RUNX1 mutations contribute to the progression of MDS due to disruption of antitumor cellular defense: a study on patients with lower-risk MDS

The immunobiology of myelodysplastic neoplasms: a mini-review

This mini review summarizes the immunobiology of myelodysplastic syndromes, specifically focusing on the interactions between immune cells, cytokines, and dysplastic cells within the tumor microenvironment in the bone marrow. We elucidate in detail how immune dysregulation and evasion influence the initiation and progression of myelodysplastic syndromes, as well as resistance to therapy and progression to AML. In addition, we highlight a range of therapeutic strategies, including the most recent breakthroughs and experimental therapies for treating MDS. Finally, we address the existing knowledge gaps in the understanding of the immunobiology of MDS and propose future research directions, promising advancements toward enhancing clinical outcomes and survival for patients with MDS.

Defining the mutational profile of lower-risk myelodysplastic neoplasm patients with respect to disease progression using next-generation sequencing and pyrosequencing

Introduction

Lower-risk myelodysplastic neoplasms (LR-MDS) comprise the majority of MDS. Despite favourable prognoses, some patients remain at risk of rapid progression. We aimed to define the mutational profile of LR-MDS using next-generation sequencing (NGS), Sanger Sequencing (SSeq), and pyrosequencing.

Material and methods

Samples from 5 primary LR-MDS (67 exons of SF3B1, U2AF1, SRSF2, ZRSR2, TET2, ASXL1, DNMT3A, TP53, and RUNX1 genes) were subjected to NGS. Next, a genomic study was performed to test for the presence of identified DNA sequence variants on a larger group of LR-MDS patients (25 bone marrow [BM], 3 saliva [SAL], and one peripheral blood [PB] sample/s). Both SSeq (all selected DNA sequence variants) and pyrosequencing (9 selected DNA sequence variants) were performed.

Results

Next-generation sequencing results identified 13 DNA sequence variants in 7 genes, comprising 8 mutations in 6 genes (ASXL1, DNMT3A, RUNX1, SF3B1, TET2, ZRSR2) in LR-MDS. The presence of 8 DNA variants was detected in the expanded LR-MDS group using SSeq and pyrosequencing. Mutation acquisition was observed during LR-MDS progression. Four LR-MDS and one acute myeloid leukaemia myelodysplasia-related patient exhibited the presence of at least one mutation. ASXL1 and SF3B1 alterations were most commonly observed (2 patients). Five DNA sequence variants detected in BM (patients: 9, 13) were also present in SAL.

Conclusions

We suggest using NGS to determine the LR-MDS mutational profile at diagnosis and suspicion of disease progression. Moreover, PB and SAL molecular testing represent useful tools for monitoring LR-MDS at higher risk of progression. However, the results need to be confirmed in a larger group.

Cytogenetics and molecular genetics of myelodysplastic neoplasms

According to the 2022 World Health Organization (WHO) Classification (5th edition), the term myelodysplastic neoplasms (abbreviated MDS) has been introduced to replace myelodysplastic syndromes. MDS are a group of clonal hematopoietic stem cell diseases characterized by cytopenia(s), dysplasia in one or more of lineages, ineffective hematopoiesis, and an increased risk of progression to bone marrow failure or to acute myeloid leukemia (AML). Current NCCN guidelines and recent review articles have provided in depth discussion on the clinical diagnosis and management of MDS. This review will focus on discussion of the WHO and International Consensus Classification (ICC) updates on the role of cytogenetics and molecular genetics in the diagnosis and risk stratification of MDS.

A Novel RUNX1 Genetic Variant Identified in a Young Male with Severe Osteoporosis

This case describes a young man with an unusual cause of severe osteoporosis and markedly deranged bone microarchitecture resulting in multiple fractures. A potentially pathogenic germline variant in the runt-related transcription factor 1 (RUNX1) gene was discovered by a focused 51-gene myeloid malignancy panel during investigation for his unexplained normochromic normocytic anemia. Further bone-specific genetic testing and a pedigree analysis were declined by the patient. Recent experimental evidence demonstrates that RUNX1 plays a key role in the regulation of osteogenesis and bone homeostasis during skeletal development, mediated by the bone morphogenic protein and Wnt signaling pathways. Therefore, rarer causes of osteoporosis, including those affecting bone formation, should be considered in young patients with multiple unexpected minimal trauma fractures. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

The RUNX Family of Proteins, DNA Repair, and Cancer

The RUNX family of transcription factors, including RUNX1, RUNX2, and RUNX3, are key regulators of development and can function as either tumor suppressors or oncogenes in cancer. Emerging evidence suggests that the dysregulation of RUNX genes can promote genomic instability in both leukemia and solid cancers by impairing DNA repair mechanisms. RUNX proteins control the cellular response to DNA damage by regulating the p53, Fanconi anemia, and oxidative stress repair pathways through transcriptional or non-transcriptional mechanisms. This review highlights the importance of RUNX-dependent DNA repair regulation in human cancers.

Understanding the Continuum between High-Risk Myelodysplastic Syndrome and Acute Myeloid Leukemia

Myelodysplastic syndrome (MDS) is a clonal hematopoietic neoplasm characterized by bone marrow dysplasia, failure of hematopoiesis and variable risk of progression to acute myeloid leukemia (AML). Recent large-scale studies have demonstrated that distinct molecular abnormalities detected at earlier stages of MDS alter disease biology and predict progression to AML. Consistently, various studies analyzing these diseases at the single-cell level have identified specific patterns of progression strongly associated with genomic alterations. These pre-clinical results have solidified the conclusion that high-risk MDS and AML arising from MDS or AML with MDS-related changes (AML-MRC) represent a continuum of the same disease. AML-MRC is distinguished from de novo AML by the presence of certain chromosomal abnormalities, such as deletion of 5q, 7/7q, 20q and complex karyotype and somatic mutations, which are also present in MDS and carry crucial prognostic implications. Recent changes in the classification and prognostication of MDS and AML by the International Consensus Classification (ICC) and the World Health Organization (WHO) reflect these advances. Finally, a better understanding of the biology of high-risk MDS and the mechanisms of disease progression have led to the introduction of novel therapeutic approaches, such as the addition of venetoclax to hypomethylating agents and, more recently, triplet therapies and agents targeting specific mutations, including FLT3 and IDH1/2. In this review, we analyze the pre-clinical data supporting that high-risk MDS and AML-MRC share the same genetic abnormalities and represent a continuum, describe the recent changes in the classification of these neoplasms and summarize the advances in the management of patients with these neoplasms.