前列腺癌组织中PTEN蛋白的表达及其与肿瘤细胞凋亡的关系

Expression of PTEN protein in tissues of prostatic carcinoma and its correlation with apoptosis of cancer cells

目的 :探讨抑癌基因PTEN蛋白在前列腺癌 (Pca)组织中的表达及其与肿瘤细胞凋亡的关系 .方法 :采用免疫组织化学S P法和DNA原位末端标记TUNEL法分别测定 4 2例Pca及 10例正常前列腺组织 (NP)中PTEN蛋白的表达和肿瘤细胞凋亡 ,并分析PTEN基因表达缺失与肿瘤细胞凋亡的关系 .结果 :NP组织中PTEN蛋白全部阳性表达 ;而Pca中PTEN基因表达缺失率达 6 4 .3% ,且与肿瘤细胞分化程度、临床分期和有否淋巴结转移密切相关 ;PTEN基因表达缺失与肿瘤细胞凋亡成负相关 (r=- 0 .74 6 ,P <0 .0 0 1) .结论 :前列腺癌组织中PTEN表达缺失率较高 ;PTEN基因失活在Pca的发生发展中起重要作用 ,且导致肿瘤细胞凋亡减少 ;联合检测PTEN蛋白和凋亡指数 ,有助于对肿瘤细胞的分化程度作出正确评价 ,以指导临床治疗及估计预后 .

AIM: To investigate the expression of PTEN protein in tissues of prostatic carcinoma (Pca) and its correlation with the apoptosis of cancer cells. METHODS: Expression of PTEN protein and apoptotic index (AI) were detected by S-P immunohistochemical and terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling (TUNEL) technique in 42 cases of Pca and 10 cases of normal prostate (NP). The relationship between the PTEN gene deletion and AI in Pca was analyzed. RESULTS: All of the ten cases of NP were positive for PTEN protein. The overall deletion rate of PTEN gene in Pca was 64.3% and it was strongly associated with the degree of differentiation, clinical stage and lymph metastasis in Pca (P<0.05), but it had no correlation with the age of patients. The PTEN gene deletion was negatively correlated with AI in Pca (r = -0.746, P<0.001). CONCLUSION: There is a higher deletion rate of PTEN gene in Pca, which may play an important role in the genesis and development of some Pca and result in the reduction of cell apoptosis in Pca. Detection of PTEN protein and AI in Pca may be helpful to evaluate the degree of cell differentiation, decide on therapeutic strategies and deduce prognosis.