采用对比基因杂交技术建立嗅神经母细胞瘤基因畸变模型

Cytogenetic aberrations of esthesioneuroblastoma studied by comparative genomic hybridization

目的 建立嗅神经母细胞瘤 (ENB)的基因畸变模型并分析其特征。方法 采用对比基因杂交 (CGH)技术对 12例原发、3例复发、7例转移ENB标本进行基因检测 ,用特殊软件系统对所采集照片的荧光信号进行量化分析 ,确定肿瘤DNA与正常对照DNA之间的基因差别。结果 ENB常见DNA丢失主要见于 1p、2q、3p/q、4p/q、5p/q、6q、8p/q、9p、10p/q、11p、12q、13q、18q和 2 1q ,DNA过度表达见于 1p、7q、9q、11q、14q、16p/q、17p/q、19p/q、2 0p/q和 2 2p/q。ENB的 1p2 1 p31DNA丢失与该类肿瘤患者预后差有明显相关性。死于ENB的患者均具有以下共性 :1p2 1 p31DNA丢失、临床分期为C或D期、分化程度低 (Ⅲ或Ⅳ级 )。对 4例发生转移、复发的患者 ,将检测结果与其原发病灶基因畸变情况进行对比分析表明 ,转移、复发病灶与其原发病灶间具有高度的克隆一致性。结论 采用CGH能建立ENB的典型基因畸变模型 ,该模型有助于解释此肿瘤的生物学特性并对其预后进行评估 ,并与神经母细胞瘤、小细胞肺癌以及头颈部鳞癌进行鉴别。

Objective To characterize the cytogenetic alterations of esthesioneuroblastoma (ENB). Methods Comparative genomic hybridization (CGH) was performed on genomic DNA extracted from 12 patients with primary ENB, 4 patients with tumor recurrence and 7 with metastasis. Equal amounts of biotin labeled tumor DNA and digoxigenin labeled normal reference DNA were hybridized to normal metaphase chromosomes. Tumor DNA was visualized by fluorescein (FITC) and normal DNA by rhodamin ( TRITC ) and detected by fluorescence microscopy. The signal intensities of the different fluorochromes were quantitated as gray levels along the single chromosomes. The over and under represented DNA segments were determined by computation of FITC/TRITC ratio images and average ratio profiles. Results Consensus deletion regions were most frequently observed on chromosomes 1p, 2q, 3p/q, 4p/q, 5p/q, 6q, 8p/q, 9p, 10p/q, 11p, 12q, 13q, 18q, and 21q. DNA over representations were identified on chromosomes 1p, 7q, 9q, 11q, 14q, 16p/q, 17p/q, 19p/q, 20p/q and 22p/q. The genetic pattern of ENB was distinct from that of other small round cell tumor types and neuroblastomas. The deletion on chromosome band 1p21 p31 was associated with bad prognosis. In particular, all patients died whose tumors had combined 1p21 p31 deletion, with tumors in clinical stage C or D, and of low differentiation (grade Ⅲ or Ⅳ). Clonality analysis revealed a high concordance between pairs of primaries and metastases. Conclusion CGH analysis identifies characteristic cytogenetic aberrations of esthesioneuroblastoma associated with its malignant phenotype.