MicroRNA-223 regulates granulopoiesis but is not required for HSC maintenance in mice

Advantages of nanomedicine over the conventional treatment in Acute myeloid leukemia

Leukemia is a cancer of blood cells that mainly affects the white blood cells. In acute myeloid leukemia (AML) sudden growth of cancerous cells occurs in blood and bone marrow, and it disrupts normal blood cell production. Most patients are asymptomatic, but it spreads rapidly and can become fatal if left untreated. AML is the prevalent form of leukemia in children. Risk factors of AML include chemical exposure, radiation, genetics, etc. Conventional diagnostic methods of AML are complete blood count tests and bone marrow aspiration, while conventional treatment methods involve chemotherapy, radiation therapy, and bone marrow transplant. There is a risk of cancer cells spreading progressively to the other organs if left untreated, and hence, early diagnosis is required. The conventional diagnostic methods are time- consuming and have drawbacks like harmful side effects and recurrence of the disease. To overcome these difficulties, nanoparticles are employed in treating and diagnosing AML. These nanoparticles can be surface- modified and can be used against cancer cells. Due to their enhanced permeability effect and high surface-to-volume ratio they will be able to reach the tumour site which cannot be reached by traditional drugs. This review article talks about how nanotechnology is more advantageous over the traditional methods in the treatment and diagnosis of AML.

MiR-223-3p promotes genomic stability of hematopoietic progenitors after radiation

When hematopoietic cells are overwhelmed with ionizing radiation (IR) DNA damage, the alternative non-homologous end-joining (aNHEJ) repair pathway is activated to repair stressed replication forks. While aNHEJ can rescue cells overwhelmed with DNA damage, it can also mediate chromosomal deletions and fusions, which can cause mis-segregation in mitosis and resultant aneuploidy. We previously reported that a hematopoietic microRNA, miR-223-3p, normally represses aNHEJ. We found that miR-223-/- mice have increased survival of hematopoietic stem and progenitor cells (HSPCs) after sublethal IR. However, this came at the cost of significantly more genomic aberrancies, with miR-223-/- hematopoietic progenitors having increased metaphase aberrancies, including chromothripsis, and increased sequence abnormalities, especially deletions, which is consistent with aNHEJ. These data imply that when an HSPC is faced with substantial DNA damage, it may trade genomic damage for its own survival by choosing the aNHEJ repair pathway, and this choice is regulated in part by miR-223-3p.

Alterations in microRNA Expression during Hematopoietic Stem Cell Mobilization

Simple Summary

Lymphoproliferative disorders comprise a heterogeneous group of hematological malignancies characterized by abnormal lymphocyte proliferation. Autologous hematopoietic stem cell transplantation plays a very important role in the treatment of lymphoproliferative diseases. The key element in this process is the effective mobilization of hematopoietic cells from the marrow niche to the peripheral blood. Mobilization of HSC is regulated by many factors, out of which miRNAs present in the hematopoietic niche via targeting cytokines, and signaling pathways may play an important regulatory role. This study investigated the expression of selected miRNAs in patients with multiple myeloma, Hodgkin’s lymphomas, and non-Hodgkin’s lymphomas undergoing mobilization procedures. The aim of the study was to evaluate the expression of hsa-miR-15a-5p, hsa-miR-16-5p, hsa-miR-34a-5p, hsa-miR-126-3p, hsa-miR-146a-5p, hsa-miR-155-5p, and hsa-miR-223-3p during the mobilization procedure, and to assess their role in mobilization efficacy. The level of miRNAs was tested at two time points before the initiation of mobilization and on the day of the first apheresis. Our results suggest that the investigated miRNAs, especially hsa-miR-146a-5p, may influence the efficacy of HSC mobilization.

Abstract

microRNAs play an important role in the regulation of gene expression, cell fate, hematopoiesis, and may influence the efficacy of CD34+ cell mobilization. The present study examines the role of hsa-miR-15a-5p, hsa-miR-16-5p, hsa-miR-34a-5p, hsa-miR-126-3p, hsa-miR-146a-5p, hsa-miR-155-5p, and hsa-miR-223-3p in the course of hematopoietic stem cell mobilization. The numbers of CD34+ cells collected in patients with hematological malignancies (39 multiple myelomas, 11 lymphomas) were determined during mobilization for an autologous hematopoietic stem cell transplantation. The miRNA level was evaluated by RT-PCR. Compared to baseline, a significant decline in hsa-miR-15a-5p, hsa-miR-16-5p, hsa-miR-126-3p, hsa-miR-146a-5p, and hsa-miR-155-5p was observed on the day of the first apheresis (day A). An increase was observed only in the expression of hsa-miR-34a-5p. On day A, a negative correlation was found between hsa-miR-15a-5p and hsa-miR-146a-5p levels and the number of CD34+ cells in peripheral blood. A negative correlation was observed between hsa-miR-146a-5p and the number of collected CD34+ cells after the first apheresis. Good mobilizers, defined according to GITMO criteria, demonstrated a lower hsa-miR-146a-5p level on day A than poor mobilizers. Patients from the hsa-miR-146a-5p “low expressors” collected more CD34+ cells than “high expressors”. Our results suggest that the investigated miRNAs, especially hsa-miR-146a-5p, may influence the efficacy of HSC mobilization.

The N-glycome regulates the endothelial-to-hematopoietic transition

Definitive hematopoietic stem and progenitor cells (HSPCs) arise from the transdifferentiation of hemogenic endothelial cells (hemECs). The mechanisms of this endothelial-to-hematopoietic transition (EHT) are poorly understood. We show that microRNA-223 (miR-223)-mediated regulation of N-glycan biosynthesis in endothelial cells (ECs) regulates EHT. miR-223 is enriched in hemECs and in oligopotent nascent HSPCs. miR-223 restricts the EHT of lymphoid-myeloid lineages by suppressing the mannosyltransferase alg2 and sialyltransferase st3gal2, two enzymes involved in protein N-glycosylation. ECs that lack miR-223 showed a decrease of high mannose versus sialylated sugars on N-glycoproteins such as the metalloprotease Adam10. EC-specific expression of an N-glycan Adam10 mutant or of the N-glycoenzymes phenocopied miR-223 mutant defects. Thus, the N-glycome is an intrinsic regulator of EHT, serving as a key determinant of the hematopoietic fate.

Progressive Control of Streptococcus agalactiae-Induced Innate Inflammatory Response Is Associated with Time Course Expression of MicroRNA-223 by Neutrophils

Group B streptococcus (GBS) is a human-pathogenic bacterium inducing a strong inflammatory response that may be detrimental for host tissues if not finely regulated. The inflammatory response can be modulated by different molecular mechanisms, among which growing evidence points toward the crucial role of microRNAs (miRNAs). Regarding innate inflammatory response, studies have reported that miR-223 is essential for the control of granulocyte proliferation and activation. Moreover, a number of investigations on miRNA expression profiling performed in various inflammatory settings have revealed that miR-223 is among the top differentially expressed miRNAs. Yet the dynamic pattern of expression of miR-223 in vivo with respect to the evolution of the inflammatory process, especially in microbial infection, remains elusive. In this study, we analyzed the kinetic expression of miR-223 in an inflammatory model of GBS-induced murine pneumonia and looked for correlates with inflammatory markers, including innate cell infiltrates. We found that miR-223 expression is rapidly induced at very early time points (3 to 6 h postinfection [p.i.]) mainly by lung-infiltrating neutrophils. Interestingly, the level of miR-223 accumulating in the lungs remains higher at later stages of infection (24 h and 48 h p.i.), and this correlates with reduced expression of primary inflammatory cytokines and chemokines and with a shift in infiltrating monocyte and macrophage subtypes toward a regulatory phenotype. Transient inhibition of miR-223 by an antagomir resulted in significant increase of CXCL2 expression and partial enhancement of infiltrating neutrophils in GBS-infected lung tissues. This suggests the potential contribution of miR-223 to the resolution phase of GBS-induced acute inflammation.

Deficient Regulatory Innate Lymphoid Cells and Differential Expression of miRNAs in Acute Myeloid Leukemia Quantified by Next Generation Sequence

Background

A new regulatory subpopulation of ILCs, ILCreg has been identified in mouse and human intestines. ILCregs share characteristics with both innate lymphoid cells and regulatory cells; however, the significance of CD45⁺Lin^-CD127⁺IL-10⁺ ILCregs in patients with AML remains unclear. Intriguingly, ILCregs constitutively express id2, id3, sox4, tgfbr1, tgfbr2, il2rb and il2rg, but the significance of miRNAs associated with these genes has yet to be explored. In this study, we evaluate ILCreg frequency, ILCreg gene-associated miRNA quantification, and its significance in patients with AML and normal donors.

Methods

Using 4 color combinations of surface and intracellular antibody staining, the CD45⁺Lin^-CD127⁺IL-10⁺ ILCregs from 12 normal donors and 42 patients newly diagnosed with AML were measured by flow cytometry. Plasma samples and bone marrow cells from 6 normal donors and 9 patients with AML were studied by next-generation sequence miRNAs quantification.

Results

Our results showed that the frequency of ILCregs was 0.8924±1.3791% in bone marrow (BM) cells from normal donors and 0.2434±0.5344% in BM cells from AML patients. The frequency of ILCreg cells in AML patients was significantly lower than that in normal donors (P<0.01). Furthermore, the frequency of the CD45⁺Lin^-CD127⁺IL-10^- subset was 4.0869±6.7701% and 0.2769±0.2526% from normal donors and AML patients, respectively. There was a statistically significant difference of CD45⁺Lin^-CD127⁺IL-10^- cells between normal donors and AML patients (p<0.01). miRNA detection results showed 376 miRNAs from plasma and 182 miRNAs from BM cell samples with expression levels with a statistically significant difference between AML patients and normal donors (both Q and P-value < 0.001). Analysis of miRNAs from ILCregs associated genes including id2, id3, sox4, tgfbr1, tgfbr2, il2rb, and il3rg, from normal donors and AML patients demonstrated 34 miRNA from plasma samples and 14 miRNA segments from BM cell samples with a statistically significant difference between AML patients and normal donors (both Q and P-value <0.001). Among them, 4 miRNAs (hsa-miR-193b-3p, hsa-miR-1270, hsa-miR-210-3p, and hsa-miR-486-3p) were detected in both plasma and BM cell samples.

Conclusion

Our study enumerated ILCregs, then measured miRNAs from those ILCregs in AML samples for the first time. The results demonstrated the deficiency of ILCreg and differential expression of miRNAs in patients with AML.

Genome-wide miRNA profiling and pivotal roles of miRs 125a-5p and 17-92 cluster in human neutrophil maturation and differentiation of acute myeloid leukemia cells

MicroRNAs (miRNAs, miRs) are short non-coding post-transcriptional regulators of gene expression in normal physiology and disease. Acute myeloid leukemia is characterized by accumulation of malignantly transformed immature myeloid precursors, and differentiation therapy, used to overcome this differentiation blockage, has become a successful therapeutic option. The human HL-60 acute leukemia cell line serves as a cell culture model for granulocytic maturation, and dimethyl sulfoxide (DMSO) incubation leads to its differentiation towards neutrophil-like cells, as assessed by biochemical, functional and morphological parameters. DMSO-induced HL-60 cell differentiation constitutes an excellent model to examine molecular processes that turn a proliferating immortal leukemic cell line into mature non-proliferating and apoptosis-prone neutrophil-like end cells. By performing genome-wide miRNA profiling and functional assays, we have identified a signature of 86 differentially expressed canonical miRNAs (51 upregulated; 35 downregulated) during DMSO-induced granulocytic differentiation of HL-60 cells. Quantitative real-time PCR was used to validate miRNA expression. Among these differentially expressed canonical miRNAs, we found miR-125a-5p upregulation and miR-17-92 cluster downregulation acted as major regulators of granulocytic differentiation in HL-60 cells. Enforced expression of miR-125a-5p promoted granulocytic differentiation in HL-60 cells, whereas miR-17-92 ectopic expression inhibited DMSO-induced HL-60 granulocytic differentiation. Ectopic expression of miR-125a-5p also promoted granulocytic differentiation in human acute promyelocytic leukemia NB4 cells, as well as in naïve human primary CD34⁺-hematopoietic progenitor/stem cells. These findings provide novel molecular insights into the identification of miRNAs regulating granulocytic differentiation of human leukemia cells and normal CD34⁺-hematopoietic progenitor/stem cells, and may assist in the development of novel miRNA-targeted therapies for leukemia.

MiR223-3p promotes synthetic lethality in BRCA1-deficient cancers

Defects in DNA repair give rise to genomic instability, leading to neoplasia. Cancer cells defective in one DNA repair pathway can become reliant on remaining repair pathways for survival and proliferation. This attribute of cancer cells can be exploited therapeutically, by inhibiting the remaining repair pathway, a process termed synthetic lethality. This process underlies the mechanism of the Poly-ADP ribose polymerase-1 (PARP1) inhibitors in clinical use, which target BRCA1 deficient cancers, which is indispensable for homologous recombination (HR) DNA repair. HR is the major repair pathway for stressed replication forks, but when BRCA1 is deficient, stressed forks are repaired by back-up pathways such as alternative nonhomologous end-joining (aNHEJ). Unlike HR, aNHEJ is nonconservative, and can mediate chromosomal translocations. In this study we have found that miR223-3p decreases expression of PARP1, CtIP, and Pso4, each of which are aNHEJ components. In most cells, high levels of microRNA (miR) 223-3p repress aNHEJ, decreasing the risk of chromosomal translocations. Deletion of the miR223 locus in mice increases PARP1 levels in hematopoietic cells and enhances their risk of unprovoked chromosomal translocations. We also discovered that cancer cells deficient in BRCA1 or its obligate partner BRCA1-Associated Protein-1 (BAP1) routinely repress miR223-3p to permit repair of stressed replication forks via aNHEJ. Reconstituting the expression of miR223-3p in BRCA1- and BAP1-deficient cancer cells results in reduced repair of stressed replication forks and synthetic lethality. Thus, miR223-3p is a negative regulator of the aNHEJ DNA repair and represents a therapeutic pathway for BRCA1- or BAP1-deficient cancers.

Differential expression of miRNAs in acute myeloid leukemia quantified by Nextgen sequencing of whole blood samples

New approaches are needed for understanding and treating acute myeloid leukemia (AML). MicroRNAs (miRs) are important regulators of gene expression in all cells and disruption of their normal expression can lead to changes in phenotype of a cell, in particular the emergence of a leukemic clone. We collected peripheral blood samples from 10 adult patients with newly diagnosed AML, prior to induction chemotherapy, and 9 controls. Two and a half ml of whole blood was collected in Paxgene RNA tubes. MiRNA was purified using RNeasy mini column (Qiagen). We sequenced approximately 1000 miRs from each of 10 AML patients and 9 controls. In subset analysis, patients with NPM1 and FLT3 mutations showed the greatest number of miRNAs (63) with expression levels that differed from control with adjusted p-value of 0.05 or less. Some of these miRs have been described previously in association with leukemia, but many are new. Our approach of global sequencing of miRs as opposed to microarray analysis removes the bias regarding which miRs to assay and has demonstrated discovery of new associations of miRs with AML. Another strength of our approach is that sequencing miRs is specific for the 5p or 3p strand of the gene, greatly narrowing the proposed target genes to study further. Our study provides new information about the molecular changes that lead to evolution of the leukemic clone and offers new possibilities for monitoring relapse and developing new treatment strategies.

miRNAs in acute myeloid leukemia

MicroRNAs (miRNAs) are small, non-coding RNAs found throughout the eukaryotes that control the expression of a number of genes involved in commitment and differentiation of hematopoietic stem cells and tumorigenesis. Widespread dysregulation of miRNAs have been found in hematological malignancies, including human acute myeloid leukemia (AML). A comprehensive understanding of the role of miRNAs within the complex regulatory networks that are disrupted in malignant AML cells is a prerequisite for the development of therapeutic strategies employing miRNA modulators. Herein, we review the roles of emerging miRNAs and the miRNAs regulatory networks in AML pathogenesis, prognosis, and miRNA-directed therapies.

miRNA-15a, miRNA-16, miRNA-126, miRNA-146a, and miRNA-223 expressions in autologous hematopoietic stem cell transplantation and their impact on engraftment

OBJECTIVE

MicroRNAs engaged in angiogenesis and hematopoiesis can influence hematopoietic stem cells (HSCs) homing after transplantation by targeting bone marrow niche microenvironment. This study aimed to examine the kinetics of miRNA-15a, miRNA-16, miRNA-126, miRNA-146a, and miRNA-223 in autologous HSC transplantation settings.

METHODS

The study comprised of 51 patients with hematological malignancies (42 multiple myeloma, 9 lymphoma). Samples were taken at four time points: before conditioning, after chemotherapy but prior to autologous HSC transplantation (day 0), on day +7, and +14 days after HSCT. The miRNA levels were evaluated by the real-time PCR method.

RESULTS

A significant, steady decline of all tested microRNAs in the course of transplantation, as compared to the baseline, was found. The study revealed that higher levels of miRNA-15a, miRNA-16, miRNA-126, and miRNA-146a on day 0 correlated with longer time to engraftment. Additionally, a positive correlation between the levels of miRNA-15a, miRNA-146a, and miRNA-223 assessed on day +7 and the time to engraftment was observed.

CONCLUSIONS

In conclusion, all investigated microRNAs changed significantly in the course of transplantation. Our results suggest that the miRNAs may participate in hematopoietic recovery in the early post-transplant period and influence engraftment efficiency after HSCT.

MicroRNA: an important regulator in acute myeloid leukemia

MicroRNAs (miRNAs) are a general class of endogenous non-coding RNAs with a length of 22 nucleotides, widely existing in diverse species and playing important roles in malignancies initiation and progression. MiRNAs are essential to many in vivo biological processes such as cell proliferation, apoptosis, immune response, and tumorigenesis. Significant progress till date has been made in understanding the roles of microRNAs in normal hematopoiesis and hematopoietic malignant diseases. In this review, we summarize the particular signatures of microRNAs in acute myeloid leukemia (AML) patients with specific karyotype and the clinical significance of microRNAs in early diagnosis and treatment. MicroRNAs hypermethylation was also proved to correlate with the pathogenesis of AML. However, the target genes and exact pathways of microRNAs participating in these processes are still unknown and more efforts need to be made in the near future.