髓母细胞瘤8号染色体短臂的杂合性丢失

Loss of heterozygosity on chromosome 8p in medulloblastoma

目的研究髓母细胞瘤8号染色体的遗传学异常,寻找与该肿瘤发病机制有关的杂合性丢失位点。方法通过微卫星分析(microsatellite analysis)方法,应用19个位于8号染色体短臂(8p)上的多态性标记物,检测髓母细胞瘤的杂合性丢失(loss of heterozygosity,LOH)。结果在所检测的23例髓母细胞瘤中,21例为原发肿瘤,2例为复发肿瘤。染色体8p总的LOH比率为51%(124个LOH/243个可分析位点)。我们在8p22-23.2之间发现了一个高比率的共同丢失区,其长度为18.14 cM。结论染色体8p22-23.1上很可能存在重要的抑癌基因,该基因的丢失可能与髓母细胞瘤发病有关。

Purpose To detect the genetic alterations on chromosome 8 in medulloblastoma, and to identify the critical deletion loci that are associated with the development of this neoplasm. Methods Microsatellite analysis was performed to detect loss of heterozygosity （LOH） in medulloblastomas by using 19 polymorphic markers mapping to 8p. Results Twenty-three cases of medulloblastoma including 21 primary, and 2 recurrent tumors were studied. The overall frequency of LOH on 8p was 51% （ 124 of 243 informative markers）. Moreover, a common deletion region was found between 8p22-23.2, which was 18. lg cM. Conclusions Our result suggests the possibility of the presence of a tumor suppressor gene at 8p22-23.2. Deletion of this tumor suppressor gene may be associated with the pathogenesis of medulloblastoma.