The effects of TNF-alpha and inhibitors of arachidonic acid metabolism on human colon HT-29 cells depend on differentiation status.
The level of differentiation could influence sensitivity of colonic epithelial cells to various stimuli. In our study, the effects of TNF-alpha, inhibitors of arachidonic acid (AA) metabolism (baicalein, BA; indomethacin, INDO; niflumic acid, NA; nordihydroguaiaretic acid, NDGA), and/or their combinations on undifferentiated or sodium butyrate (NaBt)-differentiated human colon adenocarcinoma HT-29 cells were compared. NaBt-treated cells became growth arrested (blocked in G0/G1 phase of the cell cycle), and showed down-regulated Bcl-xL and up-regulated Bak proteins and increased expression of cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX). These cells were more perceptive to anti-proliferative and apoptotic effects of TNF-alpha. Both inhibitors of LOX (BA and NDGA) and COX (INDO and NA) in higher concentrations modulated cell cycle changes accompanying NaBt-induced differentiation and induced various level of cell death in undifferentiated and differentiated cells. Most important is our finding that TNF-alpha action on proliferation and cell death can be potentiated by co-treatment of cells with AA metabolism inhibitors, and that these effects were more significant in undifferentiated cells. TNF-alpha and INDO co-treatment was associated with accumulation of cells in G0/G1 cell cycle phase, increased reactive oxygen species production, and elevated caspase-3 activity. These results indicate the role of differentiation status in the sensitivity of HT-29 cells to the anti-proliferative and proapoptotic effects of TNF-alpha, AA metabolism inhibitors, and their combinations, and imply promising possibility for novel anti-cancer strategies.
Laboratory of Cytokinetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, CZ-612 65 Brno, Královopolská 135, Czech Republic.
Martina
M
Kovaríková
Jirina
J
Hofmanová
Karel
K
Soucek
Alois
A
Kozubík
D000230:Adenocarcinoma / Q000188:drug therapy / Q000473:pathology; D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism; D016718:Arachidonic Acid / Q000378:metabolism*; D002087:Butyrates / Q000494:pharmacology; D053148:Caspase 3; D020169:Caspases / Q000187:drug effects / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D004357:Drug Synergism; D044950:Flavanones; D005419:Flavonoids / Q000494:pharmacology; D019073:HT29 Cells / Q000187:drug effects; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology*; D009637:Masoprocol / Q000494:pharmacology; D008565:Membrane Proteins; D009544:Niflumic Acid / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D002087:Butyrates; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D044950:Flavanones; D005419:Flavonoids; D007527:Isoenzymes; D016859:Lipoxygenase Inhibitors; D008565:Membrane Proteins; D014409:Tumor Necrosis Factor-alpha; D016718:Arachidonic Acid; C006680:baicalein; D009544:Niflumic Acid; D009637:Masoprocol; D001094:Arachidonate 5-Lipoxygenase; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D007213:Indomethacin