title: Buffering of intracellular calcium in response to increased extracellular levels in mortal, immortal, and transformed human breast epithelial cells.
abstract: Extracellular levels of calcium at 1.05 mM or higher induce terminal differentiation and senescence in the mortal (MCF-10M) line of human breast epithelial cells, but does not retard the growth or induce differentiation in the immortal (MCF-10A) and oncogene transformed (MCF-10AneoT) lines. Intracellular levels of calcium and inositol triphosphate were determined in MCF-10M, MCF-10A, and MCF-10AneoT, under conditions of low and high extracellular calcium. We hereby report that increases in extracellular calcium is translated into significant increases in intracellular levels of calcium and inositol triphosphate in MCF-10M, but not in MCF-10A and MCF-10AneoT. This difference in the apparent calcium buffering capacity between the mortal and the immortalized human breast epithelial cells could account for the latter's unperturbed growth potential in high extracellular calcium environment.
authors.affiliation: Department of Pathology, Michigan Cancer Foundation, Detroit 48201.
authors.forename: J
authors.initials: J
authors.lastname: Ochieng
authors.forename: Q S
authors.initials: QS
authors.lastname: Tahin
authors.forename: C C
authors.initials: CC
authors.lastname: Booth
authors.forename: J
authors.initials: J
authors.lastname: Russo
mesh_terms: D001940:Breast / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002454:Cell Differentiation; D002455:Cell Division; D002460:Cell Line; D002461:Cell Line, Transformed; D002471:Cell Transformation, Neoplastic; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D014407:Tumor Cells, Cultured
chemical_list: D007295:Inositol Phosphates; D002118:Calcium