title: Influence of spontaneous calcium events on cell-cycle progression in embryonal carcinoma and adult stem cells.
abstract: Spontaneous Ca(2+) events have been observed in diverse stem cell lines, including carcinoma and mesenchymal stem cells. Interestingly, during cell cycle progression, cells exhibit Ca(2+) transients during the G(1) to S transition, suggesting that these oscillations may play a role in cell cycle progression. We aimed to study the influence of promoting and blocking calcium oscillations in cell proliferation and cell cycle progression, both in neural progenitor and undifferentiated cells. We also identified which calcium stores are required for maintaining these oscillations. Both in neural progenitor and undifferentiated cells calcium oscillations were restricted to the G1/S transition, suggesting a role for these events in progression of the cell cycle. Maintenance of the oscillations required calcium influx only through inositol 1,4,5-triphosphate receptors (IP(3)Rs) and L-type channels in undifferentiated cells, while neural progenitor cells also utilized ryanodine-sensitive stores. Interestingly, promoting calcium oscillations through IP(3)R agonists increased both proliferation and levels of cell cycle regulators such as cyclins A and E. Conversely, blocking calcium events with IP(3)R antagonists had the opposite effect in both undifferentiated and neural progenitor cells. This suggests that calcium events created by IP(3)Rs may be involved in cell cycle progression and proliferation, possibly due to regulation of cyclin levels, both in undifferentiated cells and in neural progenitor cells.
authors: Department of Physics, Institute of Exact Sciences, Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, Brazil. rrresende@hotmail.com
authors: R R
authors: RR
authors: Resende
authors: A
authors: A
authors: Adhikari
authors: J L
authors: JL
authors: da Costa
authors: E
authors: E
authors: Lorençon
authors: M S
authors: MS
authors: Ladeira
authors: S
authors: S
authors: Guatimosim
authors: A H
authors: AH
authors: Kihara
authors: L O
authors: LO
authors: Ladeira
mesh_terms: D053687:Adult Stem Cells / Q000166:cytology / Q000502:physiology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D018236:Carcinoma, Embryonal / Q000378:metabolism* / Q000473:pathology; D002453:Cell Cycle / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000502:physiology
chemical_list: D053496:Inositol 1,4,5-Trisphosphate Receptors; D018844:Cyclin-Dependent Kinases; D002118:Calcium