title: [Bufalin induces apoptosis in osteosarcoma U-2OS and U-2OS methotrexate 300-resistant cell lines in vitro].
abstract: OBJECTIVE
  To study the growth inhibition and apoptosis induction effects of bufalin on human osteosarcoma cell lines in vitro.
  
  
  METHODS
  U-2OS and U-2OS/methotrexate (MTX) 300-resistant cell lines were treated with bufalin. Cell viability was assessed by MTT assay. Cell-cycle status, apoptosis-inducing effects, and the expression of apoptosis-related proteins were evaluated by flow cytometry, fluorescent staining, DNA fragmentation assay, and Western blotting.
  
  
  RESULTS
  Bufalin inhibited cell growth in both U-2OS and U-2OS/MTX300 cells. The IC(50) values of bufalin for U-2OS and U-2OS/MTX300 cells were (8.49 ± 2.1) ng/ml and (10.19 ± 1.7) ng/ml, respectively. The induction of G(2)/M cell-cycle arrest was also seen in the bufalin-treated cells. The bufalin-induced apoptosis was confirmed by increased expression of tumor suppressor protein p53, bax and decreased expression of bcl-2.
  
  
  CONCLUSIONS
  Bufalin inhibits the growth of and induces apoptosis in both MTX-sensitive and MTX-resistant human osteosarcoma U-2OS cell lines. The apoptosis-inducing effect of bufalin is not influenced by the presence of high levels of DHFR.
authors.affiliation: Department of Orthopaedic Oncology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.forename: Jun-qiang
authors.initials: JQ
authors.lastname: Yin
authors.forename: Qiang
authors.initials: Q
authors.lastname: Jia
authors.forename: Jing-nan
authors.initials: JN
authors.lastname: Shen
authors.forename: Gang
authors.initials: G
authors.lastname: Huang
authors.forename: Xian-biao
authors.initials: XB
authors.lastname: Xie
authors.forename: Chang-ye
authors.initials: CY
authors.lastname: Zou
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001859:Bone Neoplasms / Q000378:metabolism / Q000473:pathology*; D002018:Bufanolides / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm; D006801:Humans; D008727:Methotrexate / Q000494:pharmacology; D012516:Osteosarcoma / Q000378:metabolism / Q000473:pathology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D013762:Tetrahydrofolate Dehydrogenase / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D002018:Bufanolides; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; D013762:Tetrahydrofolate Dehydrogenase; C022777:bufalin; D008727:Methotrexate