家族性胶质瘤中9号、10号和17号染色体的杂合性缺失分析

Loss of heterozygosity analysis of chromosomes 9, 10 and 17 in gliomas in families.

作者信息

Watling C J, van Meyel D J, Ramsay D A, Macdonald D R, Cairncross J G

机构信息

Department of Clinical Neurological Sciences, University of Western Ontario, London, Canada.

出版信息

Can J Neurol Sci. 1995 Feb;22(1):17-21. doi: 10.1017/s0317167100040440.

DOI:10.1017/s0317167100040440

PMID:7750067

Abstract

BACKGROUND

Studies of sporadic malignant gliomas have identified structural abnormalities in a number of chromosomal regions, especially losses of DNA on 9p, 10 and 17p.

PURPOSE

We undertook the following molecular analysis in families with glioma to determine the frequency of chromosomal losses in these regions and to test the utility of microsatellite markers in demonstrating losses of heterozygosity.

METHODS

Genomic DNA was extracted from tumor tissue and venous blood from 20 patients with a family history of glioma. Dinucleotide repeat polymorphisms (microsatellites) were analyzed by polymerase chain reaction to assess loss of constitutional heterozygosity (LOH) on 9p, 10 and 17p. Three polymorphic markers on chromosome 9 (D9S104, D9S161, D9S165), one on chromosome 10 (D10S209), and two on 17p (D17S786, D17S796) were used. Autoradiographic films were analyzed for LOH after radioactively labelled polymerase chain reaction products were resolved on denaturing formamide-acrylamide gels.

RESULTS

Of 20 patients informative for at least one of three chromosome 9 markers, 12 (60%) showed LOH at one or more loci; of 9 informative for the chromosome 10 marker, 4 (44%) showed LOH; and of 16 informative for at least one of two chromosome 17 markers, 7 (44%) showed LOH at one or both loci. These LOH rates do not include instances of tumor nullizygosity (0-35%) and therefore represent minimum frequencies of chromosomal losses at these loci.

CONCLUSIONS

Microsatellite markers can be used to detect LOH in archival glioma tissue. As in sporadic gliomas, frequent LOH was observed on 9p (9p21-22), 10 and 17p, supporting the notion that these regions may harbour tumor suppressor genes important in glioma development. Further work will be required to determine whether the proportion of LOH in these chromosomal regions is higher in familial gliomas than sporadic ones, as might occur with an inherited suppressor gene conferring susceptibility to gliomas in families.

摘要

背景

散发性恶性胶质瘤的研究已在多个染色体区域发现结构异常，尤其是9p、10和17p上的DNA缺失。

目的

我们对胶质瘤家族进行了以下分子分析，以确定这些区域染色体缺失的频率，并测试微卫星标记在显示杂合性缺失方面的效用。

方法

从20例有胶质瘤家族史的患者的肿瘤组织和静脉血中提取基因组DNA。通过聚合酶链反应分析二核苷酸重复多态性（微卫星），以评估9p、10和17p上的组成性杂合性缺失（LOH）。使用了9号染色体上的三个多态性标记（D9S104、D9S161、D9S165）、10号染色体上的一个标记（D10S209）以及17p上的两个标记（D17S786、D17S796）。在放射性标记的聚合酶链反应产物在变性甲酰胺 - 丙烯酰胺凝胶上分离后，分析放射自显影片以检测LOH。

结果

在20例对9号染色体的三个标记中至少一个有信息价值的患者中，12例（60%）在一个或多个位点显示LOH；在9例对10号染色体标记有信息价值的患者中，4例（44%）显示LOH；在16例对17号染色体的两个标记中至少一个有信息价值的患者中，7例（44%）在一个或两个位点显示LOH。这些LOH率不包括肿瘤纯合性缺失的情况（0 - 35%），因此代表了这些位点染色体缺失的最低频率。

结论

微卫星标记可用于检测存档胶质瘤组织中的LOH。与散发性胶质瘤一样，在9p（9p21 - 22）、10和17p上观察到频繁的LOH，支持这些区域可能含有在胶质瘤发生中起重要作用的肿瘤抑制基因这一观点。需要进一步的工作来确定这些染色体区域中LOH的比例在家族性胶质瘤中是否高于散发性胶质瘤，这可能是由于家族中存在赋予胶质瘤易感性的遗传性抑制基因所致。