Transforming growth factor-β and forskolin increase all classes of insulin-like growth factor-I transcripts in normal human osteoblast-like cells

Ryo Okazaki, Susan K. Durham, B. Lawrence Riggs, Cheryl A Conover

Research output: Contribution to journalArticle

32 Scopus citations


In this study, we examined regulation of insulin-like growth factor I (IGF-I) gene expression and transcript splicing in normal human osteoblast-like cells. Previous studies in rat osteoblastic cells have indicated that transforming growth factor-β (TGF-β) inhibits IGF-I expression, whereas inducers of intracellular cAMP stimulate IGF-I expression. However, in human osteoblast-like cells both TGF-β and forskolin increased IGF-I mRNA levels in a time- and dose-dependent manner. All 4 classes of IGF-I transcript that can result from alternate leader exon usage and splicing of the human IGF-I gene were induced proportionally. Although human osteoblasts increase IGF-I mRNA in response to important skeletal regulatory factors, some responses may be species-specific.

Original languageEnglish (US)
Pages (from-to)963-970
Number of pages8
JournalBiochemical and Biophysical Research Communications
Issue number3
StatePublished - 1995


ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology
  • Cell Biology

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