title: Synergistic effect of vitamin D derivatives and retinoids on C2C12 skeletal muscle cells.
abstract: The response of C2C12 myoblasts to 1 nM 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], two vitamin D analogues (KH 1060 and EB 1089, which are 20-epi-22-oxa and 22,24-diene-analogues, respectively), 100 nM retinoids (9-cis retinoic acid, all-trans retinoic acid) and to combination treatments, after 72 h incubation, was studied. The incubation with 1,25(OH)2D3 was ineffective on either cell proliferation or [3H]thymidine incorporation (expressed as DPM per cell) or protein content per cell. On the contrary, all the other treatments inhibited cell proliferation, this inhibition being synergistic when the vitamin D derivatives were combined with 9-cis or all-trans retinoic acid, and increased [3H]thymidine incorporation and protein content per cell. The levels of the VDR protein remarkably increased in comparison with control cells, except for the incubation with 9-cis retinoic acid. This increase was particularly accentuated in C2C12 cells treated with KH 1060 and 9-cis retinoic acid in combination. These results, taken together, suggest a role for vitamin D derivatives and retinoids on C2C12 cells.
authors.affiliation: Department of Biochemical Sciences, University of Florence, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Stio
authors.forename: Alessandra
authors.initials: A
authors.lastname: Celli
authors.forename: Cristina
authors.initials: C
authors.lastname: Treves
mesh_terms: D000077556:Alitretinoin; D000818:Animals; D001692:Biological Transport; D002117:Calcitriol / Q000031:analogs & derivatives* / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004357:Drug Synergism; D007700:Kinetics; D051379:Mice; D018482:Muscle, Skeletal / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D012176:Retinoids / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D014212:Tretinoin / Q000494:pharmacology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology*
chemical_list: D012176:Retinoids; C074279:KH 1060; D014807:Vitamin D; D000077556:Alitretinoin; D014212:Tretinoin; D002117:Calcitriol; C078903:seocalcitol