Epigenetic Regulation of microRNAs in Cancer: Shortening the Distance from Bench to Bedside

The impact of COVID-19 on microRNA and CD marker expression in AML patients

Acute myeloid leukaemia (AML) is an aggressive leukaemia characterised by uncontrolled blast cell proliferation. miRNAs and Clusters of Differentiation (CD) molecules play essential roles in AML progression. This study aims to investigate the effect of COVID-19 on the expression of circulating miRNA and CD molecules in AML. This cross-sectional study recruited 32 AML patients and 20 controls. Blood samples were collected and analysed using molecular cytogenetic, miRNA/mRNA expression, and flow cytometry techniques. The expression of miRNAs varied significantly between patients with AML and control individuals. The co-expression of these miRNAs was higher (P < 0.05), indicating that the presence of one miRNA led to increased expression of other miRNAs. A differential correlation was observed between miRNAs and CD markers. Additionally, miRNA 16, miRNA 21, and miRNA 221 showed significant downregulation (P < 0.05 and P < 0.01, respectively) in AML patients with COVID-19 infection compared to those without a disease. Interestingly, this study identified a higher expression level (P < 0.01) of miRNA 137 as a novel biomarker for AML patients. Moreover, the expression of miRNA 137 showed a high correlation (P < 0.05) with most of the CD markers examined in this study and FISH features data. Furthermore, a strong correlation (P < 0.01) was observed between CD markers and miRNA among AML patients with positive and negative COVID-19 infection. These data demonstrated that COVID-19 contributed to increased expression of microRNAs in AML patients. MicroRNA 137 was identified as a novel microRNA that exhibited significant differences between patients and healthy individuals, highlighting its role in AML pathogenesis.

MicroRNA-98: the multifaceted regulator in human cancer progression and therapy

MicroRNA-98 (miR-98) stands as an important molecule in the intricate landscape of oncology. As a subset of microRNAs, these small non-coding RNAs have accompanied a new era in cancer research, underpinning their significant roles in tumorigenesis, metastasis, and therapeutic interventions. This review provides a comprehensive insight into the biogenesis, molecular properties, and physiological undertakings of miR-98, highlighting its double-edged role in cancer progression-acting both as a tumor promoter and suppressor. Intriguingly, miR-98 has profound implications for various aspects of cancer progression, modulating key cellular functions, including proliferation, apoptosis, and the cell cycle. Given its expression patterns, the potential of miR-98 as a diagnostic and prognostic biomarker, especially in liquid biopsies and tumor tissues, is explored, emphasizing the hurdles in translating these findings clinically. The review concludes by evaluating therapeutic avenues to modulate miR-98 expression, addressing the challenges in therapy resistance, and assessing the efficacy of miR-98 interventions. In conclusion, while miR-98's involvement in cancer showcases promising diagnostic and therapeutic avenues, future research should pivot towards understanding its role in tumor-stroma interactions, immune modulation, and metabolic regulation, thereby unlocking novel strategies for cancer management.

Oncogenes and tumor suppressor genes: functions and roles in cancers

Cancer, being the most formidable ailment, has had a profound impact on the human health. The disease is primarily associated with genetic mutations that impact oncogenes and tumor suppressor genes (TSGs). Recently, growing evidence have shown that X-linked TSGs have specific role in cancer progression and metastasis as well. Interestingly, our genome harbors around substantial portion of genes that function as tumor suppressors, and the X chromosome alone harbors a considerable number of TSGs. The scenario becomes even more compelling as X-linked TSGs are adaptive to key epigenetic processes such as X chromosome inactivation. Therefore, delineating the new paradigm related to X-linked TSGs, for instance, their crosstalk with autosome and involvement in cancer initiation, progression, and metastasis becomes utmost importance. Considering this, herein, we present a comprehensive discussion of X-linked TSG dysregulation in various cancers as a consequence of genetic variations and epigenetic alterations. In addition, the dynamic role of X-linked TSGs in sex chromosome-autosome crosstalk in cancer genome remodeling is being explored thoroughly. Besides, the functional roles of ncRNAs, role of X-linked TSG in immunomodulation and in gender-based cancer disparities has also been highlighted. Overall, the focal idea of the present article is to recapitulate the findings on X-linked TSG regulation in the cancer landscape and to redefine their role toward improving cancer treatment strategies.

Apoptosis, a Metabolic "Head-to-Head" between Tumor and T Cells: Implications for Immunotherapy

Induction of apoptosis represents a promising therapeutic approach to drive tumor cells to death. However, this poses challenges due to the intricate nature of cancer biology and the mechanisms employed by cancer cells to survive and escape immune surveillance. Furthermore, molecules released from apoptotic cells and phagocytes in the tumor microenvironment (TME) can facilitate cancer progression and immune evasion. Apoptosis is also a pivotal mechanism in modulating the strength and duration of anti-tumor T-cell responses. Combined strategies including molecular targeting of apoptosis, promoting immunogenic cell death, modulating immunosuppressive cells, and affecting energy pathways can potentially overcome resistance and enhance therapeutic outcomes. Thus, an effective approach for targeting apoptosis within the TME should delicately balance the selective induction of apoptosis in tumor cells, while safeguarding survival, metabolic changes, and functionality of T cells targeting crucial molecular pathways involved in T-cell apoptosis regulation. Enhancing the persistence and effectiveness of T cells may bolster a more resilient and enduring anti-tumor immune response, ultimately advancing therapeutic outcomes in cancer treatment. This review delves into the pivotal topics of this multifaceted issue and suggests drugs and druggable targets for possible combined therapies.

Fetal Brain-Derived Exosomal miRNAs from Maternal Blood: Potential Diagnostic Biomarkers for Fetal Alcohol Spectrum Disorders (FASDs)

Fetal alcohol spectrum disorders (FASDs) are leading causes of neurodevelopmental disability but cannot be diagnosed early in utero. Because several microRNAs (miRNAs) are implicated in other neurological and neurodevelopmental disorders, the effects of EtOH exposure on the expression of these miRNAs and their target genes and pathways were assessed. In women who drank alcohol (EtOH) during pregnancy and non-drinking controls, matched individually for fetal sex and gestational age, the levels of miRNAs in fetal brain-derived exosomes (FB-Es) isolated from the mothers' serum correlated well with the contents of the corresponding fetal brain tissues obtained after voluntary pregnancy termination. In six EtOH-exposed cases and six matched controls, the levels of fetal brain and maternal serum miRNAs were quantified on the array by qRT-PCR. In FB-Es from 10 EtOH-exposed cases and 10 controls, selected miRNAs were quantified by ddPCR. Protein levels were quantified by ELISA. There were significant EtOH-associated reductions in the expression of several miRNAs, including miR-9 and its downstream neuronal targets BDNF, REST, Synapsin, and Sonic hedgehog. In 20 paired cases, reductions in FB-E miR-9 levels correlated strongly with reductions in fetal eye diameter, a prominent feature of FASDs. Thus, FB-E miR-9 levels might serve as a biomarker to predict FASDs in at-risk fetuses.

Signaling pathways governing the behaviors of leukemia stem cells

Leukemia is a malignancy in the blood that develops from the lymphatic system and bone marrow. Although various treatment options have been used for different types of leukemia, understanding the molecular pathways involved in the development and progression of leukemia is necessary. Recent studies showed that leukemia stem cells (LSCs) play essential roles in the pathogenesis of leukemia by targeting several signaling pathways, including Notch, Wnt, Hedgehog, and STAT3. LSCs are highly proliferative cells that stimulate tumor initiation, migration, EMT, and drug resistance. This review summarizes cellular pathways that stimulate and prevent LSCs' self-renewal, metastasis, and tumorigenesis.

Strategies of Helicobacter pylori in evading host innate and adaptive immunity: insights and prospects for therapeutic targeting

Helicobacter pylori (H. pylori) is the predominant pathogen causing chronic gastric mucosal infections globally. During the period from 2011 to 2022, the global prevalence of H. pylori infection was estimated at 43.1%, while in China, it was slightly higher at approximately 44.2%. Persistent colonization by H. pylori can lead to gastritis, peptic ulcers, and malignancies such as mucosa-associated lymphoid tissue (MALT) lymphomas and gastric adenocarcinomas. Despite eliciting robust immune responses from the host, H. pylori thrives in the gastric mucosa by modulating host immunity, particularly by altering the functions of innate and adaptive immune cells, and dampening inflammatory responses adverse to its survival, posing challenges to clinical management. The interaction between H. pylori and host immune defenses is intricate, involving evasion of host recognition by modifying surface molecules, manipulating macrophage functionality, and modulating T cell responses to evade immune surveillance. This review analyzes the immunopathogenic and immune evasion mechanisms of H. pylori, underscoring the importance of identifying new therapeutic targets and developing effective treatment strategies, and discusses how the development of vaccines against H. pylori offers new hope for eradicating such infections.

MicroRNAs: Key modulators of inflammation-associated diseases

Inflammation is a multifaceted biological and pathophysiological response to injuries, infections, toxins, and inflammatory mechanisms that plays a central role in the progression of various diseases. MicroRNAs (miRNAs) are tiny, 19-25 nucleotides long, non-coding RNAs that regulate gene expression via post-transcriptional repression. In this review, we highlight the recent findings related to the significant roles of miRNAs in regulating various inflammatory cascades and immunological processes in the context of many lifestyle-related diseases such as diabetes, cardiovascular diseases, cancer, etc. We also converse on how miRNAs can have a dual impact on inflammatory responses, suggesting that regulation of their functions for therapeutic purposes may be disease-specific.

Trials and Tribulations of MicroRNA Therapeutics

The discovery of the link between microRNAs (miRNAs) and a myriad of human diseases, particularly various cancer types, has generated significant interest in exploring their potential as a novel class of drugs. This has led to substantial investments in interdisciplinary research fields such as biology, chemistry, and medical science for the development of miRNA-based therapies. Furthermore, the recent global success of SARS-CoV-2 mRNA vaccines against the COVID-19 pandemic has further revitalized interest in RNA-based immunotherapies, including miRNA-based approaches to cancer treatment. Consequently, RNA therapeutics have emerged as highly adaptable and modular options for cancer therapy. Moreover, advancements in RNA chemistry and delivery methods have been pivotal in shaping the landscape of RNA-based immunotherapy, including miRNA-based approaches. Consequently, the biotechnology and pharmaceutical industry has witnessed a resurgence of interest in incorporating RNA-based immunotherapies and miRNA therapeutics into their development programs. Despite substantial progress in preclinical research, the field of miRNA-based therapeutics remains in its early stages, with only a few progressing to clinical development, none reaching phase III clinical trials or being approved by the US Food and Drug Administration (FDA), and several facing termination due to toxicity issues. These setbacks highlight existing challenges that must be addressed for the broad clinical application of miRNA-based therapeutics. Key challenges include establishing miRNA sensitivity, specificity, and selectivity towards their intended targets, mitigating immunogenic reactions and off-target effects, developing enhanced methods for targeted delivery, and determining optimal dosing for therapeutic efficacy while minimizing side effects. Additionally, the limited understanding of the precise functions of miRNAs limits their clinical utilization. Moreover, for miRNAs to be viable for cancer treatment, they must be technically and economically feasible for the widespread adoption of RNA therapies. As a result, a thorough risk evaluation of miRNA therapeutics is crucial to minimize off-target effects, prevent overdosing, and address various other issues. Nevertheless, the therapeutic potential of miRNAs for various diseases is evident, and future investigations are essential to determine their applicability in clinical settings.

Transcription Silencing and CpGs Hypermethylation as Therapeutic Gene Editing in Clinical Colorectal Adenocarcinoma Repression

Background/Aims

Colorectal cancer is the most common cancer in oncopathology, with an increasing incidence among the elderly during the last decade. Various genetic and environmental factors play important roles in the emergence of colorectal adenocarcinoma. Non-coding RNAs, approximately 20-22 nucleotides, are transcribed irregularly in many cancer cells and play a critical role in many metabolic pathways in clinical cancer cases. DNA methylation is a critical epigenetic alteration that controls gene expression. In the current study, transcriptional silencing and CpG hypermethylation were developed as a therapeutic gene editing strategy for the clinical repression of colorectal adenocarcinoma.

Methods

A human colorectal adenocarcinoma cell line (Caco2) and a normal lung fibroblast cell line (Wi38) were utilized as the paradigms in this research to examine the effect of mir155 molecule transfection and CpGs-island (CGI) methylation. Cell counting was achieved using six-well and 24-well plates before transfection using a hemocytometer. The two cell lines were transfected with the mir155 agomir and antagomir molecules. The transfection efficiency, cell viability, cell IC50, and target gene expression were measured, and CGIs-methylation was achieved by bisulfate conversion.

Results

The outcomes revealed the downregulation of oncogenes (AKT1 and VCAM1 genes as cancer-associated genes) and the upregulation of tumor suppressor genes (TSGs, Tp53 and KEAP1). In addition, CpG-islands methylation showed significant blocking of the oncogene promoter regions, and the switch on of TSG promoter regions was continuous.

Conclusions

miRNA-CGI-methylation led to the regression of Caco2 cell proliferation, suggesting the potential use of RNA silencing and DNA methylation in targeted gene therapy for colorectal cancer.

Epigenetic regulation in lung cancer

Lung cancer is indeed a major cause of cancer-related deaths worldwide. The development of tumors involves a complex interplay of genetic, epigenetic, and environmental factors. Epigenetic mechanisms, including DNA methylation (DNAm), histone modifications, and microRNA expression, play a crucial role in this process. Changes in DNAm patterns can lead to the silencing of important genes involved in cellular functions, contributing to the development and progression of lung cancer. MicroRNAs and exosomes have also emerged as reliable biomarkers for lung cancer. They can provide valuable information about early diagnosis and treatment assessment. In particular, abnormal hypermethylation of gene promoters and its effects on tumorigenesis, as well as its roles in the Wnt signaling pathway, have been extensively studied. Epigenetic drugs have shown promise in the treatment of lung cancer. These drugs target the aberrant epigenetic modifications that are involved in the development and progression of the disease. Several factors have been identified as drug targets in non-small cell lung cancer. Recently, combination therapy has been discussed as a successful strategy for overcoming drug resistance. Overall, understanding the role of epigenetic mechanisms and their targeting through drugs is an important area of research in lung cancer treatment.

Construction of a Programmable Feedback Network with Continuously Activatable Molecular Beacon Fluorescence for One-Step Quantification of Long Noncoding RNAs in Clinical Breast Tissues

Long noncoding RNAs (lncRNAs) are key regulators in numerous pathological and physiological processes, and their aberrant expression is implicated in many diseases. Herein, we develop a programmable feedback network with continuously activatable molecular beacon (MB) fluorescence for one-step quantification of mammalian-metastasis-associated lung adenocarcinoma transcript 1 (lncRNA MALAT1) in clinical breast tissues. We introduce a functional MB with three domains, including a substrate for lncRNA MALAT1 recognition, a template for strand displacement amplification (SDA), and a reporter for signal output with FAM fluorescence being quenched by BHQ1. When MALAT1 is present, it recognizes and unfolds the MB, leading to the recovery of FAM fluorescence. Once the MB is opened, multiple rounds of SDA reaction are automatically initiated by recruiting primer, KF DNA polymerase, and Nt.BbvCI nicking enzyme, inducing the opening of more MBs and the dissociation of more FAM/BHQ1 pairs. Consequently, a feedback network is constructed through multicycle cascade SDA, achieving the exponential accumulation of fluorescence signals for accurate quantification of MALAT1. In this assay, only two oligonucleotides (i.e., MB and primer) are involved for the establishment of a feedback amplification network, greatly simplifying the design of the reaction system. Moreover, this assay requires only one step to realize the isothermal exponential amplification for real-time monitoring of MALAT1 with attomolar sensitivity. This assay displays single-base mismatch selectivity with high anti-interference capability, and it can further quantify endogenous MALAT1 at the single-cell level and differentiate MALAT1 expression between breast cancer patient tissues and healthy person tissues.

Noncoding RNA as an influential epigenetic modulator with promising roles in cancer therapeutics

The epigenetic landscape has an important role in cellular homeostasis and its deregulation leads to cancer. Noncoding (nc)RNA networks function as major regulators of cellular epigenetic hallmarks via regulation of vital processes, such as histone modification and DNA methylation. They are integral intracellular components affecting multiple oncogenic pathways. Thus, it is important to elucidate the effects of ncRNA networks on epigenetic programming that lead to the initiation and progression of cancer. In this review, we summarize the effects of epigenetic modification influenced by ncRNA networks and crosstalk between diverse classes of ncRNA, which could aid the development of patient-specific cancer therapeutics targeting ncRNAs, thereby altering cellular epigenetics.

Circulating microRNAs as Potential Biomarkers in Pancreatic Cancer-Advances and Challenges

There is an urgent unmet need for robust and reliable biomarkers for early diagnosis, prognosis, and prediction of response to specific treatments of many aggressive and deadly cancers, such as pancreatic cancer, and liquid biopsy-based miRNA profiling has the potential for this. MiRNAs are a subset of non-coding RNAs that regulate the expression of a multitude of genes post-transcriptionally and thus are potential diagnostic, prognostic, and predictive biomarkers and have also emerged as potential therapeutics. Because miRNAs are involved in the post-transcriptional regulation of their target mRNAs via repressing gene expression, defects in miRNA biogenesis pathway and miRNA expression perturb the expression of a multitude of oncogenic or tumor-suppressive genes that are involved in the pathogenesis of various cancers. As such, numerous miRNAs have been identified to be downregulated or upregulated in many cancers, functioning as either oncomes or oncosuppressor miRs. Moreover, dysregulation of miRNA biogenesis pathways can also change miRNA expression and function in cancer. Profiling of dysregulated miRNAs in pancreatic cancer has been shown to correlate with disease diagnosis, indicate optimal treatment options and predict response to a specific therapy. Specific miRNA signatures can track the stages of pancreatic cancer and hold potential as diagnostic, prognostic, and predictive markers, as well as therapeutics such as miRNA mimics and miRNA inhibitors (antagomirs). Furthermore, identified specific miRNAs and genes they regulate in pancreatic cancer along with downstream pathways can be used as potential therapeutic targets. However, a limited understanding and validation of the specific roles of miRNAs, lack of tissue specificity, methodological, technical, or analytical reproducibility, harmonization of miRNA isolation and quantification methods, the use of standard operating procedures, and the availability of automated and standardized assays to improve reproducibility between independent studies limit bench-to-bedside translation of the miRNA biomarkers for clinical applications. Here I review recent findings on miRNAs in pancreatic cancer pathogenesis and their potential as diagnostic, prognostic, and predictive markers.

Decoding the role of miRNAs in multiple myeloma pathogenesis: A focus on signaling pathways

Multiple myeloma (MM) is a cancer of plasma cells that has been extensively studied in recent years, with researchers increasingly focusing on the role of microRNAs (miRNAs) in regulating gene expression in MM. Several non-coding RNAs have been demonstrated to regulate MM pathogenesis signaling pathways. These pathways might regulate MM development, apoptosis, progression, and therapeutic outcomes. They are Wnt/β-catenin, PI3K/Akt/mTOR, P53 and KRAS. This review highlights the impending role of miRNAs in MM signaling and their relationship with MM therapeutic interventions.

Unleash Multifunctional Role of miRNA Biogenesis Gene Variants (XPO5*rs34324334 and RAN*rs14035) with Susceptibility to Hepatocellular Carcinoma

Numerous reports have explored the roles of different genetic variants in miRNA biogenesis mechanisms and the progression of various types of carcinomas. The goal of this study is to explore the association between XPO5*rs34324334 and RAN*rs14035 gene variants and susceptibility to hepatocellular carcinoma (HCC). In a cohort of 234 participants (107 HCC patients and 127 unrelated cancer-free controls) from the same geographic region, we characterized allelic discrimination using PCR-RFLP and performed subgroup analysis and multivariate regression. We found that the frequency of the XPO5*rs34324334 (A) variant was correlated with elevated risk of HCC under allelic (OR = 10.09, p-value < 0.001), recessive (OR = 24.1, p-value < 0.001), and dominant (OR = 10.1, p-value < 0.001) models. A/A genotype was associated with hepatitis C cirrhosis (p-value = 0.012), ascites (p-value = 0.003), and higher levels of alpha-fetoproteins (p-value = 0.011). Carriers of the RAN*rs14035 (T) variant were more likely to develop HCC under allelic (OR = 1.76, p-value = 0.003) and recessive (OR = 3.27, p-value < 0.001) models. Our results suggest that XPO5*rs34324334 and RAN*rs14035 variants are independent risk factors for developing HCC.

Therapeutic targeting approach on epithelial-mesenchymal plasticity to combat cancer metastasis

Epithelial-mesenchymal plasticity (EMP) is a process in which epithelial cells lose their characteristics and acquire mesenchymal properties, leading to increased motility and invasiveness, which are key factors in cancer metastasis. Targeting EMP has emerged as a promising therapeutic approach to combat cancer metastasis. Various strategies have been developed to target EMP, including inhibition of key signaling pathways, such as TGF-β, Wnt/β-catenin, and Notch, that regulate EMP, as well as targeting specific transcription factors, such as Snail, Slug, and Twist, that promote EMP. Additionally, targeting the tumor microenvironment, which plays a critical role in promoting EMP, has also shown promise. Several preclinical and clinical studies have demonstrated the efficacy of EMP-targeting therapies in inhibiting cancer metastasis. However, further research is needed to optimize these strategies and improve their clinical efficacy. Overall, therapeutic targeting of EMP represents a promising approach for the development of novel cancer therapies that can effectively inhibit metastasis, a major cause of cancer-related mortality.

The Crosstalk Between Autophagy and MicroRNAs in Esophageal Carcinoma:

Esophageal cancer (EC) is considered one of the most prevalent and aggressive malignancies worldwide, with a variety of molecular alterations thought to contribute to its incidence, development, progression, and invasion. However, the exact underlying mechanism has not been elucidated. Autophagy is a highly conserved degradative and recycling process that can function with a dual role in either the progression or the treatment of EC. Since microRNAs (miRNAs) are described as upstream regulators capable of controlling both oncogenic pathways and autophagic flux, the present study has aimed to review the crosstalk between autophagy and miRNAs and the potential perspective of these mechanisms in EC prevention and treatment.

Inflammatory microRNAs in cardiovascular pathology: another brick in the wall

The regulatory role of microRNAs (miRNAs) is mainly mediated by their effect on protein expression and is recognized in a multitude of pathophysiological processes. In recent decades, accumulating evidence has interest in these factors as modulatory elements of cardiovascular pathophysiology. Furthermore, additional biological processes have been identified as new components of cardiovascular disease etiology. In particular, inflammation is now considered an important cardiovascular risk factor. Thus, in the present review, we will focus on the role of a subset of miRNAs called inflamma-miRs that may regulate inflammatory status in the development of cardiovascular pathology. According to published data, the most representative candidates that play functional roles in thromboinflammation are miR-21, miR-33, miR-34a, miR-146a, miR-155, and miR-223. We will describe the functions of these miRNAs in several cardiovascular pathologies in depth, with specific emphasis on the molecular mechanisms related to atherogenesis. We will also discuss the latest findings on the role of miRNAs as regulators of neutrophil extracellular traps and their impact on cardiovascular diseases. Overall, the data suggest that the use of miRNAs as therapeutic tools or biomarkers may improve the diagnosis or prognosis of adverse cardiovascular events in inflammatory diseases. Thus, targeting or increasing the levels of adequate inflamma-miRs at different stages of disease could help mitigate or avoid the development of cardiovascular morbidities.

Crosstalk between colorectal cancer cells and cancer-associated fibroblasts in the tumor microenvironment mediated by exosomal noncoding RNAs

Colorectal cancer (CRC) is a common malignant tumor of the digestive system, and its morbidity rates are increasing worldwide. Cancer-associated fibroblasts (CAFs), as part of the tumor microenvironment (TME), are not only closely linked to normal fibroblasts, but also can secrete a variety of substances (including exosomes) to participate in the regulation of the TME. Exosomes can play a key role in intercellular communication by delivering intracellular signaling substances (e.g., proteins, nucleic acids, non-coding RNAs), and an increasing number of studies have shown that non-coding RNAs of exosomal origin from CAFs are not only closely associated with the formation of the CRC microenvironment, but also increase the ability of CRC to grow in metastasis, mediate tumor immunosuppression, and are involved in the mechanism of drug resistance in CRC patients receiving. It is also involved in the mechanism of drug resistance after radiotherapy in CRC patients. In this paper, we review the current status and progress of research on CAFs-derived exosomal non-coding RNAs in CRC.

Mutual Regulation of ncRNAs and Chromatin Remodeling Complexes in Normal and Pathological Conditions

Chromatin remodeling is the one of the main epigenetic mechanisms of gene expression regulation both in normal cells and in pathological conditions. In recent years, a growing number of investigations have confirmed that epigenetic regulators are tightly connected and form a comprehensive network of regulatory pathways and feedback loops. Genes encoding protein subunits of chromatin remodeling complexes are often mutated and change their expression in diseases, as well as non-coding RNAs (ncRNAs). Moreover, different mechanisms of their mutual regulation have already been described. Further understanding of these processes may help apply their clinical potential for establishment of the diagnosis, prognosis, and treatment of the diseases. The therapeutic targeting of the chromatin structure has many limitations because of the complexity of its regulation, with the involvement of a large number of genes, proteins, non-coding transcripts, and other intermediary molecules. However, several successful strategies have been proposed to target subunits of chromatin remodeling complexes and genes encoding them, as well as the ncRNAs that regulate the operation of these complexes and direct them to the target gene regions. In our review, we focus on chromatin remodeling complexes and ncRNAs, their mutual regulation, role in cellular processes and potential clinical application.

Arsenic resistance protein 2 and microRNA biogenesis: Biological implications in cancer development

Arsenic resistance protein 2 (Ars2) is a nuclear protein that plays a critical role in the regulation of microRNA (miRNA) biogenesis. Ars2 is required for cell proliferation and for the early stages of mammalian development through a possible effect on miRNA processing. Increasing evidence reveal that Ars2 is highly expressed in proliferating cancer cells, suggesting that Ars2 may be a potential therapeutic target for cancer. Therefore, development of the novel Ars2 inhibitors could represent the novel therapeutic strategies for treatment of cancer. In this review, we briefly discuss the mechanisms by which Ars2 regulates miRNA biogenesis and its impact on cell proliferation and cancer development. Particularly, we mainly discuss the role of Ars2 in the regulation of cancer development and highlight pharmacological targeting of Ars2 as a promising cancer therapeutic strategy.

The importance of hsa-miR-28 in human malignancies

MicroRNA production in tumorigenesis is dysregulated by a variety of processes, such as proliferation and removal of microRNA genes, aberrant transcriptional regulation of microRNAs, disrupted epigenetic alterations, and failures in the miRNA biogenesis machinery. Under some circumstances, miRNAs may act as tumorigenic and maybe anti-oncogenes. Tumor aspects such as maintaining proliferating signals, bypassing development suppressors, delaying apoptosis, stimulating metastasis and invasion, and promoting angiogenesis have been linked to dysfunctional and dysregulated miRNAs. MiRNAs have been found as possible biomarkers for human cancer in a great deal of research, which requires additional evaluation and confirmation. It is known that hsa-miR-28 can function as an oncogene or tumor suppressor in many malignancies, and it does this by modulating the expression of several genes and the downstream signaling network. MiR-28-5p and miR-28-3p, which originate from the same RNA hairpin precursor miR-28, have essential roles in a variety of cancers. This review outlines the function and mechanisms of miR-28-3p and miR-28-5p in human cancers and illustrates the miR-28 family's potential utility as a diagnostic biomarker for prognosis and early detection of cancers.

Clinical Value of Serum miR-106a in the Diagnosis and Prognosis of Human Papillomavirus-Positive Cervical Cancer

INTRODUCTION

Cervical cancer (CC) is a prevailing malignant tumor in women, mainly caused by human papillomavirus (HPV) infection. This study investigated miR-106a expression in the serum of HPV-positive CC patients and estimated its value in diagnosis and prognosis.

METHODS

We enrolled 120 CC patients as study subjects, with another 80 healthy women as controls. Clinical baseline data and clinicopathological indexes including age, tumor size, differentiation degree, FIGO stage, lymph node metastasis, and squamous cell carcinoma antigen (SCC-Ag) were recorded. Serum miR-106a expression was measured using reverse transcription-quantitative polymerase chain reaction. Receiver operating characteristic curve was employed to estimate the efficacy of miR-106a in diagnosing CC or HPV-positive CC. Under a 5-year follow-up, patient survival was recorded, and the impact of miR-106a on overall survival rate was analyzed by the Kaplan-Meier method. The logistic regression model was used to analyze whether miR-106a was an independent prognostic factor for HPV infection in CC patients.

RESULTS

Serum miR-106a was upregulated in CC patients and the level >1.365 assisted the CC diagnosis. miR-106a expression in HPV-positive CC patients was elevated relative to HPV-negative CC patients, and serum miR-106a level >1.300 distinguishing HPV positive and HPV negative. HPV positivity was linked with tumor differentiation degree, FIGO stage, lymph node metastasis, and SCC-Ag in CC patients, but not with age and tumor size. High expression of miR-106a in HPV-positive CC patients increased the risk of poor prognosis, and miR-106a expression is an independent prognostic factor for HPV infection in CC patients.

CONCLUSION

High expression of miR-106a assists in the diagnosis of HPV-positive CC and predicts poor prognosis.

Locus-Specific Bisulfate NGS Sequencing of GSTP1, RNF219, and KIAA1539 Genes in the Total Pool of Cell-Free and Cell-Surface-Bound DNA in Prostate Cancer: A Novel Approach for Prostate Cancer Diagnostics

The locus-specific methylation of three genes (GSTP1, RNF219, and KIAA1539, also known as FAM214B) in the total pool of blood cell-free DNA, including cell-free DNA from plasma and cell-surface-bound DNA, of patients with prostate cancer and healthy donors was studied on the MiSeq platform. Our study found a higher methylation index of loci for total cell-free DNA compared with cell-free DNA. For total cell-free DNA, the methylation of GSTP1 in each of the 11 positions provided a complete separation of cancer patients from healthy donors, whereas for cell-free DNA, there were no positions in the three genes allowing for such separation. Among the prostate cancer patients, the minimum proportion of GSTP1 genes methylated in any of the 17 positions was 12.1% of the total circulated DNA fragments, and the minimum proportion of GSTP1 genes methylated in any of the 11 diagnostically specific positions was 8.4%. Total cell-free DNA was shown to be more convenient and informative as a source of methylated DNA molecules circulating in the blood than cell-free DNA.

The role of circulating miRNAs in mechanism of action and prediction of therapeutic responses of metformin in polycystic ovarian syndrome

OBJECTIVE

To study the involvement of microribonucleic acids (miRNAs) in the pathogenesis of chronic anovulation and mechanism of metformin treatment in polycystic ovary syndrome (PCOS).

DESIGN

Case-control and prospective validation cohort study.

SETTING

Tertiary university hospital.

PATIENT(S)

A total of 146 patients with PCOS and chronic anovulation and 20 non-PCOS controls were enrolled. Patients who resumed ovulation after metformin treatment (MET-OV) and remained anovulatory after metformin treatment (MET-AO) were assigned to MET-OV and MET-AO groups, respectively.

INTERVENTION(S)

All patients with PCOS received metformin treatment for 6 months.

MAIN OUTCOME MEASURE(S)

Baseline and chronological changes in the plasma levels of 14 miRNAs (miR-21, 93, 132, 193b, 221, 222, 223, 27a, 125b, 200b, 212, 320a, 429, and 483) selected by literature review, anthropometric data, and hormonal as well as metabolic profiles were measured. Predictive modeling based on baseline circulatory miRNA levels and clinical parameters was performed to predict ovulation recovery after metformin treatment.

RESULT(S)

No significant differences were observed in the baseline hormonal and metabolic profiles between the MET-OV and MET-AO groups. However, the expression of miR-27a, miR-93, and miR-222 was significantly higher in the MET-OV group than that for the MET-AO and control groups. After 6 months of metformin treatment, the levels of insulin, luteinizing hormone, and 6 circulating miRNAs (miR-21, 27a, 93, 221, 222, and 223) and homeostatic model assessment for insulin resistance decreased significantly in the MET-OV group, but remained unchanged in the MET-AO group. The area under curve, sensitivity, and specificity of the adjusted prediction model, based on miRNA levels and clinical parameters using logistic regression analysis for predicting ovulatory response after metformin treatment, were 0.807, 0.892, and 0.632, respectively.

CONCLUSION(S)

The present study demonstrated a distinct pattern of baseline expression and chronological changes in the levels of several circulatory miRNAs between the MET-OV and MET-AO groups, suggesting that aberrantly overexpressed diabetogenic miRNAs are involved in the pathophysiology of chronic anovulation in PCOS, and their down-regulation might contribute toward the therapeutic effects of metformin. This could provide new insights into the mechanism of action and applicability of individualized metformin therapy in women with PCOS.

Deciphering the Role of p53 and TAp73 in Neuroblastoma: From Pathogenesis to Treatment

Neuroblastoma (NB) is an embryonic cancer that develops from neural crest stem cells, being one of the most common malignancies in children. The clinical manifestation of this disease is highly variable, ranging from spontaneous regression to increased aggressiveness, which makes it a major therapeutic challenge in pediatric oncology. The p53 family proteins p53 and TAp73 play a key role in protecting cells against genomic instability and malignant transformation. However, in NB, their activities are commonly inhibited by interacting proteins such as murine double minute (MDM)2 and MDMX, mutant p53, ΔNp73, Itch, and Aurora kinase A. The interplay between the p53/TAp73 pathway and N-MYC, a known biomarker of poor prognosis and drug resistance in NB, also proves to be decisive in the pathogenesis of this tumor. More recently, a strong crosstalk between microRNAs (miRNAs) and p53/TAp73 has been established, which has been the focused of great attention because of its potential for developing new therapeutic strategies. Collectively, this review provides an updated overview about the critical role of the p53/TAp73 pathway in the pathogenesis of NB, highlighting encouraging clues for the advance of alternative NB targeted therapies.

Epigenomic reprogramming in iAs-mediated carcinogenesis

Arsenic is a naturally occurring metal carcinogen found in the Earth's crust. Millions of people worldwide are chronically exposed to arsenic through drinking water and food. Exposure to inorganic arsenic has been implicated in many diseases ranging from acute toxicities to malignant transformations. Despite the well-known deleterious health effects of arsenic exposure, the molecular mechanisms in arsenic-mediated carcinogenesis are not fully understood. Since arsenic is non-mutagenic, the mechanism by which arsenic causes carcinogenesis is via alterations in epigenetic-regulated gene expression. There are two possible ways by which arsenic may modify the epigenome-indirectly through an arsenic-induced generation of reactive oxygen species which then impacts chromatin remodelers, or directly through interaction and modulation of chromatin remodelers. Whether directly or indirectly, arsenic modulates epigenetic gene regulation and our understanding of the direct effect of this modulation on chromatin structure is limited. In this chapter we will discuss the various ways by which inorganic arsenic affects the epigenome with consequences in health and disease.

The Role of microRNAs in the Gonocyte Theory as Target of Malignancy: Looking for Potential Diagnostic Biomarkers

Some pediatric patients with cryptorchidism preserve cells with gonocyte characteristics beyond their differentiation period, which could support the theory of the gonocyte as a target for malignancy in the development of testicular neoplasia. One of the key molecules in gonocyte malignancy is represented by microRNAs (miRNAs). The goal of this review is to give an overview of miRNAs, a class of small non-coding RNAs that participate in the regulation of gene expression. We also aim to review the crucial role of several miRNAs that have been further described in the regulation of gonocyte differentiation to spermatogonia, which, when transformed, could give rise to germ cell neoplasia in situ, a precursor lesion to testicular germ cell tumors. Finally, the potential use of miRNAs as diagnostic and prognostic biomarkers in testicular neoplasia is addressed, due to their specificity and sensitivity compared to conventional markers, as well as their applications in therapeutics.

Microbiomes, Epigenomics, Immune Response, and Splicing Signatures Interplay: Potential Use of Combination of Regulatory Pathways as Targets for Malignant Mesothelioma

Malignant mesotheliomas (MM) are hard to treat malignancies with poor prognosis and high mortality rates. This cancer is highly misdiagnosed in Sub-Saharan African countries. According to literature, the incidence of MM is likely to increase particularly in low-middle-income countries (LMICs). The burden of asbestos-induced diseases was estimated to be about 231,000 per annum. Lack of awareness and implementation of regulatory frameworks to control exposure to asbestos fibers contributes to the expected increase. Exposure to asbestos fibers can lead to cancer initiation by several mechanisms. Asbestos-induced epigenetic modifications of gene expression machinery and non-coding RNAs promote cancer initiation and progression. Furthermore, microbiome-epigenetic interactions control the innate and adaptive immunity causing exacerbation of cancer progression and therapeutic resistance. This review discusses epigenetic mechanisms with more focus on miRNAs and their interaction with the microbiome. The potential use of epigenetic alterations and microbiota as specific biomarkers to aid in the early detection and/or development of therapeutic targets is explored. The advancement of combinatorial therapies to prolong overall patient survival or possible eradication of MM especially if it is detected early is discussed.

Glaucocalyxin A Inhibits the Malignancies of Gastric Cancer Cells by Downregulating MDM2 and RNF6 via MiR-3658 and the SMG1-UPF mRNA Decay Pathway

Gastric cancer (GC) ranks as the most common gastrointestinal cancer and is among the leading causes of cancer death worldwide. Glaucocalyxin A (GLA), an entkauranoid diterpene isolated from Rab-dosia japonica var., possesses various bioactivities. To date, the data on the effect of GLA on GC are still minimal, and the molecular mechanisms remain largely unknown. Herein, we found that GLA could significantly inhibit the proliferation, cell adhesion, and invasion of HGT-1, SNU-1, SNU-6, and NCI-N87 GC cells in a dose-dependent manner. GLA enhanced the apoptosis of the GC cells as evidenced by the increased caspase-3 activity and the elevated levels of cleaved caspase-3 and cleaved PARP in GC cells in the presence of GLA. We then showed that the downregulation of Murine Double Minute Clone 2 (MDM2) and Ring Finger Protein 6 (RNF6) by GLA was implicated in the GLA-induced inhibition of the GC cells. Furthermore, MDM2 and RNF6 were identified as the targets of miR-3658 that was downregulated in the GC cells and upregulated by GLA. Moreover, it was shown that miR-3658 was hypermethylated in the GC cells, and GLA could rescue the expression of miR-3658 via demethylation by abrogating EZH2-mediated epigenetic silencing. In addition to the miR-3658-MDM2/RNF6 regulatory axis, activation of the SMG1-UPF mRNA decay pathway contributed to the downregulation of MDM2 and RNF6 by GLA in the GC cells. The inhibitory effect of GLA on gastric cancer and the expression of MDM2 and RNF6 was also validated in in vivo study. Our findings suggest that has the therapeutic potential for GC by downregulating oncogenes via posttranscriptional regulation.

Tumor Suppressor microRNAs in Gastrointestinal Cancers: A Mini-Review

BACKGROUND

Gastrointestinal (GI) cancer is associated with a group of cancers affecting the organs in the GI tract, with a high incidence and mortality rate. This type of cancer development involves a series of molecular events that arise by the dysregulation of gene expressions and microRNAs (miRNAs).

OBJECTIVES

This mini-review focuses on elucidating the mechanism of tumor suppressor miRNA-mediated oncogenic gene silencing, which may contribute to a better understanding of miRNA-mediated gene expression regulation of cell cycle, proliferation, invasion, and apoptosis in GI cancers. In this review, the biological significance of tumor suppressor miRNAs involved in gastrointestinal cancers is briefly explained.

METHODS

The articles were searched with the keywords 'miRNA', 'gastrointestinal cancers', 'esophageal cancer', 'gastric cancer', 'colorectal cancer', 'pancreatic cancer', 'liver cancer', and 'gall bladder cancer' from the Google Scholar and PubMed databases. A total of 71 research and review articles have been collected and referred for this study.

RESULTS

This review summarises recent research enhancing the effectiveness of miRNAs as novel prognostic, diagnostic, and therapeutic markers for GI cancer treatment strategies. The expression pattern of various miRNAs has been dysregulated in GI cancers, which are associated with proliferation, cell cycle regulation, apoptosis, migration, and invasion.

CONCLUSION

The role of tumor suppressor miRNAs in the negative regulation of oncogenic gene expression was thoroughly explained in this review. Its potential role as a microRNA therapeutic candidate is also discussed. Profiling and regulating tumor suppressor miRNA expression in gastrointestinal cancers using miRNA mimics could be used as a prognostic, diagnostic, and therapeutic marker, as well as an elucidating molecular therapeutic approach to tumor suppression.

miR-153-3p inhibited osteogenic differentiation of human DPSCs through CBFβ signaling

Dental pulp stem cells (DPSCs) have multilineage differentiation potential and especially show a great foreground in bone regeneration engineering. The mechanism of osteogenic differentiation of DPSCs needs to be explored exactly. As a kind of endogenous and non-coding small RNAs, microRNAs (miRNAs) play an important role in many biological processes including osteogenic differentiation. However, the mechanism of miR-153-3p in osteogenic differentiation of DPSCs is still unknown. Core-binding factors-beta (CBFβ) is a non-DNA-binding factor that combines with the runt-related transcription factor family transcription factors to mediate their DNA-binding affinities, and plays a critical role in regulating osteogenic differentiation. In this study, we explored the mechanisms of miR-153-3p and CBFβ in DPSC osteogenesis. The expression of miR-153-3p and CBFβ was tested under the osteogenic condition, and the influence led by changing the expression of miR-153-3p or CBFβ had also been detected. A luciferase reporter assay confirmed that miR-153-3p directly targeted to CBFβ. The osteogenic markers, alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2), and bone morphogenetic protein 2 (BMP2), were tested in protein level or mRNA level. ALP and Alizarin red staining were used to detect the osteoblast activity and mineral deposition. In osteogenic condition, the expressions of CBFβ and osteogenic markers were upregulated, whereas that of miR-153-3p was downregulated. miR-153-3p negatively regulated the osteogenic differentiation, and overexpression of CBFβ could offset the negative effect of miR-153-3p. Our findings provided a novel strategy for DPSC application in treatment of bone deficiencies and facilitated bone regeneration.

Crucial Roles of miR-625 in Human Cancer

Genetic and epigenetic characteristics are core factors of cancer. MicroRNAs (miRNAs) are small non-coding RNAs which regulate gene expression at the post-transcriptional level via binding to corresponding mRNAs. Recently, increasing evidence has proven that miRNAs regulate the occurrence and development of human cancer. Here, we mainly review the abnormal expression of miR-625 in a variety of cancers. In summarizing the role and potential molecular mechanisms of miR-625 in various tumors in detail, we reveal that miR-625 is involved in a variety of biological processes, such as cell proliferation, invasion, migration, apoptosis, cell cycle regulation, and drug resistance. In addition, we discuss the lncRNA-miRNA-mRNA and circRNA-miRNA-mRNA networks and briefly explain the specific mechanisms of competing endogenous RNAs. In conclusion, we reveal the potential value of miR-625 in cancer diagnosis, treatment, and prognosis and hope to provide new ideas for the clinical application of miR-625.

Noncoding RNAs in Cardiac Hypertrophy and Heart Failure

Heart failure is a major global health concern. Noncoding RNAs (ncRNAs) are involved in physiological processes and in the pathogenesis of various diseases, including heart failure. ncRNAs have emerged as critical components of transcriptional regulatory pathways that govern cardiac development, stress response, signaling, and remodeling in cardiac pathology. Recently, studies of ncRNAs in cardiovascular disease have achieved significant development. Here, we discuss the roles of ncRNAs, including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs) that modulate the cardiac hypertrophy and heart failure.

Epigenetic modification and BRAF gene mutation in thyroid carcinoma

Thyroid cancer remains the most prevailing endocrine malignancy, and a progressively increasing incidence rate has been observed in recent years, with 95% of thyroid cancer represented by differentiated thyroid carcinomas. The genetics and epigenetics of thyroid cancer are gradually increasing, and gene mutations and methylation changes play an important roles in its occurrence and development. Although the role of RAS and BRAF mutations in thyroid cancer have been partially clarified,but the pathogenesis and molecular mechanisms of thyroid cancer remain to be elucidated. Epigenetic modification refer to genetic modification that does not change the DNA sequence of a gene but causes heritable phenotypic changes in its expression. Epigenetic modification mainly includes four aspects: DNA methylation, chromatin remodelling, noncoding RNA regulation, and histone modification. This article reviews the importance of thyroid cancer epigenetic modification and BRAF gene mutation in the treatment of thyroid cancer.

The long noncoding RNA noncoding RNA activated by DNA damage (NORAD)-microRNA-496-Interleukin-33 axis affects carcinoma-associated fibroblasts-mediated gastric cancer development

Carcinoma-associated fibroblasts (CAFs) are one of the crucial parts of in the tumor microenvironment and contribute to tumor progression. Interleukin-33 (IL-33), a tissue-derived nuclear cytokine from the IL-1 family, has been found abnormally expressed in tumor cells and Fibroblast. However, the role and mechanism of IL-33 in the interaction between gastric cancer (GC) cells and CAFs need investigation. Presently, we inquire into the function of lncRNA NORAD-miR-496 axis-mediated IL-33 in modulating the GC-CAFs interaction. Real-time reverse transcription-polymerase chain reaction (RT-PCR) was adopted to gauge the expression of NORAD, miR-496, and IL-33 in GC tissues and cells, and gain- or loss-of-function assays were conducted to investigate the role of them in GC. A GC cell-CAFs co-culture model was established to explore the interaction between CAFs and GCs. As exhibited, NORAD was up-regulated in GC tissues and cells, while miR-496 was remarkably down-regulated. Overexpressing NORAD substantially promoted the proliferation, migration, invasion, and EMT of GC cells and repressed cell death, while overexpressing miR-496 had the opposite effects. Additionally, NORAD enhanced the IL-33 expression and the release of IL-33 from GC cells. The dual-luciferase reporter assay confirmed that miR-496 was a target of NORAD and targeted IL-33. CAFs aggravated the malignant behaviors of GC cells as indicated by both experiments. However, NORAD knockdown in CAFs reversed CAFs-mediated promotive effects on GC cells. In conclusion, NORAD enhanced the promotive effect of CAFs in GC cells by up-regulating IL-33 and targeting miR-496, which provided new insights into the microenvironment of GC cells and CAFs.Abbreviation ANOVA: Analysis of Variance; BCA:Bicinchoninic acid; CAFs: carcinoma-associated fibroblasts; CCK-8: cell counting kit-8; ceRNA: competing endogenous RNA; DAPI: 4',6-diamidino-2-phenylindole; DMEM: Dulbecco's minimal essential medium/Ham's; ECL: enhanced chemiluminiscent; ELISA: Enzyme-Linked Immunosorbent Assay; EMT: epithelial-mesenchymal transition; FBS: fetal bovine serum; FISH:Fluorescence in situ hybridization; FITC:fluorescein isothiocyanate; FSP:fibroblast-specific protein; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GC: gastric cancer; IHC: immunohistochemistry; IL: Interleukin; lncRNA: long Noncoding RNA; miR-496: microRNA-496; MMP-14:matrix metalloproteinase-14; MUT:mutant; MYH9: myosin heavy chain 9; NFs: normal fibroblasts; NORAD: Noncoding RNA activated by DNA damage; ORF: open reading frame; PBS: phosphate-buffered saline; PMSF: Phenylmethylsulfonyl fluoride; PVDF: polyvinylidene difluoride; RIPA: Radio-Immunoprecipitation Assay; RT-PCR: Real-time reverse transcription polymerase chain reaction; S100A4:S100 calcium binding protein A4; SDS-PAGE: sodium dodecyl sulfate-polyacrylamide gel electrophoresis; sh-NC: short-hairpin RNA negative control; sh-NORAD: short-hairpin RNA of NORAD; α-SMA: α-smooth muscle actin; TBST: Tris-buffered saline with Tween-20; TGF-β1: Transforming growth factor β1; TUNEL: TdT-mediated dUTP Nick-End Labeling; TWIST1: the twist-related protein 1; VEGF-C: vascular endothelial growth factor C; WT: Wildtype.

miRNAs in the Era of Personalized Medicine: From Biomarkers to Therapeutics

In recent years, interest in personalized medicine has considerably increased [...].