Low-dose doxorubicin-induced necrosis in Jurkat cells and its acceleration and conversion to apoptosis by antioxidants.
We treated rapidly growing Jurkat cells with 40 nmol/l of doxorubicin for 72 h. After 36 h, the G2-arrested cells became larger and some of them started endoreplication. Nuclear staining with Hoechst 33342 combined with propidium iodide (PI) exclusion revealed that about 90% of the cells were necrotic at 72 h, although apoptotic cells accounted for only 8%. Incubation with 40 nmol/l of aclarubicin or cytosine beta-d-arabinofuranoside for 60 h induced necrosis both in Jurkat and ml-1 cells. Pre-necrotic Jurkat cells incubated with 40 nmol/l of doxorubicin had much higher intracellular reactive oxygen species (ROS) levels than pre-apoptotic ones. Addition of Tempol or Desferal accelerated doxorubicin-induced necrosis and partially converted it into apoptosis. Both antioxidants reduced surviving colony numbers of prenecrotic Jurkat cells. n-acetyl-l-cysteine had little effect on the apoptotic conversion but profoundly accelerated necrosis. Because an apoptosis-resistant Jurkat subclone was also refractory to doxorubicin-induced necrosis, apoptosis and necrosis might share some common pathways. Low-dose doxorubicin increased micronuclei-positive cell percentages and also suppressed high-dose doxorubicin-induced apoptosis in Jurkat and ml-1 cells. Some of the prenecrotic cells, therefore, might survive and obtain genomic instability. Antioxidants may be useful to suppress, at least to some extent, this vicious consequence.
Sugimoto
Koichi
K
Department of Haematology, Juntendo University School of Medicine, Tokyo, Japan. ksugimot@med.juntendo.ac.jp
Tamayose
Kenji
K
Sasaki
Makoto
M
Hayashi
Keiko
K
Oshimi
Kazuo
K
D000970:Antineoplastic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis; D003497:Cyclic N-Oxides / Q000494:pharmacology; D003676:Deferoxamine / Q000494:pharmacology; D004317:Doxorubicin / Q000494:pharmacology*; D005434:Flow Cytometry; D006801:Humans; D020287:In Situ Nick-End Labeling; D019169:Jurkat Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D008856:Microscopy, Fluorescence; D009336:Necrosis; D017382:Reactive Oxygen Species / Q000378:metabolism; D013113:Spin Labels
D000970:Antineoplastic Agents; D000975:Antioxidants; D003497:Cyclic N-Oxides; D017382:Reactive Oxygen Species; D013113:Spin Labels; D004317:Doxorubicin; D003676:Deferoxamine; C001803:tempol