Calcium-dependent proliferation of NG108-15 neuroblastoma cells.
While there is increasing evidence that Ca2+ plays an important role in regulating cell proliferation, the precise mechanisms have not been clearly elucidated so far. In order to gain insight into how Ca2+ controls cell division, the rate of proliferation, cell volume, viability and attachment to the culture support were measured in NG108-15 neuroblastoma cells in the presence of various extracellular Ca2+ concentrations ([Ca2+]o). Culture medium [Ca2+]o was decreased from 1.8 mmol/l to various values down to 1 micromol/l with EGTA. The rate of cell proliferation was almost independent of [Ca2+]o between 1.8 mmol/l and 45 micromol/l. It was decreased by about 50% at 12 umol/l Ca2+ and was almost zero in the presence of 1 micromol/l Ca2+. As we hawe shown previously (Rouzaire-Dubois and Dubois 1998) long-term hypertonicity increased the cell volume and decreased the rate of proliferation. The effects of hypertonicity and decrease in [Ca2+]o on cell proliferation were synergistic and can be described by cell size-dependent and independent mechanisms, respectively. Relative to control conditions (1.8 mmol/l Ca2+), decreases in [Ca2+]o to 12 and 1 micromol/l decreased the cell viability to 76 and 52% and the cell adhesion to dishes to 16 and 3%, respectively. Altogether, these results indicate that the effects of alteration in [Ca2+]o and cell size on neuroblastoma cell proliferation are independent and act on different signalling pathways controlling cell division.
Rouzaire-Dubois
B
B
Laboratoire de Neurobiologie Cellulaire et Moleculaire, CNRS, 91198 Gif-sur-Yvette, France.
Dubois
J M
JM
D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D051379:Mice; D009447:Neuroblastoma / Q000473:pathology* / Q000503:physiopathology*; D051381:Rats
D002118:Calcium