Reifenberger J, Reifenberger G, Liu L, James C D, Wechsler W, Collins V P
Department of Pathology, Sahlgrenska Hospital, Gothenburg, Sweden.
Am J Pathol. 1994 Nov;145(5):1175-90.
The molecular genetic alterations of oligodendroglial tumors and mixed gliomas of the central nervous system were studied in a series of 37 cases (8 oligodendrogliomas, 13 anaplastic oligodendrogliomas, 8 oligoastrocytomas, and 8 anaplastic oligoastrocytomas). A total of 180 polymorphic loci and 5 nonpolymorphic gene loci, distributed over all chromosomes, were examined by restriction fragment length polymorphism analysis. Loss of heterozygosity was most frequently observed for loci on 19q with a commonly deleted region at 19q13.2-q13.4 distal to the CYP2a gene and proximal to the D19S22 locus. The incidence of allelic loss on 19q was particularly high (81%) in oligodendroglial tumors and equal to 31% in mixed gliomas. More than 75% of the tumors with allelic deletions on 19q also showed loss of heterozygosity for loci on 1p with one tumor showing only loss of alleles distal to the NGFB gene (1p13-pter). Seven (19%) tumors had lost alleles from 17p with the deleted region including the TP53 tumor suppressor gene in all cases. Sequencing of the TP53 transcripts from exons 2 to 10, however, did not reveal mutations of the remaining allele in any of these tumors. Anaplastic oligodendrogliomas and anaplastic oligoastrocytomas demonstrated an increased incidence of additional allelic losses involving most frequently chromosomes 9p and 10. Gene amplification was detected in two anaplastic tumors, affecting the epidermal growth factor receptor gene in both cases, with additional amplification of the renin gene at 1q32 in one of these cases. In total our results indicate both differences and similarities between the molecular genetic alterations in tumors with oligodendroglial and astrocytic differentiation. The loss of genetic information from 19q and 1p as well as the rarity of TP53 mutations in oligodendroglial tumors suggests that the early events in their oncogenesis are distinct from those associated with astrocytic tumors. However, similarities are indicated by the allelic losses on 9p and 10 in the anaplastic tumors, suggesting the utilization of common pathways of progression.
对37例中枢神经系统少突胶质细胞瘤和混合性胶质瘤（8例少突胶质细胞瘤、13例间变性少突胶质细胞瘤、8例少突星形细胞瘤和8例间变性少突星形细胞瘤）进行了分子遗传学改变的研究。通过限制性片段长度多态性分析，检测了分布于所有染色体上的总共180个多态性位点和5个非多态性基因位点。杂合性缺失最常见于19q上的位点，常见缺失区域位于CYP2a基因远端和D19S22位点近端的19q13.2 - q13.4。19q上等位基因缺失的发生率在少突胶质细胞瘤中特别高（81%），在混合性胶质瘤中为31%。超过75%在19q上有等位基因缺失的肿瘤在1p上的位点也显示杂合性缺失，其中1例肿瘤仅在NGFB基因（1p13 - pter）远端显示等位基因缺失。7例（19%）肿瘤在17p上有等位基因缺失，所有病例中缺失区域均包括TP53肿瘤抑制基因。然而，对这些肿瘤中从外显子2到10的TP53转录本进行测序，未发现其余等位基因有任何突变。间变性少突胶质细胞瘤和间变性少突星形细胞瘤显示涉及最常见染色体9p和10的额外等位基因缺失发生率增加。在2例间变性肿瘤中检测到基因扩增，2例均影响表皮生长因子受体基因，其中1例在1q32处肾素基因还有额外扩增。总体而言，我们的结果表明少突胶质细胞和星形细胞分化肿瘤的分子遗传学改变既有差异又有相似之处。少突胶质细胞瘤中19q和1p遗传信息的丢失以及TP53突变的罕见性表明其肿瘤发生的早期事件与星形细胞瘤相关事件不同。然而，间变性肿瘤中9p和10上等位基因缺失表明存在相似性，提示利用了共同的进展途径。
