Prognostic effect of RUNX1 mutations in myelodysplastic syndromes: a meta-analysis

Iron Overload, Oxidative Stress, and Somatic Mutations in MDS: What Is the Association?

INTRODUCTION

Iron overload (IOL) accumulates in myelodysplastic syndromes (MDS) from expanded erythropoiesis and transfusions. Somatic mutations (SM) are frequent in MDS and stratify patient risk. MDS treatments reversing or limiting transfusion dependence are limited.

METHODS

The literature was reviewed on how IOL and oxidative stress interact with specific SM in MDS to influence cellular physiology. PubMed searches included keywords of each specific mutation combined with iron, oxidative stress, and reactive oxygens species (ROS). Papers relevant to hematopoietic stem/progenitor cells, the bone marrow microenvironment, MDS, AML or other myeloid disorders were preferred. Included were the most frequent SM in MDS, SM of the International Prognostic Scoring System-Molecular (IPSS-M), of familial predisposing conditions and the CMML PSS-molecular.

RESULTS

About 31 SM plus four familial conditions were searched. Discussed are the frequency of each SM, whether function is gained or lost, early or late SM status, a function of the unmutated gene, and function considering iron and oxidative stress.

DISCUSSION

Given limited effective MDS therapies, considering how IOL and ROS interact with SM to influence cellular physiology in the hematopoietic system, increasing bone marrow failure progression or malignant transformation may be of benefit and support optimization of measures to reduce IOL or neutralize ROS.

Prognostic significance of GATA2 in patients with MDS/AML: a systematic review and meta-analysis

GATA2 deficiency syndrome is a heterogeneous disorder characterized by a high risk of developing myelodysplastic syndrome (MDS)/acute myeloid leukaemia (AML). We conducted a meta-analysis of the literature to explore the prognostic significance of GATA2 mutations in patients diagnosed with MDS/AML, as previous studies have yielded conflicting findings regarding the impact of GATA2 mutations on patient outcomes. We conducted a comprehensive literature search of databases such as PubMed, Embase, the Cochrane Library, and the Web of Science to obtain studies on the prognostic significance of GATA2 mutations in patients with MDS/AML that were published through January 2024. We extracted the hazard ratio (HR) and 95% confidence interval (CI) for overall survival (OS), disease-free survival (DFS), and event-free survival (EFS). The meta-analysis was conducted by choosing either a fixed-effect model or a random-effect model, depending on the variability observed among the studies. A total of 13 cohort studies were included in the final meta-analysis, including 2714 patients with MDS, of whom 644 had GATA2 mutations. The results revealed that GATA2 mutations had an adverse impact on OS (HR = 1.54, 95% CI = 1.08-2.18, P = 0.02) and EFS (HR = 1.32, 95% CI = 1.01-1.72, P = 0.04), but no significant effect on DFS (HR = 1.21, 95% CI = 0.89-1.64, P = 0.23). GATA2 mutations were associated with a significantly shorter OS in MDS patients (HR = 2.56, 95% CI = 1.42-4.06, P = 0.002) but not in AML patients (HR = 1.08, 95% CI = 0.92-1.26, P = 0.37). Our meta-analysis revealed that GATA2 mutations are associated with unfavourable outcomes in patients with MDS/AML. Furthermore, patients harbouring these mutations should be prioritized for aggressive therapeutic interventions.

A de novo germline RUNX1 variant preceding development of concurrent T-lymphoblastic leukemia and myelodysplastic syndrome

Germline variants of the RUNX1 gene are associated with RUNX1 Familial Platelet Disorder with Associated Myeloid Malignancies (RUNX1-FPDMM), which is characterized by an increased risk of developing myelodysplastic syndrome (MDS) and/or acute myeloid leukemia. Patients with FPDMM have also been described to develop B- or T-cell acute lymphoblastic leukemia. We present a pediatric patient with RUNX1-FPDMM that evolved into concurrent MDS and T-cell acute lymphoblastic leukemia after a decade of monitoring with serial blood counts. We aim to highlight the treatment challenges and clinical decision-making that may be anticipated in this unique disorder, as well as the potentially curative role for allogenic hematopoietic stem cell transplant in the first complete remission.

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.

The clinical phenotype of germline RUNX1 mutations in relation to the accompanying somatic variants and RUNX1 isoform expression

Germline RUNX1 mutations lead to familial platelet disorder with associated myeloid malignancy (FPDMM), characterized by thrombocytopenia, abnormal bleeding, and an elevated risk of developing myelodysplastic neoplasia (MDS) and acute myeloid leukemia (AML) at young age. However, it is not known why or how germline carriers of RUNX1 mutations have a particular propensity to develop myeloid hematologic malignancies, but the acquisition and composition of somatic mutations are believed to initiate and determine disease progression. We present a novel family pedigree that shares a common germline RUNX1R204* variant and exhibits a spectrum of somatic mutations and related myeloid malignancies (MM). RUNX1 mutations are associated with inferior clinical outcome; however, the proband of this family developed MDS with ring sideroblasts (MDS-RS), classified as a low-risk MDS subgroup. His relatively indolent clinical course is likely due to a specific somatic mutation in the SF3B1 gene. While the three main RUNX1 isoforms have been ascribed various roles in normal hematopoiesis, they are now being increasingly recognized as involved in myeloid disease. We investigated the RUNX1 transcript isoform patterns in the proband and his sister, who carries the same germline RUNX1R204* variant, and has FPDMM but no MM. We demonstrate a RUNX1a increase in MDS-RS, as previously reported in MM. Interestingly, we identify a striking unbalance of RUNX1b and -c in FPDMM. In conclusion, this report reinforces the relevance of somatic variants on the clinical phenotypic heterogeneity in families with germline RUNX1 deficiency and investigates a potential new role for RUNX1 isoform disequilibrium as a mechanism for development of MM.

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

Patients with lower-risk myelodysplastic syndromes (LR-MDS) have a generally favorable prognosis; however, a small proportion of cases progress rapidly. This study aimed to define molecular biomarkers predictive of LR-MDS progression and to uncover cellular pathways contributing to malignant transformation. The mutational landscape was analyzed in 214 LR-MDS patients, and at least one mutation was detected in 137 patients (64%). Mutated RUNX1 was identified as the main molecular predictor of rapid progression by statistics and machine learning. To study the effect of mutated RUNX1 on pathway regulation, the expression profiles of CD34 + cells from LR-MDS patients with RUNX1 mutations were compared to those from patients without RUNX1 mutations. The data suggest that RUNX1-unmutated LR-MDS cells are protected by DNA damage response (DDR) mechanisms and cellular senescence as an antitumor cellular barrier, while RUNX1 mutations may be one of the triggers of malignant transformation. Dysregulated DDR and cellular senescence were also observed at the functional level by detecting γH2AX expression and β-galactosidase activity. Notably, the expression profiles of RUNX1-mutated LR-MDS resembled those of higher-risk MDS at diagnosis. This study demonstrates that incorporating molecular data improves LR-MDS risk stratification and that mutated RUNX1 is associated with a suppressed defense against LR-MDS progression.