Osteoinduction Using Recombinant Bone Morphogenetic Protein-7 Gene

Purpose: The aim of this study was to develop recombinant human Bone Morphogenetic Protein-7 (BMP7)-stable cells and recombinant human BMP7 adenoviruses (AdBMP7) for osteoinduction and osteoregeneration in musculoskeletal diseases. Materials and Methods: The human BMP7 cDNA was amplified from a human osteosarcoma cell line, U2OS using a reverse transcription-polymerase chain reaction and cloned into a eukaryotic expression vector. The BMP7-stable HEK293 cells (HEK293/BMP7) were prepared by transfecting the recombinant BMP7 plasmid vector. The recombinant human BMP7 adenovirus (AdBMP7) was constructed using the AdEasy vector system. The BMP7 expression levels in HEK293/BMP7 and AdBMP7 were measured by activity staining for alkaline phosphatase in mouse C2C12 promyoblast cells. The BMP7-stable HEK293 cells, AdBMP7 itself, or AdBMP7-transduced human fibroblasts were injected into the subcutaneous tissues and the calf muscles of immunocompromised mice. The amount of ectopic bone formation was evaluated by radiographic and histological analyses. Results: Ectopic bone formation was observed after injecting the BMP7-stable HEK293 cells with either the AdBMP7 itself or AdBMP7-transduced human fibroblasts into the subcutaneous tissues and calf muscles of immunocompromised mice. Conclusion: These results showed that HEK293/BMP7 cells and AdBMP7 have a significant potential for bone formation and the regeneration of various bone diseases.