Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/38086
標題: Ornithine decarboxylase prevents methotrexate-induced apoptosis by reducing intracellular reactive oxygen species production
作者: Huang, C.C.
洪慧芝
Hsu, P.C.
Hung, Y.C.
Liao, Y.F.
Liu, C.C.
Hour, C.T.
Kao, M.C.
Tsay, G.J.
Hung, H.C.
Liu, G.Y.
關鍵字: apoptosis
caspase
methotrexate
ODC
ROS
apo-1/fas receptor/ligand system
drug-induced apoptosis
cell-death
chemotherapeutic drugs
hydrogen-peroxide
oxidative stress
t-lymphocytes
nih3t3 cells
bcl-2
leukemia
期刊/報告no:: Apoptosis, Volume 10, Issue 4, Page(s) 895-907.
摘要: Methotrexate (MTX), a folate antagonist, was developed for the treatment of malignancies, and is currently used in rheumatoid arthritis (RA) and other chronic inflammatory disorders. It has been proven in short-term and long-term prospective studies that low doses of MTX (0.75 mg/Kg/week) are effective in controlling the inflammatory manifestations of RA. Low-concentrations of MTX achieve apoptosis and clonal deletion of activated peripheral T cells. One of the mechanisms of the anti-inflammatory and immunosuppressive effects may be the production of reactive oxygen species (ROS). However, the drug resistance of MTX in malignancies remains poorly understood. Ornithine decarboxylase (ODC) plays an important role in diverse biological functions, including cell development, differentiation, transformation, growth and apoptosis. In our previous studies, ODC overexpression was shown to prevent TNF alpha-induced apoptosis via reducing ROS. Here, we also investigated one mechanism of MTX-induced apoptosis and of drug resistance as to the anti-apoptotic effects of ODC during MTX treatment. We found MTX could induce caspase-dependent apoptosis and promote ROS generation together with disrupting the mitochondrial membrane potential (Delta Psi(m)) of HL-60 and Jurkat T cells. Putrescine and ROS scavengers could reduce MTX-induced apoptosis, which leads to the loss of Delta Psi(m), through reducing intracellular ROS. Overexpression of ODC in parental cells had the same effects as putrescine and the ROS scavengers. Moreover, ODC overexpression prevented the decline of Bcl-2 that maintains Delta Psi(m), the cytochrome c release and activations of caspase 9 and 3 following MTX treatment. The results demonstrate that MTX-induced apoptosis is ROS-dependent and occurs along a mitochondria-mediated pathway. Overexpressed ODC cells are resistant to MTX-induced apoptosis by reducing intracellular ROS production.
URI: http://hdl.handle.net/11455/38086
ISSN: 1360-8185
文章連結: http://dx.doi.org/10.1007/s10495-005-2947-z
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