮caspase-3、caspase-9、Bax表达均明显高于正常组（P<0.05），但随着增生程度的加重，caspase-3、caspase-9、Bax表达明显降低（P> 0.05）。相关性分析显示，鳞癌组织中Bcl-2与Bax、caspase-3、caspase-9呈负相关（P< 0.05）。RT-PCR结果表明，与正常组织相比，鳞癌组织中Bcl-2高表达，而caspase-3、caspase-9、Bax的mRNA表达显著下调（P<0.05）。结论 本实验在中国地鼠鳞癌组织中caspase-3、caspase-9、Bax表达降低而Bcl-2表达上升，揭示了caspase-3、caspase-9、Bax、Bcl-2表达与口腔鳞癌的发生、发展密切相关，可以为口腔颊囊黏膜癌的基因治疗提供一些线索或并为评价OSCC的生物学特征及预后提供参考。

Expression of apoptosis-related genes caspase-3, caspase-9, Bax and Bcl-2 during oral buccal mucosa carcinogenesis in Chinese hamster

Objective To study the expression and significance of apoptosis-related genes caspase-3, caspase-9, Bax and Bcl-2 in oral normal mucosa, oral simple hyperplasia, oral epithelial dysplasia and oral squamous cell carcinomas (OSCC) in Chinese hamsters. Methods The expressions of mRNA and protein of caspase-3, caspase-9, Bax and Bcl-2 in the oral normal mucosa, oral simple hyperplasia, oral epithelial dysplasia and OSCC tissues in Chinese hamsters were examined by immunohistochemistry and RT-PCR. Results During the process of oral carcinogenesis, the expression of Bcl-2 protein was significantly higher in OSCC than in oral normal mucosa, oral simple hyperplasia, and oral epithelial dysplasia (P<0.05). In dysplastic epithelia, the protein expressions of caspase-3, caspase-9 and Bax were more than that of normal epithelia, and along with the increased dysplasis, the expression level was decreased. Further analysis showed that expression of Bcl-2 was negatively related with the expressions of Bax, caspase-3 and caspase-9 (P<0.05). The result of RT-PCR showed that Bcl-2 was significantly increased in OSCC compared with normal mucosa, while the expressions of caspase-3, caspase-9 and Bax were decreased (P<0.05). Conclusions In the Chinese hamster squamous carcinoma, the expressions of caspase-3, caspase-9 and Bax are reduced and the Bcl-2 expression are increased, indicating that the expressions of caspase-3, caspase-9, Bax and Bcl-2 are closely related with the occurrence and development of oral squamous cell cancinoma. This study can offer some clues for gene therapy of OSCC, or can provide a reference for evaluating the biological characteristics and prognosis of OSCC.