中文摘要：

目的探讨少突胶质细胞肿瘤染色体1p／19q联合缺失及其与p53、10号染色体上磷酸酶及张力蛋白同源物（PTEN）和O2-甲基鸟嘌呤-DNA甲基转移酶（MGMT）蛋白表达的关系。方法收集少突胶质细胞肿瘤标本68例，其中WHO-Ⅱ级少突胶质细胞瘤42例，WHO-Ⅲ级间变性少突胶质细胞瘤26例。采用荧光原位杂交（FISH）方法分析肿瘤组织中1p／19q缺失状态；采用免疫组织化学方法对肿瘤组织中p53、PTEN和MGMT蛋白表达进行半定量分析，并进一步分析其与1p／19q联合缺失的相关性。结果68例少突胶质细胞肿瘤中，染色体1P、19q缺失率及1p／19q联合缺失率分别为67．65％（46／68）、61．76％（42／68）、57．35％（39／68）。1p／19q联合缺失率在Ⅱ级和Ⅲ级少突胶质细胞肿瘤之间，差异无统计学意义（P〉0．05）。1p／19q联合缺失在额叶肿瘤的发生率（76．67％，23／30）明显高于颞叶（45．00％，9／20）及其他部位肿瘤（38．89％，7／18），差异有统计学意义（P〈0．05）。1p／19q联合缺欠与患者性别及发病年龄无明显相关（P〉0．05）。p53和MGMT蛋白表达与肿瘤分级呈正相关，而PTEN表达与肿瘤分级呈负相关，差异均有统计学意义（P〈0．05）。1p／19q联合缺失与p53和MGMT蛋白低表达相关（P〈O．05），而与PTEN蛋白表达无明显相关（P〉0．05）。结论在少突胶质细胞肿瘤中，染色体1p／19q联合缺失与p53和MGMT蛋白表达水平呈负相关。

英文摘要：

Objective To investigate the frequencies of chromosome l p/19q co-deletion and its correlation with p53, phosphatase and tensin homolog deleted on chromosome ten （PTEN） and O6-methyl- guanine DNA methyhransferase （MGMT） protein expression in oligodendroglial tumors. Methods Sam- ples of 68 oligodendroglial tumors （42 oligodendrogliomas and 26 anaplastic oligodendrogliomas） were col- lected. The 1p/19q status was detected by Fluorescence in Situ Hybridization （FISH） and the expression levels of p53, PTEN and MGMT protein were estimated semi-quantitatively by immunohistochemistry, then the correlations with lp/19q co-deletion were analyzed by t-test. Results The frequencies of lp deletion, 19q deletion, and lp/19q co-deletion were 67.65% （46/68）, 61.76% （42/68） and 57.35% （39/68） respectively in 68 oligodendroglial tumor samples. There was no obvious difference of lp/19q co-deletion between low-grade oligedendroglioma and anaplastic oligodendroglioma （ P 〉 0. 05 ）. The frequency of 1 p/ 19q co-deletion in frontal lobe （76. 67%, 23/30） was higher than that in temporal （45.00%, 9/20） and the other lobes （38.89%, 7/18 ） （P 〈 0. 05 ）. There was no significant correlation between 1 p/19q co-de- letion, age and gender （P 〉 0. 05 ）. io53 and MGMT protein expression were positively correlated with tumor grade, but PTEN protein expression negatively correlated with tumor grade in oligodendroglial tumors （ P 〈 0. 05 ）. Furthermore, there was a significant association between 1 p/19q co-deletion and low p53 and MGMT protein expression （ P 〈 0. 05 ） , but there was no significant correlation with PTEN protein expres- sion in oligodendroglial tumors （P 〉 0. 05 ）. Conclusion The combined deletion of chromosome 1 p/19q negatively correlates with the expression of p53 and MGMT protein in oligodendroglial tumors, which may be valuable in the diagnosis, treatment and prognostic prediction for oligodendroglial tumors.