title: 1,25-dihydroxyvitamin D3 and retonic acid analogues induce differentiation in breast cancer cells with function- and cell-specific additive effects.
abstract: Vitamin D3 derivatives and retinoids can induce cell cycle arrest, differentiation and cell death in many cell lines. These compounds can act cooperatively in some of their functions and may be of potential use either individually or in combination in the treatment of breast cancer. The effects of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), all-trans retinoic acid (ATRA) and several analogues were evaluated on malignant phenotypic traits of breast cancer cell lines MCF-7, T-47D and MDA-MB-231. Both 1,25(OH)2D3 and ATRA caused a decrease in anchorage independent colony formation in MCF-7 and T-47D cells in a dose-dependent manner. The effects of 1,25(OH)2D3 10(-10) and 10(-9) M were synergistic with ATRA 10(-8) M in T-47D cells but were antagonistic in both MCF-7 and in T-47D cells at most concentrations. Both 1,25(OH)2D3 and ATRA individually induced an accumulation of MCF-7 cells in the G1 phase of the cell cycle and an associated increase in p21WAFI/CiP1, p27KiP1 and a dephosphorylation of Rb but the effects were not additive. Both compounds inhibited the invasive capacity of MDA-MB-231 cells. 1,25(OH)2D3 but not ATRA caused an increase in E-cadherin levels in MDA-MB-231 cells. These two functions were not additive. The compounds 1,25(OH)2D3, a noncalcemic analogue 1,25(OH)2-16-ene-23-yne-D3, ATRA, AGN195183, an RARalpha-specific agonist, and AGN190168 (tazarotene), an RARbeta/gamma-selective agonist, induced differentiation as determined by measurements of lipid droplet formation. The individual effects of 1,25(OH)2-16-ene-23-yne-D3 combined with ATRA or with tazarotene at 10(-9) M each were additive in MCF-7 and MDA-MB-231 cells on lipid formation. The data demonstrate that both 1,25(OH)2D3, ATRA, and selected analogues induce a more differentiated phenotype in breast cancer cells with additive effects that are function- and cell-specific.
authors.affiliation: Department of Medicine, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark 07103, USA.
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.forename: D
authors.initials: D
authors.lastname: Lee
authors.forename: V
authors.initials: V
authors.lastname: Sysounthone
authors.lastname: Chandraratna RAS
authors.forename: S
authors.initials: S
authors.lastname: Christakos
authors.forename: R
authors.initials: R
authors.lastname: Korah
authors.forename: R
authors.initials: R
authors.lastname: Wieder
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000473:pathology*; D002117:Calcitriol / Q000494:pharmacology*; D002120:Calcium Channel Agonists / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D010641:Phenotype; D014212:Tretinoin / Q000031:analogs & derivatives / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D002120:Calcium Channel Agonists; D014212:Tretinoin; D002117:Calcitriol