Li Chunmei, Takino Hisashi, Eimoto Tadaaki, Ishida Takashi, Inagaki Atsushi, Ueda Ryuzo, Suzuki Ritsuro, Yoshino Tadashi, Nakagawa Atsuko, Nakamura Shigeo, Inagaki Hiroshi
Department of Pathology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
Mod Pathol. 2007 Jun;20(6):648-55. doi: 10.1038/modpathol.3800781. Epub 2007 Apr 20.
In anaplastic large-cell lymphomas positive for anaplastic lymphoma kinase (ALK) protein, the ALK gene is most commonly fused to the NPM gene, and less commonly to TPM3, TFG, ATIC, and other rare genes. Although this lymphoma is generally associated with a favorable clinical outcome, 25% of the patients die of the disease within 5 years. In this study, we developed three assays, all of which can be used with archival formalin-fixed, paraffin-embedded tissues: (1) a sensitive reverse transcription-polymerase chain reaction (RT-PCR) assay for various X-ALK fusion genes, (2) a 5' rapid amplification of cDNA ends (RACE) assay to identify unknown fusion partners, and (3) a real-time RT-PCR assay to quantify the amount of the NPM-ALK fusion transcript. In 26 cases of ALK(+) anaplastic large-cell lymphoma, the RT-PCR assay showed that the ALK was fused to NPM in 21 cases, to TPM3 in three, and to TFG in one. The 5' RACE assay detected ATIC-ALK fusion in the remaining case. The real-time quantitative RT-PCR assay showed that the NPM-ALK transcript was over expressed in four of 20 quantifiable cases. Patients with NPM-ALK overexpression showed a significantly unfavorable overall survival compared with those with a low expression of this transcript. The RT-PCR and 5' RACE assays developed here may be useful for identification of known and unknown gene partners fused to the ALK gene. Overexpression of the NPM-ALK fusion transcript may be associated with a poor prognosis of the patients with ALK(+) anaplastic large-cell lymphomas.
在间变性淋巴瘤激酶（ALK）蛋白呈阳性的间变性大细胞淋巴瘤中，ALK基因最常与NPM基因融合，较少与TPM3、TFG、ATIC及其他罕见基因融合。尽管这种淋巴瘤通常与良好的临床预后相关，但25%的患者会在5年内死于该疾病。在本研究中，我们开发了三种检测方法，所有这些方法都可用于存档的福尔马林固定、石蜡包埋组织：（1）一种针对各种X-ALK融合基因的灵敏逆转录-聚合酶链反应（RT-PCR）检测方法；（2）一种用于鉴定未知融合伙伴的5' cDNA末端快速扩增（RACE）检测方法；（3）一种用于定量NPM-ALK融合转录本数量的实时RT-PCR检测方法。在26例ALK（+）间变性大细胞淋巴瘤病例中，RT-PCR检测显示，21例中ALK与NPM融合，3例与TPM3融合，1例与TFG融合。5' RACE检测在其余病例中检测到ATIC-ALK融合。实时定量RT-PCR检测显示，在20例可定量的病例中，有4例NPM-ALK转录本过度表达。与该转录本低表达的患者相比，NPM-ALK过度表达的患者总生存期明显较差。此处开发的RT-PCR和5' RACE检测方法可能有助于鉴定与ALK基因融合的已知和未知基因伙伴。NPM-ALK融合转录本的过度表达可能与ALK（+）间变性大细胞淋巴瘤患者的不良预后相关。
