Establishment of an osteogenic cell line derived from adult mouse bone marrow stroma by use of a recombinant retrovirus.
In order to characterize fibroblastic colony-forming units (CFU-F) from murine bone marrow in relation to osteogenesis, adherent cells of 7-day-old BALB/c mouse bone marrow cultures were infected with a recombinant retrovirus (N2/ delta fosB) containing the bacterial neomycin resistance gene. One of the G418-resistant clones, MN7, was selected for further analysis on the basis of its high expression of the bone-specific alkaline phosphatase. The cells have now been in culture for more than 1 year and maintain a stable phenotype. The osteogenic nature of the immortalized clone MN7 was demonstrated as follows: (1) Mineralization was detected by 85Sr uptake and with the Von Kossa staining method only after in vitro cultivation on a collagen type I matrix. (2) Osteoblastic phenotype markers, including the synthesis of type I collagen, osteonectin, and the bone-specific isoenzyme of alkaline phosphatase were expressed in vitro. (3) MN7 cells responded to bone effectors such as parathyroid hormone and 1,25-dihydroxyvitamin D3. (4) Intraperitoneal injection of MN7 cells into 1-day-old BALB/c mice produced typical osteosarcomas in all animals. We conclude that MN7, derived entirely in vitro from a stromal CFU-F colony, represents a stable murine osteosarcoma cell line expressing the osteoblastic phenotype and provides the first direct evidence needed to establish adult mouse marrow-derived, nonhematopoietic stromal cells as osteoprogenitors.
Mathieu
E
E
University of Antwerp, UIA, Department of Biochemistry, Belgium.
Schoeters
G
G
vander Plaetse
F
F
Merregaert
J
J
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001854:Bone Marrow Cells; D002113:Calcification, Physiologic; D002460:Cell Line; D003094:Collagen / Q000378:metabolism; D004274:DNA, Recombinant; D051379:Mice; D008807:Mice, Inbred BALB C; D010012:Osteogenesis; D015676:Osteonectin / Q000378:metabolism; D012516:Osteosarcoma / Q000000981:diagnostic imaging / Q000378:metabolism; D011859:Radiography; D012190:Retroviridae; D014162:Transfection
D004274:DNA, Recombinant; D015676:Osteonectin; D003094:Collagen; D000469:Alkaline Phosphatase