title: Melatonin inhibition of MCF-7 human breast-cancer cells growth: influence of cell proliferation rate.
abstract: We have studied whether the cell proliferation rate modifies the inhibitory actions of melatonin on MCF-7 cell growth. The proliferative rate of cells was altered by plating them at different densities (5 x 10(4) to 100 x 10(4) cells/dish) in media with low charcoal-stripped serum concentrations. In this way, population doubling time ranged from 33 h (for density = 100 x 10(4) cells/dish) to 75 h (for density = 5 x 10(4) cells/dish). Melatonin (10(-9)M) only inhibited fast proliferating MCF-7 cells, increasing their cell doubling time, and did not significantly modify the length of doubling time in the cultures with low proliferation rate, in which doubling time was already long. These data clearly show that there is a direct relation between proliferative rate of cells and melatonin inhibitory actions on MCF-7 cells.
authors.affiliation: Department of Physiology and Pharmacology, School of Medicine, University of Cantabria, Santander, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Cos
authors.forename: E J
authors.initials: EJ
authors.lastname: Sánchez-Barceló
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D002452:Cell Count; D002455:Cell Division / Q000187:drug effects*; D006801:Humans; D008550:Melatonin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D008550:Melatonin