Prognostic Markers of Myelodysplastic Syndromes

The impact of COVID-19 on microRNA and CD marker expression in AML patients

Acute myeloid leukaemia (AML) is an aggressive leukaemia characterised by uncontrolled blast cell proliferation. miRNAs and Clusters of Differentiation (CD) molecules play essential roles in AML progression. This study aims to investigate the effect of COVID-19 on the expression of circulating miRNA and CD molecules in AML. This cross-sectional study recruited 32 AML patients and 20 controls. Blood samples were collected and analysed using molecular cytogenetic, miRNA/mRNA expression, and flow cytometry techniques. The expression of miRNAs varied significantly between patients with AML and control individuals. The co-expression of these miRNAs was higher (P < 0.05), indicating that the presence of one miRNA led to increased expression of other miRNAs. A differential correlation was observed between miRNAs and CD markers. Additionally, miRNA 16, miRNA 21, and miRNA 221 showed significant downregulation (P < 0.05 and P < 0.01, respectively) in AML patients with COVID-19 infection compared to those without a disease. Interestingly, this study identified a higher expression level (P < 0.01) of miRNA 137 as a novel biomarker for AML patients. Moreover, the expression of miRNA 137 showed a high correlation (P < 0.05) with most of the CD markers examined in this study and FISH features data. Furthermore, a strong correlation (P < 0.01) was observed between CD markers and miRNA among AML patients with positive and negative COVID-19 infection. These data demonstrated that COVID-19 contributed to increased expression of microRNAs in AML patients. MicroRNA 137 was identified as a novel microRNA that exhibited significant differences between patients and healthy individuals, highlighting its role in AML pathogenesis.

Upregulation of S100A6 and its relation with CD34+ cells apoptosis in high-risk myelodysplastic syndromes patients

Objectives

Myelodysplastic syndromes (MDS) are a group of myeloid malignancies characterized by peripheral blood cytopenia and hematopoietic dysplasia that often progress to acute myeloid leukemia (AML). Increased apoptosis of normal hematopoietic cells and decreased apoptosis of malignant clonal hematopoietic cells in patients with MDS is some of the mechanisms leading to ineffective hematopoietic cells in the bone marrow. S100 calcium-binding protein A6 (S100A6) is upregulated in many malignancies. The overexpression of S100A6 in these malignancies has been associated with proliferation, migration, and invasion phenotypes in cancer cells, and we aimed to investigate the expression of S100A6 in CD34+ cells and the relationship between S100A6 expression and apoptosis of CD34+ cells in high-risk patients with MDS.

Methods

We measured S100A6 mRNA expression in bone marrow (BM) CD34+ cells from high-risk patients with MDS using RT-PCR. Next, we examined S100A6 expression in CD34+ cells using flow cytometry. We also analyzed the correlation between CD34+ cell apoptosis and S100A6 expression in high-risk patients with MDS.

Results

Our data showed increased S100A6 mRNA expression in CD34+ cells in patients with MDS (1.05 ± 0.69 vs. 0.17 ± 0.12; P＜0.01). The expression of S100A6 in BM CD34+ cells also increased (58.40 ± 13.18 vs. 45.83 ± 15.01). The expression of S100A6 in CD34+ cells and apoptosis of CD34+ cells were negatively correlated in patients (r = -0.75; P < 0.01).

Conclusions

Collectively, S100A6 may be a potential marker of CD34+ cells in high-risk patients with MDS and may participate in the pathological behaviors of CD34+ cells, such as evasion of apoptosis. Thus, S100A6 may be a potential target for eliminating minimal residual disease.

The Genetic Landscape of Myelodysplastic Neoplasm Progression to Acute Myeloid Leukemia

Myelodysplastic neoplasm (MDS) represents a heterogeneous group of myeloid disorders that originate from the hematopoietic stem and progenitor cells that lead to the development of clonal hematopoiesis. MDS was characterized by an increased risk of transformation into acute myeloid leukemia (AML). In recent years, with the aid of next-generation sequencing (NGS), an increasing number of molecular aberrations were discovered, such as recurrent mutations in FLT3, NPM1, DNMT3A, TP53, NRAS, and RUNX1 genes. During MDS progression to leukemia, the order of gene mutation acquisition is not random and is important when considering the prognostic impact. Moreover, the co-occurrence of certain gene mutations is not random; some of the combinations of gene mutations seem to have a high frequency (ASXL1 and U2AF1), while the co-occurrence of mutations in splicing factor genes is rarely observed. Recent progress in the understanding of molecular events has led to MDS transformation into AML and unraveling the genetic signature has paved the way for developing novel targeted and personalized treatments. This article reviews the genetic abnormalities that increase the risk of MDS transformation to AML, and the impact of genetic changes on evolution. Selected therapies for MDS and MDS progression to AML are also discussed.

Antibiotic-Resistant Pyrexia of Unknown Origin: An Unusual Presentation of Myelodysplastic Syndrome

A 74-year-old male presented to the emergency department (ED) with complaints of high-grade fever, productive cough, and difficulty breathing for three weeks, and a significant weight loss in the past six months. Despite a detailed investigation, diagnosis could not be achieved. Multiple empiric regimens were tried but no response was observed. Bone marrow biopsy was conducted after suspicious peripheral film result, which concluded that the patient was having myelodysplastic syndrome. Although pyrexia of unknown origin has a diverse group of diseases to evaluate for, and rare entities are difficult to diagnose, meticulous evaluation may give significant evidence for targeted diagnostic workup.

MicroRNAs in the Myelodysplastic Syndrome

The myelodysplastic syndrome (MDS) holds a special place among blood cancers, as it represents a whole spectrum of hematological disorders with impaired differentiation of hematopoietic precursors, bone marrow dysplasia, genetic instability and is noted for an increased risk of acute myeloid leukemia. Both genetic and epigenetic factors, including microRNAs (miRNAs), are involved in MDS development. MicroRNAs are short non-coding RNAs that are important regulators of normal hematopoiesis, and abnormal changes in their expression levels can contribute to hematological tumor development. To assess the prognosis of the disease, an international assessment system taking into account a karyotype, the number of blast cells, and the degree of deficiency of different blood cell types is used. However, the overall survival and effectiveness of the therapy offered are not always consistent with predictions. The search for new biomarkers, followed by their integration into the existing prognostic system, will allow for personalized treatment to be performed with more precision. Additionally, this paper explains how miRNA expression levels correlate with the prognosis of overall survival and response to the therapy offered.

The miRNA Profile in Non-Hodgkin's Lymphoma Patients with Secondary Myelodysplasia

Myelodysplastic syndromes are a group of clonal diseases of hematopoietic stem cells and are characterized by multilineage dysplasia, ineffective hematopoiesis, peripheral blood cytopenias, genetic instability and a risk of transformation to acute myeloid leukemia. Some patients with non-Hodgkin lymphomas (NHLs) may have developed secondary myelodysplasia before therapy. Bone marrow (BM) hematopoiesis is regulated by a spectrum of epigenetic factors, among which microRNAs (miRNAs) are special. The aim of this work is to profile miRNA expression in BM cells in untreated NHL patients with secondary myelodysplasia. A comparative analysis of miRNA expression levels between the NHL and non-cancer blood disorders samples revealed that let-7a-5p was upregulated, and miR-26a-5p, miR-199b-5p, miR-145-5p and miR-150-5p were downregulated in NHL with myelodysplasia (p < 0.05). We for the first time developed a profile of miRNA expression in BM samples in untreated NHL patients with secondary myelodysplasia. It can be assumed that the differential diagnosis for blood cancers and secondary BM conditions based on miRNA expression profiles will improve the accuracy and relevance of the early diagnosis of cancerous and precancerous lesions in BM.