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Leukemia Apr 2021Mechanisms-of-resistance to decitabine and 5-azacytidine, mainstay treatments for myeloid malignancies, require investigation and countermeasures. Both are nucleoside...
Mechanisms-of-resistance to decitabine and 5-azacytidine, mainstay treatments for myeloid malignancies, require investigation and countermeasures. Both are nucleoside analog pro-drugs processed by pyrimidine metabolism into a deoxynucleotide analog that depletes the key epigenetic regulator DNA methyltranseferase 1 (DNMT1). Here, upon serial analyses of DNMT1 levels in patients' bone marrows on-therapy, we found DNMT1 was not depleted at relapse. Showing why, bone marrows at relapse exhibited shifts in expression of key pyrimidine metabolism enzymes in directions adverse to pro-drug activation. Further investigation revealed the origin of these shifts. Pyrimidine metabolism is a network that senses and regulates deoxynucleotide amounts. Deoxynucleotide amounts were disturbed by single exposures to decitabine or 5-azacytidine, via off-target depletion of thymidylate synthase and ribonucleotide reductase respectively. Compensating pyrimidine metabolism shifts peaked 72-96 h later. Continuous pro-drug exposures stabilized these adaptive metabolic responses to thereby prevent DNMT1-depletion and permit exponential leukemia out-growth as soon as day 40. The consistency of the acute metabolic responses enabled exploitation: simple treatment modifications in xenotransplant models of chemorefractory leukemia extended noncytotoxic DNMT1-depletion and leukemia control by several months. In sum, resistance to decitabine and 5-azacytidine originates from adaptive responses of the pyrimidine metabolism network; these responses can be anticipated and thus exploited.
Topics: Animals; Antimetabolites, Antineoplastic; Azacitidine; Cell Line, Tumor; DNA (Cytosine-5-)-Methyltransferase 1; DNA Methylation; Decitabine; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Humans; Metabolic Networks and Pathways; Mice; Pyrimidines; Uridine Kinase
PubMed: 32770088
DOI: 10.1038/s41375-020-1003-x -
Leukemia Apr 2023Combination therapies targeting malignancies aim to increase treatment efficacy and reduce toxicity. Hypomethylating drug 5-Aza-2'-deoxycytidine (5-Aza-2') enhances...
Combination therapies targeting malignancies aim to increase treatment efficacy and reduce toxicity. Hypomethylating drug 5-Aza-2'-deoxycytidine (5-Aza-2') enhances transcription of tumor suppressor genes and induces replication errors via entrapment of DNMT1, yielding DNA-protein crosslinks. Post-translational modification by SUMO plays major roles in the DNA damage response and is required for degradation of entrapped DNMT1. Here, we combine SUMOylation inhibitor TAK981 and DNA-hypomethylating agent 5-Aza-2'-deoxycytidine to improve treatment of MYC driven hematopoietic malignancies, since MYC overexpressing tumors are sensitive to SUMOylation inhibition. We studied the classical MYC driven malignancy Burkitt lymphoma, as well as diffuse large B-cell lymphoma (DLBCL) with and without MYC translocation. SUMO inhibition prolonged the entrapment of DNMT1 to DNA, resulting in DNA damage. An increase in DNA damage was observed in cells co-treated with TAK981 and 5-Aza-2'. Both drugs synergized to reduce cell proliferation in vitro in a B cell lymphoma cell panel, including Burkitt lymphoma and DLBCL. In vivo experiments combining TAK981 (25 mg/kg) and 5-Aza-2' (2.5 mg/kg) showed a significant reduction in outgrowth of Burkitt lymphoma in an orthotopic xenograft model. Our results demonstrate the potential of tailored combination of drugs, based on insight in molecular mechanisms, to improve the efficacy of cancer therapies.
Topics: Humans; Burkitt Lymphoma; Decitabine; Sumoylation; Azacitidine; Hematologic Neoplasms; Lymphoma, Large B-Cell, Diffuse; DNA; Cell Line, Tumor
PubMed: 36792656
DOI: 10.1038/s41375-023-01838-8 -
Cancer Letters Nov 2022The development of more effective targeted therapies for hepatocellular carcinoma (HCC) patients due to its aggressiveness is urgently needed. DNA methyltransferase...
The development of more effective targeted therapies for hepatocellular carcinoma (HCC) patients due to its aggressiveness is urgently needed. DNA methyltransferase inhibitors (DNMTis) represented the first clinical breakthrough to target aberrant cancer epigenomes. However, their clinical efficacies are still limited, in part due to an "epigenetic switch" in which a large group of genes that are demethylated by DNMTi treatment remain silenced by polycomb repressive complex 2 (PRC2) occupancy. EZH2 is the member of PRC2 that catalyzes the placement of H3K27me3 marks. EZH2 overexpression is correlated with poor HCC patient survival. We tested the combination of a DNMTi (5-aza-2'-deoxycytidine, DAC) and the EZH2 inhibitor (EZH2i) GSK126 in human HCC cell lines on drug sensitivity, DNA methylation, nucleosome accessibility, and gene expression profiles. Compared with single agent treatments, all HCC cell lines studied showed increased sensitivity after receiving both drugs concomitant with prolonged anti-proliferative changes and sustained reactivation of nascently-silenced genes. The increased number of up-regulated genes after combination treatment correlated with prolonged anti-proliferation effects and increased nucleosome accessibility. Combination treatments also activate demethylated promoters that are repressed by PRC2 occupancy. Furthermore, 13-31% of genes down-regulated by DNA methylation in primary HCC tumors were reactivated through this combination treatment scheme in vitro. Finally, the combination treatment also exacerbates anti-tumor immune responses, while most of these genes were downregulated in over 50% of primary HCC tumors. We have linked the anti-tumor effects of DAC and GSK126 combination treatments to detailed epigenetic alterations in HCC cells, identified potential therapeutic targets and provided a rationale for treatment efficacy for HCC patients.
Topics: Carcinoma, Hepatocellular; Cell Line, Tumor; DNA; DNA (Cytosine-5-)-Methyltransferases; Decitabine; Enhancer of Zeste Homolog 2 Protein; Enzyme Inhibitors; Gene Expression Regulation, Neoplastic; Histones; Humans; Liver Neoplasms; Nucleosomes; Polycomb Repressive Complex 2
PubMed: 36087682
DOI: 10.1016/j.canlet.2022.215899 -
Journal of Translational Medicine Mar 2023The mechanism of tumor immune escape and progression in colorectal cancer (CRC) is widely investigated in-vitro to help understand and identify agents that might play a...
BACKGROUND
The mechanism of tumor immune escape and progression in colorectal cancer (CRC) is widely investigated in-vitro to help understand and identify agents that might play a crucial role in response to treatment and improve the overall survival of CRC patients. Several mechanisms of immune escape and tumor progression, including expression of stemness markers, inactivation of immunoregulatory genes by methylation, and epigenetic silencing, have been reported in CRC, indicating the potential of demethylating agents as anti-cancer drugs. Of these, a chemotherapeutic demethylating agent, Decitabine (DAC), has been reported to induce a dual effect on both DNA demethylation and histone changes leading to an increased expression of target biomarkers, thus making it an attractive anti-tumorigenic drug.
METHODS
We compared the effect of DAC in primary 1076 Col and metastatic 1872 Col cell lines isolated and generated from patients' tumor tissues. Both cell lines were treated with DAC, and the expression of the NY-ESO-1 cancer-testis antigen, the PD-L1 immunoinhibitory marker, and the CD44, Nanog, KLF-4, CD133, MSI-1 stemness markers were analyzed using different molecular and immunological assays.
RESULTS
DAC treatment significantly upregulated stemness markers in both primary 1076 Col and meta-static 1872 Col cell lines, although a lower effect occurred on the latter: CD44 (7.85 fold; ***p = 0.0001 vs. (4.19 fold; *p = 0.0120), Nanog (4.1 fold; ***p < 0.0001 vs.1.69 fold; ***p = 0.0008), KLF-4 (4.33 fold; ***p < 0.0001 vs.2.48 fold; ***p = 0.0005), CD133 (16.77 fold; ***p = 0.0003 vs.6.36 fold; *p = 0.0166), and MSI-1 (2.33 fold; ***p = 0.0003 vs.2.3 fold; ***p = 0.0004), respectively. Interestingly, in the metastatic 1872 Col cells treated with DAC, the expression of both PD-L1 and NY-ESO-1 was increased tenfold (*p = 0.0128) and fivefold (***p < 0.0001), respectively.
CONCLUSIONS
We conclude that the upregulation of both stemness and immune checkpoint markers by DAC treatment on CRC cells might represent a mechanism of immune evasion. In addition, induction of NY-ESO-1 may represent an immuno-therapeutic option in metastatic CRC patients. Finally, the combination of DAC and anti-PD-1/anti-PD-L1 antibodies treatment should represent a potential therapeutic intervention for this group of patients.
Topics: Male; Humans; Decitabine; Antigens, Neoplasm; Membrane Proteins; Immunotherapy; Colorectal Neoplasms; Cell Line, Tumor
PubMed: 37004094
DOI: 10.1186/s12967-023-04073-y -
Systematic Reviews Sep 2018Hypomethylating agents (HMA), azacitidine, and decitabine are frequently used in the management of myelodysplastic syndromes (MDS). However, there are no clinical trials... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Hypomethylating agents (HMA), azacitidine, and decitabine are frequently used in the management of myelodysplastic syndromes (MDS). However, there are no clinical trials that have directly compared these agents. We conducted a systematic review and indirectly compared the efficacy of azacitidine to decitabine in MDS.
METHODS
We conducted a comprehensive search of several databases (MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Scopus) through June 28, 2018, without language or time restrictions. Studies were screened by two independent reviewers, and differences were resolved by consensus. The fixed effect model and adjusted indirect comparison methods were used to pool relative risks (RR) of major outcomes of interest (mortality, response rate, quality of life, hematologic improvement, hospitalization, leukemia transformation, transfusion independence).
RESULTS
Only four trials met the eligibility criteria. Two trials compared azacitidine to the best supportive care (BSC) and included 549 patients, and the other two compared decitabine to BSC and included 403 patients. The risk of bias was unclear overall. Compared to BSC, azacitidine was significantly associated with lower mortality (RR = 0.83, 95% CI 0.74-0.94, I = 89%) whereas decitabine did not significantly reduce mortality (RR = 0.88, 95% CI 0.77-1.00, I = 53%). Both drugs were associated with higher partial and complete response compared to BSC. Indirect comparisons were not statistically significant for all the studied outcomes, except for complete response where azacitidine was less likely to induce complete response compared to decitabine (RR = 0.11, 95% CI = 0.01-0.86, very low-certainty evidence).
CONCLUSIONS
Azacitidine and decitabine are both associated with improved outcomes compared to BSC. The available indirect evidence comparing the two agents warrants very low certainty and cannot reliably confirm the superiority of either agent. Head-to-head trials are needed. In the meantime, the choice of agent should be driven by patient preferences, adverse effects, drug availability, and cost.
Topics: Humans; Azacitidine; Blood Transfusion; Decitabine; Mortality; Myelodysplastic Syndromes; Network Meta-Analysis; Quality of Life
PubMed: 30227896
DOI: 10.1186/s13643-018-0805-7 -
International Journal of Nanomedicine 2019Acute myeloid leukemia mainly affects adult patients. Complete remission for patients younger than 60 years, who are candidates for standard induction therapy, is...
BACKGROUND
Acute myeloid leukemia mainly affects adult patients. Complete remission for patients younger than 60 years, who are candidates for standard induction therapy, is achieved in 60%-80% of cases. However, the prognosis is still poor for older patients, who are unfit for intensive chemotherapy, and only a few therapies are available. Hypomethylating agents, such as decitabine, are approved for such patients. The current dosing regimen consists of one administration per day, for 5 days, each 4 weeks.
METHODS
Here, we present the synthesis of a decitabine prodrug, combined with its encapsulation into a lipid-based nanocapsule formulation. Decitabine (C12) was synthetized, then loaded into nanocapsules. Its stability in phosphate buffer ans human plasma was checked. Its activity was evaluated by Cell proliferation assays and cell-cycle analysis on human erythroleukemia cells. Then its pharmacokinetics was determined on a rat model.
RESULTS
Decitabine (C12) was obtained with a yield of 50%. Drug loading into nanocarriers of 27.45±0.05 nm was 5.8±0.5 mg/mL. The stability of decitabine was improved and its activity on leukemia cells was not altered. Finally, pharmacokinetics studies showed a prolonged mean residence time of the drug.
CONCLUSION
Decitabine (C12) as a prodrug showed high encapsulation efficiency, a good stability in plasma with no impact on its activity on leukemia cells and improved pharmacokinetics.
Topics: Animals; Antimetabolites, Antineoplastic; Cell Cycle; Cell Proliferation; Decitabine; Drug Stability; Humans; Leukemia, Erythroblastic, Acute; Lipids; Male; Nanocapsules; Plasma; Rats; Rats, Wistar; Tissue Distribution; Tumor Cells, Cultured
PubMed: 30988610
DOI: 10.2147/IJN.S190482 -
Frontiers in Immunology 2022DNA vaccines containing a fusion of the gene encoding chemokine MIP-3α (CCL20), the ligand for CCR6 on immature dendritic cells (DCs), to melanoma-associated antigen...
INTRODUCTION
DNA vaccines containing a fusion of the gene encoding chemokine MIP-3α (CCL20), the ligand for CCR6 on immature dendritic cells (DCs), to melanoma-associated antigen genes have enhanced anti-tumor immunity and efficacy compared to those lacking the chemokine gene. Previous work has shown that type-I interferon (IFNα or IFN) and 5-Aza-2'-deoxycytidine (5Aza) significantly enhance the therapeutic benefit of DNA vaccines as measured by reduced tumor burden and improved mouse survival.
METHODS
Here, we explored mouse intratumoral immune correlates underlying the therapeutic benefit of this combination regimen (vaccine, IFN, and 5Aza) as compared to vaccine alone and IFN and 5Aza without vaccine, focusing on chemokine mRNA expression by qRT-PCR and inflammatory cellular infiltration into the tumor microenvironment (TME) by flow cytometry and immunohistochemistry (IHC).
RESULTS
The combination group significantly upregulated intratumoral mRNA expression of key immune infiltration chemokines XCL1 and CXCL10. Flow cytometric analyses of tumor suspensions exhibited greater tumor infiltration of CD8+ DCs, CCR7+ DCs, and NK cells in the combination group, as well as reduced levels of myeloid-derived suppressor cells (MDSCs) in vaccinated groups. The mice receiving combination therapy also had greater proportions of effector/memory T-cells (Tem), in addition to showing an enhanced infiltration of Tem and central memory CD8+ T-cells, (Tcm). Tem and Tcm populations both correlated with smaller tumor size. Immunohistochemical analysis of tumors confirmed that CD8+ cells were more abundant overall and especially in the tumor parenchyma with combination therapy.
DISCUSSION
Efficient targeting of antigen to immature DCs with a chemokine-fusion vaccine offers a potential alternative approach to classic and dendritic cell-based vaccines. Combining this approach with IFNα and 5Aza treatments significantly improved vaccine efficacy. This treatment creates an environment of increased inflammatory chemokines that facilitates the trafficking of CD8+ DCs, NK cells, and CD8+ T-cells, especially memory cells, while reducing the number of MDSCs. Importantly, in the combination group, CD8+ cells were more able to penetrate the tumor mass in addition to being more numerous. Further analysis of the pathways engaged by our combination therapy is expected to provide additional insights into melanoma pathogenesis and facilitate the development of novel treatment strategies.
Topics: Animals; Mice; Decitabine; Interferon-alpha; Melanoma; RNA, Messenger; Tumor Microenvironment; Vaccines, DNA; Cancer Vaccines
PubMed: 36741387
DOI: 10.3389/fimmu.2022.1074644 -
Neuro-oncology Dec 2022Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults. Despite maximal treatment, median survival remains dismal at 14-24 months....
BACKGROUND
Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults. Despite maximal treatment, median survival remains dismal at 14-24 months. Immunotherapies, such as checkpoint inhibition, have revolutionized management of some cancers but have little benefit for GBM patients. This is, in part, due to the low mutational and neoantigen burden in this immunogenically "cold" tumor.
METHODS
U87MG and patient-derived cell lines were treated with 5-aza-2'-deoxycytidine (DAC) and underwent whole-exome and transcriptome sequencing. Cell lines were then subjected to cellular assays with neoantigen and cancer testis antigen (CTA) specific T cells.
RESULTS
We demonstrate that DAC increases neoantigen and CTA mRNA expression through DNA hypomethylation. This results in increased neoantigen presentation by MHC class I in tumor cells, leading to increased neoantigen- and CTA-specific T-cell activation and killing of DAC-treated cancer cells. In addition, we show that patients have endogenous cancer-specific T cells in both tumor and blood, which show increased tumor-specific activation in the presence of DAC-treated cells.
CONCLUSIONS
Our work shows that DAC increases GBM immunogenicity and consequent susceptibility to T-cell responses in vitro. Our results support a potential use of DAC as a sensitizing agent for immunotherapy.
Topics: Adult; Male; Humans; Glioblastoma; Decitabine; Antigens, Neoplasm; T-Lymphocytes; Testis; Cell Line, Tumor
PubMed: 35468205
DOI: 10.1093/neuonc/noac107 -
Hematology. American Society of... Dec 2019Patients with higher-risk myelodysplastic syndrome (HR-MDS) are defined by the original or revised International Prognostic Scoring System and specific genetic features.... (Review)
Review
Patients with higher-risk myelodysplastic syndrome (HR-MDS) are defined by the original or revised International Prognostic Scoring System and specific genetic features. Treatment of HR-MDS is challenging. Allogeneic hematopoietic stem cell transplantation, the only curative approach, is feasible in a minority of fit or intermediate fitness patients aged <70 to 75 years who are willing to face the risks of the procedure. Response to azacitidine and decitabine, the only approved drugs for HR-MDS and considered the standard of care, is partial and transient in most patients. The development of novel more personalized and efficient drugs is an unmet medical need. During the last decade, there have been substantial advances in understanding the multiple molecular, cellular, and immunological disturbances involved in the pathogenesis of myelodysplastic syndrome. As a result, a number of clinical and translational studies of new more focused treatment approaches for HR-MDS patients are underway. In contrast to acute myeloid leukemia, they have not resulted in any new drug approval. This review addresses the benefits and limitations of current treatment alternatives, offers a practical individualized treatment approach, and summarizes the clinical trials in progress for HR-MDS.
Topics: Aged; Allografts; Azacitidine; Clinical Trials as Topic; Decitabine; Female; Hematopoietic Stem Cell Transplantation; Humans; Myelodysplastic Syndromes; Translational Research, Biomedical
PubMed: 31808894
DOI: 10.1182/hematology.2019000042 -
Medicine Sep 2022This analysis aimed to assess the effect of decitabine combined with allogeneic hematopoietic stem cell transplantation (allo-HSCT) in treating recurrent and refractory... (Meta-Analysis)
Meta-Analysis
Efficacy of decitabine combined with allogeneic hematopoietic stem cell transplantation in the treatment of recurrent and refractory acute myeloid leukemia (AML): A systematic review and meta-analysis.
BACKGROUND
This analysis aimed to assess the effect of decitabine combined with allogeneic hematopoietic stem cell transplantation (allo-HSCT) in treating recurrent and refractory acute myeloid leukemia.
METHOD
The present analysis was carried out according to the principles of Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline statement. Web of Science, Embase, PubMed, The Cochrane Library, CNKI, VIP, and WanFang Data databases were searched for trials published from their corresponding inception to September 13, 2021. Retrospective research or published randomized controlled trials in Chinese or English were ruled out. The methodological quality of the included studies was assessed using the Physiotherapy Evidence Database scale. Mean differences with 95% confidence intervals were used to analyze continuous data. The I2 test was used to determine heterogeneity, and the meta-analysis was conducted using Revman 5.4.
RESULTS
Eight studies including 795 participants in total were identified. Decitabine and allo-HSCT showed significant reductions in recurrence after transplantation (odds ratio [OR] = 0.29, 95% confidence interval [CI] (0.17, 0.50), P < .00001), leukemia-free survival (OR = 2.17, 95% CI (1.47, 3.21), P < .0001), graft related death (OR = 0.50, 95% CI (0.25, 0.98), P = .04), and significant improvements in complete remission (OR = 0.39, 95% CI = 0.23-0.68, P = .0007) and partial remission (OR = 0.46, 95%CI = 0.27-0.78, P = .004). The median follow-up time, acute graft-versus-host disease, and no remission had no significant difference between treatment and control groups (the median follow-up time: OR = -1.76, 95% CI (-6.28, 2.76), P = .45; acute graft-versus-host disease: OR = 0.72, 95% CI (0.50, 1.03), P = .08; no remission: OR = 3.19, 95%CI = 2.06-4.94, P = .05). Overall, the magnitude of the effect was found to be in the small to moderate range.
CONCLUSION
Decitabine combined with allo-HSCT can obtain lower recurrence risk and longer disease-free survival time, and improve the prognosis of patients. The safety is relatively stable. Due to the varying quality level of the included studies, the validation of multiple high-quality studies still needs improvement.
Topics: Decitabine; Graft vs Host Disease; Hematopoietic Stem Cell Transplantation; Humans; Leukemia, Myeloid, Acute; Retrospective Studies
PubMed: 36123842
DOI: 10.1097/MD.0000000000030644