癌基因MDM_2和抑癌基因p53在肉瘤组织中的变化及其相关性

目的：研究ＭＤＭ２癌基因和ｐ５３抑癌基因在人肉瘤发生中的作用。方法：应用分子杂交和免疫组化技术检测了５０例肉瘤组织、１３例良性间叶瘤和１０例癌组织中ＭＤＭ２及ｐ５３的分子改变。结果：ｐ５３过表达率在肉瘤为２４／５０（４８％）；ＭＤＭ２扩增和过表达在肉瘤为１９／４９（３８．８％）和２７／４９（５５％），而在良性间叶瘤分别为１／１３（７．７％）和１／１２（８．３％），癌组均为１／１０（１０％）；ＭＤＭ２基因的异常在不同类型肉瘤间存在差异性；ＭＤＭ２扩增和过表达间存在不一致性：１９例扩增中１６例有过表达，而１１例过表达者无基因扩增。两基因改变的相关分析发现，２４例ｐ５３阳性中１８例有ＭＤＭ２改变。结论：ＭＤＭ２癌基因异常与间叶性肿瘤的恶性表型高度相关，并有一定类型特异性；ＭＤＭ２与ｐ５３的改变在肉瘤的发生中密切相关

Alteration and correlation of MDM 2 and p53 genes in human sarcomas

Purpose To study the roles played by MDM 2 oncogene and p53 antioncogene in development of human sarcomas. Methods 50 cases of human sarcomas, 13 benign mensenchymal tumors and 10 carcinomas were analyzed on alterations in MDM 2 and p53 genes by dot blot and immunohistochemistry. Results The overexpression of p53 in sarcomas was 24/50 (48 0%); amplification and overexpression of MDM 2 in sarcomas were 19/49 (38 8%), 27/49 (55 1%), while in benign tumors the frequences were 1/13 (7 7%) and 1/12 (8 3%), respectively. The changes in carcinoma group was both the same of 1/10 (10%). It seemed that abnormality of MDM 2 was some type specific distribution in sarcomas; and amplification and overexpression of MDM 2 was not always coexistent; 16 overexpression was detected in 19 cases with gene amplification, however, 11 was only presented elevated expression. The correlation in both gene changes was: in 24 p53 positive cases there were 18 with MDM 2 alteration. Conclusion The described investigation suggested that mutations in MDM 2 oncogene was closely related with malignant phenotype of sarcomas, and was some type specific; MDM 2 might be highly correlated with p53 in development of sarcomas.