The Effects Of Arsenic Trioxide Nanopaticles On NB4Cells Of PTEN Protein And The Mitochondrial Apoptotic Pathway

We Prepare arsenic trioxide (As2O3) nanopaticles with sol-gel method.MTT assay wasused to analyze the role of the proliferative inhibition between As2O3nanoparticles andtraditional As2O3solution on NB4cells. Hoechst and PI staining were used to analyzemorphologic changes of NB4cells treated with As2O3nano-particles and As2O3solution,the perentage of apoptosis was detected by flow cytometry. Rhodamine123staining wasused to detect the mitochondrial membrane potentia of NB4cells treated with twoformulations.Observing the effection of p-PTEN,p-AKT,Bax,caspase-3,caspase-9and AIFof NB4cells after using As2O3nanoparticles and As2O3solution by Western blot, topreliminary discuss the mechanisms of As2O3nanoparticles on NB4cells.The inhibition of cell proliferation experiments showed As2O3nanopaticles and arsenictrioxide were both able to inhibit the growth of NB4cells. The inhibition rate increased withthe adding of concentration and time. And the growth inhibition rate of cells treated byAs2O3nanopaticles was significantly higher than that of arsenic trioxide with the sameconcentration and incubation time. The cells apoptosis experimental result showed thatAs2O3nanopaticles and arsenic trioxide mainly led to NB4cells apoptosis,the apoptosis rateof cells treated by As2O3nanopaticles was significantly higher than that of arsenic trioxidewith the same incubation time,and showed dose-response relationship.Rhodamine123staining experiments showed that two formulations can reduce the mitochondrial membranepotential of NB4cells in a dose-dependent manner;the effect of cells treated by As2O3nanopaticles was significantly higher than that of arsenic trioxide with the same incubationtime.Western blot result showed that1.5μmol/L,3μmol/L As2O3nanopaticles can lower theexpression of p-AKT and PTEN compared with As2O3; with the same concentration, As2O3nanopaticles can increase the expression of p-PTEN and Bax compared with As2O3;Theexpression of caspase-3and caspase-9in the group of As2O3were in a dose-dependentmanner,and the expression of both in the group of1.5μmol/L As2O3nanoparticles werehigher than As2O3,but lower in the group of3.0μmol/L As2O3nanoparticles compared with3.0μmol/L As2O3.Then AIF was studied,the result showed that the expression of AIF washigher in the group of3.0μmol/L As2O3nanoparticles.In conclusion,As2O3and the lowconcentration of As2O3nanoparticles mainly started caspase-dependent mitochondrial pathway to induce apoptosis,while the high concentration of As2O3nanoparticles mainlystarted caspase-independent mitochondrial pathway to induce apoptosis.So according to the experimental results we get the following conclusion that:⑴The inhibition on NB4cells of As2O3nanopaticles and arsenic trioxide are inconcentration and time dependent manner,and the effect of As2O3nanopaticles is moresignificant.⑵As2O3nanoparticles and arsenic trioxide both can inhibit proliferation of NB4cells,and the effect are in concentration-dependent. The inhibition effect of As2O3nanoparticles is obviously stronger than that of arsenic trioxide.⑶The mechanism of As2O3nanoparticles to induce apoptosis on NB4cells are strongerthan As2O3might related with upregulating the expression of p-PTEN,inhibiting theactivation of AKT and starting the mitochondrial apoptotic pathway.