Mdm2和p53基因在颅内非生殖细胞瘤性生殖细胞肿瘤中的表达意义

Significance of mdm2 and p53 gene expressions in the development of intracranial nongerminomatous germ cell tumors

目的研究鼠双微基因2（mdm2）基因和p53基因在颅内非生殖细胞瘤性生殖细胞肿瘤患者（NGGCTs）中的表达及意义。方法利用半定量RT-PCR技术检测了15例NGGCTs肿瘤（成熟畸胎瘤6例，未成熟畸胎瘤5例，卵黄囊瘤2例，绒毛膜上皮癌2例）中mdm2和p53mRNA的表达．并与正常人群进行比较，另外检测p53基因5～8外显子的突变情况。结果p53和mdm2mRNA在各类NGGCTs中均有较高水平表达，与正常对照组比较差异有统计学意义（e=-0．000）；p53mRNA在各类肿瘤中表达强度差异无统计学意义（P=0．056）：mdm2基因在非生殖细胞瘤性恶性生殖细胞肿瘤（NGMGCTs）中表达强度较成熟畸胎瘤高，差异有统计学意义（P=0．000）；mdm2和p53mRNA的表达强度无显著相关性（r=0．418．P=0．121）；15例NGGCTs肿瘤均未检测到p53基因的突变。结论mdm2基因异常表达与NGMGCTs肿瘤关系密切，p53基因突变并非NGGCTs形成的主要原因．mdm2和p53之间相互作用共同影响NGGCTs肿瘤的发生发展过程。

Objective To explore the significance of abnormal expressions of p53 and mdm2 genes in the intmcranial nongerminomatous germ cell tumors （NGGCTs）. Methods Fifteen patients with NGGCTs, including 6 with mature teratoma, 5 with immature teratoma, 2 with Yolk sac tumor and 2 with chorioearcinoma, were selected; semiquantitative RT-PCR was employed to observe their mRNA expressions of rodin2 andp53 genes; thep53 gene mutation in exon 5-8 was also detected. Results High-level mRNA expressions of p53 and mdm2 genes in patients with NGMGCTs were observed as compared with those in the normal group （P=0.000）. The mRNA expression of the P53 gene was not statistically different among various sub-kinds of tumors （P=0.056）. Significantly high mRNA expression of mdm2 gene in patients with NGMGCTs was noted than that in patients with mature teratoma （P=0.000）. No significant relation was observed between mRNA expressions of mdm2 and p53 genes （r = 0.418, P= 0.121） and no p53 gene mutation was found in all the patients. Conclusions The abnormal expression of mdm2 gene might relate to the development of NGMGCTs and p53 gene mutation might not be the main cause of the oncogenesis of NGGCTs. The interaction of mdm2 and p53 genes plays a promotive role in the oncogenesis and development of NGGCTs.