Taniwaki M, Nishida K, Ueda Y, Misawa S, Nagai M, Tagawa S, Yamagami T, Sugiyama H, Abe M, Fukuhara S
Third Department of Internal Medicine, Kyoto Prefectural University of Medicine, Japan.
Blood. 1995 Jun 1;85(11):3223-8.
The breakpoint of 14q32 translocations found in B-cell malignancies was delineated specifically in both metaphase spreads and interphase nuclei by double-color fluorescence in situ hybridization (FISH) using bacteriophage clones containing the human immunoglobulin gamma chain gene locus (Ig gamma) and a cosmid clone, CY24-68, containing VH segments. CY24-68 is more telomeric than Ig gamma, separated by approximately 1 megabase (Mb). FISH studies were performed on four patients with non-Hodgkin's lymphoma (NHL), one with acute lymphoblastic leukemia (ALL), one with plasma cell leukemia (PCL), and three cell lines. In each patient with t(8;14), t(14;18), and t(3;14), the signal of Ig gamma gene was observed on der(14) and that of CY24-68 at respective partner sites of these translocations, 8q24.1, 18q21.3, and 3q27. Interphase nuclei with a signal of Ig gamma clearly separated from that of CY24-68 were more frequently encountered in all of the patients (45% to 74%) than those in normal controls (4% to 5%). Even in cases where only interphase nuclei were available for FISH studies, 14q32 translocations are detected as shown in two patients each with NHL and t(11;14)-carrying PCL. In two cell lines, HS-1 derived from ALL carrying t(8;14) and FR4 derived from a plasmacytoma carrying a complex form of t(8;14), the signal of Ig gamma was observed at the breakpoint region 8q24.1 of the der(8) in addition to the der(14), indicating that translocation event occurred within the Ig gamma locus. Intense Ig gamma signal was found at the breakpoint region on the der(14)t(11;14) in HBL-2 derived from NHL, indicating amplification of the Ig gamma gene, and presumably the resultant chimeric DNA between Ig gamma and DNA sequences at 11q13. The present approach allowed us to unequivocally detect tumor-specific breakpoints of 14q32 translocations. Furthermore, interphase FISH provides a rapid diagnostic procedure to detect 14q32 translocations in B-cell malignancies.
通过使用包含人类免疫球蛋白γ链基因座（Igγ）的噬菌体克隆和一个包含VH片段的黏粒克隆CY24-68，在中期染色体铺展和间期核中，利用双色荧光原位杂交（FISH）技术，明确界定了在B细胞恶性肿瘤中发现的14q32易位的断点。CY24-68比Igγ更靠近端粒，两者相距约1兆碱基（Mb）。对4例非霍奇金淋巴瘤（NHL）患者、1例急性淋巴细胞白血病（ALL）患者、1例浆细胞白血病（PCL）患者以及3个细胞系进行了FISH研究。在每例t(8;14)、t(14;18)和t(3;14)患者中，在der(14)上观察到Igγ基因的信号，而CY24-68的信号则在这些易位的相应伙伴位点，即8q24.1、18q21.3和3q27处。在所有患者中（45%至74%），与正常对照（4%至5%）相比，Igγ信号与CY24-68信号明显分离的间期核更为常见。即使在仅有间期核可用于FISH研究的情况下，如2例NHL患者和2例携带t(11;14)的PCL患者，也能检测到14q32易位。在2个细胞系中，源自携带t(8;14)的ALL的HS-1和源自携带复杂形式t(8;14)的浆细胞瘤的FR4，除了在der(14)上，在der(8)的断点区域8q24.1也观察到了Igγ信号，这表明易位事件发生在Igγ基因座内。在源自NHL的HBL-2中，在der(14)t(11;14)的断点区域发现了强烈的Igγ信号，表明Igγ基因发生了扩增，推测由此产生了Igγ与11q13处DNA序列之间的嵌合DNA。本方法使我们能够明确检测14q32易位的肿瘤特异性断点。此外，间期FISH为检测B细胞恶性肿瘤中的14q32易位提供了一种快速诊断程序。
