Kaneko H, Inoue R, Yamada Y, Sukegawa K, Fukao T, Tashita H, Teramoto T, Kasahara K, Takami T, Kondo N
Department of Pediatrics, Gifu University School of Medicine, Tsukasa-mati, Japan.
Int J Cancer. 1996 Dec 20;69(6):480-3. doi: 10.1002/(SICI)1097-0215(19961220)69:6<480::AID-IJC11>3.0.CO;2-5.
Bloom syndrome (BS) is a rare autosomal recessive genetic disorder characterized by lupus-like erythematous telangiectasias of the face, sun sensitivity, stunted growth infertility and immunodeficiency. In addition, BS patients are highly predisposed to cancers. Although recently the causative gene of BS (BLM) was identified as a DNA helicase homologue, the function of BLM in DNA replication has not been elucidated. In this study, p53 mutation and microsatellite instability in B-cell lymphomas originating from 2 sibling BS patients were investigated. In the originally developed tumor of both patients, no p53 mutation was detected. In one patient, however, after treatment by ionizing radiation the B-cell lymphoma recurred, showing a 9-bp deletion in exon 7. In lymphoma cells and an EB-virus-transformed cell line from BS lymphocytes of this patient, microsatellite instability was also detected from the reduced length of microsatellite DNA markers, although in the other patient microsatellite instability was not detected. Thus, 2 B-cell lymphomas, despite having the same BLM mutation, showed different phenotypes in terms of p53 mutation and microsatellite instability.
布卢姆综合征（BS）是一种罕见的常染色体隐性遗传病，其特征为面部出现狼疮样红斑性毛细血管扩张、对日光敏感、生长发育迟缓、不孕不育及免疫缺陷。此外，BS患者极易患癌症。尽管最近已确定BS的致病基因（BLM）是一种DNA解旋酶同源物，但BLM在DNA复制中的功能尚未阐明。在本研究中，对源自2名患BS的同胞患者的B细胞淋巴瘤中的p53突变和微卫星不稳定性进行了研究。在两名患者最初发生的肿瘤中，均未检测到p53突变。然而，其中一名患者在接受电离辐射治疗后，B细胞淋巴瘤复发，其外显子7出现了9个碱基对的缺失。在该患者的淋巴瘤细胞及来自其BS淋巴细胞的EB病毒转化细胞系中，也检测到微卫星DNA标记长度缩短导致的微卫星不稳定性，不过在另一名患者中未检测到微卫星不稳定性。因此，2例B细胞淋巴瘤尽管具有相同的BLM突变，但在p53突变和微卫星不稳定性方面表现出不同的表型。
