title: Effect of 25-hydroxyvitamin D3 and 1 α,25 dihydroxyvitamin D3 on differentiation and apoptosis of human osteosarcoma cell lines.
abstract: Osteosarcoma (OS) is a malignant bone tumor predominantly affecting children and adolescents. OS has a 60% survival rate with current treatments; hence, there is a need to identify novel adjuncts to chemotherapeutic regimens. In this pilot study, we investigated the dose-response to 1α,25-dihdroxyvitamin D(3) (1,α 25(OH)(2) D(3)) and 25-hydroxyvitamin D(3) (25(OH)D(3)) by human OS cell lines, SaOS-2, and 143B. We hypothesized that 1,α 25(OH)(2) D(3) and 25(OH)D(3) would stimulate differentiation and induce apoptosis in OS cells in a dose-dependent manner. Human OS cell lines, SaOS-2, and 143B, were treated with 1,α 25(OH)(2)D(3) or 25(OH)D(3) or an ethanol control, respectively, at concentrations ranging from 1 to 1,000 nM. Ki67 (a marker of cellular proliferation) immunocytochemistry revealed no significant changes in the expression of Ki-67 or MIB-1 in 1α,25(OH)(2)D(3) or 25(OH)D(3) treated SaOS-2 or 143B cells. Both control and 1α,25(OH)(2) D(3) treated SaOS-2 and 143B cells expressed vitamin D receptor (VDR). Markers of osteoblastic differentiation in 143B cells and SaOS-2 cells were induced by both 25(OH)D(3) and 1α,25(OH)(2) D, and evident by increases in alkaline phosphatase (ALP) activity, osteocalcin (OCN) mRNA expression, and mineralization of extra-cellular matrix (ECM) by alizarin red staining. An increasing trend in apoptosis in response to 25(OH)D(3), in both SaOS-2 and 143B cells was detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) staining. With 1α,25(OH)(2)D(3) treatment, apoptosis was evident at higher concentrations only. These preliminary findings suggest that OS cells express VDR and respond to 25(OH)D(3) and 1α,25(OH)(2)D(3) by undergoing differentiation and apoptosis.
authors: Department of Dietetics and Nutrition, University of Kansas Medical Center, Kansas City, Kansas, USA.
authors: Lindsey
authors: L
authors: Thompson
authors: Shanshan
authors: S
authors: Wang
authors: Ossama
authors: O
authors: Tawfik
authors: Kimberly
authors: K
authors: Templeton
authors: Jakica
authors: J
authors: Tancabelic
authors: David
authors: D
authors: Pinson
authors: H Clarke
authors: HC
authors: Anderson
authors: John
authors: J
authors: Keighley
authors: Rama
authors: R
authors: Garimella
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D002112:Calcifediol / Q000494:pharmacology / Q000627:therapeutic use*; D002117:Calcitriol / Q000494:pharmacology / Q000627:therapeutic use*; D002453:Cell Cycle / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D015675:Osteocalcin / Q000378:metabolism; D012516:Osteosarcoma / Q000188:drug therapy* / Q000378:metabolism; D010865:Pilot Projects; D012333:RNA, Messenger / Q000378:metabolism; D018167:Receptors, Calcitriol / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000378:metabolism; D013778:Tetrazolium Salts; D013844:Thiazoles; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D050071:Bone Density Conservation Agents; D019394:Ki-67 Antigen; D012333:RNA, Messenger; D018167:Receptors, Calcitriol; D016160:Retinoblastoma Protein; D013778:Tetrazolium Salts; D013844:Thiazoles; D016159:Tumor Suppressor Protein p53; D015675:Osteocalcin; C070380:3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium; D000469:Alkaline Phosphatase; D002117:Calcitriol; D002112:Calcifediol