2-NDC from dithiocarbamates improves ATRA efficiency and ROS-induced apoptosis via downregulation of Bcl2 and Survivin in human acute promyelocytic NB4 cells

Although it has been widely considered that all-trans retinoic acid (ATRA) is an efficient therapeutic agent for acute promyelocytic leukemia (APL), there is an urgent need for extending and examining new therapeutics in medicine. Dithiocarbamates (DTCs) are one of the recent important chemical synthetic compounds used in cancer therapy. The aim of this study was to evaluate the apoptosis-inducing effect of 2-nitro-1-phenylethylpiperidine-1-carbodithioate (2-NDC) as an active derivative from DTCs, in combination with ATRA on human APL NB4 cells. The viability of treated NB4 cells was measured by 3-(4,5-dimethyltiazol-2-yl)-2,5-diphenyltetrazolium bromide assay in various concentrations (10–120 µM). The proapoptotic effects of 2-NDC were investigated by acridine orange/ethidium bromide staining, DNA ladder formation, and flow cytometry. We also assessed the oxidative stress-inducing effect of 2-NDC and in combination with ATRA on the NB4 cells. The alteration in gene expression levels of Bax, Bcl2, and Survivin was measured through a real-time polymerase chain reaction. Furthermore, we redetected the interaction between 2-NDC and antiapoptotic proteins Bcl2 and Survivin via molecular docking. We found that 2-NDC induced apoptosis in NB4 cells in a time–dosage-dependent manner. Also, 2-NDC triggered apoptosis by expanding intracellular reactive oxygen species, combined with ATRA. Bax/Bcl2 ratio was modulated and Survivin was downregulated in NB4 cells upon 2-NDC treatment. Molecular docking studies indicated that 2-NDC binds to the baculovirus inhibitor of apoptosis protein repeat domain of Survivin and Bcl homology 3 domain of Bcl2 with various affinities. Based on the present observations, it seems that this derivative can be estimated as an appropriate candidate for future pharmaceutical evaluations.