p53单抗M126在膀胱移行细胞癌中的表达及其意义

Expression of p53 fusion protein monoclonal antibody M126 in transitional cell carcinoma of bladder and its correlation with histopathologic stages

目的探讨Ｍ１２６与膀胱移行细胞癌的组织学分级和病理分期之间的关系。方法用ＰＣＲ扩增编码ｐ５３Ｎ端１８０个氨基酸的ＤＮＡ片断并将其克隆在谷胱苷肽转移酶（ＧＳＴ）的表达质粒ＰＧＥＸ２Ｔ中。用重组质粒转化大肠杆菌，诱导产生ｐ５３ＧＳＴ融合蛋白，免疫小鼠，制备Ｍ１２６单抗。用Ｍ１２６对６０例膀胱移行细胞癌石蜡切片进行免疫组化染色，结果４６例（７７％）表达融合蛋白，平均阳性细胞指数为（３４５±２９．０）％，并与肿瘤的组织学分级和病理分期相关（Ｐ＜０００１，Ｐ＜００５）。与进口单抗ＰＡｂ１８０１相比较，Ｍ１２６识别不同的抗原表位，染色强度和阳性细胞指数均明显增高，而且对不经微波修复的抗原也有很好的反应性。结论作为第一株国产抗ｐ５３单抗。

Objective To clarify the relationship between the histologic grading and the pathological staging of bladder cancer. Methods p53 DNA fragment encoding N terminal 180 a.a was obtained by PCR and was cloncd into P GEX 2T plasmid expressing glutathone S transferase (GST).Monoclonal antibody M126 was generated from the mice immunized with p53 fusion protein.The expression of M126 was determined in specimens of 60 primary transitional cell carcinomas,using a breast cancer specimen as positive control and normal bladder tissues as negative controls. Results An exceptionally high proportion 46/60 (77%) of the specimens was found to stain positively for M126 in the cell nuclei and the mean LI was 34.46±29% (range 6%～90%),which was significantly related to the histological grade ( P <0.001, P <0.05) and the pathological stage (pT category )( P <0.001).The present study also compared the immunoreactivity of M126 with other anti p53 monoclonal antibodies such as PAb 1801,and demonstrated that M126 not only recognized transitional cell carcinoma cells with high specificity and reactivity,but also stained p53 strongly with or without microwave oven treating. Conclusions The first domestic product of anti p53 monoclonal antibody,M126,is very useful in investigating the overexpressiono f p53 in bladder cancer as well as in other malignant neoplasms.