title: Different transcriptional strategies for ccn2/ctgf gene induction between human chondrocytic and breast cancer cell lines.
abstract: Connective tissue growth factor (CTGF/CCN2) plays a critical role in endochondral bone formation; however, CCN2 also promotes angiogenesis and bone metastasis in breast cancer. Chondrocytic HCS-2/8 cells and breast cancer MDA231 cells produce over 6 times more CCN2 than any other cell type. In this study, we demonstrate that these cell lines employ different transcriptional strategies for ccn2 gene induction. Four tandem copies of the dominant transcriptional enhancer in chondrocytes (4 x TRENDIC) were chimerically connected to an SV40 promoter-luciferase construct and subsequently analyzed. The enhancement of the promoter activity by 4 x TRENDIC was greater in the HCS-2/8 cells (7-fold) than in the other 4 cell lines (3-4 fold). The TRENDIC-binding protein complex was detected at a higher signal in the HCS-2/8 cells than in the other cell lines. In addition, the HCS-2/8 nuclear factors strongly targeted not only TRENDIC, but also the previously reported basal control element and a novel enhancer element in the ccn2 promoter. In contrast, high-level ccn2 gene induction in MDA231 cells was largely dependent on Smad signaling through the Smad-binding element in the ccn2 promoter. Based on these results, we propose a model of differential transcription of the ccn2 gene between the chondrocytic cell line and the breast cancer cell line, and therefore imply that these cells utilize distinct transcriptional strategies to obtain the enhanced CCN2 production that is not observed in other types of cells.
authors.affiliation: Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1, Shikata-cho, Okayama 700-8525, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Eguchi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kubota
authors.forename: Kazumi
authors.initials: K
authors.lastname: Kawata
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Mukudai
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Ohgawara
authors.forename: Kohei
authors.initials: K
authors.lastname: Miyazono
authors.forename: Kyouji
authors.initials: K
authors.lastname: Nakao
authors.forename: Seiji
authors.initials: S
authors.lastname: Kondo
authors.forename: Masaharu
authors.initials: M
authors.lastname: Takigawa
mesh_terms: D001483:Base Sequence; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D002813:Chondrosarcoma / Q000235:genetics / Q000378:metabolism / Q000469:parasitology; D055513:Connective Tissue Growth Factor; D004591:Electrophoresis, Polyacrylamide Gel; D024202:Electrophoretic Mobility Shift Assay; D004742:Enhancer Elements, Genetic; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics* / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D008957:Models, Genetic; D009154:Mutation; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D051785:Smad Proteins / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation
chemical_list: C526317:CCN2 protein, human; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D051785:Smad Proteins; D055513:Connective Tissue Growth Factor