Cell cycle dependent gene expression in quiescent stimulated and asynchronously cycling arterial smooth muscle cells in culture

✍ Scribed by Michel Campan; Claude Desgranges; Alain-Pierre Gadeau; Dominique Millet; Francis Belloc

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 892 KB
• Volume: 150
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041500309

✦ Synopsis

Abstract

The expression of a set of cell cycle dependent (CCD) genes (c‐fos, c‐myc, ornithine decarboxylase (ODC), and thymidine kinase (TK)) was comparatively studied in cultured arterial smooth muscle cells (SMC) during exit from quiescence and exponential proliferation. These genes, which were not expressed in quiescent SMC, were chronologically induced after serum stimulation. c‐fos mRNA were rapidly and transiently expressed very early in the G~1~ phase; c‐myc and ODC peaked a few hours after serum stimulation and then remained at an intermediary level throughout the first cell cycle; TK mRNA and activity then appeared at the G~1~/S boundary and peak in G~2~/M phases. Except for c‐fos, the other genes were also expressed in asynchronously cycling SMC (ACSMC); their expression was studied in elutriated subpopulations representative of cell cycle progression. c‐fos mRNA were undetectable in any sorted subpopulations, even in the pure early G~1~ population. Despite a slight increase as the cell cycle advanced, c‐myc and ODC genes were expressed throughout the ACSMC cell cycle. A faint TK activity was found in G~1~ subpopulations and increased in populations enriched in other phases; in contrast, TK mRNA remained highly expressed in all elutriated subpopulations. This study demonstrates significant modulations in CCD gene expression between quiescent stimulated and asynchronously cycling SMC in culture. This suggests that the events occurring during the emergence of SMC from quiescence are probably different from those in the G~1~ phase of ACSMC.