The diagnosis, prognosis, and therapeutic application of MicroRNAs in haematological malignancies

Extracellular vesicles in cattle infected with bovine leukaemia virus: isolation and molecular analysis

Introduction

Exosomes are nanosized lipid bilayer membranous microvesicles, extracellularly released from a variety of mammalian cells. They mediate intercellular signalling by transporting several types of RNA, lipids and proteins and participate in the intercellular exchange of DNA, RNA, micro RNA, proteins and other components. These microvesicles are present in all body fluids in physiological and pathological conditions and reflect the state of the host organism. The aim of the study was the isolation and molecular determination of exosomes in blood and supernatant fluids of bovine dendritic cell cultures infected with bovine leukaemia virus (BLV).

Material and Methods

Exosomes were isolated by ultracentrifugation from the blood sera, plasma and supernatant of bovine BLV-infected and uninfected control dendritic cell cultures and their presence was confirmed with scanning electron and transmission electron microscopy. Western blot analysis of the structural BLV glycoprotein 51 (Env) and protein 24 (Gag) and of the tetraspanin exosomal markers CD9, CD63 and flotillin-1 was undertaken in BLV+ and control BLV- cattle.

Results

In exosomes of leukaemic cattle both BLV proteins and exosomal markers were detected. In healthy control animals only exosomal markers were determined.

Conclusion

Proteins of BLV were released with exosomes and could be transferred into recipient cells as an alternative propagation route not requiring virus infection.

Recent advances in the roles of exosomal microRNAs (exomiRs) in hematologic neoplasms: pathogenesis, diagnosis, and treatment

In clinical diagnosis, the capability of exosomes to serve as biomarkers is one of the most important biological functions of exosomes. The superior stability of exosome biomarkers makes them superior to those isolated from traditional samples such as serum and urine. Almost all body fluids contain exosomes, which contain proteins, nucleic acids, and lipids. Several molecular components of exosomes, including exosome proteins and microRNAs (miRNAs), are promising diagnostic biomarkers. These exosomes may carry genetic information by containing messenger RNA (mRNA) and miRNA. The miRNAs are small noncoding RNAs that regulate protein-coding genes by acting as translational repressors. It has been shown that miRNAs are mis-expressed in a range of conditions, including hematologic neoplasms. Additionally, miRNAs found within exosomes have been linked with specific diseases, including hematologic neoplasms. Numerous studies suggest that circulating exosomes contain miRNAs similar to those found in parental cancer cells. Exosomes contain miRNAs that are released by almost all kinds of cells. MiRNAs are packaged into exosomes and delivered to recipient cells, and manipulate its function. It has been recognized that exosomes are new therapeutic targets for immunotherapy and biomedicine of cancers. The current review discusses the current evidence around exosomal miRNAs involved in the pathogenesis, diagnosis, and treatment of hematologic neoplasms. Video Abstract.

AL amyloidosis clonal plasma cells are regulated by microRNAs and dependent on anti-apoptotic BCL2 family members

BACKGROUND

Noncoding RNAs such as microRNAs (miRNAs) have attracted attention as biological pathway regulators, which differ from chromosomal translocations and gene point mutations. Their involvement in the molecular mechanisms underlying light chain (AL) amyloidosis pathogenesis is yet to be elucidated.

AIMS

To decipher specific miRNA expression profile in AL-amyloidosis and to examine how miRNAs are involved in AL pathogenesis.

METHODS

The expression profile of miRNAs and mRNA from bone marrow (BM)-derived CD138+ cells were determined using the NanoString nCounter assay and RNA-Seq, respectively. The effect of aberrantly expressed miRNAs on potential molecular targets was analyzed by qRT-PCR, Western blot, Mito-potential assay, and Annexin-PI staining.

RESULTS

Genes which were significantly differentially expressed between AL-amyloidosis and MM, were found to be involved in cell growth and apoptotic mechanisms. Specifically, BCL2L1, MCL1, and BCL2 were upregulated in AL-amyloidosis compared with MM and controls. The levels of miR-181a-5p and miR-9-5p, which regulate the above-mentioned genes, were lower in BM samples from AL-amyloidosis compared with controls, providing a mechanism for BCL2 family gene upregulation. When miR-9-5p and miR-181a-5p were overexpressed in ALMC1 cells, BCL2L1, MCL1, and BCL2 were downregulated and induced apoptosis. Treatment of ALMC-1 cells with venetoclax, (BCL-2 inhibitor), resulted in the upregulation of those miRNAs, the downregulation of BCL2, MCL1, and BCL2L1 mRNA and protein levels, and subsequent apoptosis.

CONCLUSION

Our findings suggest that miR-9-5p and miR-181a-5p act as tumor-suppressors whose downregulation induces anti-apoptotic mechanisms underlying the pathogenesis of AL-amyloidosis. The study highlights the post-transcriptional regulation in AL-amyloidosis and provides pathogenetic evidence for the potential use of BCL-2 inhibitors in this disease.

MicroRNA-199a-3p Exhibits Beneficial Effects in Asymptomatic Atherosclerosis by Inhibiting Vascular Smooth Muscle Cell Proliferation and Migration

Atherosclerosis (AS) is a serious healthy burden worldwide, it occurs accompany with the disfunction of vascular smooth muscle cells (VSMCs). MicroRNAs play pivotal role in the pathogenesis of various diseases. This study aimed to investigate the expression and clinical value of miR-199a-3p in patients with asymptomatic AS, and further explore its regulatory role on VSMCs biological function. Quantitative real-time PCR was used to estimate the expression of miR-199a-3p. Correlation of miR-199a-3p with carotid intima-media thickness (CIMT) and C-reactive protein (CRP) was evaluated by Pearson correlation coefficient. A receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic value of miR-199a-3p. Effects of miR-199a-3p on cell proliferation and migration in VSMCs were analyzed using cell-counting method and Transwell assay. Luciferase reporter assay was performed for the target gene analysis. Serum expression of miR-199a-3p was decreased in asymptomatic AS patients compared with the healthy controls. The negative correlations of miR-199a-3p with CIMT and CRP were obtained. The decreased miR-199a-3p was proved to have diagnostic accuracy with an area under the ROC curve (AUC) of 0.912, and was an independent predictor for the occurrence of asymptomatic AS. In VSMCs, overexpression of miR-199a-3p led to inhibited cell proliferation and migration, while the knockdown of miR-199a-3p resulted in the opposite results. SP1 was proved to be the target gene of miR-199a-3p. Taken together, downregulated expression of miR-199a-3p is a candidate diagnostic biomarker in the patients with asymptomatic AS. Overexpression of miR-199a-3p exists suppressive effects on VSMC proliferation and migration, indicating that miR-199a-3p may be a potential therapeutic target for AS treatment.

miRNAs mediated drug resistance in hematological malignancies

Despite improvements in the therapeutic approaches for hematological malignancies in the last decades, refractory disease still occurs, and cancer drug resistance still remains a major hurdle in the clinical management of these cancer patients. The investigation of this problem has been extensive and different mechanism and molecules have been associated with drug resistance. MicroRNAs (miRNAs) have been described as having an important action in the emergence of cancer, including hematological tumors, and as being major players in their progression, aggressiveness and response to treatments. Moreover, miRNAs have been strongly associated with cancer drug resistance and with the modulation of the sensitivity of cancer cells to a wide array of anticancer drugs. Furthermore, this role has also been reported for miRNAs packaged into extracellular vesicles (EVs-miRNAs), which in turn have been described as essential for the horizontal transfer of drug resistance to sensitive cells. Several studies have been suggesting the use of miRNAs as biomarkers for drug response and clinical outcome prediction, as well as promising therapeutic tools in hematological diseases. Indeed, the combination of miRNA-based therapeutic tools with conventional drugs contributes to overcome drug resistance. This review addresses the role of miRNAs in the pathogenesis of hematological malignances, namely multiple myeloma, leukemias and lymphomas, highlighting their important action (either in their cell-free circulating form or within circulating EVs) in drug resistance and their potential clinical applications.

Diagnostic and prognostic significance of aberrant miR-652-3p levels in patients with acute decompensated heart failure and acute kidney injury

Objective

This study aimed to examine a novel microRNA (miR-652-3p) biomarker to improve early diagnosis of acute kidney injury (AKI) in patients with acute decompensated heart failure (ADHF) and to evaluate the survival predictive value of miR-652-3p.

Methods

We retrospectively analyzed the data of 196 patients with ADHF, including 65 who developed AKI during hospitalization. Neutrophil gelatinase-associated lipocalin (NGAL) levels were measured in serum and urine samples. Real-time quantitative PCR was applied to evaluate miR-652-3p mRNA expression. The diagnostic performance of miR-652-3p was examined using receiver operating characteristic curve analysis. The prognostic value of miR-652-3p was also analyzed.

Results

Serum and urinary NGAL and miR-652-3p levels were elevated in patients with ADHF and AKI. Serum and urinary miR-652-3p expression had diagnostic value in predicting AKI onset in patients with ADHF, and it had improved diagnostic performance when used with NGAL. Patients with AKI and high miR-652-3p levels had a high failure rate of renal recovery and poor 180-day survival.

Conclusion

Serum and urinary miR-652-3p may be a candidate biomarker for early diagnosis of AKI in patients with ADHF and for predicting the prognosis of AKI. The combination of NGAL and miR-652-3p may accurately predict AKI onset in ADHF.

Exosome: From leukemia progression to a novel therapeutic approach in leukemia treatment

Exosomes, as small vesicles, are released by tumor cells and tumor microenvironment (cells and function as key intercellular mediators and effects on different processes including tumorigenesis, angiogenesis, drug resistance, and evasion from immune system. These functions are due to exosomes' biomolecules which make them as efficient markers in early diagnosis of the disease. Also, exosomes have been recently applied in vaccination. The potential role of exosomes in immune response toward leukemic cells makes them efficient immunotherapeutic agents treating leukemia. Furthermore, variations in exosomes contents make them beneficial to be used in treating different diseases. This review introduces the role of exosomes in the development of hematological malignancies and evaluates their functional role in the treatment of these malignancies.

Abnormal microRNA expression in the course of hematological malignancies

Research on the carcinogenesis process is currently focused primarily on understanding its genetic basis and molecular abnormalities that may be predictive factors and therapeutic targets. It was clearly confirmed recently that microRNAs are involved in the mechanisms of leukocyte development, differentiation, and apoptosis, as well as in the pathogenesis of proliferative diseases of the hematopoietic system. Currently, research strategies allow determination of the deregulation of microRNA profiles in relation to other cytogenetic aberrations, as well as prognostic factors and primary end points. The problem of the possibility of their use as therapeutic targets is also increasingly discussed. In this article, we analyze literature data on abnormalities in microRNA expression in proliferative diseases of the hematopoietic system in the context of classic cytogenetic and molecular aberrations.

miR-223 decreases cell proliferation and enhances cell apoptosis in acute myeloid leukemia via targeting FBXW7

The expression of microRNA-223 (miR-233) has been investigated in various types of cancer. However, to the best of our knowledge, the expression and function of miR-223 in acute myeloid leukemia (AML) remains to be elucidated. The expression of miR-223 was measured by reverse transcription-quantitative polymerase chain reaction. Following transfection with miR-223, cell viability assays, cell apoptosis assays, western blot analysis and luciferase assays were conducted in AML cell lines. In the present study, it was initially observed that miR-223 was downregulated in AML patients compared with healthy subjects. It was also demonstrated that miR-223 inhibited cell proliferation and enhanced cell apoptosis in AML cell lines. Additionally, the present study provided evidence that miR-223 may directly target F-box and WD repeat domain containing 7 in AML. The identification of candidate target genes of miR-223 may provide an understanding of the potential mechanisms underlying the development of AML. In conclusion, the results of the present study have therapeutic implications and may be exploited for further treatment of AML.