OBJECTIVE: In order to illustrate the possible roles of PML-RARalpha protein in arsenic trioxide (AsO3)-induced NB4 cell apoptosis. METHODS: Effects of As2O3 on the subcellular localization of PML-RARalpha in NB4 cells were studied. RESULTS: (1) Anti-PML serum staining was reduced and PML granules emerged in the perinuclear cytoplasm in a diffuse pattern in HL-60 cells under As2O3 treatment; (2) abnormal PML/PML-RARalpha granules were decreased; (3) NB4 cells accumulated anti-PML serum staining granules in the cytoplasms were increased and similar accumulation also found in apoptotic cells; and (4) pretreatment with all-trans retinoic acid (ATRA) for 24 or 48 hours did not alter the As2O3 effects. CONCLUSION: As2O3-induced apoptosis was independent of the retinoic acid signal pathway, and it might be regulated by PML/PML-RARalpha and/or other related genes.
OBJECTIVE: In order to illustrate the possible roles of PML-RARalpha protein in arsenic trioxide (AsO3)-induced NB4 cell apoptosis. METHODS: Effects of As2O3 on the subcellular localization of PML-RARalpha in NB4 cells were studied. RESULTS: (1) Anti-PML serum staining was reduced and PML granules emerged in the perinuclear cytoplasm in a diffuse pattern in HL-60 cells under As2O3 treatment; (2) abnormal PML/PML-RARalpha granules were decreased; (3) NB4 cells accumulated anti-PML serum staining granules in the cytoplasms were increased and similar accumulation also found in apoptotic cells; and (4) pretreatment with all-trans retinoic acid (ATRA) for 24 or 48 hours did not alter the As2O3 effects. CONCLUSION:As2O3-induced apoptosis was independent of the retinoic acid signal pathway, and it might be regulated by PML/PML-RARalpha and/or other related genes.