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Defining mechanisms of resistance to hypomethylating agents (HMAs) and biomarkers predictive of treatment response remains challenging in myelodysplastic neoplasm (MDS). Currently available prognostic tools that predict overall survival and transformation to acute myeloid leukaemia have not been powered to predict responses to HMAs. Noguera-Castells et al. comprehensively characterized the epigenomic profile in patients with MDS treated with azacitidine and described a methylation signature-based prognostic tool in predicting responses to azacitidine. Commentary on: Noguera-Castells et al. DNA methylation profiling of myelodysplastic syndromes and clinical response to azacitidine: a multicentre retrospective study. Br J Haematol 2024;204:1838-1843., (© 2024 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

In myelodysplastic syndrome (MDS), resistance to hypomethylating agents (HMA) portends a poor prognosis, underscoring the importance of understanding the molecular mechanisms leading to HMA-resistance. In this study, P39 and Kasumi-1 cells and their azacitidine-resistant and decitabine-resistant sublines were evaluated comparatively with transcriptomic and methylomic analyses. Expression profiling and genome-wide methylation microarray showed downregulation of PTEN associated with DNA hypermethylation in P39 cell lines resistant to azacitidine and decitabine. This pattern of PTEN dysregulation was also confirmed in a cohort of patients failing treatment with HMA. DNA hypomethylation of MDM2 was detected with downregulation of MDM2 in HMA resistant cell lines. Long-read sequencing revealed significant RNA hypomethylation of MDM2 resulting in alternative splicing and production of a truncated MDM2 transcript in azacitidine-resistant P39 cells. The expression of this MDM2 truncated transcript was also significantly increased in HMA-resistant patients compared with HMA-responsive patients. In conclusion, epigenetic and epi-transcriptomic dysregulation of PTEN and MDM2 were associated with resistance to hypomethylating agents.

Myelodysplastic syndrome (MDS) is a clonal myeloid neoplasm characterized by ineffective hematopoiesis, cytopenia, dysplasia, and clonal instability, leading to leukemic transformation. Hypomethylating agents are the mainstay of treatment in higher-risk MDS. However, treatment resistance and disease transformation into acute myeloid leukemia (AML) is observed in the majority of patients and is indicative of a dismal outcome. The residual cell clones resistant to therapy or cell clones acquiring new genetic aberrations are two of the key events responsible for drug resistance. Bulk tumor sequencing often fails to detect these rare subclones that confer resistance to therapy. In this study, we employed a single-cell DNA (sc-DNA) sequencing approach to study the clonal heterogeneity and clonal evolution in two MDS patients refractory to HMA. In both patients, different single nucleotide variations (SNVs) or insertions and deletions (INDELs) were detected with bulk tumor sequencing. Rare cell clones with mutations that are undetectable by bulk tumor sequencing were detected by sc-DNA sequencing. In addition to SNVs and short INDELs, this study also revealed the presence of a clonal copy number loss of DNMT3A , TET2 , and GATA2 as standalone events or in association with the small SNVs or INDELs detected during HMA resistance and disease progression.

Myelodysplastic syndrome (MDS) is a heterogeneous, clonal hematological disorder characterized by ineffective hematopoiesis, cytopenia, morphologic dysplasia, and predisposition to acute myeloid leukemia (AML). Stem cell genomic instability, microenvironmental aberrations, and somatic mutations contribute to leukemic transformation. The hypomethylating agents (HMAs), azacitidine and decitabine are the standard of care for patients with higher-risk MDS. Although these agents induce responses in up to 40-60% of patients, primary or secondary drug resistance is relatively common. To improve the treatment outcome, combinational therapies comprising HMA with targeted therapy or immunotherapy are being evaluated and are under continuous development. This review provides a comprehensive update of the molecular pathogenesis and immune-dysregulations involved in MDS, mechanisms of resistance to HMA, and strategies to overcome HMA resistance.

Background: Patients with acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS) suffer from a significant symptom burden and psychological, spiritual, social needs comparable to patients with solid metastatic malignancy. Referral to palliative care services for these haematological patients remains limited or often confined to the last days of life. We pioneered a palliative care (PC) program integrated with standard haematological care. The purpose of this trial will study the interventions by the PC team and preliminary results in the clinical outcomes., Methods: This project is a non-blinded, randomized, controlled trial. In this study, we examine the clinical outcomes of the integrated PC program for MDS/AML patients when the 2nd lines disease treatment failed and in the presence of prognostic indicators. In group 1, patients will receive standard haematological care associated with PC (i.e., intervention group). In contrast, in group 2, patients will receive standard haematological care only (i.e., control group) with PC service only on a request basis. Patients who join the program would have to complete a standardized questionnaire to assess their quality of life and their psychological and physical symptoms., Results: This is to exam the impact of the early integrated palliative care with enhanced psychosocial interventions to both advanced MDS/AML patients and their primary family members in Hong Kong., Discussion: This protocol will not display any result. If future results demonstrate that the enhanced PC interventions are effective, they will provide a quality treatment plan for patients with MDS/AML., Trial Registration: The Hong Kong University/Hospital Authority Hong Kong West Institutional Review Board (HKU/HA HKW IRB). The registration number is UW 19-824.

Myelodysplastic syndrome (MDS) is a group of heterogeneous clonal hematopoietic stem cell disorders characterized by cytopenia, ineffective hematopoiesis, and progression to secondary acute myeloid leukemia in high-risk cases. Conventional prognostication relies on clinicopathological parameters supplemented by cytogenetic information. However, recent studies have shown that genetic aberrations also have critical impacts on treatment outcome. Moreover, these genetic alterations may themselves be a target for treatment. The mutation landscape in MDS is shaped by gene aberrations involved in DNA methylation (TET2, DNMT3A, IDH1/2), histone modification (ASXL1, EZH2), the RNA splicing machinery (SF3B1, SRSF2, ZRSR2, U2AF1/2), transcription (RUNX1, TP53, BCOR, PHF6, NCOR, CEBPA, GATA2), tyrosine kinase receptor signaling (JAK2, MPL, FLT3, GNAS, KIT), RAS pathways (KRAS, NRAS, CBL, NF1, PTPN11), DNA repair (ATM, BRCC3, DLRE1C, FANCL), and cohesion complexes (STAG2, CTCF, SMC1A, RAD21). A detailed understanding of the pathogenetic mechanisms leading to transformation is critical for designing single-agent or combinatorial approaches in target therapy of MDS.

Npm1(+/-) heterozygous mice develop a haematological disorder with features resembling human myelodysplastic syndrome (MDS). Promoter hypermethylation of the NPM1 gene may lead to suppressed gene transcription and hence functional haploinsufficiency, which contributes to the development of MDS. Thirty-one patients with MDS and eight normal individuals were studied for promoter methylation and mRNA expression of NPM1. Methylation-specific PCR (MSP), COBRA and bisulfite sequencing were used to examine the NPM1 methylation status. Quantitative PCR was used to assess the expression of NPM1. NPM1 DNA methylation was rare, occurring in one of 31 cases as determined by MSP. There was no significant difference in NPM1 mRNA expression between MDS and normal blood samples. In conclusion, the finding suggests that NPM1 methylation is rare in MDS and does not play a major role in its pathogenesis.

Npm1+/- heterozygous mice develop a haematological disorder with features resembling human myelodysplastic syndrome (MDS). Promoter hypermethylation of the NPM1 gene may lead to suppressed gene transcription and hence functional haploinsufficiency, which contributes to the development of MDS. Thirty-one patients with MDS and eight normal individuals were studied for promoter methylation and mRNA expression of NPM1. Methylation-specific PCR (MSP), COBRA and bisulfite sequencing were used to examine the NPM1 methylation status. Quantitative PCR was used to assess the expression of NPM1. NPM1 DNA methylation was rare, occurring in one of 31 cases as determined by MSP. There was no significant difference in NPM1 mRNA expression between MDS and normal blood samples. In conclusion, the finding suggests that NPM1 methylation is rare in MDS and does not play a major role in its pathogenesis. [ABSTRACT FROM AUTHOR]