Pomykala H M, Bohlander S K, Broeker P L, Olopade O I, Díaz M O
Department of Medicine, University of Chicago Pritzker School of Medicine, Illinois 60637.
Mol Cell Biol. 1994 Nov;14(11):7604-10. doi: 10.1128/mcb.14.11.7604-7610.1994.
Interstitial deletions of the short arm of chromosome 9 are associated with glioma, acute lymphoblastic leukemia, melanoma, mesothelioma, lung cancer, and bladder cancer. The distal breakpoints of the deletions (in relation to the centromere) in 14 glioma and leukemia cell lines have been mapped within the 400 kb IFN gene cluster located at band 9p21. To obtain information about the mechanism of these deletions, we have isolated and analyzed the nucleotide sequences at the breakpoint junctions in two glioma-derived cell lines. The A1235 cell line has a complex rearrangement of chromosome 9, including a deletion and an inversion that results in two breakpoint junctions. Both breakpoints of the distal inversion junction occurred within AT-rich regions. In the A172 cell line, a tandem heptamer repeat was found on either side of the deletion breakpoint junction. The distal breakpoint occurred 5' of IFNA2; the 256 bp sequenced from the proximal side of the breakpoint revealed 95% homology to long interspersed nuclear elements. One- and two-base-pair overlaps were observed at these junctions. The possible role of sequence overlaps, and repetitive sequences, in the rearrangement is discussed.
9号染色体短臂的间质缺失与胶质瘤、急性淋巴细胞白血病、黑色素瘤、间皮瘤、肺癌和膀胱癌有关。在14个胶质瘤和白血病细胞系中，缺失的远端断点（相对于着丝粒）已定位在位于9p21带的400 kb干扰素基因簇内。为了获得有关这些缺失机制的信息，我们分离并分析了两个胶质瘤来源的细胞系中断点连接处的核苷酸序列。A1235细胞系有9号染色体的复杂重排，包括一个缺失和一个倒位，导致两个断点连接。远端倒位连接的两个断点都发生在富含AT的区域内。在A172细胞系中，在缺失断点连接的两侧发现了串联七聚体重复序列。远端断点发生在IFNA2的5'端；从断点近端测序的256 bp显示与长散在核元件有95%的同源性。在这些连接处观察到了1个和2个碱基对的重叠。讨论了序列重叠和重复序列在重排中的可能作用。
