title: Effects of pamidronate on human alveolar osteoblasts in vitro.
abstract: OBJECTIVE
  Administration of bisphosphonates has recently been associated with the development of osteonecrotic lesions of the jaw (ONJ). To elucidate the potential contributions of osteogenic cells to the development and regeneration of ONJ, we have isolated primary cells from human alveolar and long/iliac bones, and examined the effects of pamidronate on cell viability, proliferation, osteogenesis, and wound healing.
  
  
  METHODS
  Primary human osteoblasts and bone marrow stromal cells were isolated from alveolar and iliac/long bone and marrow tissue. Cellular proliferation, alkaline phosphatase activity, apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling, caspase-3, and 4,6-diamidino-2-phenylindole dihydrochloride assays) and wound healing in an in vitro scratch assay were assessed after exposure to pamidronate at a range of clinically relevant doses.
  
  
  RESULTS
  Primary alveolar osteoblasts proliferated at significantly higher rates than long/iliac bone osteoblasts in vitro. Upon exposure of alveolar osteoblasts and long/iliac bone marrow stromal cells to pamidronate for more than 72 hours, we have observed significantly decreased cell viability, proliferation, osteogenesis, and in vitro wound healing at ≥6 × 10(-5) mol/L pamidronate, with the induction of apoptosis in approximately 20% of cell population.
  
  
  CONCLUSIONS
  The remodeling activity of alveolar bone, indicated by higher proliferation of alveolar osteoblasts, could be negatively affected by exposure to high concentrations of pamidronate over extended periods. The absence of anabolic effects of pamidronate on alveolar osteoblasts and the induction of apoptosis in osteogenic cells could negatively affect bone balance at this site and contribute to osteonecrosis of the jaw.
authors.affiliation: Department of Biomedical Engineering, Columbia University, New York, NY 10032, USA. dm2453@columbia.edu
authors.forename: Darja
authors.initials: D
authors.lastname: Marolt
authors.forename: Matthew
authors.initials: M
authors.lastname: Cozin
authors.forename: Gordana
authors.initials: G
authors.lastname: Vunjak-Novakovic
authors.forename: Serge
authors.initials: S
authors.lastname: Cremers
authors.forename: Regina
authors.initials: R
authors.lastname: Landesberg
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis / Q000187:drug effects; D000539:Alveolar Process / Q000166:cytology / Q000187:drug effects*; D017209:Apoptosis / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001854:Bone Marrow Cells / Q000187:drug effects; D016723:Bone Remodeling / Q000187:drug effects; D053148:Caspase 3 / Q000032:analysis; D018929:Cell Culture Techniques; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004164:Diphosphonates / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005456:Fluorescent Dyes; D006801:Humans; D020287:In Situ Nick-End Labeling; D007211:Indoles; D010006:Osteoblasts / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects; D000077268:Pamidronate; D017154:Stromal Cells / Q000187:drug effects; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D005456:Fluorescent Dyes; D007211:Indoles; C007293:DAPI; D000469:Alkaline Phosphatase; D053148:Caspase 3; D000077268:Pamidronate