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Biphasic calcium response of platelet‐derived growth factor stimulated glioblastoma cells is a function of cell confluence
Author(s) -
Vereb György,
Feuerstein Burt G.,
Hyun William C.,
Fulwyler Mack J.,
Balázs Margit,
Szöllősi János
Publication year - 2005
Publication title -
cytometry part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.316
H-Index - 90
eISSN - 1552-4930
pISSN - 1552-4922
DOI - 10.1002/cyto.a.20178
Subject(s) - confluence , cell cycle , microbiology and biotechnology , cell growth , growth factor , bromodeoxyuridine , cell culture , biology , cell , platelet derived growth factor , cell division , platelet derived growth factor receptor , calcium , medicine , receptor , biochemistry , genetics , computer science , programming language
Background Previous reports have linked the spiking or two‐phased character of calcium transients evoked by platelet‐derived growth factor (PDGF) to the position of cells in the cell cycle without regard to cell–cell contact and communication. Because cell confluence can regulate growth factor receptor expression and dephosphorylation, we investigated the effect of cell culture confluence and cell cycle on calcium responses of PDGF‐BB–stimulated A172 glioblastoma cells. Methods Digital imaging cytometry was used to correlate the peak and duration of calcium response with bromodeoxyuridine positivity and DNA content and with culture confluence on a cell‐by‐cell basis. Results In serum‐starved cultures, complete two‐phase calcium signals and shorter, lower spikes occurred independent of cell cycle phase. However, the confluence of cell culture seemed essential for inducing a complete response because cells in sparse cultures exhibited mostly short spikes with lower peaks or no transients at all. Conclusion Because cell confluence, by virtue of cell–cell contacts, is assumed to be an important regulator of proliferation, one is tempted to speculate that in transformed cells the ability to produce stronger growth signals upon reaching confluence and facing contact inhibition could provide a proliferative advantage. © 2005 International Society for Analytical Cytology