Identification of miR-34 regulatory networks in settings of disease and antimiR-therapy: Implications for treating cardiac pathology and other diseases

MicroRNAs and therapeutic potentials in acute and chronic cardiac disease

microRNAs (miRNAs) are small regulatory RNAs implicated in various cardiac disorders. In this review, the role of miRNAs is discussed in relation to acute myocardial infarction and chronic heart failure. In both settings, miRNAs are altered, contributing to injury and adverse remodeling. Notably, miRNA profiles differ between acute ischemic injury and progressive heart failure. Owing to miRNA variabilities between disease stages and delivery difficulties, translation of animal studies to the clinic remains challenging. The identification of distinct miRNA signatures could lead to the development of miRNA therapies tailored to different disease stages. Here, we summarize the current understanding of miRNAs in acute and chronic cardiac diseases, identify knowledge gaps and discuss progress in developing miRNA-based treatment strategies.

IDMIR: identification of dysregulated miRNAs associated with disease based on a miRNA-miRNA interaction network constructed through gene expression data

Micro ribonucleic acids (miRNAs) play a pivotal role in governing the human transcriptome in various biological phenomena. Hence, the accumulation of miRNA expression dysregulation frequently assumes a noteworthy role in the initiation and progression of complex diseases. However, accurate identification of dysregulated miRNAs still faces challenges at the current stage. Several bioinformatics tools have recently emerged for forecasting the associations between miRNAs and diseases. Nonetheless, the existing reference tools mainly identify the miRNA-disease associations in a general state and fall short of pinpointing dysregulated miRNAs within a specific disease state. Additionally, no studies adequately consider miRNA-miRNA interactions (MMIs) when analyzing the miRNA-disease associations. Here, we introduced a systematic approach, called IDMIR, which enabled the identification of expression dysregulated miRNAs through an MMI network under the gene expression context, where the network's architecture was designed to implicitly connect miRNAs based on their shared biological functions within a particular disease context. The advantage of IDMIR is that it uses gene expression data for the identification of dysregulated miRNAs by analyzing variations in MMIs. We illustrated the excellent predictive power for dysregulated miRNAs of the IDMIR approach through data analysis on breast cancer and bladder urothelial cancer. IDMIR could surpass several existing miRNA-disease association prediction approaches through comparison. We believe the approach complements the deficiencies in predicting miRNA-disease association and may provide new insights and possibilities for diagnosing and treating diseases. The IDMIR approach is now available as a free R package on CRAN (https://CRAN.R-project.org/package=IDMIR).

The roles of miRNAs in adult skeletal muscle satellite cells

Satellite cells are bona fide muscle stem cells that are indispensable for successful post-natal muscle growth and regeneration after severe injury. These cells also participate in adult muscle adaptation in several capacities. MicroRNAs (miRNAs) are post-transcriptional regulators of mRNA that are implicated in several aspects of stem cell function. There is evidence to suggest that miRNAs affect satellite cell behavior in vivo during development and myogenic progenitor behavior in vitro, but the role of miRNAs in adult skeletal muscle satellite cells is less studied. In this review, we provide evidence for how miRNAs control satellite cell function with emphasis on satellite cells of adult skeletal muscle in vivo. We first outline how miRNAs are indispensable for satellite cell viability and control the phases of myogenesis. Next, we discuss the interplay between miRNAs and myogenic cell redox status, senescence, and communication to other muscle-resident cells during muscle adaptation. Results from recent satellite cell miRNA profiling studies are also summarized. In vitro experiments in primary myogenic cells and cell lines have been invaluable for exploring the influence of miRNAs, but we identify a need for novel genetic tools to further interrogate how miRNAs control satellite cell behavior in adult skeletal muscle in vivo.

In Vivo Inhibition of miR-34a Modestly Limits Cardiac Enlargement and Fibrosis in a Mouse Model with Established Type 1 Diabetes-Induced Cardiomyopathy, but Does Not Improve Diastolic Function

MicroRNA 34a (miR-34a) is elevated in the heart in a setting of cardiac stress or pathology, and we previously reported that inhibition of miR-34a in vivo provided protection in a setting of pressure overload-induced pathological cardiac hypertrophy and dilated cardiomyopathy. Prior work had also shown that circulating or cardiac miR-34a was elevated in a setting of diabetes. However, the therapeutic potential of inhibiting miR-34a in vivo in the diabetic heart had not been assessed. In the current study, type 1 diabetes was induced in adult male mice with 5 daily injections of streptozotocin (STZ). At 8 weeks post-STZ, when mice had established type 1 diabetes and diastolic dysfunction, mice were administered locked nucleic acid (LNA)-antimiR-34a or saline-control with an eight-week follow-up. Cardiac function, cardiac morphology, cardiac fibrosis, capillary density and gene expression were assessed. Diabetic mice presented with high blood glucose, elevated liver and kidney weights, diastolic dysfunction, mild cardiac enlargement, cardiac fibrosis and reduced myocardial capillary density. miR-34a was elevated in the heart of diabetic mice in comparison to non-diabetic mice. Inhibition of miR-34a had no significant effect on diastolic function or atrial enlargement, but had a mild effect on preventing an elevation in cardiac enlargement, fibrosis and ventricular gene expression of B-type natriuretic peptide (BNP) and the anti-angiogenic miRNA (miR-92a). A miR-34a target, vinculin, was inversely correlated with miR-34a expression, but other miR-34a targets were unchanged. In summary, inhibition of miR-34a provided limited protection in a mouse model with established type 1 diabetes-induced cardiomyopathy and failed to improve diastolic function. Given diabetes represents a systemic disorder with numerous miRNAs dysregulated in the diabetic heart, as well as other organs, strategies targeting multiple miRNAs and/or earlier intervention is likely to be required.

Targeting the microRNA-34a as a Novel Therapeutic Strategy for Cardiovascular Diseases

Cardiovascular diseases (CVDs) are still the main cause of morbidity and mortality worldwide and include a group of disorders varying from vasculature, myocardium, arrhythmias and cardiac development. MicroRNAs (miRs) are endogenous non-coding RNAs with 18–23 nucleotides that regulate gene expression. The miR-34 family, including miR-34a/b/c, plays a vital role in the regulation of myocardial physiology and pathophysiological processes. Recently, miR-34a has been implicated in cardiovascular fibrosis, dysfunction and related cardiovascular disorders as an essential regulator. Interestingly, there is a pivotal link among miR-34a, cardiovascular fibrosis, and Smad4/TGF-β1 signaling. Notably, both loss-of-function and gain-of-function approaches identified the critical roles of miR-34a in cardiovascular apoptosis, autophagy, inflammation, senescence and remodeling by modulating multifunctional signaling pathways. In this article, we focus on the current understanding of miR-34a in biogenesis, its biological effects and its implications for cardiac pathologies including myocardial infarction, heart failure, ischaemia reperfusion injury, cardiomyopathy, atherosclerosis, hypertension and atrial fibrillation. Thus, further understanding of the effects of miR-34a on cardiovascular diseases will aid the development of effective interventions. Targeting for miR-34a has emerged as a potential therapeutic target for cardiovascular dysfunction and related diseases.

Endothelial and systemic upregulation of miR-34a-5p fine-tunes senescence in progeria

Endothelial defects significantly contribute to cardiovascular pathology in the premature aging disease Hutchinson-Gilford progeria syndrome (HGPS). Using an endothelium-specific progeria mouse model, we identify a novel, endothelium-specific microRNA (miR) signature linked to the p53-senescence pathway and a senescence-associated secretory phenotype (SASP). Progerin-expressing endothelial cells exert profound cell-non-autonomous effects initiating senescence in non-endothelial cell populations and causing immune cell infiltrates around blood vessels. Comparative miR expression analyses revealed unique upregulation of senescence-associated miR34a-5p in endothelial cells with strong accumulation at atheroprone aortic arch regions but also, in whole cardiac- and lung tissues as well as in the circulation of progeria mice. Mechanistically, miR34a-5p knockdown reduced not only p53 levels but also late-stage senescence regulator p16 with no effect on p21 levels, while p53 knockdown reduced miR34a-5p and partially rescued p21-mediated cell cycle inhibition with a moderate effect on SASP. These data demonstrate that miR34a-5p reinforces two separate senescence regulating branches in progerin-expressing endothelial cells, the p53- and p16-associated pathways, which synergistically maintain a senescence phenotype that contributes to cardiovascular pathology. Thus, the key function of circulatory miR34a-5p in endothelial dysfunction-linked cardiovascular pathology offers novel routes for diagnosis, prognosis and treatment for cardiovascular aging in HGPS and potentially geriatric patients.

Circulating MicroRNAs as Biomarkers of Accelerated Sarcopenia in Chronic Heart Failure

Background:

Sarcopenia is a critical finding in patients with chronic heart failure (CHF). However, the search for a definitive biomarker to predict muscle and functional decline in CHF remains elusive.

Objectives:

We aimed to correlate the circulating levels of selected miRs with the indexes of sarcopenia during healthy aging and in patients with CHF.

Methods:

We analyzed the association of circulating microRNAs (miRs) levels including miR-21, miR-434-3p, miR424-5p, miR-133a, miR-455-3p and miR-181a with sarcopenia indexes in male, 61–73 years old healthy controls and patients with CHF (N = 89–92/group).

Results:

Patients with CHF had lower hand-grip strength (HGS), appendicular skeletal mass index (ASMI) and physical capacity than healthy controls. Circulating miR-21 levels were higher and miR-181a, miR-133a, miR-434-3p and miR-455-3p levels were lower in patients with CHF than healthy controls. Among the sarcopenia indexes, HGS showed the strongest correlation with miR-133a while ASMI showed the strongest correlations with miR-133a, miR-434-3p and miR-455-3p. Among the miRs, miR-434-3p showed the highest area under the curve in testing for sensitivity and specificity for CHF. These changes were associated with higher expressions of the markers of inflammation, oxidative stress and muscle damage in CHF patients.

Conclusion:

Taken together, our data show that circulating miRs can be useful markers of muscle health and physical capacity in the sarcopenic elderly with CHF.

Elevated miR-34a expression and altered transcriptional profile are associated with adverse electromechanical remodeling in the heart of male rats exposed to social stress

This study investigated epigenetic risk factors that may contribute to stress-related cardiac disease in a rodent model. Experiment 1 was designed to evaluate the expression of microRNA-34a (miR-34a), a known modulator of both stress responses and cardiac pathophysiology, in the heart of male adult rats exposed to a single or repeated episodes of social defeat stress. Moreover, RNA sequencing was conducted to identify transcriptomic profile changes in the heart of repeatedly stressed rats. Experiment 2 was designed to assess cardiac electromechanical changes induced by repeated social defeat stress that may predispose rats to cardiac dysfunction. Results indicated a larger cardiac miR-34a expression after repeated social defeat stress compared to a control condition. This molecular modification was associated with increased vulnerability to pharmacologically induced arrhythmias and signs of systolic left ventricular dysfunction. Gene expression analysis identified clusters of differentially expressed genes in the heart of repeatedly stressed rats that are mainly associated with morphological and functional properties of the mitochondria and may be directly regulated by miR-34a. These results suggest the presence of an association between miR-34a overexpression and signs of adverse electromechanical remodeling in the heart of rats exposed to repeated social defeat stress, and point to compromised mitochondria efficiency as a potential mediator of this link. This rat model may provide a useful tool for investigating the causal relationship between miR-34a expression, mitochondrial (dys)function, and cardiac alterations under stressful conditions, which could have important implications in the context of stress-related cardiac disease.

Transcriptome analysis of islets from diabetes-resistant and diabetes-prone obese mice reveals novel gene regulatory networks involved in beta-cell compensation and failure

The mechanisms underpinning beta-cell compensation for obesity-associated insulin resistance and beta-cell failure in type 2 diabetes remain poorly understood. We used a large-scale strategy to determine the time-dependent transcriptomic changes in islets of diabetes-prone db/db and diabetes-resistant ob/ob mice at 6 and 16 weeks of age. Differentially expressed genes were subjected to cluster, gene ontology, pathway and gene set enrichment analyses. A distinctive gene expression pattern was observed in 16 week db/db islets in comparison to the other groups with alterations in transcriptional regulators of islet cell identity, upregulation of glucose/lipid metabolism, and various stress response genes, and downregulation of specific amino acid transport and metabolism genes. In contrast, ob/ob islets displayed a coordinated downregulation of metabolic and stress response genes at 6 weeks of age, suggestive of a preemptive reconfiguration in these islets to lower the threshold of metabolic activation in response to increased insulin demand thereby preserving beta-cell function and preventing cellular stress. In addition, amino acid transport and metabolism genes were upregulated in ob/ob islets, suggesting an important role of glutamate metabolism in beta-cell compensation. Gene set enrichment analysis of differentially expressed genes identified the enrichment of binding motifs for transcription factors, FOXO4, NFATC1, and MAZ. siRNA-mediated knockdown of these genes in MIN6 cells altered cell death, insulin secretion, and stress gene expression. In conclusion, these data revealed novel gene regulatory networks involved in beta-cell compensation and failure. Preemptive metabolic reconfiguration in diabetes-resistant islets may dampen metabolic activation and cellular stress during obesity.

Identification of miRNA-34a and miRNA-155 as prognostic markers for mantle cell lymphoma

Objective

MicroRNAs (miRNAs) with functional relevance have not been previously identified in mantle cell lymphoma (MCL). Here, we aimed to evaluate the relationships between miR-34a and miR-155-5p and MCL clinicopathology and prognosis.

Methods

Seventy-five paraffin-embedded tissue samples from patients with MCL who completed at least four cycles of chemotherapy from January 2006 to October 2016, and 27 samples from control patients with reactive lymphoid hyperplasia (RLH), were collected. MiRNA expression levels were measured by qRT-PCR.

Results

The miR-155-5p levels were significantly higher in patients with MCL than in the controls. The Eastern Cooperative Oncology Group (ECOG) ≥ 2 and Sex-Determining Region Y-Box transcription factor 11 (SOX11) < median value (M) groups presented lower miR-34a expression than the ECOG < 2 and SOX11 ≥ M groups, respectively. MiR-155-5p expression differed between low, intermediate, and high MCL International Prognostic Index risk groups. The AUCs of miR-34a and miR-155-5p were 0.5819 and 0.7784, respectively. The median survival times of the miR-34a ≤ 0.2150 and miR-155-5p > 2.11 groups were shorter than those of the miR-34a > 0.2150 and miR-155-5p ≤ 2.11 groups, respectively.

Conclusions

Low miR-34a and elevated miR-155-5p levels may be correlated with poor prognosis in MCL.

miRNA interplay: mechanisms and consequences in cancer

Canonically, microRNAs (miRNAs) control mRNA expression. However, studies have shown that miRNAs are also capable of targeting non-coding RNAs, including long non-coding RNAs and miRNAs. The latter, termed a miRNA:miRNA interaction, is a form of self-regulation. In this Review, we discuss the three main modes of miRNA:miRNA regulation: direct, indirect and global interactions, and their implications in cancer biology. We also discuss the cell-type-specific nature of miRNA:miRNA interactions, current experimental approaches and bioinformatic techniques, and how these strategies are not sufficient for the identification of novel miRNA:miRNA interactions. The self-regulation of miRNAs and their impact on gene regulation has yet to be fully understood. Investigating this hidden world of miRNA self-regulation will assist in discovering novel regulatory mechanisms associated with disease pathways.

LncRNA Tincr regulates PKCɛ expression in a miR-31-5p-dependent manner in cardiomyocyte hypertrophy

Cardiomyocyte hypertrophy is a fatal factor in heart disease resulting in heart failure and even mortality. Although many studies have been focusing on the pathogenesis of cardiomyocyte hypertrophy, the exact molecular mechanisms are still unexclusive. In this study, we first found that the expression level of lncRNA Tincr was significantly decreased in the myocardial tissues of TAC mouse models of cardiomyocyte hypertrophy, and this result was further confirmed in H9C2 cells, a widely used rat myoblast cell lines. More intriguingly, we demonstrated that the aberration of Tincr is essential to the pathogenesis of cardiomyocyte hypertrophy, indicated by the re-induction of Tincr improving the heart functions of hypertrophic mice. In mechanism, we identified miR-31-5p as a direct target of Tincr using a widely used online bioinformatics tool StarBase, and this result was further experimentally validated using dual-luciferase reporter assay and real-time PCR. Also, we identified PRKCE as a direct target of miR-31-5p, and loss function of miR-31-5p significantly blocks the positive regulatory effect of Tincr on PRKCE expression in H9C2 cells. The knockdown of Tincr resulted in increased cardiomyocyte size, and, however, inhibition of miR-31-5p or overexpression of PRKCE significantly reversed the increased cardiomyocyte size. Taken together, our study showed that a novel Tincr-miR-31-5p axis targeting PRKCE was involved in cardiomyocyte hypertrophy, indicating that it may provide potential therapy in cardiomyocyte hypertrophy.

Global miRNA to miRNA Interactions: Impacts for miR-21

miRNAs inherently alter the cellular environment by regulating target genes. miRNAs may also regulate other miRNAs, with far-reaching influence on miRNA and mRNA expression. We explore this realm of small RNA regulation with a focus on the role of the oncogenic miR-21 and its impact on other miRNA species.

PD-1 inhibitor inducing exosomal miR-34a-5p expression mediates the cross talk between cardiomyocyte and macrophage in immune checkpoint inhibitor-related cardiac dysfunction

Background

Immune checkpoint inhibitors (ICIs) have been an important therapeutic advancement in the field of cancer medicine. Recent reports provided greater insights into the cardiovascular adverse events, which prohibited the use of ICIs. Cardiovascular adverse events occur in different forms, such as myocarditis and cardiomyopathy, myocardial fibrosis, heart failure and pericardial disease. Cardiac aging overlapped with the occurrence of some cardiac diseases. Exosomes mediate cell–cell cross talk in cardiac diseases by transferring a variety of biomolecules, including microRNAs (miRs). miR-34a-5p is a well-known miR associated with the cardiac senescence. This study aimed to investigate whether cardiovascular adverse effects of the programmed cell death 1 (PD-1) inhibitor, a widely used ICI, were related to exosomal-transferred miR-34a-5p in cardiac senescence in a mouse model.

Methods and results

The upregulation of miR-34a-5p in cardiomyocytes induced by exosomes derived from PD-1 inhibitor–treated macrophages, accompanied by cardiac senescence, caused cardiac injury in mouse hearts. miR-34a-5p was identified as an exosomal transfer RNA to induce cardiac senescence–related injury. Inhibiting miR-34a-5p in macrophages attenuated the exosome^{PD-1 inhibitor}-induced pro-senescent effect in cardiomyocytes. TargetScan and luciferase assay showed that miR-34a-5p targeted the serine/threonine-protein phosphatase 1 regulatory subunit 10 (PNUTS) 3′-untranslated region.

Conclusions

Exosomes derived from PD-1 inhibitor–treated macrophages exerted a pro-senescent effect by modulating the miR-34a-5p/PNUTS signaling pathway. The findings might supply new targets to ameliorate cardiac injury in patients with cancer receiving PD-1 inhibitor treatment.

Discovery and Functional Prediction of Long Non-Coding RNAs Common to Ischemic Stroke and Myocardial Infarction

Objective

Ischemic stroke and myocardial infarction are 2 of the leading causes of mortality. Both conditions are caused by arterial occlusion, resulting in ischemic necrosis of the cells in the cortex and heart. Long non-coding RNAs (lncRNAs) are a group of non-coding RNAs longer than 200 nucleotides without protein-coding potential. Thousands of lncRNAs have been identified but their involvement in ischemic stroke and myocardial infarction has not been studied extensively. Therefore, this study aimed to identify the role of lncRNAs, particularly those that are commonly altered in these two ischemic injuries.

Methods

We combined diverse RNA sequencing data obtained from public databases and performed extensive bioinformatics analyses to determine reliable lncRNAs commonly identified from these datasets. Using sequence analysis, we also detected the lncRNAs that may act as microRNA (miRNA) regulators.

Results

We found several altered lncRNAs that were common in ischemic stroke and myocardial infarction models. Some of these lncRNAs, including zinc finger NFX1-type containing 1 antisense RNA 1 and small nucleolar RNA host gene 1, were previously reported to be involved in the pathogenesis of each of these models. Interestingly, several lncRNAs had binding sites for miRNAs that were previously reported to be involved in the hypoxic response, suggesting the possible role of these lncRNAs as regulators in ischemic responses.

Conclusion

The lncRNAs identified in this study will be useful in determining the regulatory networks in ischemic stroke and myocardial infarction and in identifying potential specific markers for each of these ischemic diseases.

Immune checkpoint inhibitor induces cardiac injury through polarizing macrophages via modulating microRNA-34a/Kruppel-like factor 4 signaling

Cancer immunotherapy has become a well-established treatment option for some cancers; however, its use is hampered by its cardiovascular adverse effects. Immune checkpoint inhibitors (ICIs)-related cardiac toxicity took place in kinds of different forms, such as myocarditis, acute coronary syndrome, and pericardial disease, with high mortality rates. This study aimed to investigate the roles of programmed death-1 (PD-1) inhibitor, one of widespread used ICIs, in the development of murine cardiac injury. PD-1 inhibitor is known to transduce immunoregulatory signals that modulate macrophages polarization to attack tumor cells. Hence, this study explored whether the cardiovascular adverse effects of PD-1 inhibitor were related to macrophage polarization. MicroRNA-34a (miR-34a), which appears to regulate the polarization of cultured macrophages to induce inflammation, is examined in cardiac injury and macrophage polarization induced by the PD-1 inhibitor. As a target of miR-34a, Krüppel-like factor 4 (KLF4) acted as an anti-inflammation effector to take cardiac protective effect. Further, it investigated whether modulating the miR-34a/KLF4-signaling pathway could influence macrophage polarization. The PD-1 inhibitor markedly induced M1 phenotype macrophage polarization with impaired cardiac function, whereas miR-34a inhibitor transfection treatment reversed M1 polarization and cardiac injury in vivo. In vitro, PD-1 inhibitor-induced M1 polarization was accompanied by an increase in the expression of miR-34a but a decrease in the expression of KLF4. TargetScan and luciferase assay showed that miR-34a targeted the KLF4 3′-untranslated region. Either miR-34a inhibition or KLF4 overexpression could abolish M1 polarization induced by the PD-1 inhibitor. The findings strongly suggested that the PD-1 inhibitor exerted its effect in promoting M1 polarization and cardiac injury by modulating the miR-34a/KLF4-signaling pathway and inducing myocardial inflammation. These findings might help us to understand the pathogenesis of cardiac injury during immunotherapy, and provide new targets in ameliorating cardiac injury in patients with cancer receiving PD-1 inhibitor treatment.

Non-coding RNAs in Physiological Cardiac Hypertrophy

Non-coding RNA (ncRNA) is a class of RNAs that are not act as translational protein templates. They are involved in the regulation of gene transcription, RNA maturation and protein translation, participating in a variety of physiological and physiological processes. NcRNAs have important functions, and are recently one of the hotspots in biomedical research. Cardiac hypertrophy is classified into physiological cardiac hypertrophy and pathological cardiac hypertrophy. Different from pathological cardiac hypertrophy, physiological cardiac hypertrophy usually developed during exercise, pregnancy, normal postnatal growth, accompanied with preservation or improvement of systolic function, while no cardiac fibrosis. In this chapter, we will briefly introduce the definition, characteristics, and functions of ncRNAs, including miRNAs, lncRNAs, and circRNAs, as well as a summary of the existing bioinformatics online databases which commonly used in the study of ncRNAs. Specially, this chapter will be focused on the characteristics and the underlying mechanisms about physiological cardiac hypertrophy. Furthermore, the regulatory mechanism of ncRNAs in physiological hypertrophy and the latest research progress will be summarized. Taken together, exploring physiologic cardiac hypertrophy-specific ncRNAs might be a unique research perspective that provides new point of view for interventions in heart failure and other cardiovascular diseases.

Vascular transcriptome landscape of Trail-/- mice: Implications and therapeutic strategies for diabetic vascular disease

Circulating plasma TRAIL levels are suppressed in patients with cardiovascular and diabetic diseases. To identify novel targets in vascular metabolic diseases, genome-wide transcriptome of aortic tissue from Trail^-/- versus Trail^+/+ mice were interrogated. We found 861 genes differentially expressed with TRAIL deletion. Gene enrichment analyses showed many of these genes were related to inflammation, cell-to-cell cytoskeletal interactions, and transcriptional modulation. We identified vascular protective and pathological gene clusters, with Ifi205 as the most significantly reduced vascular protective gene, whereas Glut1, the most significantly increased pathological gene with TRAIL deletion. We hypothesized that therapeutic targets could be devised from such integrated analysis and validated our findings from vascular tissues of diabetic mice. From the differentially expressed gene targets, enriched transcription factor (TF) and microRNA binding motifs were identified. The top two TFs were Elk1 and Sp1, with enrichment to eight gene targets common to both. miR-520d-3p and miR-377-3p were the top enriched microRNAs with TRAIL deletion; with four overlapping genes enriched for both microRNAs. Our findings offer an alternate in silico approach for therapeutic target identification and present a deeper understanding of gene signatures and pathways altered with TRAIL suppression in the vasculature.

Advances in the discovery of microRNA-based anticancer therapeutics: latest tools and developments

Introduction: MicroRNAs (miRNAs) are small endogenous non-coding RNAs that repress the expression of their target genes by reducing mRNA stability and/or inhibiting translation. miRNAs are known to be aberrantly regulated in cancers. Modulators of miRNA (mimics and antagonists) have emerged as novel therapeutic tools for cancer treatment.Areas covered: This review summarizes the various strategies that have been applied to correct the dysregulated miRNA in cancer cells. The authors also discuss the recent advances in the technical development and preclinical/clinical evaluation of miRNA-based therapeutic agents.Expert opinion: Application of miRNA-based therapeutics for cancer treatment is appealing because they are able to modulate multiple dysregulated genes and/or signaling pathways in cancer cells. Major obstacles hindering their clinical development include drug delivery, off-target effects, efficacious dose determination, and safety. Tumor site-specific delivery of novel miRNA therapeutics may help to minimize off-target effects and toxicity. Combination of miRNA therapeutics with other anticancer treatment modalities could provide a synergistic effect, thus allowing the use of lower dose, minimizing off-target effects, and improving the overall safety profile in cancer patients. It is critical to identify individual miRNAs with cancer type-specific and context-specific regulation of oncogenes and tumor-suppressor genes in order to facilitate the precise use of miRNA anticancer therapeutics.

BMP10 preserves cardiac function through its dual activation of SMAD-mediated and STAT3-mediated pathways

Bone morphogenetic protein 10 (BMP10) is a cardiac peptide growth factor belonging to the transforming growth factor β superfamily that critically controls cardiovascular development, growth, and maturation. It has been shown that BMP10 elicits its intracellular signaling through a receptor complex of activin receptor-like kinase 1 with morphogenetic protein receptor type II or activin receptor type 2A. Previously, we generated and characterized a transgenic mouse line expressing BMP10 from the α-myosin heavy chain gene promoter and found that these mice have normal cardiac hypertrophic responses to both physiological and pathological stimuli. In this study, we report that these transgenic mice exhibit significantly reduced levels of cardiomyocyte apoptosis and cardiac fibrosis in response to a prolonged administration of the β-adrenoreceptor agonist isoproterenol. We further confirmed this cardioprotective function with a newly generated conditional Bmp10 transgenic mouse line, in which Bmp10 was activated in adult hearts by tamoxifen. Moreover, the intraperitoneal administration of recombinant human BMP10 was found to effectively protect hearts from injury, suggesting potential therapeutic utility of using BMP10 to prevent heart failure. Gene profiling and biochemical analyses indicated that BMP10 activates the SMAD-mediated canonical pathway and, unexpectedly, also the signal transducer and activator of transcription 3 (STAT3)-mediated signaling pathway both in vivo and in vitro Additional findings further supported the notion that BMP10's cardioprotective function likely is due to its dual activation of SMAD- and STAT3-regulated signaling pathways, promoting cardiomyocyte survival and suppressing cardiac fibrosis.

New opportunities for targeting redox dysregulation in cardiovascular disease

Despite substantial promise, the use of antioxidant therapy to improve cardiovascular outcomes has been disappointing. Whilst the fundamental biology supporting their use continues to build, the challenge now is to differentially target dysregulated redox signalling domains and to identify new ways to deliver antioxidant substances. Looking further afield to other disciplines, there is an emerging ‘tool-kit’ containing sophisticated molecular and drug delivery applications. Applying these to the cardiovascular redox field could prove a successful strategy to combat the increasing disease burden. Excessive reactive oxygen species production and protein modifications in the mitochondria has been the target of successful drug development with several positive outcomes emerging in the cardiovascular space, harnessing both improved delivery mechanisms and enhanced understanding of the biological abnormalities. Using this as a blueprint, similar strategies could be applied and expanded upon in other redox-hot-spots, such as the caveolae sub-cellular region, which houses many of the key cardiovascular redox proteins such as NADPH oxidase, endothelial nitric oxide synthase, angiotensin II receptors, and beta adrenoceptors. The expanded tool kit of drug development, including gene and miRNA therapies, nanoparticle technology and micropeptide targeting, can be applied to target dysregulated redox signalling in subcellular compartments of cardiovascular cells. In this review, we consider the opportunities for improving cardiovascular outcomes by utilizing new technology platforms to target subcellular ‘bonfires’ generated by dysregulated redox pathways, to improve clinical outcomes.

The Genomic Origins of Small Mitochondrial RNAs: Are They Transcribed by the Mitochondrial DNA or by Mitochondrial Pseudogenes within the Nucleus (NUMTs)?

Several studies have linked mitochondrial genetic variation to phenotypic modifications; albeit the identity of the mitochondrial polymorphisms involved remains elusive. The search for these polymorphisms led to the discovery of small noncoding RNAs, which appear to be transcribed by the mitochondrial DNA ("small mitochondrial RNAs"). This contention is, however, controversial because the nuclear genome of most animals harbors mitochondrial pseudogenes (NUMTs) of identical sequence to regions of mtDNA, which could alternatively represent the source of these RNAs. To discern the likely contributions of the mitochondrial and nuclear genome to transcribing these small mitochondrial RNAs, we leverage data from six vertebrate species exhibiting markedly different levels of NUMT sequence. We explore whether abundances of small mitochondrial RNAs are associated with levels of NUMT sequence across species, or differences in tissue-specific mtDNA content within species. Evidence for the former would support the hypothesis these RNAs are primarily transcribed by NUMT sequence, whereas evidence for the latter would provide strong evidence for the counter hypothesis that these RNAs are transcribed directly by the mtDNA. No association exists between the abundance of small mitochondrial RNAs and NUMT levels across species. Moreover, a sizable proportion of transcripts map exclusively to the mtDNA sequence, even in species with highest NUMT levels. Conversely, tissue-specific abundances of small mitochondrial RNAs are strongly associated with the mtDNA content. These results support the hypothesis that small mitochondrial RNAs are primarily transcribed by the mitochondrial genome and that this capacity is conserved across Amniota and, most likely, across most metazoan lineages.

Effects of HIV-1 gp120 and TAT-derived microvesicles on endothelial cell function

The aims of this study were twofold. The first was to determine if human immunodeficiency virus (HIV)-1 glycoprotein (gp) 120 and transactivator of transcription (Tat) stimulate the release of endothelial microvesicles (EMVs). The second was to determine whether viral protein-induced EMVs are deleterious to endothelial cell function (inducing endothelial cell inflammation, oxidative stress, senescence and increasing apoptotic susceptibility). Human aortic endothelial cells (HAECs) were treated with recombinant HIV-1 proteins Bal gp120 (R5), Lav gp120 (X4), or Tat. EMVs released in response to each viral protein were isolated and quantified. Fresh HAECs were treated with EMVs generated under control conditions and from each of the viral protein conditions for 24 h. EMV release was higher (P < 0.05) in HAECs treated with R5 (141 ± 21 MV/µl)_, X4 (132 ± 20 MV/µl), and Tat (130 ± 20 MV/µl) compared with control (61 ± 13 MV/µl). Viral protein EMVs induced significantly higher endothelial cell release of proinflammatory cytokines and expression of cell adhesion molecules than control. Reactive oxygen species production was more pronounced (P < 0.05) in the R5-, X4- and Tat-EMV-treated cells. In addition, viral protein-stimulated EMVs significantly augmented endothelial cell senescence and apoptotic susceptibility. Concomitant with these functional changes, viral protein-stimulated EMVs disrupted cell expression of micro-RNAs 34a, 126, 146a, 181b, 221, and miR-Let-7a (P < 0.05). These results demonstrate that HIV-1 gp120 and Tat stimulate microvesicle release from endothelial cells, and these microvesicles confer pathological effects on endothelial cells by inducing inflammation, oxidative stress, and senescence as well as enhancing susceptibility to apoptosis. Viral protein-generated EMVs may contribute to the increased risk of vascular disease in patients with HIV-1. NEW & NOTEWORTHY Human immunodeficiency virus (HIV)-1-related proteins glycoprotein (gp) 120 and transactivator of transcription (Tat)-mediated endothelial damage and dysfunction are poorly understood. Endothelial microvesicles (EMVs) serve as indicators and potent mediators of endothelial dysfunction. In the present study we determined if HIV-1 R5- and X4-tropic gp120 and Tat stimulate EMV release in vitro and if viral protein-induced EMVs are deleterious to endothelial cell function. gp120 and Tat induced a marked increase in EMV release. Viral protein-induced EMVs significantly increased endothelial cell inflammation, oxidative stress, senescence, and apoptotic susceptibility in vitro. gp120- and Tat-derived EMVs promote a proinflammatory, pro-oxidative, prosenescent, and proapoptotic endothelial phenotype and may contribute to the endothelial damage and dysfunction associated with gp120 and Tat.

Noncoding RNAs regulating cardiac muscle mass

Noncoding RNAs, including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs) play roles in the development and homeostasis of nearly every tissue of the body, including the regulation of processes underlying heart growth. Cardiac hypertrophy can be classified as either physiological (beneficial heart growth) or pathological (detrimental heart growth), the latter of which results in impaired cardiac function and heart failure and is predictive of a higher incidence of death due to cardiovascular disease. Several miRNAs have a functional role in exercise-induced cardiac hypertrophy, while both miRNAs and lncRNAs are heavily involved in pathological heart growth and heart failure. The latter have the potential to act as an endogenous sponge RNA and interact with specific miRNAs to control cardiac hypertrophy, adding another level of complexity to our understanding of the regulation of cardiac muscle mass. In addition to tissue-specific effects, ncRNA-mediated tissue cross talk occurs via exosomes. In particular, miRNAs can be internalized in exosomes and secreted from various cardiac and vascular cell types to promote angiogenesis, as well as protection and repair of ischemic tissues. ncRNAs hold promising therapeutic potential to protect the heart against ischemic injury and aid in regeneration. Numerous preclinical studies have demonstrated the therapeutic potential of ncRNAs, specifically miRNAs, for the treatment of cardiovascular disease. Most of these studies employ antisense oligonucleotides to inhibit miRNAs of interest; however, off-target effects often limit their potential to be translated to the clinic. In this context, approaches using viral and nonviral delivery tools are promising means to provide targeted delivery in vivo.

Comparison of Cardiac miRNA Transcriptomes Induced by Diabetes and Rapamycin Treatment and Identification of a Rapamycin-Associated Cardiac MicroRNA Signature

Rapamycin (Rap), an inhibitor of mTORC1, reduces obesity and improves lifespan in mice. However, hyperglycemia and lipid disorders are adverse side effects in patients receiving Rap treatment. We previously reported that diabetes induces pansuppression of cardiac cytokines in Zucker obese rats (ZO-C). Rap treatment (750 μg/kg/day for 12 weeks) reduced their obesity and cardiac fibrosis significantly; however, it increased their hyperglycemia and did not improve their cardiac diastolic parameters. Moreover, Rap treatment of healthy Zucker lean rats (ZL-C) induced cardiac fibrosis. Rap-induced changes in ZL-C's cardiac cytokine profile shared similarities with that of diabetes-induced ZO-C. Therefore, we hypothesized that the cardiac microRNA transcriptome induced by diabetes and Rap treatment could share similarities. Here, we compared the cardiac miRNA transcriptome of ZL-C to ZO-C, Rap-treated ZL (ZL-Rap), and ZO (ZO-Rap). We report that 80% of diabetes-induced miRNA transcriptome (40 differentially expressed miRNAs by minimum 1.5-fold in ZO-C versus ZL-C; p ≤ 0.05) is similar to 47% of Rap-induced miRNA transcriptome in ZL (68 differentially expressed miRNAs by minimum 1.5-fold in ZL-Rap versus ZL-C; p ≤ 0.05). This remarkable similarity between diabetes-induced and Rap-induced cardiac microRNA transcriptome underscores the role of miRNAs in Rap-induced insulin resistance. We also show that Rap treatment altered the expression of the same 17 miRNAs in ZL and ZO hearts indicating that these 17 miRNAs comprise a unique Rap-induced cardiac miRNA signature. Interestingly, only four miRNAs were significantly differentially expressed between ZO-C and ZO-Rap, indicating that, unlike the nondiabetic heart, Rap did not substantially change the miRNA transcriptome in the diabetic heart. In silico analyses showed that (a) mRNA-miRNA interactions exist between differentially expressed cardiac cytokines and miRNAs, (b) human orthologs of rat miRNAs that are strongly correlated with cardiac fibrosis may modulate profibrotic TGF-β signaling, and (c) changes in miRNA transcriptome caused by diabetes or Rap treatment include cardioprotective miRNAs indicating a concurrent activation of an adaptive mechanism to protect the heart in conditions that exacerbate diabetes.

Understanding Key Mechanisms of Exercise-Induced Cardiac Protection to Mitigate Disease: Current Knowledge and Emerging Concepts

The benefits of exercise on the heart are well recognized, and clinical studies have demonstrated that exercise is an intervention that can improve cardiac function in heart failure patients. This has led to significant research into understanding the key mechanisms responsible for exercise-induced cardiac protection. Here, we summarize molecular mechanisms that regulate exercise-induced cardiac myocyte growth and proliferation. We discuss in detail the effects of exercise on other cardiac cells, organelles, and systems that have received less or little attention and require further investigation. This includes cardiac excitation and contraction, mitochondrial adaptations, cellular stress responses to promote survival (heat shock response, ubiquitin-proteasome system, autophagy-lysosomal system, endoplasmic reticulum unfolded protein response, DNA damage response), extracellular matrix, inflammatory response, and organ-to-organ crosstalk. We summarize therapeutic strategies targeting known regulators of exercise-induced protection and the challenges translating findings from bench to bedside. We conclude that technological advancements that allow for in-depth profiling of the genome, transcriptome, proteome and metabolome, combined with animal and human studies, provide new opportunities for comprehensively defining the signaling and regulatory aspects of cell/organelle functions that underpin the protective properties of exercise. This is likely to lead to the identification of novel biomarkers and therapeutic targets for heart disease.

Inhibition of microRNA-143-3p attenuates myocardial hypertrophy by inhibiting inflammatory response

MicroRNA-143-3p (miR-143-3p) is involved in the initiation of inflammatory response and the progression of cardiovascular diseases. Myocardial hypertrophy is a common symptom in numerous cardiovascular diseases. In the current study, we attempted to demonstrate the role of miR-143-3p in the development of myocardial hypertrophy by focusing on its association with inflammation. Myocardial hypertrophy was induced by transverse aortic constriction (TAC) method in vivo and by H₂ O₂ administration in vitro. The expression status of miR-143-3p and downstream effectors were detected in animal heart tissues and H9c2 cells. Furthermore, the effect of miR-143-3p inhibition on H₂ O₂ -induced changes in ERK5/PPARδ/NF-κB axis was assessed. TAC induced oxidative stress and inflammation in rat heart tissues, which was associated with the increased expressions of miR-143-3p and p-ERK5. However, the up-regulated expression of miR-143-3p had no effect on the expression of ERK5, which was a direct target of miR-143-3p. The results of in vitro assays showed that H₂ O₂ administration increased the levels of miR-143-3p and p-EKR5 and induced the activation of NF-κB pathway. After the inhibition of miR-143-3p, the activation of EKR5 and NF-κB pathway was suppressed, whereas the expression of PPARδ was up-regulated. The current study demonstrated that miR-143-3p is crucial to the initiation of inflammatory response induced by myocardial hypertrophy. The activation of ERK5 following miR-143-3p up-regulation appears to be a complementary response to induce the subsequent anti-inflammatory signaling transduction, which needed further exploration.

Downregulation of miR-34a promotes endothelial cell growth and suppresses apoptosis in atherosclerosis by regulating Bcl-2

Several miRNAs have been demonstrated to be involved in endothelial dysfunction during atherosclerosis (AS). However, the detailed roles and underlying mechanisms of miR-34a in AS-associated endothelial cell apoptosis are far from being addressed. Apolipoprotein E-deficient (ApoE^-/-) mice fed with high-fat diet (HFD) were used as in vivo model of AS. Oxidized low-density lipoprotein (ox-LDL)-treated human aortic endothelial cells (HAECs) were applied as in vitro model of AS. The effects of miR-34a on atherosclerotic lesions were evaluated by hematoxylin-eosin (HE) and Oil Red O staining. Pecam-1⁺ endothelial cells were isolated from the aortic arch with flow cytometry. qRT-PCR and western blot were employed to measure gene and protein expression. The effects of miR-34a on cell viability, cell cycle distribution, and apoptosis were assessed by Cell counting kit (CCK)-8 and flow cytometry analysis. The relationship between miR-34a and Bcl-2 was confirmed by online softwares, luciferase reporter assay, and RNA immunoprecipitation (RIP). miR-34a was upregulated in HFD-induced ApoE^-/- mice and ox-LDL-treated HAECs. Anti-miR-34a decreased atherosclerotic lesions and inhibited Pecam-1⁺ endothelial cells apoptosis in HFD-induced ApoE^-/- mice. Moreover, anti-miR-34a significantly promoted cell viability, alleviated cell cycle arrest, and restrained apoptosis in ox-LDL-treated HAECs. Furthermore, Bcl-2 was identified as a target of miR-34a, and miR-34a inhibited Bcl-2 expression via binding to its 3'UTR. Rescue experiments demonstrated that Bcl-2 overexpression dramatically reversed miR-34a-mediated inhibition of cell growth and promotion of apoptosis in ox-LDL-exposed HAECs. Depletion of miR-34a facilitated endothelial cell growth and blocked apoptosis in AS by upregulating Bcl-2, offering a promising avenue for AS therapy.

Dysregulated miRNAs and their pathogenic implications for the neurometabolic disease propionic acidemia

miRNome expression profiling was performed in a mouse model of propionic acidemia (PA) and in patients’ plasma samples to investigate the role of miRNAs in the pathophysiology of the disease and to identify novel biomarkers and therapeutic targets. PA is a potentially lethal neurometabolic disease with patients developing neurological deficits and cardiomyopathy in the long-term, among other complications. In the PA mouse liver we identified 14 significantly dysregulated miRNAs. Three selected miRNAs, miR-34a-5p, miR-338-3p and miR-350, were found upregulated in brain and heart tissues. Predicted targets involved in apoptosis, stress-signaling and mitochondrial function, were inversely found down-regulated. Functional analysis with miRNA mimics in cellular models confirmed these findings. miRNA profiling in plasma samples from neonatal PA patients and age-matched control individuals identified a set of differentially expressed miRNAs, several were coincident with those identified in the PA mouse, among them miR-34a-5p and miR-338-3p. These two miRNAs were also found dysregulated in childhood and adult PA patients’ cohorts. Taken together, the results reveal miRNA signatures in PA useful to identify potential biomarkers, to refine the understanding of the molecular mechanisms of this rare disease and, eventually, to improve the management of patients.

microRNA profiling in atherosclerosis, diabetes, and migraine

microRNAs (miRNAs) are a broad group of endogenous small non-coding molecules that reduce the transcription of mRNA and play a key role in post-transcriptional gene processes. miRNAs are involved in onset and progression of several human disorders such as infectious and immune non-infectious diseases, cancers, metabolic and cardiovascular disorders. They regulate the expression of gene targets (e.g. oncogenes and tumor suppressor genes) and act as gene repressors with mRNA binding and cleavage. The increasing evidence that miRNAs play a key role in the pathogenesis of cardiovascular conditions could radically change the future management approach to these disorders. This review focuses on current knowledge about the influence of miRNAs on cardiovascular disease, with particular regard to common conditions such as atherosclerosis, diabetes and migraine. Key messages miRNAs are a group of endogenous small non-coding RNA segments measuring 19-25 nucleotides that are involved in physiologic processes and onset and progression of disorders such as infectious and immune non-infectious diseases, cancers, metabolic and cardiovascular disorders. miRNAs expression guarantees vascular integrity, by regulating apoptosis, VEGF pathway and VCAM 1 expression (-126), and is involved in atherosclerotic plaque formation process and progression. Hyperglycemia, overt diabetes, and their complications are associated with overexpression of several miRNAs. An altered expression of miRNAs has also been postulated in migraine patients, although only a few preliminary studies have so far been performed with this respect.

New Treatment Strategies for Alcohol-Induced Heart Damage

High-dose alcohol misuse induces multiple noxious cardiac effects, including myocyte hypertrophy and necrosis, interstitial fibrosis, decreased ventricular contraction and ventricle enlargement. These effects produce diastolic and systolic ventricular dysfunction leading to congestive heart failure, arrhythmias and an increased death rate. There are multiple, dose-dependent, synchronic and synergistic mechanisms of alcohol-induced cardiac damage. Ethanol alters membrane permeability and composition, interferes with receptors and intracellular transients, induces oxidative, metabolic and energy damage, decreases protein synthesis, excitation-contraction coupling and increases cell apoptosis. In addition, ethanol decreases myocyte protective and repair mechanisms and their regeneration. Although there are diverse different strategies to directly target alcohol-induced heart damage, they are partially effective, and can only be used as support medication in a multidisciplinary approach. Alcohol abstinence is the preferred goal, but control drinking is useful in alcohol-addicted subjects not able to abstain. Correction of nutrition, ionic and vitamin deficiencies and control of alcohol-related systemic organ damage are compulsory. Recently, several growth factors (myostatin, IGF-1, leptin, ghrelin, miRNA, and ROCK inhibitors) and new cardiomyokines such as FGF21 have been described to regulate cardiac plasticity and decrease cardiac damage, improving cardiac repair mechanisms, and they are promising agents in this field. New potential therapeutic targets aim to control oxidative damage, myocyte hypertrophy, interstitial fibrosis and persistent apoptosis In addition, stem-cell therapy may improve myocyte regeneration. However, these strategies are not yet approved for clinical use.

Sex differences in response to miRNA-34a therapy in mouse models of cardiac disease: identification of sex-, disease- and treatment-regulated miRNAs

KEY POINTS

MicroRNA (miRNA)-based therapies are in development for numerous diseases, including heart disease. Currently, very limited basic information is available on the regulation of specific miRNAs in male and female hearts in settings of disease. The identification of sex-specific miRNA signatures has implications for translation into the clinic and suggests the need for customised therapy. In the present study, we found that a miRNA-based treatment inhibiting miRNA-34a (miR-34a) was more effective in females in a setting of moderate dilated cardiomyopathy than in males. Furthermore, the treatment showed little benefit for either sex in a setting of more severe dilated cardiomyopathy associated with atrial fibrillation. The results highlight the importance of understanding the effect of miRNA-based therapies in cardiac disease settings in males and females.

ABSTRACT

MicroRNA (miRNA)-34a (miR-34a) is elevated in the diseased heart in mice and humans. Previous studies have shown that inhibiting miR-34a in male mice in settings of pathological cardiac hypertrophy or ischaemia protects the heart against progression to heart failure. Whether inhibition of miR-34a protects the female heart is unknown. Furthermore, the therapeutic potential of silencing miR-34a in settings of dilated cardiomyopathy (DCM) and atrial fibrillation (AF) has not been assessed previously. In the present study, we examined the effect of silencing miR-34a in males and females in (1) a model of moderate DCM and (2) a model of severe DCM with AF. The cardiac disease models were administered with a locked nucleic acid-modified oligonucleotide (LNA-antimiR-34a) at 6-7 weeks of age when the models display cardiac dysfunction and conduction abnormalities. Cardiac function and morphology were measured 6 weeks after treatment. In the present study, we show that inhibition of miR-34a provides more protection in the DCM model in females than males. Disease prevention in LNA-antimiR-34a treated DCM female mice was characterized by attenuated heart enlargement and lung congestion, lower expression of cardiac stress genes (B-type natriuretic peptide, collagen gene expression), less cardiac fibrosis and better cardiac function. There was no evidence of significant protection in the severe DCM and AF model in either sex. Sex- and treatment-dependent regulation of miRNAs was also identified in the diseased heart, and may explain the differential response of males and females. These studies highlight the importance of examining the impact of miRNA-based drugs in both sexes and under different disease conditions.

MicroRNA gene expression signatures in long-surviving malignant pleural mesothelioma patients

Malignant pleural mesothelioma (MPM) is a tumor originating in the mesothelium, the membrane lining the thoracic cavities, and is induced by exposure to asbestos. Australia suffers one of the world's highest rates of MPM and the incidence is yet to peak. The prognosis for patients with MPM is poor and median survival following diagnosis is 4–18 months. Currently, no or few effective therapies exist for MPM. Trials of targeted agents such as antiangiogenic agents (VEGF, EGFR) or ribonuclease inhibitors (ranpirnase) largely failed to show efficacy in MPM Tsao et al. (2009) [1]. A recent study, however, showed that cisplatin/pemetrexed + bevacizumab (a recombinant humanized monoclonal antibody that inhibit VEGF) treatment has a survival benefit of 2.7 months Zalcman et al. (2016) [2]. It remains to be seen if this targeted therapy will be accepted as a new standard for MPM. Thus the unmet needs of MPM patients remain very pronounced and almost every patient will be confronted with drug resistance and recurrence of disease. We have identified unique gene signatures associated with prolonged survival in mesothelioma patients undergoing radical surgery (EPP, extrapleural pneumonectomy), as well as patients who underwent palliative surgery (pleurectomy/decortication). In addition to data published in Molecular Oncology, 2015;9:715-26 (GSE59180) Kirschner et al. (2015) , we describe here additional data using a system-based approach that support our previous observations. This data provides a resource to further explore microRNA dynamics in MPM.