Establishment and Characterization of a Simian Virus 40‐Immortalized Osteoblastic Cell Line from Normal Human Bone

We established a human osteoblastic cell line immortalized by simian virus 40 (SV40) in vitro, and designated it SV‐HFO. Immunocytochemically, the cells were positive for SV40 large T‐antigen, vimentin and osteocalcin, but negative for keratin and epithelial membrane antigen. The cells had characteristic morphologic and ultrastructural features of osteoblasts, produced alkaline phosphatase, and synthesized osteocalcin, the levels of which were elevated by treatment of the cells with 1α,25‐dihydroxyvitamin D(3). The cells proliferated and showed such osteoblastic properties even under serum‐free conditions. The cells grew in soft agar, but did not form tumors when transplanted into athymic nude mice. Karyotypic analysis by the Q‐banding technique showed that these cells were of human origin. The SV‐HFO cell line is expected to serve as a suitable model for studying metabolism and carcinogenesis in human bone.