涎腺腺样囊性癌Pin1、β-连接素和细胞周期素D1的表达及意义

目的 研究人肽基脯氨酰顺反异构酶（简称Pin1）、β-连接素（β-catenin）和细胞周期素D1（cyclin D1）在涎腺腺样囊性癌（SACC）中的表达，探讨其在SACC增殖和转移中的作用。方法 采用免疫组织化学方法检测65例SACC中Pin1、β-catenin和cyclin D1的表达情况，同时采用Western blot和RT-PCR方法分别在SACC83、SACC-LM、ACC-2和ACC—M4种SACC细胞株中检测Pin1蛋白水平和mRNA水平的表达。结果 65例SACC中Pin1高表达的51例（78％），cyclin D1高表达的41例（63％），二者的表达呈正相关（P=0．02）。14例（22％）SACC出现β-catenin在胞质中累积，其中6例（9％）表现为明显的β-catenin的细胞核表达；其余51例SACC中β-catenin仅在细胞膜上表达，伴淋巴结转移或浸润的病例中大都出现了β-catenin在细胞膜上表达减弱或缺失（11／14）。Western blot和RT-PCR检测结果显示，Pin1蛋白和mRNA在4种SACC细胞株中都呈现高表达。结论 研究结果提示Pin1的过度表达在SACC中常见，其过度表达和β-catenin信号传导通路的改变可能与SACC的细胞增殖及癌的转移相关。

Expression of Pin1,β-catenin and cyclin D1 in salivary adenoid cystic carcinoma and its significance

OBJECTIVE: To investigate the expression of Pin1, beta-catenin and cyclin D1 in salivary adenoid cystic carcinomas (SACC) and to evaluate the role of beta-catenin and Pin1 in SACC carcinogenesis. METHODS: The expressions of Pin1, beta-catenin and cyclin D1 were examined in the specimens of 65 patitents with SACC by immunohistochemistry, and Pin1 protein and mRNA expressions detected by Western blot and RT-PCR in four SACC cell lines. RESULTS: Pin1 was overexpressed in 51 cases of ACC (78%), and 41 (63%) cases showed positive immunoreactivity for cyclin D1 protein in the nuclear fraction in tumor tissues. Fourteen (22%) cases showed positive immunoreactivity for beta-catenin protein in the nuclear/cytoplasmic fraction in tumor tissues, 6 of which exhibited quite evident expression of beta-catenin in nucleolus. The expression of membranous beta-catenin was down-regulated in most of the patients with lymph node metastasis (11/14). CONCLUSIONS: The results suggest that Pin1 and beta-catenin signalling pathway were activated in SACC and might play a pivotal role in SACC carcinogenesis and metastasis.