Ohira Miki, Morohashi Aiko, Inuzuka Hiroyuki, Shishikura Tomotane, Kawamoto Takemasa, Kageyama Hajime, Nakamura Yohko, Isogai Eriko, Takayasu Hajime, Sakiyama Shigeru, Suzuki Yutaka, Sugano Sumio, Goto Takeshi, Sato Shuji, Nakagawara Akira
Division of Biochemistry, Chiba Cancer Center Research Institute, 666-2 Nitona, Chiba 260-8717, Japan.
Oncogene. 2003 Aug 21;22(35):5525-36. doi: 10.1038/sj.onc.1206853.
Neuroblastoma (NBL), one of the most common childhood solid tumors, has a distinct nature in different prognostic subgroups: NBL in patients under 1 year of age usually regresses spontaneously, whereas that in patients over 1 year of age often grows aggressively and eventually kills the patient. To understand the molecular mechanism of biology and tumorigenesis of NBL, we decided to perform a comprehensive approach to unveil the gene expression profiles among the NBL subsets. We constructed the subset-specific oligo-capping cDNA libraries from the primary NBL tissues with favorable (F: stage 1, high expression of TrkA and a single copy of MYCN) and unfavorable (UF: stage 3 or 4, decreased expression of TrkA and MYCN amplification) characteristics and randomly cloned 4654 cDNAs. Among 4243 cDNAs sequenced successfully, 1799 (42.4%) were the genes with unknown function. Excluding the housekeeping genes, an expression profile of each subset was extremely different. To determine the genes expressed differentially between F and UF subsets, we performed semiquantitative reverse transcriptase (RT)-PCR for each of the 1842 independent genes using RNA obtained from 16 F and 16 UF NBLs as template. This revealed that 278 genes were highly expressed in the F subset as compared to the UF one, while, surprisingly, only 27 genes were expressed at higher levels in the UF rather than the F subset. These differentially expressed genes included 194 genes with unknown function. Many of the genes expressed at high levels in the F subset were related to catecholamine biosynthesis, small GTPases, synapse formation, synaptic vesicle transport, and transcription factors regulating differentiation of the neural crest-derived cells. On the other hand, the genes expressed at high levels in the UF subset included transcription factors and/or receptors that might regulate neuronal growth and differentiation. The chromosomal mapping of those genes showed some clusters. Thus, our mass-identification and characterization of the differentially expressed genes between the subsets may become a powerful tool for finding the important genes of NBL as well as developing new diagnostic and therapeutic strategies against aggressive NBL.
神经母细胞瘤（NBL）是儿童最常见的实体瘤之一，在不同预后亚组中具有独特的性质：1岁以下患者的NBL通常会自发消退，而1岁以上患者的NBL往往生长迅速，最终导致患者死亡。为了了解NBL生物学和肿瘤发生的分子机制，我们决定采用综合方法揭示NBL亚组之间的基因表达谱。我们从具有良好（F：1期，TrkA高表达且MYCN单拷贝）和不良（UF：3期或4期，TrkA表达降低且MYCN扩增）特征的原发性NBL组织构建了亚组特异性寡聚帽cDNA文库，并随机克隆了4654个cDNA。在成功测序的4243个cDNA中，1799个（42.4%）是功能未知的基因。排除管家基因后，每个亚组的表达谱差异极大。为了确定F和UF亚组之间差异表达的基因，我们以从16个F和16个UF NBL获得的RNA为模板，对1842个独立基因中的每一个进行了半定量逆转录酶（RT）-PCR。结果显示，与UF亚组相比，278个基因在F亚组中高表达，而令人惊讶的是，只有27个基因在UF亚组中表达水平高于F亚组。这些差异表达的基因包括194个功能未知的基因。在F亚组中高表达的许多基因与儿茶酚胺生物合成、小GTP酶、突触形成、突触小泡运输以及调节神经嵴衍生细胞分化的转录因子有关。另一方面，在UF亚组中高表达的基因包括可能调节神经元生长和分化的转录因子和/或受体。这些基因的染色体定位显示出一些簇。因此，我们对亚组之间差异表达基因的大规模鉴定和表征可能成为寻找NBL重要基因以及开发针对侵袭性NBL的新诊断和治疗策略的有力工具。
