MicroRNA-181 as a prognostic biomarker for survival in acute myeloid leukemia: a meta-analysis

The potential role of serum extracellular vesicle derived small RNAs in AML research as non-invasive biomarker

BACKGROUND

Extracellular vesicles (EV) are cell-derived vesicles released by all cells in health and disease. Accordingly, EVs are also released by cells in acute myeloid leukemia (AML), a hematologic malignancy characterized by uncontrolled growth of immature myeloid cells, and these EVs likely carry markers and molecular cargo reflecting the malignant transformation occurring in diseased cells. Monitoring antileukemic or proleukemic processes during disease development and treatment is essential. Therefore, EVs and EV-derived microRNA (miRNA) from AML samples were explored as biomarkers to distinguish disease-related patterns ex vivo or in vivo.

METHODOLOGY

EVs were purified from serum of healthy (H) volunteers and AML patients by immunoaffinity. EV surface protein profiles were analyzed by multiplex bead-based flow cytometry (MBFCM) and total RNA was isolated from EVs prior to miRNA profiling via small RNA sequencing.

RESULTS

MBFCM revealed different surface protein patterns in H versus AML EVs. miRNA analysis showed individual as well as highly dysregulated patterns in H and AML samples.

CONCLUSIONS

In this study, we provide a proof-of-concept for the discriminative potential of EV derived miRNA profiles as biomarkers in H versus AML samples.

Microenvironment and drug resistance in acute myeloid leukemia: Do we know enough?

Acute myeloid leukemia (AMLs), as the name suggests, often develop suddenly and are very progressive forms of cancer. Unlike in acute promyelocytic leukemia, a subtype of AML, the outcomes in most other AMLs remain poor. This is mainly attributed to the acquired drug resistance and lack of targeted therapy. Different studies across laboratories suggest that the cellular mechanisms to impart therapy resistance are often very dynamic and should be identified in a context-specific manner. Our review highlights the progress made so far in identifying the different cellular mechanisms of mutation-independent therapy resistance in AML. It reiterates that for more effective outcomes cancer therapies should acquire a more tailored approach where the protective interactions between the cancer cells and their niches are identified and targeted.

Using Circ-ANAPC7 as a Novel Type of Biomarker in the Monitoring of Acute Myeloid Leukemia

INTRODUCTION

Circular RNAs (circRNAs) are a novel class of RNAs which occupy gene expression at the transcriptional or post-transcriptional level, involve in many physiological processes, and participate in many diseases, especially in cancer. Our previous study showed 1 altered circRNA named circ-anaphase promoting complex subunit 7 (ANAPC7) that was upregulated in acute myeloid leukemia (AML). To further clear the expression and clinical significance of circ-ANAPC7, we enlarged the sample size and illuminated the diagnostic and monitoring value of circ-ANAPC7 in AML.

METHODS

Real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was supposed to confirm the expression of circ-ANAPC7 of AML patients. We assessed the correlation of circ-ANAPC7 and clinical variables using the Spearman correlation test. The receiver operating characteristic (ROC) curve was carried out to evaluate the diagnostic value.

RESULTS

Circ-ANAPC7 was first found to be upregulated in AML, and its expression was correlated to white blood cell counts in peripheral blood and blast percentage in bone marrow. ROC curve analysis revealed that circ-ANAPC7 has a significant value of auxiliary AML diagnosis (area under the curve = 0.915, p < 0.001). Furthermore, the expression level of circ-ANAPC7 was changed accompanied with disease condition transformation.

CONCLUSION

Circ-ANAPC7 was upregulated in newly diagnosed and relapsed AML. It may serve as potential biomarkers for AML patient's diagnosis and monitoring.

MiR-181b serves as diagnosis and prognosis biomarker in severe community-acquired pneumonia

Severe community-acquired pneumonia (SCAP) is a common critical disease in the intensive care unit (ICU). This study aims to evaluate the clinical significance of miR-181b in SCAP, which has been revealed to be dysregulated in acute respiratory distress syndrome events due to SCAP. There were 50 SCAP patients and 26 healthy volunteers were recruited in this study. The expression of miR-181b was detected by RT-qPCR and the difference between SCAP and healthy controls was evaluated. The diagnosis and prognosis value of miR-181b was assessed by the receiver operating characteristics (ROC), Kaplan-Meier, and Cox regression analysis. miR-181b was significantly downregulated in SCAP compared with healthy controls. The downregulation of miR-181b showed a significant association with the white blood cell count, absolute neutrophils, and the C-reactive protein of patients. The downregulation of miR-181b could distinguish SCAP patients from healthy controls and predicate the poor prognosis of SCAP patients. Downregulated miR-181b serves as a diagnosis and prognosis biomarker for SCAP, which may be useful biological information for the early detection and risk estimation of SCAP.

Circulating miR-181a and miR-223 expression with the potential value of biomarkers for the diagnosis of systemic lupus erythematosus and predicting lupus nephritis

BACKGROUND

MicroRNAs (miRNAs) contribute to the development and progression of systemic lupus erythematosus (SLE) by affecting a wide range of targeted genes and facilitating the development of lupus nephritis (LN). The present study aimed to analyze the serum expression of miR-181a and miR-223 in SLE patients and to assess whether they could serve as novel biomarkers for SLE diagnosis and to distinguish LN.

METHODS

The study included 70 control subjects and 116 patients with SLE (67 non-LN and 49 LN groups). Circulating miR-181a and miR-223 expression levels were analyzed among the Egyptian population using a real-time polymerase chain reaction.

RESULTS

Up-regulation of miR-181a was detected among SLE patients compared to healthy controls and higher values were reported among the LN group compared to the non-LN group. Down-regulation of miR-223 was reported among SLE patients compared to controls and lower values were reported among the LN group compared to the non-LN group. The higher miR-181a expression and the lower miR-223 expression were associated with higher stages of LN. SLE disease activity index, proteinuria and serum creatinine were independently correlated with miR-181a and miR-223 among SLE patients by linear regression analysis. Receiver-operating characteristic curve analysis revealed that combined miR-181a and miR-223 expression increased the sensitivity and specificity for the diagnosis of SLE and further distinguished LN from non-LN patients.

CONCLUSIONS

miR-181a and miR-223 could play a role in evaluating SLE disease progression and prognosis. Combined miR-181a and miR-223 expression analysis could serve as novel serum-based biomarkers in the diagnosis of SLE and predicting LN among Egyptians.

Unravelling the Epigenome of Myelodysplastic Syndrome: Diagnosis, Prognosis, and Response to Therapy

Simple Summary

Myelodysplastic syndrome (MDS) is a type of blood cancer that mostly affects older individuals. Invasive tests to obtain bone samples are used to diagnose MDS and many patients do not respond to therapy or stop responding to therapy in the short-term. Less invasive tests to help diagnose, prognosticate, and predict response of patients is a felt need. Factors that influence gene expression without changing the DNA sequence (epigenetic modifiers) such as DNA methylation, micro-RNAs and long-coding RNAs play an important role in MDS, are potential biomarkers and may also serve as targets for therapy.

Abstract

Myelodysplastic syndrome (MDS) is a malignancy that disrupts normal blood cell production and commonly affects our ageing population. MDS patients are diagnosed using an invasive bone marrow biopsy and high-risk MDS patients are treated with hypomethylating agents (HMAs) such as decitabine and azacytidine. However, these therapies are only effective in 50% of patients, and many develop resistance to therapy, often resulting in bone marrow failure or leukemic transformation. Therefore, there is a strong need for less invasive, diagnostic tests for MDS, novel markers that can predict response to therapy and/or patient prognosis to aid treatment stratification, as well as new and effective therapeutics to enhance patient quality of life and survival. Epigenetic modifiers such as DNA methylation, long non-coding RNAs (lncRNAs) and micro-RNAs (miRNAs) are perturbed in MDS blasts and the bone marrow micro-environment, influencing disease progression and response to therapy. This review focusses on the potential utility of epigenetic modifiers in aiding diagnosis, prognosis, and predicting treatment response in MDS, and touches on the need for extensive and collaborative research using single-cell technologies and multi-omics to test the clinical utility of epigenetic markers for MDS patients in the future.

Identification of Acute Myeloid Leukemia Bone Marrow Circulating MicroRNAs

BACKGROUND

In addition to their roles in different biological processes, microRNAs in the tumor microenvironment appear to be potential diagnostic and prognostic biomarkers for various malignant diseases, including acute myeloid leukemia (AML). To date, no screening of circulating miRNAs has been carried out in the bone marrow compartment of AML. Accordingly, we investigated the circulating miRNA profile in AML bone marrow at diagnosis (AMLD) and first complete remission post treatment (AMLPT) in comparison to healthy donors (HD).

METHODS

Circulating miRNAs were isolated from AML bone marrow aspirations, and a low-density TaqMan miRNA array was performed to identify deregulated miRNAs followed by quantitative RT-PCR to validate the results. Bioinformatic analysis was conducted to evaluate the diagnostic and prognostic accuracy of the highly and significantly identified deregulated miRNA(s) as potential candidate biomarker(s).

RESULTS

We found several deregulated miRNAs between the AMLD vs. HD vs. AMLPT groups, which were involved in tumor progression and immune suppression pathways. We also identified significant diagnostic and prognostic signatures with the ability to predict AML patient treatment response.

CONCLUSIONS

This study provides a possible role of enriched circulating bone marrow miRNAs in the initiation and progression of AML and highlights new markers for prognosis and treatment monitoring.

Role of microRNA dysregulation in childhood acute leukemias: Diagnostics, monitoring and therapeutics: A comprehensive review

MicroRNAs (miRNAs) are short noncoding RNAs that regulate the expression of genes by sequence-specific binding to mRNA to either promote or block its translation; they can also act as tumor suppressors (e.g., let-7b, miR-29a, miR-99, mir-100, miR-155, and miR-181) and/or oncogenes (e.g., miR-29a, miR-125b, miR-143-p3, mir-155, miR-181, miR-183, miR-196b, and miR-223) in childhood acute leukemia (AL). Differentially expressed miRNAs are important factors associated with the initiation and progression of AL. As shown in many studies, they can be used as noninvasive diagnostic and prognostic biomarkers, which are useful in monitoring early stages of AL development or during therapy (e.g., miR-125b, miR-146b, miR-181c, and miR-4786), accurate classification of different cellular or molecular AL subgroups (e.g., let-7b, miR-98, miR-100, miR-128b, and miR-223), and identification and development of new therapeutic agents (e.g., mir-10, miR-125b, miR-203, miR-210, miR-335). Specific miRNA patterns have also been described for commonly used AL therapy drugs (e.g., miR-125b and miR-223 for doxorubicin, miR-335 and miR-1208 for prednisolone, and miR-203 for imatinib), uncovering miRNAs that are associated with treatment response. In the current review, the role of miRNAs in the development, progression, and therapy monitoring of pediatric ALs will be presented and discussed.

The Significance of miRNAs as a Prognostic Biomarker for Survival Outcome in T Cell - Acute Lymphoblastic Leukemia Patients: A Systematic Review and Meta-Analysis

Purpose

T-cell acute lymphoblastic leukemia (T-ALL) affects lymphoid cells. Previous studies have reported that miRNAs play a significant role in T-ALL prognosis and have the potential to function as biomarkers in T-ALL. Therefore, this systematic review and meta-analysis study was designed to evaluate the overall prognostic impact of miRNAs in T-ALL patients.

Methods

Eligible studies published between Jan 2010 and April 2018 were retrieved from online bibliographic databases based on multiple keywords to generate search strings. Meta-analysis was performed using the outcome measure, Hazard Ratio (HR). A survival analysis of all studies was conducted and a subsequent forest plot was generated to evaluate the pooled effect size, across all T-ALL patients. Subgroup analysis was conducted based on demographic characteristics and commonly represented miRNAs among the included studies.

Results

A total of 17 studies were included for systematic review, among which 16 studies were eligible for meta-analysis, which, in total discussed 32 different miRNAs. The mean effect size of HR value was 0.929 (CI 0.878–0984), which indicates a decrease in risk of death by 7.1%. The analysis was based on the random effects model with the heterogeneity measure index (I²) being 84.92%. The pooled effect size (HR) of upregulated and downregulated miRNA expressions on survival outcome in the T-ALL patient was 0.787 (CI 0.732–0.845) and 1.225 (CI 1.110–1.344) respectively. The subgroup analysis was performed based on demographic characteristics (age, gender, lactate dehydrogenase, WBC count) and expression of miR221 and miR46a.

Conclusion

Our systematic review and meta-analysis findings suggest that the overall miRNA expression is potentially associated with a decreased likelihood of death in T-ALL patients. Although our findings are inconclusive, the results point toward miRNA expression allowing for prognostic evaluation of T-ALL patients.

Extracellular vesicles impose quiescence on residual hematopoietic stem cells in the leukemic niche

Progressive remodeling of the bone marrow microenvironment is recognized as an integral aspect of leukemogenesis. Expanding acute myeloid leukemia (AML) clones not only alter stroma composition, but also actively constrain hematopoiesis, representing a significant source of patient morbidity and mortality. Recent studies revealed the surprising resistance of long-term hematopoietic stem cells (LT-HSC) to elimination from the leukemic niche. Here, we examine the fate and function of residual LT-HSC in the BM of murine xenografts with emphasis on the role of AML-derived extracellular vesicles (EV). AML-EV rapidly enter HSC, and their trafficking elicits protein synthesis suppression and LT-HSC quiescence. Mechanistically, AML-EV transfer a panel of miRNA, including miR-1246, that target the mTOR subunit Raptor, causing ribosomal protein S6 hypo-phosphorylation, which in turn impairs protein synthesis in LT-HSC. While HSC functionally recover from quiescence upon transplantation to an AML-naive environment, they maintain relative gains in repopulation capacity. These phenotypic changes are accompanied by DNA double-strand breaks and evidence of a sustained DNA-damage response. In sum, AML-EV contribute to niche-dependent, reversible quiescence and elicit persisting DNA damage in LT-HSC.

MicroRNA in leukemia: Tumor suppressors and oncogenes with prognostic potential

Leukemia is known as a progressive malignant disease, which destroys the blood-forming organs and results in adverse effects on the proliferation and development of leukocytes and their precursors in the blood and bone marrow. There are four main classes of leukemia including acute leukemia, chronic leukemia, myelogenous leukemia, and lymphocytic leukemia. Given that a variety of internal and external factors could be associated with the initiation and progression of different types of leukemia. One of the important factors is epigenetic regulators such as microRNAs (miRNAs) and long noncoding RNAs (ncRNA). MiRNAs are short ncRNAs which act as tumor suppressor (i.e., miR-15, miR-16, let-7, and miR-127) or oncogene (i.e., miR-155, miR-17-92, miR-21, miR-125b, miR-93, miR-143-p3, miR-196b, and miR-223) in leukemia. It has been shown that deregulation of these molecules are associated with the initiation and progression of leukemia. Hence, miRNAs could be used as potential therapeutic candidates in the treatment of patients with leukemia. Moreover, increasing evidence revealed that miRNAs could be used as diagnostic and prognostic biomarkers in monitoring patients in early stages of disease or after received chemotherapy regimen. It seems that identification and development of new miRNAs could pave to the way to the development new therapeutic platforms for patients with leukemia. Here, we summarized various miRNAs as tumor suppressor and oncogene which could be introduced as therapeutic targets in treatment of leukemia.

MicroRNA‑339‑5p inhibits cell proliferation of acute myeloid leukaemia by directly targeting SOX4

In recent decades, microRNAs (miRNAs) have been considered novel gene regulators. Dysregulated miRNAs serve crucial roles in the formation and progression of acute myeloid leukaemia (AML). Therefore, the roles of differentially expressed miRNAs in AML require extensive investigation to obtain insight into the treatment of patients with AML. The present study demonstrated significant miR‑339‑5p downregulation in AML samples and cell lines. miR‑339‑5p overexpression attenuated AML cell proliferation by inducing cell cycle arrest and promoting cell apoptosis. Additionally, sex‑determining region Y‑related high‑mobility group box 4 (SOX4) was identified as a direct target gene of miR‑339‑5p in AML. Furthermore, SOX4 expression was significantly upregulated in AML samples; this upregulation was inversely correlated with the expression levels of miR‑339‑5p. Additionally, a series of rescue experiments demonstrated that SOX4 resumption reversed the effects of miR‑339‑5p overexpression on cell proliferation, cycle status and apoptosis of AML. In conclusion, miR‑339‑5p may serve its antiproliferative role in AML by directly targeting SOX4, which suggests that miR‑339‑5p may be considered an effective novel therapeutic target for treating patients with such an aggressive haematological malignancy.

Downregulation of PDIA3 inhibits proliferation and invasion of human acute myeloid leukemia cells

Introduction

Acute myeloid leukemia (AML) is a common malignancy of the hematopoietic system. In bone marrow samples of AML patients, PDIA3 expression was higher than that in the samples of healthy controls. We aimed at exploring the effect of PDIA3 siRNA on proliferation, apoptosis, migration, and invasion of AML HL-60 and HEL cells.

Materials and methods

RT-PCR was performed to identify PDIA3 expression. Cell proliferation was assessed by MTT. Flow cytometry analysis and transwell were used to detect cell apoptosis, migration and invasion. Gene set enrich-ment analysis (GSEA) was employed to explore the PDIA 3-associated pathways in AML. Western blotting was used for protein expression detection.

Results

PDIA3 siRNA significantly inhibited the proliferation of AML cells at 24 and 48 h. PDIA3 siRNA notably enhanced the percentage of apoptotic cells. The migration and invasion abilities of HL-60 and HEL cells in the PDIA3 siRNA group were significantly suppressed compared with those in the control and siNC groups. GSEA of the Cancer Genome Atlas dataset showed that Kyoto Encyclopedia of Genes and Genomes oxidative phosphorylation and amino sugar and nucleotide sugar metabolism pathways could be correlated with PDIA3 expression; this was further confirmed in AML cells by Western blotting. MAPK signaling was also blocked by PDIA3 siRNA.

Conclusion

PDIA3 siRNA effectively enhanced apoptosis, and suppressed proliferation, invasion, and migration of AML cells by regulating oxidative phosphorylation and amino sugar and nucleotide sugar metabolism pathways, and MAPK signaling, which can provide novel therapeutic targets for AML.

MiR-181a inhibits vascular inflammation induced by ox-LDL via targeting TLR4 in human macrophages

Atherosclerosis is a kind of chronic inflammation disease with lipid accumulation in in blood vessel linings. Increasing evidence has reported that microRNAs can exert crucial roles in atherosclerosis. In previous study, miR-181a has been implicated to be abnormally expressed in atherosclerosis mice, however its detailed function in atherosclerosis remains uninvestigated. Hence, in our current study, we focused on the biological role of miR-181a in atherosclerosis progression. Ox-LDL has been commonly identified as an important atherosclerosis regulator. We observed that ox-LDL induced THP-1 cell apoptosis dose-dependently and time- dependently. Meanwhile, 25 µg/ml ox-LDL can promote foam cell formation and increased miR-181a expression significantly. CD36 has been involved in atherosclerosis progression and it was found that overexpression of miR-181a inhibited its protein levels. Moreover, miR-181a mimics repressed foam cell formation, TC and TG levels induced by ox-LDL dramatically. In addition, miR-181a mimics were able to reverse THP-1 cell apoptosis, increased IL-6, IL-1β, and TNF-α protein expression triggered by 25 µg/ml ox-LDL. TLR4 has been linked to various inflammation-associated diseases. In our present study, TLR4 was indicated as miR-181a target and the binding correlation between them was validated by dual-luciferase reporter assay. In conclusion, these results improves the understanding of atherosclerosis modulated by miR-181a/TLR4 and can contribute to development of new approaches for atherosclerosis.