Therapeutic effect of folic acid combined with decitabine on diabetic mice

AIM:To evaluate the therapeutic effect of folic acid combined with decitabine on diabetic mice.METHODS:The diabetic model of db/db mice were randomly divided into model group,folic acid group,decitabine group,folic acid combined with decitabine group,and C57 mice as normal control group.The density of retinal blood vessels and retinal thickness were detected by fundus photography and optical coherence tomography,respectively.Pathological changes of retina were observed by hematoxylin-eosin(HE)staining.The homocysteine(Hcy)in serum was detected by enzyme linked immunosorbent assay(ELISA).TdT-mediated dUTP nick-end labeling(TUNEL)was used to detect apoptosis in retinal tissue.Evans blue dye was used to detect the permeability of retinal blood vessels.The platelet endothelial cell adhesion molecule-1(CD31)and vascular endothelial growth factor receptor(VEGFR)protein were detected by Western blot.The 3-nitrotyrosine(3-NT)and 4-hydroxynonanine(4-HNE)were detected by immunohistochemistry.RESULTS:The density of retinal blood vessels,retinal thickness,retinal vascular permeability and the proportion of apoptotic cells of retinal tissue in the model group increased significantly than control group(P<0.05).The Hcy in serum and the levels of CD31,VEGFR,3-NT,and 4-HNE in retinal tissue increased significantly in the model group(P<0.01).Folic acid and decitabine both reversed these changes significantly,and the combination of the folic acid and decitabine worked best.CONCLUSION:The combination of folic acid and decitabine has a more significant protective effect on the retina in diabetic mice.

Acute myelomonocytic leukemia and T-lymphoblastic lymphoma as simultaneous bilineage hematologic malignancy treated with decitabine:A case report

BACKGROUND Simultaneous bilineage hematologic malignancies are rare;however,several cases of acute myeloid leukemia(AML)and T-lymphoblastic lymphoma(T-LBL)cooccurrence have been reported.A standard treatment for simultaneous AML and T-LBL has not yet been established,and its prognosis is very poor.Further studies to develop standard treatments are required to increase patient survival rates.CASE SUMMARY A 69-year-old man complaining of pleuritic chest pain visited the emergency room.Computed tomography revealed multiple enlarged lymph nodes(LNs)in the neck and groin and pulmonary thromboembolism with pulmonary infarction.Furthermore,a peripheral blood smear performed due to leukocytosis revealed circulating blasts.Acute myelomonocytic leukemia(AMML)was diagnosed after bone marrow examination,and T-LBL positivity for terminal deoxynucleotidyl transferase,cluster of differentiation(CD)34,and CD4 was confirmed by cervical LN biopsy.Decitabine and dexamethasone were administered because he could not receive intensive chemotherapy due to poor performance status.Complete remission of AMML and T-LBL was achieved after 4 cycles of decitabine plus dexamethasone.CONCLUSION We report the therapeutic effect of decitabine,a hypomethylating agent(HMA),in patients with concurrent bilineage hematologic malignancies and suggest that further studies are required to evaluate the therapeutic effect of HMAs on both lymphoid and bilineage hematologic malignancies.

T/myeloid mixed-phenotype acute leukemia treated with venetoclax and decitabine:A case report

BACKGROUND Mixed-phenotype acute leukemia(MPAL)is characterized by acute undifferentiated leukemia with blasts co-expressing myeloid and lymphoid antigens.However,consensus regarding the ideal management strategy for MPAL is yet to be established,owing to its rarity.CASE SUMMARY A 55-year-old male was diagnosed with T/myeloid MPAL.Vincristine,prednisolone,daunorubicin,and L-asparaginase were administered as induction chemotherapy.Septic shock occurred 10 days after induction,and bone marrow examination following recovery from sepsis revealed refractory disease.Venetoclax and decitabine were administered as chemotherapy-free induction therapy to reduce the infection risk.There were no serious infections,including febrile neutropenia,at the end of the treatment.After receiving two additional cycles of venetoclax/decitabine,the patient underwent haploidentical peripheral blood stem-cell transplantation and achieved complete response(CR)to treatment.CONCLUSION CR was maintained in a patient with MPAL who underwent haploidentical peripheral blood stem-cell transplantation after additional venetoclax/decitabine cycles.

Decitabine for Relapsed Acute Lymphoblastic Leukemia after Allogeneic Hematopoietic Stem Cell Transplantation

Relapse after allogeneic hematopoietic stem cell transplantation（allo-HSCT） remains a main question on treatment failure. Current strategies for management that usually include salvage chemotherapy, donor lymphocytic infusion and second transplantation. Our study assessed the efficacy of decitabine（DAC） for treating patients with acute lymphoblastic leukemia（ALL） who relapsed after allogeneic hematopoietic stem cell transplantation（allo-HSCT）. We retrospectively analyzed the outcomes of 12 patients with relapsed ALL after allo-HSCT who received DAC therapy. Nine patients received DAC combined with chemotherapy and donor stem cell infusion, and 3 patients received single-agent DAC. Ten of the 12 patients achieved complete remission（CR）, 1 achieved a partial remission（PR）, and 1 had no response（NR） after treatment at the latest follow-up（LFU）, the median survival was 11.2 months（range, 3.8–34, 7 months）. The 1-and 2-year overall survival（OS） rates were 50%（6/12） and 25%（3/12）, respectively. Five patients were still alive; 4 had maintained CR and 1 was alive with disease. Patients with Philadelphia chromosome-positive ALL had higher survival rate than patients with Philadelphia chromosome-negative ALL（57.1% vs. 20%）. No aggravated flares of graft-versus-host disease（GVHD） were observed during DAC treatment. Therefore, DAC may be a promising therapeutic agent for ALL recurrence after allo-HSCT.

Platelet Doubling After First Decitabine Cycle Predicts Response and Survival of Myelodysplastic Syndrome Patients

Objective:Although the effect of decitabine on myelodysplastic syndrome(MDS)has been demonstrated,merely a proportion of patients respond to therapy,and no well-recognized predictors have been identified.This study was conducted to investigate the effectiveness of decitabine in real-world clinical practice,and determine the predictive factors of response and overall survival(OS)in MDS patients.

Treatment of refractory/relapsed extranodal NK/T cell lymphoma with decitabine plus anti-PD-1:A case report

BACKGROUND Extranodal natural killer/T cell lymphoma,nasal type(ENKL) is a highly aggressive malignancy characterized by its association with Epstein-Barr virus(EBV) and extranodal involvement,which shows a poor clinical outcome.Although L-asparaginase-based chemotherapy has improved the response rates of relapsed/refractory(R/R) ENKL,relapse occurs in up to 50% of patients with disseminated disease.CASE SUMMARY Immune evasion has emerged as a critical pathway for survival in ENKL and may be effectuated via STAT3-driven upregulation of programmed cell death ligand 1(PD-L1) or other molecular pathways.Anti-PD-1 is effective for R/R ENKL with EBV-driven upregulation of PD-L1 expression.Anti-PD-1 combined with decitabine showed positive preliminary results in a patient with R/R ENKL and resistance to anti-PD-1.CONCLUSION The treatment experience,in this case,demonstrated the potential ability of decitabine combined with PD-1 inhibitor to treat R/R ENKL,thus providing a new treatment strategy for this tumor.

More Benefits of Oral Administration of Arsenic-containing Qinghuang Powder Compared with Decitabine for High/Very-high Risk Myelodysplastic Syndrome

OBJECTIVE: To evaluated the benefits of oral administration of arsenic-containing Qinghuang Powder(QHP)compared with decitabine for patients with high/very-high(H/VH) risk myelodysplastic syndrome(MDS) according to the Revised International Prognostic Score System. METHODS: The OS(mOS) rate, annual OS rate and progression to acute myeloid leukemia(AML) in patients with H/VH MDS treated with QHP(QHP group, n = 27) and decitabine(decitabine group, n = 20) were retrospectively analyzed. The effects of prognostic factors of age, proportion of bone marrow blast,peripheral blood cell count, karyotype and Charlson Comorbidity Index(CCI) on OS were further analyzed. RESULTS: The m OS rate of QHP group(29 months) was signi?cantly longer than that of the decitabine group(18 months)(P = 0.043). The OS rates of 1, 2, and 3 years were signi?cantly higher in the QHP group(88.9%, 59.3%, 29.6%) than that in the decitabine group(70%, 25%, and 5%)(P = 0.01). There was no signi?cant difference of 5-year OS rate between the 2 groups(P = 0.133).The effects of prognostic factors on mOS were further analyzed, and it was found that there was no signi?cant difference of m OS rate between the QHP group(29 months) and the decitabine group(21 months) in the patients with age 65 years old(P = 0.673). The mOS rate was signi?cantly longer in QHP group(28.5 months) than that in decitabine group(18 months) in the patients with age of < 65 years old(P = 0.04). The proportions of bone marrow blast cells with 10% or < 10% had no signi?cant effects on the mOS rate of patients in the 2 groups(P = 0.429, P = 0.183). In patients with HGB 80 g/L, mOS rate was signi?cantly longer in the QHP group(57 months) than that in the decitabine group(21 months)(P = 0.047), while in patients with HGB < 80 g/L, there was no signi?cant difference of mOS rate between the 2 groups(P = 0.265). In the patients with PLT < 50×10~9/L, the mOS rate was signi?cantly longer in the QHP group(33 months) than that in the decitabine group(16 months)(P = 0.028). In the patients with PLT 50×10~9/L, there was no signi?cant difference of the mOS rate between the 2 groups(P = 0.338). In the patients with ANC < 0.8×10~9/L, the mOS rate was signi?cantly longer in the QHP group(20 months) than that in the decitabine group(7 months)(P = 0.014). In the patients with normal karyotype, the mOS was signi?cantly longer in the QHP group(32 months) than that in the decitabine group(15 months)(P = 0.009). In the patients with abnormal karyotypes, there was no significant difference of the mOS rate between the 2 groups(P = 0.882). In the patients with good karyotypes, the mOS rate was signi?cantly longer in the QHP group(37 months) than that in the decitabine group(20 months)(P = 0.019). In the patients with moderate/poor/very poor karyotype, there was no signi?cant difference of the mOS rate between the 2 groups(P = 0.685). In the patients with CCI 3, the mOS rate was signi?cantly longer in the QHP group(34 months) than that in the decitabine group(10.5 months)(P = 0.017). In patients with CCI < 3, there was no signi?cant difference of the mOS rate between the 2 groups(P = 0.581). The proportion of progression to AML in the QHP group(18.8%) was signi?cantly lower than that in the decitabine group(25%)(P = 0.03). CONCLUSION: Compared with decitabine, oral administration of arsenic-containing Qinghuang Powder could help patients to survive longer and decrease incidence of progression to acute myeloid leukemia in the treatment of patients with high/very high MDS.

AIC AR and Decitabine Enhance the Sensitivity of K562 Cells to Imatinib by Promoting Mitochondrial Activity

Although the advent of tyrosine kinase inhibitors(TKIs)has dramatically improved the survival of patients with chronic myeloid leukaemia(CML),acquired drug resistance and TKI-insensitive leukaemic stem cells(LSCs)remain major obstacles to a CML cure.In recent years,the reprogramming of mitochondrial metabolism has emerged as a hallmark of cancers,including CML,and in turn may be exploited for therapeutic purposes.Here,we investigated the effects of several drugs on the mitochondrial function of the CML cell line K562 and found that 5-aminoimidazole-4-carboxamide ribotide(AICAR)and decitabine could effectively increase the ATP content and mitochondrial biogenesis.In addition,these two drugs induced cell cycle arrest and a decrease in colony-forming capacity and promoted K562 cell differentiation.Moreover,we demonstrated that treatment with AICAR or decitabine enhanced the sensitivity o f K562 cells to imatinib,as evidenced by a combination treatment assay.Altogether,our findings indicate that TKIs combined with mitochondrial regulation may provide a therapeutic strategy for the treatment of CML.

Efficacy and safety of combined decitabine and ruxolitinib in the treatment of chronic myelomonocytic leukemia

Objective The aim of the study was to evaluate the clinical efficacy of decitabine(DEC)combined with ruxolitinib(RUX)in the treatment of chronic myelomonocytic leukemia(CMML).Methods The clinical characteristics of 12 patients with CMML were analyzed retrospectively and subsequent target sequencing was performed to investigate the efficacy of the combined treatment with DEC and RUX and the molecular signatures therein.Results Among the 12 cases,clinical improvement was observed in all patients(100%),spleen reduction was observed in six patients(67%),and hematologic improvement was observed in four patients(33%).In the CMML-1 group,the overall response was 50%(3/6),one case achieved complete response,one achieved bone marrow remission,and one achieved hematological improvement.In the CMML-2 group,the overall response was 17%(1/6),one case achieved complete response,four showed disease progression(PD),and one exhibited no response.As expected,ASXL1 mutation was predictive for the outcome of CMML(hazard ratio of 2.97,95%confidence interval of 1.21–7.06;P=0.02).Conclusion The use of DEC combined with RUX in the treatment of CMML effectively improved the clinical response and quality of life,especially for CMML-1 patients.Ongoing clinical trials will further evaluate the safety and efficacy of this novel therapeutic approach.

The Effect of Decitabine Combined with Arsenic Trioxide on DAPK Gene and HL-60 Cell Proliferation and Apoptosis

Purpose: Our study was to detect the effect of Decitabine (DAC) combined with arsenic trioxide (AS2O3) on DAPK gene and HL-60 cell proliferation and apoptosis. Methods: DAC and AS2O3 monotherapy, combination treatment and DAC pretreatment were used in this study after incubating with HL-60 cell for 24 h, 48 h, 72 h. CCK8 was used to detect the cell proliferation of HL-60 cell. Flow cytometry was used to detect the cell apoptosis. Then, we used RT-PCR to obtain the gene expression level of DAPK. Results: HL-60 cells were treated with different concentrations of DAC (20 μmol/L, 40 μmol/L, 80 μmol/L), AS2O3 (1 μmol/L, 2.5 μmol/L, 5 μmol/L) monotherapy for 24 h, 48 h, 72 h;along with the extension of the drug concentration and time, proliferation inhibition rate had gradually increased. Monotherapy of DAC, AS2O3 could inhibit the proliferation and induce apoptosis of HL-60 cells, and was time- and dose-dependent. DAC (80 μmol/L) was firstly used for pretreatment, and then, different concentrations of AS2O3 (1 μmol/L, 2.5 μmol/L, 5 μmol/L) were used for 24 h, 48 h, 72 h. It was found that cell proliferation inhibition rate and apoptosis rate had increased significantly. When the two drugs were used together, the increasing proliferation inhibition rate, apoptosis rate and DAPK had become more obvious. Conclusion: DAC and AS2O3 had a synergetic effect for the HL-60 cell proliferation inhibition, apoptosis and expression of DAPK.

Clinical Efficacy of Decitabine/Azacitidine in Combination with HAG in the Treatment of Elderly Patients with Acute Myeloid Leukemia

This study was conducted to investigate the clinical effect of combining decitabine/azacitidine with HAG in the treatment of single elderly patients with acute myeloid leukemia.Patients in Shaanxi Provincial People’s Hospital were selected for this study from January 2020 to January 2022,and all of the patients were elderly patients with acute myeloid leukemia.Around 23 patients were selected for this study,subsequently the patients were divided into two groups;Group A contained 11 patients and was given decitabine in combination with HAG;and Group B contained 12 patients,and was given azacitidine in combination with HAG.This study showed that the treatment effective rates of patients in both groups were 90.91%and 58.33%,respectively,with a small difference(p>0.05)in the data comparison.The incidence of adverse reactions in the two groups was 63.64%and 16.67%,respectively,with the incidence in group B is significantly(p<0.05)lower compared with group A.Meanwhile,compared with group B,patients in group A had a significantly(p<0.05)shorter mean time to WBC normalization,higher HB and PLT levels,lower WBC levels were lower,all the survival duration times were longer,and subpopulation indicators of peripheral blood T lymphocytes were more in line with normal values.In summary,this study demonstrated that the combination of azacitidine and HAG therapies for the treatment of elderly patients with acute myeloid leukemia is more effective,furthermore can reduce significantly the incidence of adverse treatment effects in patients.

A Study on the Effectiveness of Decitabine Combined with a Half-Dose Priming Regimen in the Treatment of Elderly Patients with Acute Myeloid Leukemia

Objective:To investigate the clinical effects of combining decitabine with a half-dose priming regimen in the treatment of elderly patients with acute myeloid leukemia.Methods:This study was conducted in Shaanxi Provincial People's Hospital from January 2019 to January 2022.Sxty patients were recruited as the research subects.The patients received different treatments and were randomly divided into two groups,with 30 cases in each group,one of which was treated with conventional priming regimen(control group),and the other was treated with decitabine combined with a half-dose priming regimen(study group).The two groups were compared and analyzed in terms of the effectiveness of treatment.Results:The rate of symptom relief in the study group was 96.67%,which was significantly higher than that in the control group(76.67%)(p<0.05).Before treatment,there was no significant difference in the quality-of-life scores between the two groups,with p>0.05.The patients in the study group had sigificantly longer discase free survival and overall survival than those in the control group,with p<0.05.The effectiveness of treatment in the study group was also better.Conclusion:The use of decitabine im combination with a half dose priming regimen for the treatment of elderly patients with acute myeloid lcukemia is effective in improving patients'quality of life,relieving symptoms.and prolonging their survival.

Decitabine induces IRF7-mediated immune responses in p53-mutated triple-negative breast cancer:a clinical and translational study

p53 is mutated in half of cancer cases.However,no p53-targeting drugs have been approved.Here,we reposition decitabine for triple-negative breast cancer(TNBC),a subtype with frequent p53 mutations and extremely poor prognosis.In a retrospective study on tissue microarrays with 132 TNBC cases,DNMT1 overexpression was associated with p53 mutations(P=0.037)and poor overall survival(OS)(P=0.010).In a prospective DEciTabinE and Carboplatin in TNBC(DETECT)trial(NCT03295552),decitabine with carboplatin produced an objective response rate(ORR)of 42%in 12 patients with stage IV TNBC.Among the 9 trialed patients with available TP53 sequencing results,the 6 patients with p53 mutations had higher ORR(3/6 vs.0/3)and better OS(16.0 vs.4.0 months)than the patients with wild-type p53.In a mechanistic study,isogenic TNBC cell lines harboring DETECT-derived p53 mutations exhibited higher DNMT1 expression and decitabine sensitivity than the cell line with wild-type p53.In the DETECT trial,decitabine induced strong immune responses featuring the striking upregulation of the innate immune player IRF7 in the p53-mutated TNBC cell line(upregulation by 16-fold)and the most responsive patient with TNBC.Our integrative studies reveal the potential of repurposing decitabine for the treatment of p53-mutated TNBC and suggest IRF7 as a potential biomarker for decitabine-based treatments.

Low-dose decitabine enhances the effect of PD-1 blockade in colorectal cancer with microsatellite stability by re-modulating the tumor microenvironment

PD-1 blockade has demonstrated impressive clinical outcomes in colorectal cancers that have high microsatellite instability.However,the therapeutic efficacy for patients with tumors with low microsatellite instability or stable microsatellites needs further improvement.Here,we have demonstrated that low-dose decitabine could increase the expression of immune-related genes such as major histocompatibility complex genes and cytokine-related genes as well as the number of lymphocytes at the tumor site in CT26 colorectal cancer-bearing mice.A more significant inhibition of tumor growth and a prolongation of survival were observed in the CT26 mouse model after treatment with a combination of PD-1 blockade and decitabine than in mice treated with decitabine or PD-1 blockade alone.The anti-tumor effect of the PD-1 blockade was enhanced by low-dose decitabine.The results of RNA sequencing and whole-genome bisulfite sequencing of decitabine-treated CT26 cells and tumor samples with microsatellite stability from the patient tumor-derived xenograft model have shown that many immune-related genes,including antigen-processing and antigen-presenting genes,were upregulated,whereas the promoter demethylation was downregulated after decitabine exposure.Therefore,decitabine-based tumor microenvironment re-modulation could improve the effect of the PD-1 blockade.The application of decitabine in PD-1 blockade-based immunotherapy may elicit more potent immune responses,which can provide clinical benefits to the colorectal cancer patients with low microsatellite instability or stable microsatellites.

Demethylating agent decitabine induces autologous cancer testis antigen specific cytotoxic T lymphocytes in vivo

Background Cancer testis antigens （CTAs） are a novel group of tumor associated antigens.Demethylating agent decitabine was reported to be able to up-regulate CTAs through its hypomethylation mechanism,thus enhance the immunogenicity of leukemia cells.However,few researches have ever focused on the questions that whether this immunostimulatory effect of decitabine could induce autologous CTA specific cytotoxic T lymphocytes （CTLs） in vivo,and if so,whether this effect contributes to disease control.In this study,we aimed to show that decitabine could induce specific autologous CTLs against some mouse CTAs in leukemia cells in vitro and in vivo.Methods Several mouse CTAs were screened by RT-PCR.CTL specific to one of the CTAs named P1A was detected and sorted by P1A specific dimer by flow cytometry.The activity of specific CTLs was measured by real time RT-PCR.Results We firstly screened expression of some CTAs in mouse leukemia cells before and after decitabine treatment and found that decitabine treatment did up-regulate expression of many CTAs.Then we measured the CTLs＇ activity specific to a mouse CTA P1A in vivo and showed that this activity increased after decitabine treatment.Finally,we sorted these in vivo induced P1A specific CTLs by flow cytometry and demonstrated their cytotoxicity against decitabine treated leukemia cells.Conclusions Our study showed the autologous immune response induced by decitabine in vivo.And more importantly,we firstly proved that this response may contribute to disease control.We believe that this immunostimulatory effect is another anti-cancer mechanism of decitabine,and this special effect would inspire new applications of decitabine in the field of leukemia treatment in the future.

骨髓增生异常综合征去甲基化药物治疗的研究进展

骨髓增生异常综合征(myelodysplastic syndrome,MDS)的发病机制涉及多阶段、多因素,基因改变与表观遗传修饰可能共同参与了这一过程。DNA甲基化是表观遗传学中一种最为重要的修饰,MDS患者常表现为总体DNA高甲基化。使用DNA甲基转移酶(DNA methyltransferase,DNMT)抑制剂降低总体甲基化水平,在MDS患者中取得了富有成效的临床反应及血液学改善。DNMT抑制剂可分为两类:5-氮杂胞苷(5-azacytidine,5-Aza-CdR)、地西他滨(5-Aza-2-deoxycytidine,decitabine)等核苷和核苷衍生物类抑制剂,它们可提高MDS患者的临床完全反应率、部分反应率及血液学改善,但缓解率、疗效尚不够令人满意;肼苯哒嗪等非核苷类抑制剂。非核苷类抑制剂与丙戊酸镁联合应用治疗MDS获得成功,为MDS去甲基化治疗药物的研究开启了一种新思路。

Gene mutations in a patient with chronic myelomonocytic leukemia and changes upon progression to acute myeloid leukemia and during treatment

Objective Chronic myelomonocytic leukemia(CMML) has been categorized as an uncommon hematological malignancy with overlapping features of myelodysplastic syndromes(MDS) and myeloproliferative neoplasms that have an inherent risk of progressing to acute myeloid leukemia(AML). Methods This study presents a case of confirmed CMML combined with M protein, in which the molecular changes upon progression to AML and under decitabine(DAC) plus bortezomib therapy were reported by tracking variant allele frequency(VAF) of mutations in a series of bone marrow samples. Results First, variable sensitivity of clones was observed during DAC treatment, and incomplete mutation clearance may be associated with low overall response rate and unsustained response. Secondly, DAC cannot prevent the new genetic alterations and accumulation of genetic progression on treatment, leading to acute transformation. Finally, autoimmunity was found to have acted as an important pathogenetic factor, increasing the additive mutations that further drive the clonal evolution in CMML. Conclusion Overall, changes in mutations and clonal architecture during CMML progression or treatment are predictive of an early evaluation of therapeutic strategies in CMML.

DNA Methyltransferases Directed Anti-Cancerous Plant Medicine (Xanthomicrol and Galloyl) Based Molecular Docking and Dynamics Simulation

DNA methyltransferases 1 (DNMT1) has been looked as crucial targets against various types of cancers. MD simulations have advanced to a point where the atomic level information of biological macromolecule (protein or DNA-protein or protein-protein) can easily be advantageous to predict the functionality. In this study we utilize xanthomicrol and galloyl compounds to investigate potential compounds for the inhibition of DNMT1, and the results of these two compounds are compared with drug decitabine. Xanthomicrol and galloyl are found to dock successfully within the active site of DNMT1. A comparison of the inhibitory potential of screened xanthomicrol inhibited DNMT1 approximately is identical with those of their corresponding drugs, decitabine. The stability of the DNMT1 with the best docked xanthomicrol, were further analysed in molecular dynamics (MD) simulation and compared with those of the respective drugs namely decitabine which revealed stabilization of these complexes within 300 ns of simulation with better stability of DNMT1.