p27kip1和Ki-67在原发性中枢神经系统生殖细胞肿瘤中表达的临床病理学意义

Clinicopathological significance of expressions of p27^(kip1) and Ki-67 in primary central nervous system germ cell tumors

目的探讨抑癌基因p27kip1和细胞周期蛋白Ki-67在原发性中枢神经系统生殖细胞肿瘤(CNSGCTs)中的表达及其临床病理学意义。方法采用免疫组织化学方法检测28例原发性CNSGCTs组织中p27kip1和Ki-67的表达,计算Ki-67增殖指数(Ki-67 LI)。结果 28例原发性CNSGCTs中,17例(60.7%)p27kip1高表达,其中成熟性畸胎瘤5例,生殖细胞瘤10例,胚胎性癌和混合性生殖细胞瘤各1例;11例(39.3%)p27kip1低表达,其中生殖细胞瘤8例,未成熟性畸胎瘤、混合性生殖细胞瘤、绒毛膜癌各1例。13例(46.4%)Ki-67 LI>50%,9例(32.1%)Ki-67 LI为25%~50%,6例(21.4%)Ki-67 LI<25%。原发性CNSGCTs组织中p27kip1表达和Ki-67 LI与肿瘤的组织学类型有关,p27kip1表达水平与患者性别、年龄,肿瘤大小、部位,预后和复发以及Ki-67 LI均无相关性(P>0.05)。结论 p27kip1在恶性程度较高的原发性CNSGCTs中呈现低表达,提示其可能通过下调细胞周期G1→S的调控点而参与生殖细胞肿瘤的发生和发展。

Objective To investigate the clinicopathological significance of expressions of tumor suppressor gene p27kip1 and expression of cyclin Ki-67 in primary central nervous system germ cell tumors（CNSGCTs）.Methods The expressions of p27kip1 and Ki-67 in tissues of 28 cases of primary CNSGCTs were detected by immunohistochemical method and Ki-67 labeling index（Ki-67 LI） was calculated.Results Among 28 cases of primary CNSGCTs,the p27kip1 expression of 17 cases（60.7%） was high,including 5 cases of mature teratomas,10 cases of germinomas,1 case of embryonal carcinoma,and 1 case of mixed GCT;and the p27kip1expression of 11 cases（39.3%） was low,including 8 cases of germinomas,1 case of immature teratoma,1 case of choriocarcinoma,and 1 case of mixed GCT.The Ki-67 LI of 13 cases（46.4%） was higher than 50%;Ki-67 LI of 9 cases（32.1%） was 25%-50%;and Ki-67 LI of 6 cases（21.4%） was lower than 25%.The expression of p27kip1 and Ki-67 LI correlated with the histological types of CNSGCTs.The expression of p27kip1did not correlate with sex,age,size of tumor,location,recurrence,prognosis,or Ki-67 LI（P〉0.05）.Conclusion The expression of p27kip1 is low in malignant primary CNSGCTs,which suggests that p27kip1 may involve in the formation and development of germ cell tumor by down-regulating the control point for transiting from Gl to S phase.