Early cytoplasmic acidification in retinamide-mediated apoptosis of human promyelocytic leukemia cells.
The retinamide-mediated apoptosis of promyelocytic cells was investigated using pHi- and DNA-sensitive fluorescent probes (BCECF and Hoechst 33342). Acidification and apoptosis were observed during prolonged (0-12 h) exposure to retinamide (1 microM), but were absent in a retinamide-resistant clone. The analysis of experiments performed by simultaneous staining with the two dyes showed that acidification and apoptosis are correlated; the half-time for acidification is about 5 h while that for apoptosis is 80% longer. On the whole, these results suggest that apoptosis is preceded by an early mechanism of acidification in human leukemia cells treated by a retinoid of clinical interest in cancer chemo prevention and therapy.
Angoli
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D
Department of General Physiology and Biochemistry, University of Milano, Italy.
Delia
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D
Wanke
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E
D017209:Apoptosis / Q000187:drug effects*; D001562:Benzimidazoles; D002453:Cell Cycle; D003593:Cytoplasm / Q000737:chemistry*; D005452:Fluoresceins; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015473:Leukemia, Promyelocytic, Acute / Q000473:pathology*; D014212:Tretinoin / Q000031:analogs & derivatives* / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D001562:Benzimidazoles; D005452:Fluoresceins; D014212:Tretinoin; C043829:2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein; C054441:retinamide; C017807:bisbenzimide ethoxide trihydrochloride