Decitabine And Arsenic Trioxide On Proliferation And Apoptosis Of NB4 Cells And Its Effects On DAPK Gene In Rats

BackgroundIn recent years, by arsenious acid and retinoic acid induced differentiation, Acutepromyelocytic leukemia(APL) treatment has improved considerably,APL treatmentwith retinoic acid alone,near complete remission rate above 85%,but still relapse.Although the outlook remains optimistic about its treatment of recurrence is still,However, patients with recurrence had higher early mortality and shorter remission 2.Hematopoietic stem cell transplantation is the best way to treat hematologicmalignancies,However, many transplant-related complications during the transplant,need to further explore ways to reduce its related complications, and the high cost oftransplantation, most patients can not afford. Recent studies showed that the majorityof acute myeloid leukemia (AML) patients, there is more than 2 or 2 aberrantmethylation, Because DNA methylation is a reversible process of geneticmodification, it is cancer or precancerous lesions in the demethylation treatment by,you can restore gene expression, so as to achieve the purpose of cancerprevention,Thus, DNA methylation to go to provide new ideas for cancer treatment.DAPK gene is a tumor suppressor gene, is also a positive start apoptosis regulatoryfactors, can promote apoptosis, the promoter methylation of tumor blood system maybe a very important mechanism of gene expression. DAC is a demethylating agent, ondrug resistance and relapse of leukemia patients have a certain effect.Study, DAC inthe treatment of myelodysplastic syndrome (MDS) and some solid tumors has a goodeffect. We used different concentrations of DAC, As2O3 and the two drugcombination treatment NB4 cells by MTT method and flow cytometry to detectapoptosis, RT-PCR detected the expression of DAPKmRNA to coast for the clinicalapplication of DAC to provide the theoretical joint As2O3 BasisMethods1.Cells proliferation was analyzed by MTT assay2.Cell apoptosis rate was examined by floe cytometry(FCM);3.The expression of DAPKmRNA was detected by RT- PCR . Result1. MTT results showed that different concentrations of decitabine and As2O3 atdifferent time have a certain degree of inhibition to the NB4 cell.At the same timepoint decitabine and As2O3 on cell growth inhibition in a dose-dependent manner(P＜0.05),the same concentration of decitabine effect reached the peak at the 72h. In thisexperiment, select decitabine1.0and 2.0μmol/L As2O3 0.5 and 1.0μmol/Lconcentration to research.2. FCM analysis showed that the control group no significant apoptosis by 48htraining (Figure 3a).And the drug treatment group apoptosis can be seen,comparedwith the control group the tate of apoptosis was increased. At the 48h reach the peak5.0% (Figure 3b)after2.0μmol/L DAC achieves and 5.8%(Figure 3c) after 1.0μmol/LAs2O3 achieves,the combination group increased 17.3%(Figure 3d),than the singledrug group increased rate of apoptosis.3. RT-PCR test results showed, NB4 cells has a low expression or did notexperession of DAPKmRNA, and it maybe re-experssion after the role of the twodrugs. With the increase of drug concentration, its expression increased.ConclusiConclusion1. Decitabine on NB4 cell proliferation and induce apoptosis in adose-dependent;2. DAC Joint As2O3 on NB4 cell proliferation and a synergistic induction ofapoptosis3. DAC on NB4 cell proliferation and induced apoptosis, one possiblemechanism is to restore or increase the expression of DAPK gene...