Accumulation of miR-155 and BIC RNA in human B cell lymphomas

miR-155 impairs ICOSL and MHC-I expression in DLBCL lymphomas

Elevated miR-155 levels in B cell malignancies, such as CLL and DLBCL, correlate with increased aggressiveness of the disease. We recently reported that, in two different mouse models of miR-155-driven B cell malignancy, miR-155 targets and down-regulates transcripts encoding ICOSL, the ligand for the Inducible T cell costimulator (ICOS), thereby impairing the capacity of T lymphocytes to recognize and eliminate malignant cells. In this report, we extend our previous findings to Human by showing that miR-155 levels negatively correlate with those of both ICOSL and MHC-I in samples from DLBCL patients. We present evidence of miR-155 reducing the levels of ICOSL transcripts in ABC, but not in GCB primary tumors (PTs) and cell lines (CLs). In contrast, there was no evidence of miR-155 targeting MHC-I transcript levels in both types of DLBCLs. Nevertheless, miR-155 and MHC-I levels inversely correlated in DLBCLs samples, suggesting the existence of indirect regulatory effects of miR-155. There was also evidence of dose-dependent effects at low miR-155 levels. Altogether, our findings indicate that the deficiency of both ICOSL and MHC-I activity, driven by high levels of miR-155, may be causative in the failure of the host immune system to recognize and eliminate malignant B cells.

Methods for Extracellular Vesicle Isolation: Relevance for Encapsulated miRNAs in Disease Diagnosis and Treatment

Extracellular vesicles (EVs) are nanovesicles that facilitate intercellular communication by carrying essential biomolecules under physiological and pathological conditions including microRNAs (miRNAs). They are found in various body fluids, such as blood, urine, and saliva, and their levels fluctuate with disease progression, making them valuable diagnostic tools. However, isolating EVs is challenging due to their small size and biological complexity. Here, we summarize the principles behind the most common EV isolation methods including ultracentrifugation, precipitation, immunoaffinity, sorting, ultrafiltration, size exclusion chromatography, and microfluidics while highlighting protocol strengths and weaknesses. We also review the main strategies to identify and quantify circulating miRNAs with a particular focus on EV-encapsulated miRNAs. Since these miRNAs hold special clinical interest derived from their superior stability and therapeutic potential, the information provided here should provide valuable guidance for future research initiatives in the promising field of disease diagnostic and treatment based on EV-encapsulated miRNAs.

The role of miR-155 in cardiovascular diseases: Potential diagnostic and therapeutic targets

Cardiovascular diseases (CVDs), such as atherosclerotic cardiovascular diseases, heart failure (HF), and acute coronary syndrome, represent a significant threat to global health and impose considerable socioeconomic burdens. The intricate pathogenesis of CVD involves various regulatory mechanisms, among which microRNAs (miRNAs) have emerged as critical posttranscriptional regulators. In particular, miR-155 has demonstrated differential expression patterns across a spectrum of CVD and is implicated in the etiology and progression of arterial disorders. This systematic review synthesizes current evidence on the multifaceted roles of miR-155 in the modulation of genes and pathological processes associated with CVD. We delineate the potential of miR-155 as a diagnostic biomarker and therapeutic target, highlighting its significant regulatory influence on conditions such as atherosclerosis, aneurysm, hypertension, HF, myocardial hypertrophy, and oxidative stress. Our analysis underscores the transformative potential of miR-155 as a target for intervention in cardiovascular medicine, warranting further investigation into its clinical applicability.

MicroRNA Gets a Mighty Award

Recent advancements in microRNAs (miRNAs) research have revealed their key roles in both normal physiological processes and pathological conditions, leading to potential applications in diagnostics and therapeutics. However, the path forward is fraught with several scientific and technical challenges. This review article briefly explores the milestones of the discovery, biogenesis, functions, and application for clinical diagnostic and therapeutic strategies of miRNAs. The potential challenges and future directions are also discussed to fully harness their capabilities.

Insights into the genetic and epigenetic mechanisms governing X-chromosome-linked-miRNAs expression in cancer; a step-toward ncRNA precision

Sex chromosomes play a significant role in establishing sex-specific differences in gene expression, thereby contributing to phenotypic diversity and susceptibility to various diseases. MicroRNAs (miRNAs), which are small non-coding RNAs encoded by both the X and Y chromosomes, exhibit sex-specific regulatory characteristics. Computational analysis has identified several X-linked miRNAs differentially expressed in sex-specific cancers. This review aims to elucidate the genetic and epigenetic mechanisms that govern the sex-specific expression of X- and Y-linked miRNAs, with particular attention to their functional role in regulating diverse cellular processes in different cancer pathways. In addition, this review provides a comprehensive understanding of the targeted therapeutic interventions and critical insights into the potential clinical implications of targeting sex-specific miRNAs. In conclusion, this review opens new horizons for further research to effectively translate these findings into viable treatment options.

Profiling Precursor microRNAs of Breast Cancer From Total RNA Sequencing Data to Gain Insights Into Their Roles and Prognostic Values

Breast cancer, a molecularly heterogeneous disease, is classified into hormone receptor-positive luminal breast cancer (LBC), human epidermal growth factor receptor 2-positive breast cancer, and triple-negative breast cancer (TNBC). Precursor microRNAs (pre-miRNAs), typically form hairpin structures with a length from 65 to 80 bases, are shown to play crucial roles in breast cancer carcinogenesis. We hypothesized that these pre-miRNAs could have been sequenced in total RNA sequencing (RNA-seq) and developed a novel algorithm to profile pre-miRNAs from raw total RNA-seq data. A total of 907 breast cancer samples curated by Malaysian Breast Cancer Genetic Study (MyBrCa) were profiled using this algorithm and a comparison was made between pre-miRNA profiles and mature miRNA profiles obtained from The Cancer Genome Atlas (TCGA) dataset. We explored differentially expressed pre-miRNAs in TNBC in comparison to LBC and conducted downstream functional analyses of the target genes. A prognostic signature was built by LASSO-Cox regression on selected pre-miRNAs and validated internally and externally by MyBrCa and TCGA datasets, respectively. As a result, 10 common differentially expressed pre-miRNAs were identified. Functional analyses of these pre-miRNAs captured certain aggressive TNBC behaviors. Importantly, a pre-miRNA signature composed of 4 out of these 10 pre-miRNAs significantly prognosticated the breast cancer patients in the MyBrCa cohort and TCGA cohort, independent of conventional prognostic factors. In conclusion, this novel algorithm allows profiling pre-miRNAs from raw total RNA-seq data, which could be cross-validated with mature miRNA profiles for cross-platform comparison. The findings of this study underscore the importance of pre-miRNAs in breast cancer carcinogenesis and as prognostic factors.

Combined replacement of lnc-MEG3 and miR-155 elicit tumor suppression in multiple myeloma

AIMS

To investigate the biological impact of simultaneous overexpression of lncRNA MEG3 and miR-155, termed a "double hit," on multiple myeloma (MM) cells compared to individual biomarker substitution.

MATERIALS AND METHODS

Human MM cells were transfected with MEG3-overexpressed plasmids and miR-155 mimics. Cell cytotoxicity, apoptosis, and gene expression were evaluated in transfected cells and clinical samples.

RESULTS

MEG3 and miR-155 were significantly downregulated in MM patients, with lower expression levels correlating with advanced disease stages and poorer survival. Dual overexpression induced potent cytotoxic effects in MM cells.

CONCLUSION

MEG3 and miR-155 are potential tumor suppressors in MM. Simultaneous overexpression of both biomarkers could represent a novel therapeutic strategy, and their levels could serve as diagnostic and prognostic markers.

Screening the human miRNA interactome reveals coordinated up-regulation in melanoma, adding bidirectional regulation to miRNA networks

Cellular protein expression is coordinated posttranscriptionally by an intricate regulatory network. The current presumption is that microRNAs (miRNAs) work by repression of functionally related targets within a system. In recent work, up-regulation of protein expression via direct interactions of messenger RNA with miRNA has been found in dividing cells, providing an additional mechanism of regulation. Herein, we demonstrate coordinated up-regulation of functionally coupled proteins by miRNA. We focused on CD98hc, the heavy chain of the amino acid transporter LAT-1, and α-2,3-sialyltransferases ST3GAL1 and ST3GAL2, which are critical for CD98hc stability in melanoma. Profiling miRNA regulation using our high-throughput miRFluR assay, we identified miRNA that up-regulated the expression of both CD98hc and either ST3GAL1 or ST3GAL2. These co-up-regulating miRNAs were enriched in melanoma datasets associated with transformation and progression. Our findings add co-up-regulation by miRNA into miRNA regulatory networks and add a bidirectional twist to the impact miRNAs have on protein regulation and glycosylation.

MicroRNA as a Potential Diagnostic and Prognostic Biomarker in Diffuse Large B-Cell Lymphoma: A Systematic Review and Meta-Analysis

BACKGROUND

Recently, microRNAs (miRNAs) have been applied as biomarkers for diffuse large B-cell lymphoma (DLBCL) patients. Early diagnosis and management of DLBCL can improve patient survival and prognosis.

AIMS

This systematic review and meta-analysis aimed to evaluate the diagnostic and prognostic accuracy of miRNA biomarkers in DLBCL patients.

METHODS

We used the keywords "diffuse large B-cell lymphoma" and "microRNA" to search databases for original publications until June 14, 2023. Specificity, sensitivity, and AUC were used to assess diagnostic accuracy, and the prognostic value was assessed using the overall survival (OS) and progression-free survival (PFS) hazard ratio (HR). A subgroup analysis was performed based on the sample type acquired to investigate the heterogeneity.

RESULTS

Thirteen diagnostic and 33 prognostic studies were included from 839 articles. The Reitsma bivariate model estimated a sensitivity of 0.788 (95% CI: 0.733-0.834, p < 0.001), a specificity of 0.727 (95% CI: 0.654-0.790, p < 0.001), and an AUC of 0.824 in. The pooled AUC was 0.7385 (95% CI: 0.6847-0.7923, p < 0.0001). The pooled OS and PFS HRs (> 1) were 2.2847 (95% CI: 1.7248-3.0263, p < 0.0001) and 2.4883 (95% CI: 1.7367-3.5650, p < 0.0001). The pooled OS and PFS HRs (< 1) were 0.4965 (95% CI: 0.3576-0.6894, p < 0.0001) and 2.4883 (95% CI: 1.7367-3.5650, p < 0.0001). MiR-155 diagnostic values had a sensitivity of 0.710 (p > 0.1) and a specificity of 0.725 (p < 0.05), with an AUC of 0.776. miR-21 diagnostic values had an AUC of 0.8468 (p < 0.0001) and OS HR of 2.8938.

CONCLUSION

MicroRNAs could serve as a powerful diagnostic and prognostic tool in DLBCL.

Retargeting target-directed microRNA-decay sites to highly expressed viral or cellular miRNAs

MicroRNAs (miRNAs) are pervasive regulators of gene expression, necessitating the development of tools to inhibit individual miRNAs for functional studies or therapeutic targeting. Specialized base-pairing configurations between a miRNA and an RNA target site can trigger the degradation of the targeting miRNA through target-directed miRNA decay (TDMD). Previous work has identified several natural sites that induce TDMD of specific miRNAs. We explored retargeting known TDMD sites for the inhibition of heterologous miRNAs, including several encoded by Kaposi's Sarcoma-associated herpesvirus (KSHV). We focused particularly on miR-K11, a viral mimic of the oncogenic miRNA miR-155. miRNA pairing architectures based on the TDMD site in the long non-coding RNA Cyrano outperformed other retargeted sites. Cyrano-like inhibitors were specific for viral miR-K11 over cellular miR-155 and vice versa. Lentiviral delivery of a Cyrano-like miR-K11 inhibitor into KSHV-transformed primary effusion lymphoma (PEL) cells impaired their viability, showing that miR-K11 promotes KSHV-dependent PEL cell survival. Surprisingly, inactivation of ZSWIM8, a key mediator of TDMD, did not substantially affect miRNA inhibition by retargeted Cyrano-based inhibitors in 293T or PEL cells. Together, our results demonstrate the feasibility of retargeting natural TDMD sites to highly expressed viral or cellular miRNAs and further define features of effective encoded miRNA inhibitors.

The Role of microRNA-155 as a Biomarker in Diffuse Large B-Cell Lymphoma

Diffuse Large B-cell Lymphoma (DLBCL) is the most common aggressive non-Hodgkin lymphoma (NHL). Despite the use of newer agents, such as polatuzumab vedotin, more than one-third of patients have ultimately relapsed or experienced refractory disease. MiRNAs are single-stranded, ~22-nucleotide-long RNAs that interact with their target RNA. They are significant regulators of post-transcriptional gene expression. One significant miRNA, miR-155, is involved in the pathophysiology of DLBCL and it is a critical modulator of hematopoiesis, inflammation, and immune responses. Targets of miR-155, such as histone deacetylase 4 (HDAC4), suppressor of cytokine signaling-1 (SOCS1) and immune cells, play a crucial role in DLBCL pathogenesis, since miR-155 regulates key pathways, transcription factors and cytokine expression and shapes the tumor microenvironment in DLBCL. In this review, we examine the role of miR-155 in DLBCL and its potential as a future diagnostic, prognostic, or predictive biomarker.

Small and long non-coding RNAs: Past, present, and future

Since the introduction of the central dogma of molecular biology in 1958, various RNA species have been discovered. Messenger RNAs transmit genetic instructions from DNA to make proteins, a process facilitated by housekeeping non-coding RNAs (ncRNAs) such as small nuclear RNAs (snRNAs), ribosomal RNAs (rRNAs), and transfer RNAs (tRNAs). Over the past four decades, a wide array of regulatory ncRNAs have emerged as crucial players in gene regulation. In celebration of Cell's 50th anniversary, this Review explores our current understanding of the most extensively studied regulatory ncRNAs-small RNAs and long non-coding RNAs (lncRNAs)-which have profoundly shaped the field of RNA biology and beyond. While small RNA pathways have been well documented with clearly defined mechanisms, lncRNAs exhibit a greater diversity of mechanisms, many of which remain unknown. This Review covers pivotal events in their discovery, biogenesis pathways, evolutionary traits, action mechanisms, functions, and crosstalks among ncRNAs. We also highlight their roles in pathophysiological contexts and propose future research directions to decipher the unknowns of lncRNAs by leveraging lessons from small RNAs.

miR-155 enhances apoptosis of macrophage through suppressing PI3K-AKT activation in Pseudomonas aeruginosa keratitis

Keratitis induced by Pseudomonas aeruginosa (P. aeruginosa) is an acute and serious corneal inflammation. As a family of gene regulators, miRNAs play a crucial role in modulating host response after microbial invasion. However, their functions in P. aeruginosa keratitis remain largely unclear. In the present study, we demonstrated that miR-155 expression was significantly increased in macrophages and corneal tissue after P. aeruginosa infection. In vivo studies demonstrated that mice with miR-155 knockdown displayed more resistance to P. aeruginosa keratitis, with a lower bacterial burden. In addition, in vitro and in vivo studies indicated that miR-155 enhanced apoptosis of macrophages after P. aeruginosa infection, and resulted in a susceptible phenotype of P. aeruginosa keratitis. Moreover, miR-155 induced apoptosis through reducing activation of PI3K-Akt signaling pathway. Our data provided evidence of miR-155 mediated apoptosis of macrophage in P. aeruginosa keratitis, which may be an underlying target for the therapy of P. aeruginosa keratitis and other infectious diseases.

Non-Coding RNAs in Myasthenia Gravis: From Immune Regulation to Personalized Medicine

Myasthenia gravis (MG) is an antibody-mediated autoimmune disorder characterized by altered neuromuscular transmission, which causes weakness and fatigability in the skeletal muscles. The etiology of MG is complex, being associated with multiple genetic and environmental factors. Over recent years, progress has been made in understanding the immunological alterations implicated in the disease, but the exact pathogenesis still needs to be elucidated. A pathogenic interplay between innate immunity and autoimmunity contributes to the intra-thymic MG development. Epigenetic changes are critically involved in both innate and adaptive immune response regulation. They can act as (i) pathological factors besides genetic predisposition and (ii) co-factors contributing to disease phenotypes or patient-specific disease course/outcomes. This article reviews the role of non-coding RNAs (ncRNAs) as epigenetic factors implicated in MG. Particular attention is dedicated to microRNAs (miRNAs), whose expression is altered in MG patients' thymuses and circulating blood. The long ncRNA (lncRNA) contribution to MG, although not fully characterized yet, is also discussed. By summarizing the most recent and fast-growing findings on ncRNAs in MG, we highlight the therapeutic potential of these molecules for achieving immune regulation and their value as biomarkers for the development of personalized medicine approaches to improve disease care.

MiRNA expression as outcome predictor in pediatric AML: systematic evaluation of a new model

Accurately predicting patient outcomes is essential for optimizing treatment and improving outcomes in pediatric acute myeloid leukemia (AML). In recent years, microRNAs have emerged as a promising prognostic marker, with a growing body of evidence supporting their potential predictive value. We systematically reviewed all previous studies that have analyzed the expression of microRNAs as predictors of survival in pediatric AML and found 16 microRNAs and 4 microRNA signatures previously proposed as predictors of survival. We then used a public access cohort of 1414 pediatric AML patients from the TARGET project to develop a new predictive model using penalized lasso Cox regression based on microRNA expression. Here we propose a new score based on a 37-microRNA signature that is associated with AML and is able to predict survival more accurately than previous microRNA-based methods.

HSV-1 and Cellular miRNAs in CSF-Derived Exosomes as Diagnostically Relevant Biomarkers for Neuroinflammation

Virus-associated chronic inflammation may contribute to autoimmunity in a number of diseases. In the brain, autoimmune encephalitis appears related to fluctuating reactivation states of neurotropic viruses. In addition, viral miRNAs and proteins can be transmitted via exosomes, which constitute novel but highly relevant mediators of cellular communication. The current study questioned the role of HSV-1-encoded and host-derived miRNAs in cerebrospinal fluid (CSF)-derived exosomes, enriched from stress-induced neuroinflammatory diseases, mainly subarachnoid hemorrhage (SAH), psychiatric disorders (AF and SZ), and various other neuroinflammatory diseases. The results were compared with CSF exosomes from control donors devoid of any neuroinflammatory pathology. Serology proved positive, but variable immunity against herpesviruses in the majority of patients, except controls. Selective ultrastructural examinations identified distinct, herpesvirus-like particles in CSF-derived lymphocytes and monocytes. The likely release of extracellular vesicles and exosomes was most frequently observed from CSF monocytes. The exosomes released were structurally similar to highly purified stem-cell-derived exosomes. Exosomal RNA was quantified for HSV-1-derived miR-H2-3p, miR-H3-3p, miR-H4-3p, miR-H4-5p, miR-H6-3p, miR-H27 and host-derived miR-21-5p, miR-146a-5p, miR-155-5p, and miR-138-5p and correlated with the oxidative stress chemokine IL-8 and the axonal damage marker neurofilament light chain (NfL). Replication-associated miR-H27 correlated with neuronal damage marker NfL, and cell-derived miR-155-5p correlated with oxidative stress marker IL-8. Elevated miR-138-5p targeting HSV-1 latency-associated ICP0 inversely correlated with lower HSV-1 antibodies in CSF. In summary, miR-H27 and miR-155-5p may constitute neuroinflammatory markers for delineating frequent and fluctuating HSV-1 replication and NfL-related axonal damage in addition to the oxidative stress cytokine IL-8 in the brain. Tentatively, HSV-1 remains a relevant pathogen conditioning autoimmune processes and a psychiatric clinical phenotype.

The role of miR-155 in urologic malignancies

MicroRNAs (miRNAs) are a class of short non-coding RNAs that play a crucial role in regulating gene expression across multiple levels. They are involved in a wide range of physiological processes, including proliferation, differentiation, apoptosis, and cell cycle control. In recent years, miRNAs have emerged as pivotal regulatory molecules in the development and progression of tumors. Among these, miR-155 has garnered significant attention due to its high expression in various diseases, particularly urologic malignancies. Since an extensive corpus of studies having focused on the roles of miR-155 in various urologic malignancies, it is essential to summarize the current evidence on this topic through a comprehensive review. Altered miR-155 expression is related to various physiological and pathological processes, including immune response, inflammation, tumor development and treatment resistance. Notably, alterations in miR-155 expression have been observed in urologic malignancies as well. The up-regulation of miR-155 expression is commonly observed in urologic malignancies, contributing to their progression by targeting specific proteins and signaling pathways. This article provides a comprehensive review of the significant role played by miR-155 in the development of urologic malignancies. Furthermore, the potential of miR-155 as a biomarker and therapeutic target in urologic malignancies is also discussed.

State of the art and future research directions of materials science applied to electrochemical biosensor developments

Centralized laboratories in which analytical processes are automated to enable the analysis of large numbers of samples at relatively low cost are used for analytical testing throughout the world. However, healthcare is changing, partly due to the general recognition that care needs to be more patient-centered and putting the patient at the center of action. One way to achieve this goal is to consider point-of-care testing (PoC) devices as alternative analytical concepts. This requires miniaturization of current analytical concepts and the use of cost-effective diagnostic tools with appropriate sensitivity and specificity. Electrochemical sensors are ideally adapted as they provide robust, low-cost, and miniaturized solutions for the detection of variable analytes, yet lack the high sensitivity comparable to more classical diagnosis approaches. Advances in nanotechnology have opened up a plethora of different nanomaterials to be applied as electrode and/or sensing materials in electrochemical biosensors. The choice of materials significantly influences the sensor's sensitivity, selectivity, and overall performance. A critical review of the state of the art with respect to the development of the utilized materials (between 2019 and 2023) and where the field is heading to are the focus of this article.

The biological role of lncRNAs in the acute lymphocytic leukemia: An updated review

The cause of leukemia, a common malignancy of the hematological system, is unknown. The structure of long non-coding RNAs (lncRNAs) is similar to mRNA but no ability to encode proteins. Numerous malignancies, including different forms of leukemia, are linked to Lnc-RNAs. It is verified that the carcinogenesis and growth of a variety of human malignancies are significantly influenced by aberrant lncRNA expression. The body of evidence linking various types of lncRNAs to the etiology of leukemia has dramatically increased during the past ten years. Some lncRNAs are therefore anticipated to function as novel therapeutic targets, diagnostic biomarkers, and clinical outcome predictions. Additionally, these lncRNAs may provide new therapeutic options and insight into the pathophysiology of diseases, particularly leukemia. Thus, this review outlines the present comprehension of leukemia-associated lncRNAs.

Carcinogenic mechanisms of virus-associated lymphoma

The development of lymphoma is a complex multistep process that integrates numerous experimental findings and clinical data that have not yet yielded a definitive explanation. Studies of oncogenic viruses can help to deepen insight into the pathogenesis of lymphoma, and identifying associations between lymphoma and viruses that are established and unidentified should lead to cellular and pharmacologically targeted antiviral strategies for treating malignant lymphoma. This review focuses on the pathogenesis of lymphomas associated with hepatitis B and C, Epstein-Barr, and human immunodeficiency viruses as well as Kaposi sarcoma-associated herpesvirus to clarify the current status of basic information and recent advances in the development of virus-associated lymphomas.

MicroRNAs: Potential prognostic and theranostic biomarkers in chronic lymphocytic leukemia

Small noncoding ribonucleic acids called microRNAs coordinate numerous critical physiological and biological processes such as cell division, proliferation, and death. These regulatory molecules interfere with the function of many genes by binding the 3'-UTR region of target mRNAs to inhibit their translation or even degrade them. Given that a large proportion of miRNAs behave as either tumor suppressors or oncogenes, any genetic or epigenetic aberration changeing their structure and/or function could initiate tumor formation and development. An example of such cancers is chronic lymphocytic leukemia (CLL), the most prevalent adult leukemia in Western nations, which is caused by unregulated growth and buildup of defective cells in the peripheral blood and lymphoid organs. Genetic alterations at cellular and molecular levels play an important role in the occurrence and development of CLL. In this vein, it was noted that the development of this disease is noticeably affected by changes in the expression and function of miRNAs. Many studies on miRNAs have shown that these molecules are pivotal in the prognosis of different cancers, including CLL, and their epigenetic alterations (e.g., methylation) can predict disease progression and response to treatment. Furthermore, miRNAs are involved in the development of drug resistance in CLL, and targeting these molecules can be considered a new therapeutic approach for the treatment of this disease. MiRNA screening can offer important information on the etiology and development of CLL. Considering the importance of miRNAs in gene expression regulation, their application in the diagnosis, prognosis, and treatment of CLL is reviewed in this paper.

Exosome regulation of immune response mechanism: Pros and cons in immunotherapy

Due to its multiple features, including the ability to orchestrate remote communication between different tissues, the exosomes are the extracellular vesicles arousing the highest interest in the scientific community. Their size, established as an average of 30-150 nm, allows them to be easily uptaken by most cells. According to the type of cells-derived exosomes, they may carry specific biomolecular cargoes used to reprogram the cells they are interacting with. In certain circumstances, exosomes stimulate the immune response by facilitating or amplifying the release of foreign antigens-killing cells, inflammatory factors, or antibodies (immune activation). Meanwhile, in other cases, they are efficiently used by malignant elements such as cancer cells to mislead the immune recognition mechanism, carrying and transferring their cancerous cargoes to distant healthy cells, thus contributing to antigenic invasion (immune suppression). Exosome dichotomic patterns upon immune system regulation present broad advantages in immunotherapy. Its perfect comprehension, from its early biogenesis to its specific interaction with recipient cells, will promote a significant enhancement of immunotherapy employing molecular biology, nanomedicine, and nanotechnology.

Detection of MicroRNAs Using Synthetic Toehold Switch in Mammalian Cells

Engineering synthetic gene circuits to control cellular functions has a broad application in the field of synthetic biology. Synthetic RNA-based switches that can operate at the transcriptional and posttranscriptional level have also drawn significant interest for the application of next-generation therapeutics and diagnostics. Thus, RNA-based switchable platforms are needed to report dynamic cellular mechanisms which play an important role in cell development and diseases. Recently, several RNA-based switches have been designed and utilized for biosensing and molecular diagnostics. However, miRNA-based switches have not been well established or characterized, especially for eukaryotic translational control. Here, we designed a novel synthetic toehold switch for detection of exogenously and endogenously expressed miRNAs in CHO, HeLa, HEK 293, and MDA-MB-231 breast cancer cells. Multiplex detection of miR-155 and miR-21 was tested using two toehold switches to evaluate the orthogonality and programmability of this synthetic platform.

Hypoxia-inducible microRNA-155 negatively regulates epithelial barrier in eosinophilic esophagitis by suppressing tight junction claudin-7

MicroRNA (miRNA)-mediated mRNA regulation directs many homeostatic and pathological processes, but how miRNAs coordinate aberrant esophageal inflammation during eosinophilic esophagitis (EoE) is poorly understood. Here, we report a deregulatory axis where microRNA-155 (miR-155) regulates epithelial barrier dysfunction by selectively constraining tight junction CLDN7 (claudin-7). MiR-155 is elevated in the esophageal epithelium of biopsies from patients with active EoE and in cell culture models. MiR-155 localization using in situ hybridization (ISH) in patient biopsies and intra-epithelial compartmentalization of miR-155 show expression predominantly within the basal epithelia. Epithelial miR-155 activity was evident through diminished target gene expression in 3D organotypic cultures, particularly in relatively undifferentiated basal cell states. Mechanistically, generation of a novel cell line with enhanced epithelial miR-155 stable overexpression induced a functionally deficient epithelial barrier in 3D air-liquid interface epithelial cultures measured by transepithelial electrical resistance (TEER). Histological assessment of 3D esophageal organoid cultures overexpressing miR-155 showed notable dilated intra-epithelial spaces. Unbiased RNA-sequencing analysis and immunofluorescence determined a defect in epithelial barrier tight junctions and revealed a selective reduction in the expression of critical esophageal tight junction molecule, claudin-7. Together, our data reveal a previously unappreciated role for miR-155 in mediating epithelial barrier dysfunction in esophageal inflammation.

Macrophage polarization in spinal cord injury repair and the possible role of microRNAs: A review

The prevention, treatment, and rehabilitation of spinal cord injury (SCI) have always posed significant medical challenges. After mechanical injury, disturbances in microcirculation, edema formation, and the generation of free radicals lead to additional damage, impeding effective repair processes and potentially exacerbating further dysfunction. In this context, inflammatory responses, especially the activation of macrophages, play a pivotal role. Different phenotypes of macrophages have distinct effects on inflammation. Activation of classical macrophage cells (M1) promotes inflammation, while activation of alternative macrophage cells (M2) inhibits inflammation. The polarization of macrophages is crucial for disease healing. A non-coding RNA, known as microRNA (miRNA), governs the polarization of macrophages, thereby reducing inflammation following SCI and facilitating functional recovery. This study elucidates the inflammatory response to SCI, focusing on the infiltration of immune cells, specifically macrophages. It examines their phenotype and provides an explanation of their polarization mechanisms. Finally, this paper introduces several well-known miRNAs that contribute to macrophage polarization following SCI, including miR-155, miR-130a, and miR-27 for M1 polarization, as well as miR-22, miR-146a, miR-21, miR-124, miR-223, miR-93, miR-132, and miR-34a for M2 polarization. The emphasis is placed on their potential therapeutic role in SCI by modulating macrophage polarization, as well as the present developments and obstacles of miRNA clinical therapy.

Noncoding rules of survival: epigenetic regulation of normal and malignant hematopoiesis

Hematopoiesis is an essential process for organismal development and homeostasis. Epigenetic regulation of gene expression is critical for stem cell self-renewal and differentiation in normal hematopoiesis. Increasing evidence shows that disrupting the balance between self-renewal and cell fate decisions can give rise to hematological diseases such as bone marrow failure and leukemia. Consequently, next-generation sequencing studies have identified various aberrations in histone modifications, DNA methylation, RNA splicing, and RNA modifications in hematologic diseases. Favorable outcomes after targeting epigenetic regulators during disease states have further emphasized their importance in hematological malignancy. However, these targeted therapies are only effective in some patients, suggesting that further research is needed to decipher the complexity of epigenetic regulation during hematopoiesis. In this review, an update on the impact of the epigenome on normal hematopoiesis, disease initiation and progression, and current therapeutic advancements will be discussed.

Progress in quantum dot-based biosensors for microRNA assay: A review

MicroRNAs (miRNAs) are responsible for post-transcriptional gene regulation, and may function as valuable biomarkers for diseases diagnosis. Accurate and sensitive analysis of miRNAs is in great demand. Quantum dots (QDs) are semiconductor nanomaterials with superior optoelectronic features, such as high quantum yield and brightness, broad absorption and narrow emission, long fluorescence lifetime, and good photostability. Herein, we give a comprehensive review about QD-based biosensors for miRNA assay. Different QD-based biosensors for miRNA assay are classified by the signal types including fluorescent, electrochemical, electrochemiluminescent, and photoelectrochemical outputs. We highlight the features, principles, and performances of the emerging miRNA biosensors, and emphasize the challenges and perspectives in this field.

Antiviral effect of miR-155 in Epithelioma papulosum cyprini (EPC) cells against viral hemorrhagic septicemia virus (VHSV) infection

MicroRNAs (miRNAs) are small non-coding RNAs known to play a significant role in the regulation of gene expression in various living organisms including fish. MiR-155 is known to enhance immunity in cells and several reports have demonstrated the antiviral properties of miR-155 in mammals. In this study, we investigated the antiviral role of miR-155 in Epithelioma papulosum cyprini (EPC) cells with viral hemorrhagic septicemia virus (VHSV) infection. EPC cells were transfected with miR-155 mimic and then infected with VHSV at different MOIs (0.01 and 0.001). The cytopathogenic effect (CPE) was observed at 0, 24, 48, and 72 h post infection (h.p.i). CPE progression appeared at 48 h.p.i in mock groups (VHSV only infected groups) and the VHSV infection group transfected with miR-155 inhibitors. On the other hand, the groups transfected with the miR-155 mimic did not show any CPE formation after infection with VHSV. The supernatant was collected at 24, 48 and 72 h.p.i., and the viral titers were measured by plaque assay. The viral titers increased at 48 and 72 h.p.i in groups infected only with VHSV. In contrast, the groups transfected with miR-155 did not show any increase in the virus titer and had a similar titer to 0 h.p.i. Furthermore, the real-time RT-PCR of immune gene expression showed upregulation of Mx1 and ISG15 at 0, 24, and 48 h.p.i in groups transfected with miR-155, while the genes were upregulated at 48 h.p.i in groups infected only with VHSV. Based on these results, miR-155 can induce the overexpression of type I interferon-related immune genes in EPCs and inhibit the viral replication of VHSV. Therefore, these results suggest that miR-155 could possess an antiviral effect against VHSV.

Role of microRNAs in Chronic Lymphocytic Leukemia

Chronic Lymphocytic Leukemia (CLL) is the most common form of leukemia in adults, with a highly variable clinical course. Improvement in the knowledge of the molecular pathways behind this disease has led to the development of increasingly specific therapies, such as BCR signaling inhibitors and BCL-2 inhibitors. In this context, the emerging role of microRNAs (miRNAs) in CLL pathophysiology and their possible application in therapy is worth noting. MiRNAs are one of the most important regulatory molecules of gene expression. In CLL, they can act both as oncogenes and tumor suppressor genes, and the deregulation of specific miRNAs has been associated with prognosis, progression, and drug resistance. In this review, we describe the role of the miRNAs that primarily impact the disease, and how these miRNAs could be used as therapeutic tools. Certainly, the use of miRNAs in clinical practice is still limited in CLL. Many issues still need to be solved, particularly regarding their biological and safety profile, even if several studies have suggested their efficacy on the disease, alone or in combination with other drugs.

Emerging roles of PHLPP phosphatases in lung cancer

Pleckstrin homologous domain leucine-rich repeating protein phosphatases (PHLPPs) were originally identified as protein kinase B (Akt) kinase hydrophobic motif specific phosphatases to maintain the cellular homeostasis. With the continuous expansion of PHLPPs research, imbalanced-PHLPPs were mainly found as a tumor suppressor gene of a variety of solid tumors. In this review, we simply described the history and structures of PHLPPs and summarized the recent achievements in emerging roles of PHLPPs in lung cancer by 1) the signaling pathways affected by PHLPPs including Phosphoinositide 3-kinase (PI3K)/AKT, RAS/RAF/mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) and Protein kinase C (PKC) signaling cascades. 2) function of PHLPPs regulatory factor USP46 and miR-190/miR-215, 3) the potential roles of PHLPPs in disease prognosis, Epidermal growth factor receptors (EGFR)- tyrosine kinase inhibitor (TKI) resistance and DNA damage, 4) and the possible function of PHLPPs in radiotherapy, ferroptosis and inflammation response. Therefore, PHLPPs can be considered as either biomarker or prognostic marker for lung cancer treatment.

Berberine induces SOCS1 pathway to reprogram the M1 polarization of macrophages via miR-155-5p in colitis-associated colorectal cancer

Berberine is approved for the treatment of intestinal infections and diarrhea and has been shown to have anti-inflammatory and anti-tumor effects in pathological intestinal tissues. However, it is unclear whether the anti-inflammatory effect of berberine contributes to its anti-tumor effect on colitis-associated colorectal cancer (CAC). In this study, we found that berberine effectively inhibited tumorigenesis and protected against colon shortening in CAC mouse model. Immunohistochemistry results showed a reduction in the number of macrophage infiltrations in the colon following berberine treatment. Further analysis revealed that most of the infiltrated macrophages were pro-inflammatory M1 type, which berberine effectively limited. However, in another CRC model without chronic colitis, berberine had no significant effect on tumor number or colon length. In vitro studies demonstrated that berberine treatment significantly reduced the percentage of M1 type and levels of Interleukin-1β (IL-1β), Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Additionally, miR-155-5p level was down-regulated, and suppressor of cytokine signaling 1 (SOCS1) expression was up-regulated in berberine-treated cells. Notably, the miR-155-5p inhibitor attenuated the regulatory effects of berberine on SOCS1 signaling and macrophage polarization. Altogether, our findings suggest that the inhibitory effect of berberine on CAC development is dependent on its anti-inflammatory activity. Moreover, miR-155-5p may be involved in the pathogenesis of CAC by regulating M1 macrophage polarization, and berberine could be a promising protective agent against miR-155-5p-mediated CAC. This study provides new insights into pharmacologic mechanisms of berberine and supports the possibility that other anti-miR-155-5p drugs may be beneficial in the treatment of CAC.

LncRNA MIR155HG Overexpression Promotes Proliferation, Migration, and Chemoresistance in Gastric Cancer Cells

Long non-coding RNAs are thought to play a vital role in a variety of human malignancies. Studies have shown that MIR155 host gene (MIR155HG) acts as an oncogene in several cancers, but the function and its mechanism of MIR155HG in gastric cancer (GC) is still poorly understood. In this study, we determined the biological functions and underlying mechanisms of MIR155HG in GC cells. We found that expression levels of MIR155HG was increased markedly in GC patients' serum. In vitro and in vivo studies demonstrated that MIR155HG modulated the malignant phenotype of GC cells, such as cell proliferation, colony forming ability, cell migration ability, and tumor growth in nude mice. Next, our results revealed that NF-κB and STAT3 signaling pathways could be involved in regulating the malignant behavior of GC cells. Our rescue experiments showed that inhibiting NF-κB and STAT3 signaling pathways attenuated the phenotypes caused by MIR155HG overexpression. Moreover, cytotoxicity and apoptosis assays revealed overexpression of MIR155HG reduced the apotosis of GC cells induced by cisplatin and 5-FU. Together, our studies suggested that MIR155HG overexpression promoted proliferation, migration, and chemoresistance of GC cells. These results might provide a lncRNA-based target for GC treatment in future.

Lymphocyte to monocyte ratio predicts survival and is epigenetically linked to miR-222-3p and miR-26b-5p in diffuse large B cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma. 10-20% of the patients present with bone marrow (BM) involvement which predicts a worse survival. This study aimed to determine the prognostic significance of serum miR-222-3p, miR-26b-5p, EBV-miR-BHRF1-2-5p, and EBV-miR-BHRF1-2-3p and correlate their levels to clinical and haematological markers in DLBCL with special emphasis on the lymphocyte-monocyte ratio (LMR) and neutrophil-monocyte ratio. We also studied the role of BM BMI1 and PIM2 proteins in predicting BM infiltration. Serum miRNAs were studied on 40 DLBCL and 18 normal individuals using qRT-PCR. BMI1 and PIM2 proteins were studied on BM biopsies by immunohistochemistry. The results were correlated with clinical and follow-up data. All the studied miRNAs were dysregulated in DLBCL serum samples. BMI1 and PIM2 were expressed in 67% and 77.5% of BM samples, respectively. LMR was significantly associated with disease-free survival (DFS) (P = 0.022), miR-222-3P (P = 0.043), and miR-26b-5p (P = 0.043). EBV-miR-BHRF1-2-3p was significantly correlated to haemoglobin level (P = 0.027). MiR-222-3p, miR-26b-5p, and EBV-miR-BHRF1-2-5p expressions were significantly correlated to each other (P = 0.001). There was no significant correlation between the studied markers and follow-up data. LMR is a simple method for predicting survival in DLBCL. MiR-222-3p and miR-26b-5p may be implicated in an immunological mechanism affecting patients' immunity and accordingly influence LMR. The correlation between miR-222-3p, miR-26b-5p, and EBV-miR-BHRF1-2-5p may indicate a common mechanism among the 3 miRNAs that may explain DLBCL pathogenesis.

Potential Pathogenic Impact of Cow’s Milk Consumption and Bovine Milk-Derived Exosomal MicroRNAs in Diffuse Large B-Cell Lymphoma

Epidemiological evidence supports an association between cow’s milk consumption and the risk of diffuse large B-cell lymphoma (DLBCL), the most common non-Hodgkin lymphoma worldwide. This narrative review intends to elucidate the potential impact of milk-related agents, predominantly milk-derived exosomes (MDEs) and their microRNAs (miRs) in lymphomagenesis. Upregulation of PI3K-AKT-mTORC1 signaling is a common feature of DLBCL. Increased expression of B cell lymphoma 6 (BCL6) and suppression of B lymphocyte-induced maturation protein 1 (BLIMP1)/PR domain-containing protein 1 (PRDM1) are crucial pathological deviations in DLBCL. Translational evidence indicates that during the breastfeeding period, human MDE miRs support B cell proliferation via epigenetic upregulation of BCL6 (via miR-148a-3p-mediated suppression of DNA methyltransferase 1 (DNMT1) and miR-155-5p/miR-29b-5p-mediated suppression of activation-induced cytidine deaminase (AICDA) and suppression of BLIMP1 (via MDE let-7-5p/miR-125b-5p-targeting of PRDM1). After weaning with the physiological termination of MDE miR signaling, the infant’s BCL6 expression and B cell proliferation declines, whereas BLIMP1-mediated B cell maturation for adequate own antibody production rises. Because human and bovine MDE miRs share identical nucleotide sequences, the consumption of pasteurized cow’s milk in adults with the continued transfer of bioactive bovine MDE miRs may de-differentiate B cells back to the neonatal “proliferation-dominated” B cell phenotype maintaining an increased BLC6/BLIMP1 ratio. Persistent milk-induced epigenetic dysregulation of BCL6 and BLIMP1 expression may thus represent a novel driving mechanism in B cell lymphomagenesis. Bovine MDEs and their miR cargo have to be considered potential pathogens that should be removed from the human food chain.

miRNAs are now starring in "No Time to Die: Overcoming the chemoresistance in cancer"

Cancer is a leading cause of death globally, with about 19.3 million new cases reported each year. Current therapies for cancer management include-chemotherapy, radiotherapy, and surgery. However, they are loaded with side effects and tend to cause toxicity in the patient's body posttreatment, ultimately hindering the response towards the treatment building up resistance. This is where noncoding RNAs such as miRNAs help provide us with a helping hand for taming the chemoresistance and providing potential holistic cancer management. MicroRNAs are promising targets for anticancer therapy as they perform critical regulatory roles in various signaling cascades related to cell proliferation, apoptosis, migration, and invasion. Combining miRNAs and anticancer drugs and devising a combination therapy has managed cancer well in various independent studies. This review aims to provide insights into how miRNAs play a mechanistic role in cancer development and progression and regulate drug resistance in various types of cancers. Furthermore, next-generation novel therapies using miRNAs in combination with anticancer treatments in multiple cancers have been put forth and how they improve the efficacy of the treatments. Exemplary studies currently in the preclinical and clinical models have been summarized. Ultimately, we briefly talk through the challenges that come forward with it and minimize them.

Epigenetic regulation in hematopoiesis and its implications in the targeted therapy of hematologic malignancies

Hematologic malignancies are one of the most common cancers, and the incidence has been rising in recent decades. The clinical and molecular features of hematologic malignancies are highly heterogenous, and some hematologic malignancies are incurable, challenging the treatment, and prognosis of the patients. However, hematopoiesis and oncogenesis of hematologic malignancies are profoundly affected by epigenetic regulation. Studies have found that methylation-related mutations, abnormal methylation profiles of DNA, and abnormal histone deacetylase expression are recurrent in leukemia and lymphoma. Furthermore, the hypomethylating agents and histone deacetylase inhibitors are effective to treat acute myeloid leukemia and T-cell lymphomas, indicating that epigenetic regulation is indispensable to hematologic oncogenesis. Epigenetic regulation mainly includes DNA modifications, histone modifications, and noncoding RNA-mediated targeting, and regulates various DNA-based processes. This review presents the role of writers, readers, and erasers of DNA methylation and histone methylation, and acetylation in hematologic malignancies. In addition, this review provides the influence of microRNAs and long noncoding RNAs on hematologic malignancies. Furthermore, the implication of epigenetic regulation in targeted treatment is discussed. This review comprehensively presents the change and function of each epigenetic regulator in normal and oncogenic hematopoiesis and provides innovative epigenetic-targeted treatment in clinical practice.

Crosstalk of Transcriptional Regulators of Adaptive Immune System and microRNAs: An Insight into Differentiation and Development

MicroRNAs (miRNAs), as small regulatory RNA molecules, are involved in gene expression at the post-transcriptional level. Hence, miRNAs contribute to gene regulation of various steps of different cell subsets' differentiation, maturation, and activation. The adaptive immune system arm, which exhibits the most specific immune responses, is also modulated by miRNAs. The generation and maturation of various T-cell subsets concomitant with B-cells is under precise regulation of miRNAs which function directly on the hallmark genes of each cell subset or indirectly through regulation of signaling pathway mediators and/or transcription factors involved in this maturation journey. In this review, we first discussed the origination process of common lymphocyte progenitors from hematopoietic stem cells, which further differentiate into various T-cell subsets under strict regulation of miRNAs and transcription factors. Subsequently, the differentiation of B-cells from common lymphocyte progenitors in bone marrow and periphery were discussed in association with a network of miRNAs and transcription factors.

Microfluidics for Profiling miRNA Biomarker Panels in AI-Assisted Cancer Diagnosis and Prognosis

Early detection of cancers and their precise subtyping are essential to patient stratification and effective cancer management. Data-driven identification of expression biomarkers coupled with microfluidics-based detection shows promise to revolutionize cancer diagnosis and prognosis. MicroRNAs play key roles in cancers and afford detection in tissue and liquid biopsies. In this review, we focus on the microfluidics-based detection of miRNA biomarkers in AI-based models for early-stage cancer subtyping and prognosis. We describe various subclasses of miRNA biomarkers that could be useful in machine-based predictive modeling of cancer staging and progression. Strategies for optimizing the feature space of miRNA biomarkers are necessary to obtain a robust signature panel. This is followed by a discussion of the issues in model construction and validation towards producing Software-as-Medical-Devices (SaMDs). Microfluidic devices could facilitate the multiplexed detection of miRNA biomarker panels, and an overview of the different strategies for designing such microfluidic systems is presented here, with an outline of the detection principles used and the corresponding performance measures. Microfluidics-based profiling of miRNAs coupled with SaMD represent high-performance point-of-care solutions that would aid clinical decision-making and pave the way for accessible precision personalized medicine.

Detection of MicroRNA Expression Dynamics Using LNA/DNA Nanobiosensor

The investigation of complex biological processes requires effective tools for probing the spatiotemporal dynamics of individual cells. Single-cell gene expression analysis, such as RNA in situ hybridization and single-cell PCR, has been demonstrated in various biological applications (Tautz and Pfeifle, Chromosoma 98(2):81-5, 1989; Stahlberg and Bengtsson, Methods 50(4):282-288, 2010; Sanchez-Freire et al., Nat Protoc 7(5):829-838, 2012). However, existing techniques require cell lysis or fixation. The dynamic information and spatiotemporal regulation of the biological process cannot be obtained with these methods. Real-time gene expression analysis in living cells remains an outstanding challenge in the field. Here, we described a single-cell gene expression analysis method in living mammalian cells using a locked nucleic acid/DNA (LNA/DNA) nanobiosensor. This LNA/DNA nanobiosensor consists of a fluorophore-labeled detecting strand and a quenching strand. The fluorophore-labeled LNA probe is designed to hybridize with the target microRNA (miRNA) specifically and displace from the quenching strand, allowing the fluorophore to fluorescence. Large-scale single-cell dynamic gene expression monitoring can be performed using time-lapse microscopy to study spatiotemporal distribution and heterogeneity in gene expression. Multiplex detection of miRNAs can be achieved using different fluorophore-labeled LNA/DNA nanobiosensors. This LNA/DNA protocol is fast, generally applicable, and easily accessible.

The Role of miR-155 in Antitumor Immunity

MicroRNAs belong to a group of short non-coding RNA molecules that are involved in the regulation of gene expression at multiple levels. Their function was described two decades ago, and, since then, microRNAs have become a rapidly developing field of research. Their participation in the regulation of cellular processes, such as proliferation, apoptosis, cell growth, and migration, made microRNAs attractive for cancer research. Moreover, as a single microRNA can simultaneously target multiple molecules, microRNAs offer a unique advantage in regulating multiple cellular processes in different cell types. Many of these cell types are tumor cells and the cells of the immune system. One of the most studied microRNAs in the context of cancer and the immune system is miR-155. MiR-155 plays a role in modulating innate and adaptive immune mechanisms in distinct immune cell types. As such, miR-155 can be part of the communication between the tumor and immune cells and thus impact the process of tumor immunoediting. Several studies have already revealed its effect on antitumor immune responses, and the targeting of this molecule is increasingly implemented in cancer immunotherapy. In this review, we discuss the current knowledge of miR-155 in the regulation of antitumor immunity and the shaping of the tumor microenvironment, and the plausible implementation of miR-155 targeting in cancer therapy.

News from around the RNA world: new avenues in RNA biology, biotechnology and therapeutics from the 2022 SIBBM meeting

Since the formalization of the Central Dogma of molecular biology, the relevance of RNA in modulating the flow of information from DNA to proteins has been clear. More recently, the discovery of a vast set of non-coding transcripts involved in crucial aspects of cellular biology has renewed the enthusiasm of the RNA community. Moreover, the remarkable impact of RNA therapies in facing the COVID19 pandemics has bolstered interest in the translational opportunities provided by this incredible molecule. For all these reasons, the Italian Society of Biophysics and Molecular Biology (SIBBM) decided to dedicate its 17th yearly meeting, held in June 2022 in Rome, to the many fascinating aspects of RNA biology. More than thirty national and international speakers covered the properties, modes of action and applications of RNA, from its role in the control of development and cell differentiation to its involvement in disease. Here, we summarize the scientific content of the conference, highlighting the take-home message of each presentation, and we stress the directions the community is currently exploring to push forward our comprehension of the RNA World 3.0.

Proviral ALV-LTR Sequence Is Essential for Continued Proliferation of the ALV-Transformed B Cell Line

Avian leukosis virus (ALV) induces B-cell lymphomas and other malignancies in chickens through insertional activation of oncogenes, and c-myc activation has been commonly identified in ALV-induced tumors. Using ALV-transformed B-lymphoma-derived HP45 cell line, we applied in situ CRISPR-Cas9 editing of integrated proviral long terminal repeat (LTR) to examine the effects on gene expression and cell proliferation. Targeted deletion of LTR resulted in significant reduction in expression of a number of LTR-regulated genes including c-myc. LTR deletion also induced apoptosis of HP45 cells, affecting their proliferation, demonstrating the significance of LTR-mediated regulation of critical genes. Compared to the global effects on expression and functions of multiple genes in LTR-deleted cells, deletion of c-myc had a major effect on the HP45 cells proliferation with the phenotype similar to the LTR deletion, demonstrating the significance of c-myc expression in ALV-induced lymphomagenesis. Overall, our studies have not only shown the potential of targeted editing of the LTR for the global inhibition of retrovirus-induced transformation, but also have provided insights into the roles of LTR-regulated genes in ALV-induced neoplastic transformation.

Waldenström Macroglobulinemia: Mechanisms of Disease Progression and Current Therapies

Waldenström macroglobulinemia is an indolent, B-cell lymphoma without a known cure. The bone marrow microenvironment and cytokines both play key roles in Waldenström macroglobulinemia (WM) tumor progression. Only one FDA-approved drug exists for the treatment of WM, Ibrutinib, but treatment plans involve a variety of drugs and inhibitors. This review explores avenues of tumor progression and targeted drug therapy that have been investigated in WM and related B-cell lymphomas.

MicroRNAs in the regulation of Th17/Treg homeostasis and their potential role in uveitis

Th17 and regulatory T cells (Tregs) play crucial roles in the pathogenesis of autoimmune diseases. Th17/Treg homeostasis is critically involved in maintaining the immune balance. Disturbed Th17/Treg homeostasis contributes to the progression of autoimmune diseases. MicroRNAs (miRNAs) have emerged as a new vital factor in the regulation of disturbed Th17/Treg homeostasis. To better understand the epigenetic mechanisms of miRNAs in regulating Treg/Th17 homeostasis, we included and evaluated 97 articles about autoimmune diseases and found that miRNAs were involved in the regulation of Treg/Th17 homeostasis from several aspects positively or negatively, including Treg differentiation and development, Treg induction, Treg stability, Th17 differentiation, and Treg function. Uveitis is one of the ocular autoimmune diseases, which is also characterized with Th17/Treg imbalance. However, our understanding of the miRNAs in the pathogenesis of uveitis is elusive and not well-studied. In this review, we further summarized miRNAs found to be involved in autoimmune uveitis and their potential role in the regulation of Th17/Treg homeostasis.

miRNA in Molecular Diagnostics

MicroRNAs are a class of small non-coding RNA molecules that regulate gene expression on post-transcriptional level. Their biogenesis consists of a complex series of sequential processes, and they regulate expression of many genes involved in all cellular processes. Their function is essential for maintaining the homeostasis of a single cell; therefore, their aberrant expression contributes to development and progression of many diseases, especially malignant tumors and viral infections. Moreover, they can be associated with certain states of a specific disease, obtained in the least invasive manner for patients and analyzed with basic molecular methods used in clinical laboratories. Because of this, they have a promising potential to become very useful biomarkers and potential tools in personalized medicine approaches. In this review, miRNAs biogenesis, significance in cancer and infectious diseases, and current available test and methods for their detection are summarized.

Apigenin Targets MicroRNA-155, Enhances SHIP-1 Expression, and Augments Anti-Tumor Responses in Pancreatic Cancer

Pancreatic cancer (PC) is a deadly disease with a grim prognosis. Pancreatic tumor derived factors (TDF) contribute to the induction of an immunosuppressive tumor microenvironment (TME) that impedes the effectiveness of immunotherapy. PC-induced microRNA-155 (miRNA-155) represses expression of Src homology 2 (SH2) domain-containing Inositol 5'-phosphatase-1 (SHIP-1), a regulator of myeloid cell development and function, thus impacting anti-tumor immunity. We recently reported that the bioflavonoid apigenin (API) increased SHIP-1 expression which correlated with the expansion of tumoricidal macrophages (TAM) and improved anti-tumor immune responses in the TME of mice with PC. We now show that API transcriptionally regulates SHIP-1 expression via the suppression of miRNA-155, impacting anti-tumor immune responses in the bone marrow (BM) and TME of mice with PC. We discovered that API reduced miRNA-155 in the PC milieu, which induced SHIP-1 expression. This promoted the restoration of myelopoiesis and increased anti-tumor immune responses in the TME of heterotopic, orthotopic and transgenic SHIP-1 knockout preclinical mouse models of PC. Our results suggest that manipulating SHIP-1 through miR-155 may assist in augmenting anti-tumor immune responses and aid in the therapeutic intervention of PC.

Long noncoding RNAs (lncRNAs) in human lymphomas

Lymphomas are a diverse group of haematologic malignancies, which occur in infection-fighting cells of the lymphatic system. Long non-coding RNAs (lncRNAs) are non-coding RNAs, which have recently received significant attention as the main mediators of gene expression. In this review, we summarize the current knowledge on lncRNAs involved in lymphomas, their molecular functions, as well as their potential clinical value. Relevant literature was identified by a PubMed search of English language papers using the following terms: Lymphoma, LncRNA, leukemia, proliferation, apoptosis, and prognosis. LncRNAs are imperative for lymphoma carcinogenesis through affecting apoptosis, cell proliferation, invasion, and response to chemotherapy. The expression level of lncRNAs can affect chemotherapy-induced apoptosis. Taken together, lncRNA dysregulation in lymphoma cells is not only an epiphenomenon but also lncRNA transcription is critically related to the initiation and progression of lymphomas. Aberrant expression of lncRNAs can lead to the transformation of normal lymphocytes into lymphoma cells.

Small ORFs as New Regulators of Pri-miRNAs and miRNAs Expression in Human and Drosophila

MicroRNAs (miRNAs) are small regulatory non-coding RNAs, resulting from the cleavage of long primary transcripts (pri-miRNAs) in the nucleus by the Microprocessor complex generating precursors (pre-miRNAs) that are then exported to the cytoplasm and processed into mature miRNAs. Some miRNAs are hosted in pri-miRNAs annotated as long non-coding RNAs (lncRNAs) and defined as MIRHGs (for miRNA Host Genes). However, several lnc pri-miRNAs contain translatable small open reading frames (smORFs). If smORFs present within lncRNAs can encode functional small peptides, they can also constitute cis-regulatory elements involved in lncRNA decay. Here, we investigated the possible involvement of smORFs in the regulation of lnc pri-miRNAs in Human and Drosophila, focusing on pri-miRNAs previously shown to contain translatable smORFs. We show that smORFs regulate the expression levels of human pri-miR-155 and pri-miR-497, and Drosophila pri-miR-8 and pri-miR-14, and also affect the expression and activity of their associated miRNAs. This smORF-dependent regulation is independent of the nucleotidic and amino acidic sequences of the smORFs and is sensitive to the ribosome-stalling drug cycloheximide, suggesting the involvement of translational events. This study identifies smORFs as new cis-acting elements involved in the regulation of pri-miRNAs and miRNAs expression, in both Human and Drosophila melanogaster.

Circulating microRNAs in Cerebrospinal Fluid and Plasma: Sensitive Tool for Detection of Secondary CNS Involvement, Monitoring of Therapy and Prediction of CNS Relapse in Aggressive B-NHL Lymphomas

Simple Summary

Lymphoma involving the central nervous system and CNS relapse present diagnostic and predictive challenges. Its diagnosis is based on conventional methods with low sensitivity and/or specificity. More powerful tools for its early detection, response evaluation, and CNS relapse prediction are needed. MicroRNAs are short post-transcriptional gene regulators that are remarkably stable and detectable extracellularly in body fluids. We evaluated the diagnostic and predictive potential of circulating oncogenic microRNAs (oncomiRs) in CSF and plasma for the detection of secondary CNS involvement in aggressive B-NHL lymphomas, as well as for detection and prediction of their CNS relapse. Our findings indicate that the evaluation of oncogenic microRNAs in CSF and plasma potentially provides a sensitive tool for the early detection of secondary CNS lymphoma, the monitoring and estimating of treatment efficacy, and the prediction and early detection of CNS relapse.

Abstract

Lymphoma with secondary central nervous system (CNS) involvement represents one of the most aggressive malignancies, with poor prognosis and high mortality. New diagnostic tools for its early detection, response evaluation, and CNS relapse prediction are needed. We analyzed circulating microRNAs in the cerebrospinal fluid (CSF) and plasma of 162 patients with aggressive B-cell non-Hodgkin’s lymphomas (B-NHL) and compared their levels in CNS-involving lymphomas versus in systemic lymphomas, at diagnosis and during treatment and CNS relapse. We identified a set of five oncogenic microRNAs (miR-19a, miR-20a, miR-21, miR-92a, and miR-155) in CSF that detect, with high sensitivity, secondary CNS lymphoma involvement in aggressive B-NHL, including DLBCL, MCL, and Burkitt lymphoma. Their combination into an oncomiR index enables the separation of CNS lymphomas from systemic lymphomas or nonmalignant controls with high sensitivity and specificity, and high Receiver Operating Characteristics (DLBCL AUC = 0.96, MCL = 0.93, BL = 1.0). Longitudinal analysis showed that oncomiR levels reflect treatment efficacy and clinical outcomes, allowing their monitoring and prediction. In contrast to conventional methods, CSF oncomiRs enable detection of early and residual CNS involvement, as well as parenchymal involvement. These circulating oncomiRs increase 1–4 months before CNS relapse, allowing its early detection and improving the prediction of CNS relapse risk in DLBCL. Similar effects were detectable, to a lesser extent, in plasma.