髓母细胞瘤β-catenin蛋白表达与10q杂合性缺失检测及其临床意义

Clinicopathoiogic significance of β-catenin protein and loss of heterozygosity on lOq in meduUoblastoma

目的探讨髓母细胞瘤β-catenin蛋白的表达及10q杂合性缺失与临床病理特征的关系。方法选择新疆医科大学第一附属医院2002至2011年间，经病理组织学诊断为不同类型的髓母细胞瘤合计50例，包括经典型髓母细胞瘤32例，促纤维增生型13例，结节型5例，采用免疫组织化学EnVision法对50例髓母细胞瘤石蜡切片β-catenin蛋白进行半定量分析，荧光原位杂交技术检测10q杂合性缺失，Kaplan-Meien和Cox回归分析β-catenin蛋白、10q杂合性缺失与临床病理特征及预后关系。结果β-catenin蛋白在经典型髓母细胞瘤胞质中阳性率为53．1％（17／32），促纤维增生型为4／13，广泛结节型为1／5；经典髓母细胞瘤10q杂合性缺失率为33．3％（8／24），促纤维增生型为2／11，结节型未见10q杂合性缺失（0／5）；三种类型间比较，差异均无统计学意义（P〉0．05）。单因素分析B．catenin蛋白阳性表达者（P=0．022）、无10q杂合性缺失（P=0．020）、肿瘤切除范围（P〈0．01）、放疗（P=0．002）、化疗（P〈0．01）与髓母细胞瘤患者预后相关。结论β-catenin蛋白阳性表达者、无10q杂合性缺失者预后较好。检测髓母细胞瘤染色体β-eatenin蛋白表达和10q杂合性缺失，有助于预后判断。

Objective To study the expression of β-catenin protein and the status of loss of heterozygosity （LOH） on chromsome 10q in medulloblastoma, with clinical correlation. Methods Immunohistochemical study for β-eatenin protein was carried out in 50 cases of medulloblastoma encountered in the First Affiliated Hospital of Xinjiang Medical University during the period from 2002 to 2011, including 32 cases of classic medulloblastoma, 13 cases of desmoplastic medulloblastoma and 5 cases of medulloblastoma with extensive nodularity. The status of LOH on 10q was also detected by fluorescence in-situ hybridization. The clinicopathologic characteristics and prognostic parameters were studied by Kaplan- Meien and Cox analysis. Results The rates of expression of 13-catenin protein in classic medulloblastoma, desmoplastie medulloblastoma and medulloblastoma with extensive nodularity were 53.1% （17/32）, 4/13 and 1/5, respectively. The rate of LOH on 10q was 33.3% （8/24） in classic medulloblastoma and 2/11 in desmoplastic medulloblastoma. There was no statistically significant difference between the two tumor types. Univariate analysis showed that the expression of β-catenin protein （ P = 0. 022 ）, lack of LOH on 10q （ P = 0. 020）, extensiveness of tumor resection （ P 〈 0. 01 ）, radiotherapy （ P = 0. 002 ） and chemotherapy （P 〈 0.01 ） represented important prognostic factors. Conclusions Medulloblastoma with expression of β-eatenin protein and without LOH on 10q carries a better prognosis. Assessment of these parameters is helpful in evaluating prognosis and subsequent patient management.