一种新的抑癌基因PTEN在肾细胞癌中的表达及生物学意义

背景与目的：PTEN基因是新发现的一种抑癌基因,定位于人染色体10q23,它的缺失和突变可能构成一个新的信号转导途径,与人类恶性肿瘤的发生普遍相关,资料报道。肾细胞癌有抑癌基因PTEN的缺失和突变。但目前尚未见到关于抑癌基因PTEN在肾细胞癌中表达的研究,本实验研究抑癌基因PTEN在肾细胞癌的表达和生物学意义。方法：应用免疫组织化学SP法检测5例正常肾组织,18例癌旁肾组织和40例肾细胞癌组织中抑癌基因PTEN的表达,分析抑癌基因PTEN的表达与肾细胞癌病理类型,淋巴结转移之间的关系。结果：5例正常肾组织和18例癌旁肾组织均有较强的PTEN蛋白的表达,正常肾组织和癌旁肾组织PTEN蛋白的表达强度,阳性细胞的分布形式无明显差异,肾小管上皮细胞的胞质呈PTEN蛋白阳性,免疫组化染色程度较强,肾小球无PTEN蛋白的表达。抑癌基因PTEN在肾细胞癌中的表达不同于正常肾组织和癌旁肾组织,12．5％,呈PTEN蛋白阴性,17．5％呈弱阳性,70％呈阳性或强阳性,PTEN蛋白阴性,弱阳性和阳性的肾细胞癌,肾门淋巴结转移率分别为80％,51．74％,10．71％,PTEN蛋白阴性和弱阳性肾细胞癌的肾门淋巴结转移率与PTEN阳性者比较,差异有显著性（P＜0．05）,结论：本实验提示肾细胞癌中存在着抑癌基因PTEN的表达缺失和异常,可能与肾细胞癌的发生,发展有关,抑癌基因PTEN是肾细胞癌的一种新的相关基因。

Expression and significance of a new tumor suppression gene PTEN in primary renal cell carcinoma

BACKGROUND & OBJECTIVE: PTEN gene is a newly discovered tumor suppressor gene, that maps to chromosome 10q23, and of longstanding interest to those studying somatic mutations in human tumors. Mutation and deletion of PTEN gene probably resulted in a new signal transduction pathway related to human malignant tumors. It was reported that PTEN gene mutated and deleted in renal cell carcinoma, however, there was no report concerning its expression in renal cell carcinoma. This study was designed to investigate expression and significance of PTEN gene in primary renal cell carcinoma. METHODS: Immunohistochemical peroxidase-conjugated streptavidin (SP) method was used to detect expression of PTEN gene in 40 cases of primary renal cell carcinoma, 18 with renal tissues closely adjacent to carcinoma and 5 case of normal renal tissues. The relationship between expression of tumor suppressor gene of PTEN and the percentage of lymph node metastasis of renal cell carcinoma was analyzed. RESULT: It was showed that PTEN gene was expressed in all 5 case of normal renal tissues and 18 cases of renal tissues closely adjacent to carcinoma. The intensity was relatively strong and it was localized mainly in cytoplasm of epithelium cells of renal tubular. Expression of PTEN in 40 cases of renal cell carcinoma were different, 12.5% were negative, 17.5% were weak positive, and 70% were strong positive. PTEN protein was localized in cytoplasm of carcinoma cells. The percentage of lymph node metastasis of renal cell carcinoma negative or weak positive of PTEN protein was 80% and 51.74%, respectively. The percentage of lymph node metastasis of renal cell carcinoma positive of PTEN protein was 10.71%, comparing with those of renal cell carcinoma negative or weak positive of PTEN protein, the difference was significant (P < 0.05). CONCLUSION: This study suggested that PTEN gene was deleted or weakly expressed in primary renal significant cell carcinoma, which is probably related to tumorigenesis and development of renal cell carcinoma.