原发性和继发性胶质母细胞瘤中p53 、p16 和Rb 的表达及意义

 目的 探讨p53、p16和Rb基因在原发性和继发性GBM中的表达差异性及意义。方法 应用RT—PCR和Western-blot检测14例原发性和16例继发性GBM中p53，p16mRNA和蛋白表达，免疫组织化学法检测Rb表达。结果 Rb免疫组织化学染色显示正常脑组织中无表达，14例原发GBM中有3例表达缺失（21．4％），16例继发GBM中有2例表达缺失（11．1％）。RT-PCR和Westernblot对比原发和继发GBM中p53和p16的表达，发现所有继发GBM中p53表达强度较原发GBM明显增加，14例原发GBM中有5例缺失（36．（1％），继发GBM中仅有1例表达缺失（6．25％）。p16表达缺失明显减少。结论 Rb的表达缺失在原发和继发GBM中没有明显的差异。细胞周期调节基因p53在mRNA和蛋白水平表达增加和p16在同样水平表达缺失是原发与继发GBM重要的细胞周期调控基因上的变化，可能是基因治疗GBM的重要靶点之一。

Expression and Significance of p53,p16 and Rb in Primary and Secondary Glioblastomas

Objective To study the expression and significance of cell cycle control gene-p53,p16 and Rb in glioblastomas.Methods To analyze the expression of p53 and p16 with RT-PCR and Western blot,and to analyze the expression of corresponding protein Rb with immunohistochemistry(IHC)of 14 cases of primary and 16 cases of secondary glioblastomas.Results Non-expression of Rb protein was founded in normal brain tissue,3 deleted in 14(21.4%)primary and 2 in 16(11.1%)secondary GBM with IHC.The expression of mutation p53 was higher in all secondary than primary GBM,5 deleted of p16 expression in 14(36.0%)primary GBM and only 1 in 16(6.25%)secondary GBM with RT-PCR and western blot.Conclusion No statistical significant difference of the expression of protein Rb between primary and secondary glioblastoma.That the expression increased of cell cycle control protein p53 and the expression deleted of another cell cycle control protein p16 may be one of the major events in the progression between primary and secondary glioblastomas,they are important cell cycle control genes and may be one of the key target genes in the therapy of GBM with gene methods.