Kimura Y, Nakazawa M, Yamada M
Graduate School of Integrated Science, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan.
J Biochem. 1998 May;123(5):876-82. doi: 10.1093/oxfordjournals.jbchem.a022019.
OS-9 gene is frequently coamplified with CDK4 gene in human sarcomas. We isolated and characterized three isoforms of OS-9 cDNA found in a myeloid leukemia HL-60 cDNA library. Isoform 1 consisted of 2,700 bp, from which a 667 amino acid sequence was deduced and found to be identical with that of OS-9 cDNA from osteosarcoma cells [Su et al. (1996) Mol. Carcinogen. 15, 270-275]. Isoform 2 cDNA lacked a 165 nucleotide sequence in the coding region. Isoform 3 cDNA had an additional 45 bp deletion in the coding region. Isoforms 2 and 3 encode 612 and 597 amino acid polypeptides, respectively. Comparison of their cDNA sequences with the genomic structure indicated that three isoforms are splice variants. Reverse transcription-polymerase chain reaction analysis showed predominant expression of isoform 2 mRNA in myeloid leukemia HL-60 cells, osteosarcoma OsA-CL cells and rhabdomyosarcoma Rh30 cells. Northern blotting revealed similar levels of expression of OS-9 gene in various tumor cell lines of sarcoma cells, carcinoma cells and myeloid leukemia cells, but 3-4 times higher expression in OsA-CL cells and Rh30 cells containing a homogeneously staining region of 12q13-15. OS-9 expression decreased in differentiation-induced HL-60 cells. Possible involvement of the OS-9 gene in cell growth is discussed.
在人类肉瘤中，OS-9基因经常与CDK4基因共同扩增。我们从髓系白血病HL-60 cDNA文库中分离并鉴定了三种OS-9 cDNA同工型。同工型1由2700 bp组成，由此推导的667个氨基酸序列与骨肉瘤细胞的OS-9 cDNA序列相同[Su等人（1996年），《分子致癌作用》15，270 - 275]。同工型2 cDNA在编码区缺少165个核苷酸序列。同工型3 cDNA在编码区还有一个45 bp的缺失。同工型2和3分别编码612和597个氨基酸的多肽。将它们的cDNA序列与基因组结构进行比较表明，这三种同工型是剪接变体。逆转录 - 聚合酶链反应分析显示，同工型2 mRNA在髓系白血病HL-60细胞、骨肉瘤OsA-CL细胞和横纹肌肉瘤Rh30细胞中主要表达。Northern印迹分析显示，OS-9基因在肉瘤细胞、癌细胞和髓系白血病细胞的各种肿瘤细胞系中的表达水平相似，但在含有12q13 - 15均匀染色区的OsA-CL细胞和Rh30细胞中的表达高3 - 4倍。在分化诱导的HL-60细胞中，OS-9表达降低。本文讨论了OS-9基因可能参与细胞生长的情况。
