Insulin-Induced Cell Cycle Progression Is Impaired in Chinese Hamster Ovary Cells Overexpressing Insulin Receptor Substrate-3

• Published in: Endocrinology (Philadelphia) 2004-12, Vol.145 (12), p.5862-5874
• Main Authors: Kaburagi, Yasushi, Yamashita, Ryo, Ito, Yuzuru, Okochi, Hitoshi, Yamamoto-Honda, Ritsuko, Yasuda, Kazuki, Sekihara, Hisahiko, Sasazuki, Takehiko, Kadowaki, Takashi, Yazaki, Yoshio
• Format: Article
• Language: English
• Subjects: AKT protein; Animals; Biological and medical sciences; c-Myc protein; CDC2-CDC28 Kinases - genetics; Cell activation; Cell cycle; Cell Cycle Proteins - genetics; Cell Division - drug effects; Cell Nucleus - metabolism; CHO Cells; Cricetinae; Critical components; Cyclin D1; Cyclin D1 - genetics; Cyclin-dependent kinase; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-dependent kinases; Cyclin-Dependent Kinases - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression; Genes, myc - physiology; Glycogen; Glycogen synthase kinase 3; Glycogen Synthase Kinase 3 - metabolism; Glycogens; GTP-binding protein; Hypoglycemic Agents - pharmacology; Insulin; Insulin - pharmacology; Insulin receptor substrate 1; Insulin Receptor Substrate Proteins; Insulin receptors; Kinases; MAP kinase; MAP Kinase Signaling System - drug effects; Myc protein; Ovaries; Phosphoproteins - genetics; Phosphoproteins - metabolism; Phosphorylation; Protein-Serine-Threonine Kinases - metabolism; Proteins; Proto-Oncogene Proteins - genetics; Proto-Oncogene Proteins - metabolism; Proto-Oncogene Proteins c-akt; ral GTP-Binding Proteins - metabolism; Rats; Receptors; Retinoblastoma Protein - metabolism; Vertebrates: endocrinology
• ISSN: 0013-7227; 1945-7170
• DOI: 10.1210/en.2004-0199

To analyze the roles of insulin receptor substrate (IRS) proteins in insulin-stimulated cell cycle progression, we examined the functions of rat IRS-1 and IRS-3 in Chinese hamster ovary cells overexpressing the human insulin receptor. In this type of cell overexpressing IRS-1 or IRS-3, we showed that: 1) overexpression of IRS-3, but not IRS-1, suppressed the G1/S transition induced by insulin; 2) IRS-3 was more preferentially localized to the nucleus than IRS-1; 3) phosphorylation of glycogen synthase kinase 3 and MAPK/ERK was unaffected by IRS-3 overexpression, whereas that of protein kinase B was enhanced by either IRS; 4) overexpressed IRS-3 suppressed cyclin D1 expression in response to insulin; 5) among the signaling molecules regulating cyclin D1 expression, activation of the small G protein Ral was unchanged, whereas insulin-induced gene expression of c-myc, a critical component for growth control and cell cycle progression, was suppressed by overexpressed IRS-3; and 6) insulin-induced expression of p21, a cyclin-dependent kinase inhibitor, was decreased by overexpressed IRS-3. These findings imply that: 1) IRS-3 may play a unique role in mitogenesis by inhibiting insulin-stimulated cell cycle progression via a decrease in cyclin D1 and p21 expressions as well as suppression of c-myc mRNA induction in a manner independent of the activation of MAPK, protein kinase B, glycogen synthase kinase 3 and Ral; and 2) the interaction of IRS-3 with nuclear proteins may be involved in this process.