title: Drug resistance modification using pulsing electromagnetic field stimulation for multidrug resistant mouse osteosarcoma cell line.
abstract: Multidrug resistance (MDR) is one of the major problems in osteosarcoma chemotherapy. Therefore, methods of overcoming MDR are urgently needed. In this study, we investigated the effects of pulsing electromagnetic field stimulation (PEMFs) on a MDR murine osteosarcoma cell line which strongly expresses P-glycoprotein (P-gp). To assess the reversal effects of PEMFs on doxorubicin (DOX) resistance, MTT assay was applied. Viable cells were assessed by the trypan blue exclusion test. Fluorescence intensity of DOX binding to nuclear DNA of each cell was measured using a cytofluorometer. Changes in P-gp expression in each cell were detected by the indirect immunofluorescence method using an antibody to Pgp. PEMFs increased DOX binding ability to nuclear DNA and inhibited cell growth, although it had no significant effect on P-gp expression. These findings indicated that PEMFs reversed the DOX resistance of the MOS/ADR1 cells by inhibiting P-gp function. The results suggested that PEMFs may be useful as a local treatment for MDR osteosarcoma.
authors: Department of Orthopaedic Surgery, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, Japan.
authors: M
authors: M
authors: Hirata
authors: K
authors: K
authors: Kusuzaki
authors: H
authors: H
authors: Takeshita
authors: S
authors: S
authors: Hashiguchi
authors: Y
authors: Y
authors: Hirasawa
authors: T
authors: T
authors: Ashihara
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism / Q000627:therapeutic use*; D001859:Bone Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000628:therapy*; D002455:Cell Division / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D003131:Combined Modality Therapy; D004273:DNA, Neoplasm / Q000187:drug effects / Q000378:metabolism; D004317:Doxorubicin / Q000378:metabolism / Q000627:therapeutic use*; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D004574:Electromagnetic Fields; D051379:Mice; D008856:Microscopy, Fluorescence; D012516:Osteosarcoma / Q000188:drug therapy / Q000378:metabolism / Q000628:therapy*; D014407:Tumor Cells, Cultured
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D004273:DNA, Neoplasm; D004317:Doxorubicin