DNA修复酶MGMT及Ki-67在星形细胞瘤中的表达及临床意义

目的：观察脑星形细胞瘤中DNA修复酶—6氧-甲基鸟嘌呤DNA甲基转移酶（MGMT）及细胞增殖核抗原（Ki-67）蛋白表达及临床意义。方法：69例样本均来源于神经外科手术切除且临床资料完整、术后病理诊断为星形细胞瘤病例，其中Ⅰ～Ⅱ级34例，Ⅲ级21例，Ⅳ级14例。应用免疫组织化学方法(ABC法)检测样本中MGMT及Ki-67蛋白的表达状况，并进行秩和相关等级检验。结果：星形细胞瘤中MGMT蛋白表达阳性率为60.9％，其中， Ⅰ～Ⅱ级、Ⅲ级和Ⅳ级分别为88.2％、23.5％和50.0％。不同分级之间MGMT蛋白表达比较差异均有显著性（P＝0.003 1），MGMT阳性表达率与肿瘤分级呈负相关（r＝－0.351 1，P＝0.003 1）；星形细胞瘤中Ki-67阳性率为62.3％，随肿瘤恶性程度的增加蛋白表达明显增强（P=0.000 0），该表达与肿瘤分级呈正相关（r＝0.690 4，P=0.000 0）；并且随Ki-67表达强度的增加，MGMT的表达强度明显下降（P＝0.015 1），Ki-67与MGMT蛋白表达呈负相关（r＝－0.291 5，P＝0.015 1）。结论：星形细胞瘤中MGMT及 Ki-67表达与肿瘤恶性程度密切相〖JP3〗关，提示MGMT和Ki-67可以作为评价星形细胞瘤预后的生物学指标。〖JP〗

Expressions of DNA repair enzyme MGMT and Ki-67 in human astrocytoma and clinical significances

Objective To explore the expressions of DNA repair enzyme 6-methyiguanine-DNA methyltransferase(MGMT) and cell multiplication nuclear antigen(Ki-67) in human astrocytomas and clinical significances.Methods Sixty nine specimens of human astrocytomas(grade Ⅰ-Ⅱ: 34 cases,grade Ⅲ:21 cases,grade Ⅳ:14 cases) were selected.The expressions of MGMT and Ki-67 were observed with immunohistochemical technique,and the relation between MGMT and Ki-67 was evaluated.Results The positive rate of MGMT in astrocytoma was 60.9%,the positive rates of grade Ⅰ-Ⅱ,grade Ⅲ and grade Ⅳ were 88.2%,23.5% and 50.0%,respectively.There were significant differences between various grades of tumor(P=0.003 1),and the expression of MGMT had negative correlation with tumor grades(r=-0.351 1).The positive rate of Ki-67 was 62.3%,and obviously increased with the grades of tumor(P=0.000 0),and the expression of ki-67 had positive correlation with tumor grades(r=0.690 4,P=0.000 0); the expression of MGMT decreased with the increase of expression of Ki-67(P=0.051),the expression of MGMT had negative correlation with Ki-67 expression(r=-0.291 5,P=0.015 1).Conclusion The expressions of MGMT and Ki-67 have close correlation with the degrees of malignancy in human astrocytomas.MGMT and Ki-67 may be used as biological parameters to estimate the prognosis of astrocytoma.