title: Morphological and biological heterogeneity of three tumorigenic cell lines derived from a single p53-/- osteoblast-like cell line, MMC2.
abstract: Osteosarcoma is a malignant tumor with heterogeneous features both in histological and biological aspects. We have established three tumorigenic cell lines, MMOS1, MMOS2, and MMOS3, from three independent tumors that developed in nude mice after the inoculation of MMC2, an osteoblast-like cell line derived from p53-/- mice. Expression patterns of the osteoblast-related genes showed a marked difference between MMOS2 and the other two cell lines, and were correlated well with the features of the original tumors, ranging from an osteoblastic osteosarcoma (MMOS2) to tumors with scarce or no osteoid formation (MMOS1 and MMOS3). The properties of malignant cells also varied in the three cell lines. MMOS1, which was the most serum-dependent in vitro, developed markedly larger tumors in vivo than the other two cell lines. MMOS3 showed the fastest growth in low-serum conditions and produced the largest number of colonies in soft agar, but did not develop lung metastases, whereas MMOS1 and MMOS2 developed lung metastases with a frequency of 30 and 50%. These data suggest that the biological activities in vivo do not necessarily reflect those in vitro. Because the three tumorigenic cell lines share MMC2 as a common precursor, our data showed an example that the heterogeneity of osteosarcoma was created by genetic alterations that took place during the transformation process of each tumor.
authors.affiliation: Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Murakami
authors.forename: Tomitaka
authors.initials: T
authors.lastname: Nakayama
authors.forename: Koichi
authors.initials: K
authors.lastname: Nishijo
authors.forename: Taisuke
authors.initials: T
authors.lastname: Hosaka
authors.forename: Takeharu
authors.initials: T
authors.lastname: Nakamata
authors.forename: Tomoki
authors.initials: T
authors.lastname: Aoyama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Okamoto
authors.forename: Tadao
authors.initials: T
authors.lastname: Tsuboyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Junya
authors.initials: J
authors.lastname: Toguchida
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001859:Bone Neoplasms; D002455:Cell Division; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured; D004195:Disease Models, Animal; D007700:Kinetics; D008175:Lung Neoplasms / Q000473:pathology / Q000556:secondary; D051379:Mice; D018345:Mice, Knockout; D010006:Osteoblasts / Q000166:cytology* / Q000473:pathology; D012516:Osteosarcoma / Q000235:genetics / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000172:deficiency / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D000469:Alkaline Phosphatase