多形性黄色星形细胞瘤的比较基因组杂交分析

Analysis of Comparative Genomic Hybridization in Pleomorphic Xanthoastrocytoma

目的研究多形性黄色星形细胞瘤(PXA)的遗传学异常,以探讨该肿瘤的发病机制。方法收集3例PXA标本,应用比较基因组杂交(CGH)分析方法,研究PXA的染色体失衡。应用免疫组化染色,分析表皮生长因子受体(EGFR)在肿瘤细胞中的表达。结果通过CGH分析,在3例PXA中都发现有遗传学异常。其中1例有多条染色体的失衡:2p14pter、4p15pter、7p21qter、11q24qter、12和15q14qter的获得,以及8p11.2pter、9p11p23、10p12pter和13q14qter的丢失。该患者于术后1年死于肿瘤复发。3例肿瘤患者中的2例检测到7号染色体的获得和8号染色体短臂的丢失。免疫组化染色结果显示,EGFR在3例PXA中均呈阴性表达。结论研究PXA的遗传学改变对了解该疾病的发病机制有重要意义。

Objective To detect genetic alterations in pleomorphic xanthoastrocytoma （PXA）, and to investigate the mechanism of development of this neoplasm. Methods Three patients with PXA were studied. Comparative genomic hybridization （CGH） was performed to study chromosomal imbalances in PXA. Using immunohistochemical analysis, the expression of EGFR was detected in PXA. Results Using CGH analysis, genetic imbalance was detected on at least one chromosome for each case. One patient revealed multiple genetic alterations, including gains of 2pl4-pter, 4pl5-pter, 7p21-qter, llq24-qter, 12 and 15ql4-qter, as well as losses of 8pll. 2-pter, 9pll-p23, 10pl2-pter, and 13ql4-qter. This patient experienced tumor recurrence and died one year later. Gain on Chromosome 7 and loss on Chromosome 8p were demonstrated in 2 of the 3 patients. Immunohistochemically, no EGFR positive reaction was found in all cases. Conclusion Detection of genetic alterations is very important in understanding the pathogenesis of PXA.