[Change of PML/PML-RARalpha protein during treatment with tetraarsenic tetrasulfide (As4S4) in patients with acute promyelocytic leukemia].

In order to explored the change of PML/PML-RARalpha protein during tetraarsenic tetrasulfide (As4S4) treatment, acute promyelocytic leukemia (APL) cells from a group of newly diagnosed APL patients were examined by indirect immunofluorescence staining with anit-PML monoclonal antibody. The results showed that all samples typically presented many microspeckle signals throughout the nucleus before treatment. The redistribution occurred as early as on the second day after As4S4 treatment, which revealed loss of microspeckles with the presentation of a few large speckles. Anti-PML staining also emerged in the perinuclear cytoplasm. At last, microspeckles and large speckles all disappeared. When the therapy was combining all-trans-retinoic acid (ATRA) with As4S4, similar results were obtained. However, APL cells from patients treated with ATRA alone performed totally different appearance, presenting microspeckles and large speckles at the same time, followed with entirely large speckles. The conclusion is that As4S4 makes redistribution of PML/PML-RARalpha protein in leukemic cells from APL patients during the treatment, which is quite different from that during the treatment of ATRA.