A murine osteosarcoma cell line with a potential to develop ossification upon transplantation.
An osteosarcoma cell line has been established from a soft tissue tumor that occurred spontaneously in a BALB / c mouse. This cell line showed ossification when transplanted into syngeneic mice. To examine the mechanism of bone formation, the expression of mRNAs for osteoblastic and chondroblastic markers and factors associated with ossification has been investigated. In culture, the cells exhibited a spindle shape in the growth phase, but had a polygonal shape in the stationary phase. Reverse transcription-polymerase chain reaction analysis showed that the cells expressed mRNAs for pro-alpha1(I) chain of type I collagen, alkaline phosphatase, osteopontin, osteocalcin, and core binding factor alpha1, suggesting differentiation into the stage of osteoblasts during the stationary phase. After transplantation, histological examination revealed small foci of pale blue material and basophilic networks that were scattered in the tumor tissues at one week. The former stained positive with alcian blue, suggesting a chondroid matrix. Pro-alpha1(II) chain of type II collagen mRNA was expressed at one week. A large part of tumors at two and three weeks consisted of basophilic networks, which stained positive via von Kossa's method, indicating a calcified woven bone. In situ hybridization analysis showed strong expression of osteopontin and osteocalcin mRNAs in tumor cells surrounding the bone matrix. Bone morphogenetic protein-6 and -7 mRNAs were detected in transplanted tumors, but not in cultured cells. These results suggest that the cell line has the properties of an osteoblastic lineage when cultured in vitro and has an ossifying ability through endochondral bone formation processes when transplanted in vivo.
Kusumi
T
T
Second Department of Pathology, Hirosaki University School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan. kusumito@cc.hirosaki-u.ac.jp
Nishi
T
T
Tanaka
M
M
Tsuchida
S
S
Kudo
H
H
D000469:Alkaline Phosphatase / Q000096:biosynthesis; D000818:Animals; D001846:Bone Development / Q000502:physiology; D018929:Cell Culture Techniques / Q000379:methods; D050657:Core Binding Factor alpha Subunits; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D005121:Extremities / Q000000981:diagnostic imaging; D005260:Female; D017403:In Situ Hybridization; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D015675:Osteocalcin / Q000096:biosynthesis; D053495:Osteopontin; D012516:Osteosarcoma / Q000473:pathology*; D011347:Procollagen / Q000096:biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D011859:Radiography; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins / Q000096:biosynthesis; D012983:Soft Tissue Neoplasms / Q000473:pathology; D013997:Time Factors; D014157:Transcription Factors / Q000096:biosynthesis; D014180:Transplantation; D014407:Tumor Cells, Cultured
D050657:Core Binding Factor alpha Subunits; D004268:DNA-Binding Proteins; D011347:Procollagen; D012333:RNA, Messenger; D012795:Sialoglycoproteins; C506896:Spp1 protein, mouse; D014157:Transcription Factors; C406688:core binding factor alpha; D015675:Osteocalcin; D053495:Osteopontin; D000469:Alkaline Phosphatase