title: Cell cycle regulator geminin is dispensable for the proliferation of vascular smooth muscle cells.
abstract: The proliferation of vascular smooth muscle cells (VSMCs) plays a major role in the pathogenesis of many cardiovascular diseases. Geminin regulates DNA replication and cell cycle progression and plays a key role in the proliferation of cancer cells. We therefore hypothesized that geminin regulates the proliferation of VSMCs. The present study demonstrates that the level of geminin expression was low in quiescent VSMCs (approximately 90% and 10% of cells in the G1 and in S/G2/M phases of the cell cycle, respectively), increased as more cells entered in S/G2/M, and then decreased as cells exited S/G2/M. Further, angiotensin II and norepinephrine stimulated expression of geminin in VSMCs. However, the DNA content, nuclear morphology, percentage of cells at different stages of the cell cycle, and rate of proliferation of VSMCs from which geminin was either depleted or overexpressed were all similar. These findings indicate geminin functions differently in VSMCs than it does in cancer cell lines and that it may provide a target for treating cancers without affecting normal cells.
authors.affiliation: Department of Cardiology, Peking University People's Hospital, Beijing 100044, China.
authors.forename: JianQiang
authors.initials: J
authors.lastname: Guo
authors.forename: NingLing
authors.initials: N
authors.lastname: Sun
mesh_terms: D000818:Animals; D059447:Cell Cycle Checkpoints / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D049109:Cell Proliferation; D004261:DNA Replication / Q000502:physiology; D064248:Geminin / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D020868:Gene Silencing; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008954:Models, Biological; D032389:Myocytes, Smooth Muscle / Q000166:cytology* / Q000502:physiology*; D009389:Neovascularization, Pathologic; D018919:Neovascularization, Physiologic; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D015854:Up-Regulation
chemical_list: D064248:Geminin; D034741:RNA, Small Interfering