cyclin-d1 and diazo-2

Nuclear factor kappa B (NF-kappaB) has been implicated in the regulation of cell proliferation and transformation. We investigated the role of the serum-induced intracellular calcium increase in the NF-kappaB--dependent cell cycle progression in Swiss 3T3 fibroblasts. Noninvasive photoactivation of a calcium chelator (Diazo-2) was used to specifically disrupt the transient rise in calcium induced by serum stimulation of starved Swiss 3T3 cells. The serum-induced intracellular calcium peak was essential for subsequent NF-kappaB activation (measured by real-time imaging of the dynamic p65 and IkappaBalpha fluorescent fusion proteins), cyclin D1 (CD1) promoter-directed transcription (measured by real-time luminescence imaging of CD1 promoter-directed firefly luciferase activity), and progression to cell division. We further showed that the serum-induced mitogen-activated protein kinase (MAPK) phosphorylation is calcium dependent. Inhibition of the MAPK- but not the PtdIns3K-dependent pathway inhibited NF-kappaB signaling, and further, CD1 transcription and cell cycle progression. These data suggest that a serum-dependent calcium signal regulates the cell cycle via a MAPK--NF-kappaB pathway in Swiss 3T3 cells.

Topics: Animals; Blood Proteins; Calcium; Calcium Signaling; Carrier Proteins; Cell Cycle; Cell Division; Chelating Agents; Cyclin D1; Diazonium Compounds; I-kappa B Proteins; MAP Kinase Signaling System; Mice; Mitogen-Activated Protein Kinase 1; Neoplasm Proteins; NF-kappa B; NF-KappaB Inhibitor alpha; Phenoxyacetates; Phosphatidylinositol 3-Kinases; Phosphorylation; Promoter Regions, Genetic; Swiss 3T3 Cells; Transcription Factor RelA; Transcription, Genetic