Gümüş Güvem, Sunguroğlu Asuman, Tükün Ajlan, Sayin Derya Beyza, Bökesoy Işik
Ankara University, Faculty of Medicine, Medical Biology Department, Ankara, Turkey.
Cancer Genet Cytogenet. 2002 Mar;133(2):168-71. doi: 10.1016/s0165-4608(01)00569-6.
Fragile sites are specific regions of chromosomes prone to breakage when cells are cultured under specific conditions. These sites are divided into two classes: common and rare. Common fragile sites are expressed in all individuals at different frequencies, whereas rare ones are found only in certain individuals. Common and rare fragile sites have been shown to display a number of characteristics of instability being preferential sites for chromosomal deletions, duplications, and rearrangements. Moreover, a majority of mapped oncogenes are located at or near these fragile sites. These observations have led to the suggestion that both classes of fragile sites may play a significant role in chromosomal rearrangements involved in oncogene activation or tumor supressor gene inactivation. For these reasons, involvement of common and rare fragile sites and their relevance to specific chromosome breakpoints in cancer have received much attention. In this study, which reports on the cytogenetic findings obtained from 256 patients with chronic myelocytic leukemia, 103 with acute myelocytic leukemia, 40 with acute lymphocytic leukemia, 33 with myelodysplastic syndrome, we documented the fragile sites involved in chromosomal aberrations involving oncogenes, tumor supressor genes, and other known genes important in cell cycle regulation localized at these sites.
脆性位点是染色体的特定区域，当细胞在特定条件下培养时容易发生断裂。这些位点分为两类：常见型和罕见型。常见脆性位点在所有个体中以不同频率表达，而罕见脆性位点仅在某些个体中出现。常见和罕见脆性位点已被证明表现出一些不稳定性特征，是染色体缺失、重复和重排的优先位点。此外，大多数已定位的癌基因位于这些脆性位点或其附近。这些观察结果表明，这两类脆性位点可能在涉及癌基因激活或肿瘤抑制基因失活的染色体重排中起重要作用。出于这些原因，常见和罕见脆性位点的参与及其与癌症中特定染色体断点的相关性受到了广泛关注。在本研究中，我们报告了从256例慢性髓性白血病患者、103例急性髓性白血病患者、40例急性淋巴细胞白血病患者、33例骨髓增生异常综合征患者中获得的细胞遗传学结果，记录了涉及癌基因、肿瘤抑制基因以及在这些位点定位的对细胞周期调控重要的其他已知基因的染色体畸变中所涉及的脆性位点。
