Apoptosis of human leukemic HL-60 cells induced to differentiate by phorbol ester treatment.
In the human leukemic HL-60 cell line, we have reported previously that monocytic/macrophage-like differentiation induced by TPA (12-O-tetradecanoylphorbol-13-acetate) was associated with a decreased sensitivity to various apoptosis-inducing stimuli (Solary, Bertrand, Pommier, Blood 1993; 81:1359-1368). In the present study, we studied further the effects of TPA alone on the induction of apoptosis in HL-60 cells. Based on morphology by electron microscopy, identification of internucleosomal DNA cleavage by gel electrophoresis and quantitation of DNA fragmentation by a filter binding assay, we observed that neither morphologic changes nor DNA damage were identified in TPA-differentiated HL-60 cells as long as they kept the adherent phenotype characteristic of this differentiation pathway. However, adherent TPA-treated HL-60 cells that secondarily detached from the flask demonstrated internucleosomal DNA fragmentation associated with morphologic changes characteristic of apoptosis. Similarly, HL-60 cells that never became adherent after TPA treatment underwent rapid apoptosis. Granulocytic differentiation by retinoic acid (RA) treatment also induced apoptosis although more slowly. Interestingly, in both TPA- and RA-treated cells, apoptotic bodies appeared to be phagocytosed by differentiated cells from the same lineage. Internucleosomal DNA fragmentation was also identified in HL-60 cells induced to differentiate by sodium butyrate and dimethylsulfoxide treatment, suggesting that apoptosis could be the common mode of death of terminally differentiated HL-60 cells.
Solary
E
E
Laboratory of Molecular Pharmacology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
Bertrand
R
R
Pommier
Y
Y
D017209:Apoptosis / Q000187:drug effects*; D002448:Cell Adhesion; D002454:Cell Differentiation / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects; D004273:DNA, Neoplasm / Q000187:drug effects / Q000378:metabolism; D006098:Granulocytes / Q000473:pathology; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000473:pathology*; D008264:Macrophages / Q000473:pathology; D008854:Microscopy, Electron; D009000:Monocytes / Q000473:pathology; D009707:Nucleosomes / Q000378:metabolism; D010587:Phagocytosis; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014212:Tretinoin / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure
D004273:DNA, Neoplasm; D009707:Nucleosomes; D014212:Tretinoin; D013755:Tetradecanoylphorbol Acetate