Cloning and characterization of three isoforms of OS-9 cDNA and expression of the OS-9 gene in various human tumor cell lines.
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.
Kimura
Y
Y
Graduate School of Integrated Science, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan.
Nakazawa
M
M
Yamada
M
M
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D015723:Gene Library; D018922:HL-60 Cells; D006801:Humans; D037102:Lectins; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D004273:DNA, Neoplasm; D037102:Lectins; D009363:Neoplasm Proteins; C098898:OS9 protein, human; D012333:RNA, Messenger; D012334:RNA, Neoplasm