Inhibitors of arachidonic acid metabolism potentiate tumour necrosis factor-alpha-induced apoptosis in HL-60 cells.
We investigated whether and how could various modulators of arachidonic acid metabolism affect apoptosis induced by tumour necrosis factor-alpha (TNF-alpha) in human myeloid leukaemia HL-60 cells. These included arachinonyltrifluoromethyl ketone (AACOCF3; cytosolic phospholipase A2 inhibitor), indomethacin (cyclooxygenase inhibitor), MK-886 (3-[1-(4-chlorobenzyl)-3-t-butyl-thio-5-isopropylindol-2-yl]-2,2-dimethyl propanoic acid; 5-lipoxygenase-activating protein inhibitor), nordihydroguaiaretic acid (general lipoxygenase inhibitor), and arachidonic acid itself. Incubation of HL-60 cells with nordihydroguaiaretic acid resulted in apoptosis and it was characterised by mitochondria membrane depolarisation, release of cytochrome c from mitochondria into cytosol and activation of caspase-3. Indomethacin and nordihydroguaiaretic acid synergistically potentiated TNF-alpha-induced apoptosis, while arachidonic acid, AACOCF3 and MK-886 did not modulate its effects. Furthermore, indomethacin potentiated apoptosis in cells treated with a differentiating agent, all-trans retinoic acid, which induces resistance to TNF-alpha. However, the observed effects were probably not associated either with the cyclooxygenase- or lipoxygenase-dependent activities of indomethacin and nordihydroguaiaretic acid, respectively. Since indomethacin may reportedly activate peroxisome proliferator-activated receptors (PPARs), the effects of specific ligands of PPARs on apoptosis were studied as well. It was found that selective PPARs ligands had no effects on TNF-alpha-induced apoptosis. The findings suggest that arachidonic acid metabolism does not play a key role in regulation of apoptosis induced by TNF-alpha in the present model. Nevertheless, our data raise the possibility that indomethacin could potentially be used to improve the treatment of human myeloid leukaemia.
Vondrácek
J
J
Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65, Brno, Czech Republic.
Stika
J
J
Soucek
K
K
Minksová
K
K
Bláha
L
L
Hofmanová
J
J
Kozubík
A
A
D017209:Apoptosis / Q000187:drug effects*; D016718:Arachidonic Acid / Q000037:antagonists & inhibitors* / Q000378:metabolism; D053148:Caspase 3; D020169:Caspases / Q000187:drug effects / Q000378:metabolism; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D003574:Cytochrome c Group / Q000187:drug effects / Q000378:metabolism; D003600:Cytosol / Q000187:drug effects / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D018922:HL-60 Cells; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D007527:Isoenzymes / Q000187:drug effects / Q000378:metabolism; D009637:Masoprocol / Q000494:pharmacology; D008565:Membrane Proteins; D020025:Peroxisome Proliferators / Q000494:pharmacology; D010741:Phospholipases A / Q000187:drug effects / Q000378:metabolism; D054467:Phospholipases A2; D011451:Prostaglandin-Endoperoxide Synthases / Q000187:drug effects / Q000378:metabolism; D011743:Pyrimidines / Q000494:pharmacology; D018160:Receptors, Cytoplasmic and Nuclear / Q000187:drug effects / Q000378:metabolism; D013844:Thiazoles / Q000494:pharmacology; D045162:Thiazolidinediones; D014157:Transcription Factors / Q000187:drug effects / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D003574:Cytochrome c Group; D007527:Isoenzymes; D008565:Membrane Proteins; D020025:Peroxisome Proliferators; D011743:Pyrimidines; D018160:Receptors, Cytoplasmic and Nuclear; D013844:Thiazoles; D045162:Thiazolidinediones; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D016718:Arachidonic Acid; D014212:Tretinoin; D009637:Masoprocol; C006253:pirinixic acid; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D010741:Phospholipases A; D054467:Phospholipases A2; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; C039671:ciglitazone; D007213:Indomethacin