title: Establishment of new multidrug-resistant human osteosarcoma cell lines.
abstract: Multidrug-resistant clones of human osteosarcoma MNNG/HOS and MG63 cells were isolated by stepwise selection on exposure to increasing doses of doxorubicin (DXR). The final clones MNNG/HOS/DXR1000 and MG63/DXR1000, established after ethylmethane sulfonate mutagenesis, showed 96-fold and 121-fold higer resistance to DXR than their parental cell lines. They were also cross-resistant to vincristine, but not to cisplatinum or methotrexate. The levels of multidrug-resistance-1 (MDR1) mRNA expression increased gradually according to the concentration of DXR in both cell lines. Although the parental MNNG/HOS cells expressed a low level of MDR1 mRNA, the parental MG63 cells showed no MDR1 expression. The IC50 values of MNNG/HOS and its resistant variant to DXR were higher than those of MG63 and its resistant clone. Multidrug-resistant associated protein (MRP) mRNA expression was detected in MNNG/HOS or MG63 parental cell lines, and in their resistant variants. MG63 and its resistant variants revealed stable expression of MRP, whereas the resistant phenotype of MNNG/HOS showed decreased MRP expression, compared to its parental cell line. No alteration in the levels of hepatocyte growth factor (HGF) or its receptor c-MET was recognized between parental lines and their resistant variants. The results indicate that our DXR-resistant variants of MNNG/HOS and MG63 reveal a classical MDR phenotype and can offer a model with which to investigate the mechanisms of multidrug resistance in osteosarcoma.
authors.affiliation: Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Oda
authors.forename: Y
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: K
authors.initials: K
authors.lastname: Harimaya
authors.forename: Y
authors.initials: Y
authors.lastname: Iwamoto
authors.forename: M
authors.initials: M
authors.lastname: Tsuneyoshi
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D000970:Antineoplastic Agents / Q000633:toxicity*; D001859:Bone Neoplasms / Q000235:genetics / Q000473:pathology*; D018929:Cell Culture Techniques / Q000379:methods; D002470:Cell Survival / Q000187:drug effects; D004317:Doxorubicin / Q000633:toxicity; D018432:Drug Resistance, Multiple; D006801:Humans; D008727:Methotrexate / Q000633:toxicity; D008769:Methylnitronitrosoguanidine / Q000633:toxicity; D012516:Osteosarcoma / Q000235:genetics / Q000473:pathology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D014750:Vincristine / Q000633:toxicity
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D012333:RNA, Messenger; D008769:Methylnitronitrosoguanidine; D014750:Vincristine; D004317:Doxorubicin; D008727:Methotrexate