microRNAs exhibit high frequency genomic alterations in human cancer

Current updates regarding biogenesis, functions and dysregulation of microRNAs in cancer: Innovative approaches for detection using CRISPR/Cas13‑based platforms (Review)

MicroRNAs (miRNAs) are short non‑coding RNAs, which perform a key role in cellular differentiation and development. Most human diseases, particularly cancer, are linked to miRNA functional dysregulation implicated in the expression of tumor‑suppressive or oncogenic targets. Cancer hallmarks such as continued proliferative signaling, dodging growth suppressors, invasion and metastasis, triggering angiogenesis, and avoiding cell death have all been demonstrated to be affected by dysregulated miRNAs. Thus, for the treatment of different cancer types, the detection and quantification of this type of RNA is significant. The classical and current methods of RNA detection, including northern blotting, reverse transcription‑quantitative PCR, rolling circle amplification and next‑generation sequencing, may be effective but differ in efficiency and accuracy. Furthermore, these approaches are expensive, and require special instrumentation and expertise. Thus, researchers are constantly looking for more innovative approaches for miRNA detection, which can be advantageous in all aspects. In this regard, an RNA manipulation tool known as the CRISPR and CRISPR‑associated sequence 13 (CRISPR/Cas13) system has been found to be more advantageous in miRNA detection. The Cas13‑based miRNA detection approach is cost effective and requires no special instrumentation or expertise. However, more research and validation are required to confirm the growing body of CRISPR/Cas13‑based research that has identified miRNAs as possible cancer biomarkers for diagnosis and prognosis, and as targets for treatment. In the present review, current updates regarding miRNA biogenesis, structural and functional aspects, and miRNA dysregulation during cancer are described. In addition, novel approaches using the CRISPR/Cas13 system as a next‑generation tool for miRNA detection are discussed. Furthermore, challenges and prospects of CRISPR/Cas13‑based miRNA detection approaches are described.

Ferroptosis: A Targetable Vulnerability for Melanoma Treatment

Melanoma is a devastating form of skin cancer characterized by a high mutational burden, limited treatment success, and dismal prognosis. Although immunotherapy and targeted therapies have significantly revolutionized melanoma treatment, the majority of patients fail to achieve durable responses, highlighting the urgent need for novel therapeutic strategies. Ferroptosis, an iron-dependent form of regulated cell death driven by the overwhelming accumulation of lipid peroxides, has emerged as a promising therapeutic approach in preclinical melanoma models. A deeper understanding of the ferroptosis landscape in melanoma based on its biology characteristics, including phenotypic plasticity, metabolic state, genomic alterations, and epigenetic changes, as well as the complex role and mechanisms of ferroptosis in immune cells could provide a foundation for developing effective treatments. In this review, we outline the molecular mechanisms of ferroptosis, decipher the role of melanoma biology in ferroptosis regulation, reveal the therapeutic potential of ferroptosis in melanoma, and discuss the pressing questions that should guide future investigations into ferroptosis in melanoma.

Circulating MicroRNAs: functional biomarkers for melanoma prognosis and treatment

MicroRNAs (miRNAs) hold significant promise as circulating cancer biomarkers and unlike many other molecular markers, they can provide valuable insights that extend beyond tumour biology. The expression of circulating miRNAs may parallel the cellular composition and dynamic activity within the tumour microenvironment and reveal systemic immune responses. The functional complexity of miRNAs-where a single miRNA can regulate multiple messenger RNAs (mRNAs) to fine tune fundamental processes, and a single mRNA can be targeted by multiple miRNAs-underscores their broad significance and impact. However, this complexity poses significant challenges for translating miRNA research into clinical practice. In melanoma, specific miRNA signatures have shown notable diagnostic, prognostic and predictive value, with lineage-specific and immune-related miRNAs frequently identified as valuable markers. In this review, we explore the role of circulating miRNAs as potential biomarkers in melanoma, and highlight the current status and advances required to translate miRNA research into therapeutic opportunities.

Novel Detection and Clinical Utility of Serum-Derived Extracellular Vesicle in Angiosarcoma

Cutaneous angiosarcoma is a rare and highly aggressive skin malignancy. The aim of this study is to explore the alteration of serum-derived extracellular vesicle (EV) in angiosarcoma patients and to evaluate its clinical utility as a novel circulating biomarker. In a microarray analysis to examine the differential expression of specific EV-associated microRNAs in sera between cutaneous angiosarcoma patients and healthy controls, 73 microRNAs with significant upregulation and 100 microRNAs with significant downregulation, respectively, were identified in patients with angio-sarcoma. Among them, quantitative PCR confirmed that miR-184, miR-3925-5p, miR-3926, and miR-5703 were upregulated in sera of cutaneous angiosarcoma patients compared with those of healthy controls and melanoma patients. Additionally, these 4 microRNAs were expressed more highly in angiosarcoma cell lines compared with normal human endothelial cell lines and were prone to elevate along with disease progression. Furthermore, a gene analysis predicted that the target gene set of microRNAs might affect the regulation of TP53 via the epigenetic regulation of MECP2. Taken together, these 4 extracellular vesicle-associated microRNAs in circulation serve as a promising liquid biomarker to identify angiosarcoma patients and trace disease progression.

Pleuropulmonary blastoma and DICER1-related tumor predisposition: from clinicopathologic observations to clinical trial

PURPOSE OF REVIEW

Pleuropulmonary blastoma (PPB) is a rare primary lung neoplasm of infancy and childhood. The purpose of this review is to highlight recent developments in our understanding of PPB and research strategies to facilitate future rare cancer research.

RECENT FINDINGS

The International PPB/DICER1 Registry has recently assembled the largest-ever cohorts of type I and Ir PPB and type II and III PPB. These analyses were strengthened by robust histologic, genetic and longitudinal data made possible by systematic data collection and abstraction and dedicated central pathology review. These cohorts have laid the groundwork for a prospective consortium-based clinical trial to assess response to camptothecins in type II and III PPB and standardize the use of chemotherapy in type I PPB.

SUMMARY

Significant strides in the study of PPB have been made through clinical, laboratory and translational research, multidisciplinary collaborations and the generous contributions of patients, families and referring physicians. Ongoing advancements will continue to depend on multidisciplinary, multiperspective global collaborations.

Update on Pediatric Surveillance Recommendations for PTEN Hamartoma Tumor Syndrome, DICER1-Related Tumor Predisposition, and Tuberous Sclerosis Complex

Phosphate and tensin homolog hamartoma tumor syndrome, DICER1-related tumor predisposition, and tuberous sclerosis complex are rare conditions, which each increases risk for distinct spectra of benign and malignant neoplasms throughout childhood and adulthood. Surveillance considerations for each of these conditions focus on patient and family education, early detection, and multidisciplinary care. In this article, we present updated surveillance recommendations and considerations for children and adolescents with phosphate and tensin homolog hamartoma tumor syndrome, DICER1-related tumor predisposition, and tuberous sclerosis complex and provide suggestions for further research in each of these conditions.

Deregulation of Exosomal miR-17, miR-20a and TGFBR2 in Head and Neck Cancer Patients

Introduction: Exosomes play significant roles in transferring cargo materials like proteins, RNAs (including miRNAs), and DNA. However, the role of serum exosome shuttled RNAs and miRNAs in head and neck cancer (HNC) remains unclear. This study assessed the diagnostic and prognostic significance of exosomal miR-17, miR-20a, and TGFBR2 in HNC patients. Methods: Exosomes were isolated, from 400 confirmed HNC patients and 400 healthy controls, and characterized by NTA, TEM, Immunolabelling, and ELISA. Quantitative PCR was used to check the expressions of exosomal molecules. Oxidative stress was also measured through ELISA in cancer patients and healthy controls. Results: Data analysis revealed significant dysregulation in the expressional levels of miR-17 (p < .0001), miR-20a (p = .0003), and TGFBR2 (p = .0005), which were found associated with aggressiveness and poor survival of HNC patients. Spearman correlation revealed a positive statistically significant association between miR-20a versus miR-17 (r = 0.534; p < .01), while a negative correlation was found between TGFBR2 versus miR-17 (r = -0.240; p = .015). Significantly decreased levels of peroxidase (POD) (p < .0001) and an increased level of 8-Oxoguanine (p < .0001) were observed. Conclusion: The results showed that these exosomal miRNAs and target gene may serve as potential and noninvasive diagnostic and prognostic markers for head and neck cancer patients.

DICER1-Related Tumor Predisposition: Identification of At-risk Individuals and Recommended Surveillance Strategies

PURPOSE

DICER1-related tumor predisposition increases risk for a spectrum of benign and malignant tumors. In 2018, the International Pleuropulmonary Blastoma (PPB)/DICER1 Registry published guidelines for testing- and imaging-based surveillance of individuals with a known or suspected germline DICER1 pathogenic or likely pathogenic (P/LP) variant. One of the goals of the Registry is to continue to refine these guidelines as additional data become available.

EXPERIMENTAL DESIGN

Individuals were enrolled in the International PPB/DICER1 Registry, the International Ovarian and Testicular Stromal Tumor Registry, and/or the NCI Natural History of DICER1 Syndrome study.

RESULTS

Review of participant records identified 713 participants with a germline DICER1 P/LP variant from 38 countries. To date, 5 cases of type I and 29 cases of type Ir PPB have been diagnosed by surveillance in enrolled individuals. One hundred and three individuals with a germline P/LP variant developed a primary ovarian Sertoli-Leydig cell tumor at a median age of 14 years (range: 11 months-66 years); 13% were diagnosed before 8 years of age, the current age of onset of pelvic surveillance. Additionally, 4% of Sertoli-Leydig cell tumors were diagnosed before 4 years of age.

CONCLUSIONS

Ongoing data collection highlights the role of lung surveillance in the early detection of PPB and suggests that imaging-based detection and early resection may decrease the risk of advanced PPB. DICER1-related ovarian tumors were detected before 8 years of age, prompting the Registry to recommend earlier initiation of ovarian surveillance with pelvic ultrasound beginning at the time of detection of a germline DICER1 P/LP variant.

CircRNAs and miRNAs: Key Player Duo in Breast Cancer Dynamics and Biomarkers for Breast Cancer Early Detection and Prevention

Breast cancer (BC) remains a significant global health issue, necessitating advanced molecular approaches for early detection and prevention. This review delves into the roles of microRNAs (miRNAs) and circular RNAs (circRNAs) in BC, highlighting their potential as non-invasive biomarkers. Utilizing in silico tools and databases, we propose a novel methodology to establish mRNA/circRNA/miRNA axes possibly indicative of early detection and possible prevention. We propose that during early tumor initiation, some changes in oncogene or tumor suppressor gene expression (mRNA) are mirrored by alterations in corresponding circRNAs and reciprocal changes in sponged miRNAs affecting tumorigenesis pathways. We used two Gene Expression Omnibus (GEO) datasets and identified five mRNA/circRNA/miRNA axes as early possible tumor initiation biomarkers. We further validated the proposed axes through a Kaplan-Meier (KM) plot and enrichment analysis of miRNA expression using patient data. Evaluating coupled differential expression of circRNAs and miRNAs in body fluids or exosomes provides greater confidence than assessing either, with more axes providing even greater confidence. The proposed methodology not only improves early BC detection reliability but also has applications for other cancers, enhancing preventive measures.

Evolving landscape of detection and targeting miRNA/epigenetics for therapeutic strategies in ovarian cancer

Ovarian cancer (OC) accounts for the highest mortality rates among all gynecologic malignancies. The high mortality of OC is often associated with delayed detection, prolonged latency, enhanced metastatic potential, acquired drug resistance, and frequent recurrence. This review comprehensively explores key aspects of OC, including cancer diagnosis, mechanisms of disease resistance, and the pivotal role of epigenetic regulation, particularly by microRNAs (miRs) in cancer progression. We highlight the intricate regulatory mechanisms governing miR expression within the context of OC and the current status of epigenetic advancement in the therapeutic development and clinical trial progression. Through network analysis we elucidate the regulatory interactions between dysregulated miRs in OC and their targets which are involved in different signaling pathways. By exploring these interconnected facets and critical analysis, we endeavor to provide a nuanced understanding of the molecular dynamics underlying OC, its detection and shedding light on potential avenues for miRs and epigenetics-based therapeutic intervention and management strategies.

Role of hydrogen sulfide-microRNA crosstalk in health and disease

The mutual regulation between hydrogen sulfide (H2S) and microRNA (miRNA) is involved in the development of many diseases, including cancer, cardiovascular disease, inflammatory disease, and high-risk pregnancy. Abnormal expressions of endogenous H2S-producing enzyme and miRNA in tissues and cells often indicate the occurrence of diseases, so the maintenance of their normal levels in the body can mitigate damages caused by various factors. Many studies have found that H2S can promote the migration, invasion, and proliferation of cancer cells by regulating the expression of miRNA, while many H2S donors can inhibit cancer progression by interfering with the proliferation, apoptosis, cell cycle, metastasis, and angiogenesis of cancer cells. Furthermore, the mutual regulation between H2S and miRNA can also prevent cell injury in cardiovascular disease and inflammatory disease through anti-inflammation, anti-oxidation, anti-apoptosis, and pro-autophagy. In addition, H2S can promote angiogenesis and relieve vasoconstriction by regulating the expression of miRNA, thereby improving fetal growth in high-risk pregnancy. In this review, we discuss the mechanism of mutual regulation between H2S and miRNA in various diseases, which may provide reliable therapeutic targets for these diseases.

MiRNA-449 family is epigenetically repressed and sensitizes to doxorubicin through ACSL4 downregulation in triple-negative breast cancer

Despite progress in breast cancer treatment, a significant portion of patients still relapse because of drug resistance. The involvement of microRNAs in cancer progression and chemotherapy response is well established. Therefore, this study aimed to elucidate the dysregulation of the microRNA-449 family (specifically, microRNA-449a, microRNA-449b-5p, and microRNA-449c-5p) and its impact on resistance to doxorubicin, a commonly used chemotherapeutic drug for the treatment of triple-negative breast cancer. We found that the microRNA-449 family is downregulated in triple-negative breast cancer and demonstrated its potential as a diagnostic biomarker. Besides, our findings indicate that the downregulation of the microRNA-449 family is mediated by the microRNAs-449/SIRT1-HDAC1 negative feedback loop. Moreover, it was found that the microRNA-449 family dysregulates the fatty acid metabolism by targeting ACSL4, which is a potential prognostic biomarker that mediates doxorubicin response through regulation of the drug extrusion pump ABCG2. Altogether, our results suggest that the microRNA-449 family might be a potential therapeutic target for the treatment of triple-negative breast cancer since it is implicated in doxorubicin response through ACSL4/ABCG2 axis regulation. Ultimately, our results also highlight the value of microRNAs-449 and ACSL4 as diagnostic and prognostic biomarkers in triple-negative breast cancer. Proposed model of miRNAs-449 downregulation in TNBC and doxorubicin response. MiRNAs-449 are downregulated in TNBC through a negative feedback loop with SIRT1 and HDAC1. Moreover, ACSL4 increases ABCG2 expression, thus diminishing the intracellular doxorubicin concentration and promoting doxorubicin resistance. MiRNAs-449 overexpression downregulates the ACSL4/ABCG2 axis and sensitizes doxorubicin-resistant cells to doxorubicin. Created with BioRender. TNBC: triple-negative breast cancer; DOX: doxorubicin; SIRT1: Sirtuin 1; HDAC1: Histone deacetylase 1; ACSL4: Acyl-CoA Synthetase Long-Chain Family Member 4; ABCG2: ATP-binding cassette superfamily G member 2.

miRNAs in pancreatic cancer progression and metastasis

Small non-coding RNA or microRNA (miRNA) are critical regulators of eukaryotic cells. Dysregulation of miRNA expression and function has been linked to a variety of diseases including cancer. They play a complex role in cancers, having both tumour suppressor and promoter properties. In addition, a single miRNA can be involved in regulating several mRNAs or many miRNAs can regulate a single mRNA, therefore assessing these roles is essential to a better understanding in cancer initiation and development. Pancreatic cancer is a leading cause of cancer death worldwide, in part due to the lack of diagnostic tools and limited treatment options. The most common form of pancreatic cancer, pancreatic ductal adenocarcinoma (PDAC), is characterised by major genetic mutations that drive cancer initiation and progression. The regulation or interaction of miRNAs with these cancer driving mutations suggests a strong link between the two. Understanding this link between miRNA and PDAC progression may give rise to novel treatments or diagnostic tools. This review summarises the role of miRNAs in PDAC, the downstream signalling pathways that they play a role in, how these are being used and studied as therapeutic targets as well as prognostic/diagnostic tools to improve the clinical outcome of PDAC.

Non-coding RNAs in disease: from mechanisms to therapeutics

Non-coding RNAs (ncRNAs) are a heterogeneous group of transcripts that, by definition, are not translated into proteins. Since their discovery, ncRNAs have emerged as important regulators of multiple biological functions across a range of cell types and tissues, and their dysregulation has been implicated in disease. Notably, much research has focused on the link between microRNAs (miRNAs) and human cancers, although other ncRNAs, such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), are also emerging as relevant contributors to human disease. In this Review, we summarize our current understanding of the roles of miRNAs, lncRNAs and circRNAs in cancer and other major human diseases, notably cardiovascular, neurological and infectious diseases. Further, we discuss the potential use of ncRNAs as biomarkers of disease and as therapeutic targets.

CMC: Cancer miRNA Census - a list of cancer-related miRNA genes

A growing body of evidence indicates an important role of miRNAs in cancer; however, there is no definitive, convenient-to-use list of cancer-related miRNAs or miRNA genes that may serve as a reference for analyses of miRNAs in cancer. To this end, we created a list of 165 cancer-related miRNA genes called the Cancer miRNA Census (CMC). The list is based on a score, built on various types of functional and genetic evidence for the role of particular miRNAs in cancer, e.g. miRNA-cancer associations reported in databases, associations of miRNAs with cancer hallmarks, or signals of positive selection of genetic alterations in cancer. The presence of well-recognized cancer-related miRNA genes, such as MIR21, MIR155, MIR15A, MIR17 or MIRLET7s, at the top of the CMC ranking directly confirms the accuracy and robustness of the list. Additionally, to verify and indicate the reliability of CMC, we performed a validation of criteria used to build CMC, comparison of CMC with various cancer data (publications and databases), and enrichment analyses of biological pathways and processes such as Gene Ontology or DisGeNET. All validation steps showed a strong association of CMC with cancer/cancer-related processes confirming its usefulness as a reference list of miRNA genes associated with cancer.

Sex-Biased Expression and Response of microRNAs in Neurological Diseases and Neurotrauma

Neurological diseases and neurotrauma manifest significant sex differences in prevalence, progression, outcome, and therapeutic responses. Genetic predisposition, sex hormones, inflammation, and environmental exposures are among many physiological and pathological factors that impact the sex disparity in neurological diseases. MicroRNAs (miRNAs) are a powerful class of gene expression regulator that are extensively involved in mediating biological pathways. Emerging evidence demonstrates that miRNAs play a crucial role in the sex dimorphism observed in various human diseases, including neurological diseases. Understanding the sex differences in miRNA expression and response is believed to have important implications for assessing the risk of neurological disease, defining therapeutic intervention strategies, and advancing both basic research and clinical investigations. However, there is limited research exploring the extent to which miRNAs contribute to the sex disparities observed in various neurological diseases. Here, we review the current state of knowledge related to the sexual dimorphism in miRNAs in neurological diseases and neurotrauma research. We also discuss how sex chromosomes may contribute to the miRNA sexual dimorphism phenomenon. We attempt to emphasize the significance of sexual dimorphism in miRNA biology in human diseases and to advocate a gender/sex-balanced science.

miRNAs Related to Immune Checkpoint Inhibitor Response: A Systematic Review

The advent of immune checkpoint inhibitors (ICIs) has represented a breakthrough in the treatment of many cancers, although a high number of patients fail to respond to ICIs, which is partially due to the ability of tumor cells to evade immune system surveillance. Non-coding microRNAs (miRNAs) have been shown to modulate the immune evasion of tumor cells, and there is thus growing interest in elucidating whether these miRNAs could be targetable or proposed as novel biomarkers for prognosis and treatment response to ICIs. We therefore performed an extensive literature analysis to evaluate the clinical utility of miRNAs with a confirmed direct relationship with treatment response to ICIs. As a result of this systematic review, we have stratified the miRNA landscape into (i) miRNAs whose levels directly modulate response to ICIs, (ii) miRNAs whose expression is modulated by ICIs, and (iii) miRNAs that directly elicit toxic effects or participate in immune-related adverse events (irAEs) caused by ICIs.

The regulatory mechanisms of oncomiRs in cancer

Cancer development is a complex process that primarily results from the combination of genetic alterations and the dysregulation of major signalling pathways due to interference with the epigenetic machinery. As major epigenetic regulators, miRNAs are central players in the control of many key tumour development factors. These miRNAs have been classified as oncogenic miRNAs (oncomiRs) when they target tumour suppressor genes and tumour suppressor miRNAs (TS miRNAs) when they inhibit oncogene protein expression. Most of the mechanisms that modulate oncomiR expression are linked to transcriptional or posttranscriptional regulation. However, non-transcriptional processes, such as gene amplification, have been described as alternative processes that are responsible for increasing oncomiR expression. The current review summarises the different mechanisms controlling the upregulation of oncomiR expression in cancer cells and the tumour microenvironment (TME). Detailed knowledge of the mechanism underlying the regulation of oncomiR expression in cancer may pave the way for understanding the critical role of oncomiRs in cancer development and progression.

Genomic instability-associated two-miRNA signature as a novel prognostic biomarker in breast cancer

BACKGROUND

Breast cancer (BC) is the most common cancer among women worldwide and a leading cause of cancer-associated deaths among women. However, there is a lack of accurate prognostic biomarkers for BC. In the present study, we aimed to identify a genomic instability (GI)-associated microRNA signature as a novel potential prognostic biomarker in BC.

METHODS

We performed an integrative analysis to investigate the relationship between GI and BC and identify GI-associated microRNAs (miRNAs). Subsequently, we conducted a discovery and validation study using multicenter cohorts. The GI-associated miRNA signature was developed in the discovery cohort and independently validated in internal and external cohorts.

RESULTS

GI-associated miRNAs expression in BC showed heterogeneity and was significantly correlated with BC prognosis. We identified a GI-associated two-miRNA signature (miR-105-5p and miR-767-5p), termed GI2miR, that stratified BC patients into high-risk and low-risk groups with significantly different clinical outcomes (log-rank p = 0.027) in The Cancer Genome Atlas (TCGA) discovery cohort (n = 763). The prognostic value of GI2miR was further validated in internal TCGA validation cohort (n = 253) (log-rank p = 0.035) and independent GSE22216 cohort (n = 210) (log-rank p = 0.036). The GI2miR demonstrated independent prognostic value in multivariate Cox proportional hazard regression analyses and stratification analysis.

CONCLUSIONS

We have developed a novel prognostic signature based on GI-associated two miRNAs for BC, which may lay the foundation for BC to improve prognosis prediction.

Differential microRNAs Expression during Cancer Development, and Chemoprevention by Natural Compounds: A Comprehensive Review

MicroRNAs are short non-coding RNAs that inhibit gene expression at the post-transcriptional level. Abnormal microRNA expression has been associated with different human diseases, including cancer. Epigenetic changes, mutation, transcriptional deregulation, DNA copy number abnormalities, and defects in the biogenesis machinery play an important role in abnormal microRNA expression. Modulation of microRNAs by natural agents has emerged to enhance the efficacy of conventional chemotherapy through combinatorial therapeutic approach. This review summarizes the current understanding of abnormal microRNA expression in cancer, the different cellular mechanisms of microRNA, and their prevention by natural compounds. Understanding microRNA expression patterns during cancer development may help to identify stage-specific molecular markers. Natural compounds that exert regulatory effects by modulating microRNAs can be used in better cancer chemopreventive strategies by directly targeting microRNAs or as a way to increase sensitivity to existing chemotherapy regimens.

miRNA-Based Technologies in Cancer Therapy

The discovery of therapeutic miRNAs is one of the most exciting challenges for pharmaceutical companies. Since the first miRNA was discovered in 1993, our knowledge of miRNA biology has grown considerably. Many studies have demonstrated that miRNA expression is dysregulated in many diseases, making them appealing tools for novel therapeutic approaches. This review aims to discuss miRNA biogenesis and function, as well as highlight strategies for delivering miRNA agents, presenting viral, non-viral, and exosomic delivery as therapeutic approaches for different cancer types. We also consider the therapeutic role of microRNA-mediated drug repurposing in cancer therapy.

[DICER1 syndrome: clinical variety endocrine manifestations and features of diagnostics]

DICER1 syndrome is a rare genetic disorder with the progressive development of malignant and non-malignant diseases in childhood. The cause of this syndrome is a dusfunction of the endoribonuclease DICER, which plays an important role in the processing of microRNAs with subsequent regulation of the control of the expression of oncogenes and tumor suppressor genes. Clinical manifestations of dyseropathies is very different and may include both endocrine manifestations - multinodular goiter, differentiated thyroid cancers, ovarian stromal tumors, pituitary blastoma, and non-endocrine formations - pleuropulmonary blastoma, cystic nephroma, pineoblastoma. The presence of somatic mutations of the DICER1 gene is a resultant stage in the pathogenesis of dyseropathies, determining the further path of oncogenesis. At present, DICER1 syndrome is diagnosed extremely rarely, which leads to late detection of the components of the disease in the patient, late diagnosis of neoplasms, lack of family counseling. Diagnosis at the early stages of the disease, the development of screening programs for the management of these patients allows minimizing the risks of developing more malignant, aggressive forms of the disease.

microRNA-382 as a tumor suppressor? Roles in tumorigenesis and clinical significance

MicroRNAs (miRNAs) are small single-stranded RNAs belonging to a class of non-coding RNAs with an average length of 18-22 nucleotides. Although not able to encode any protein, miRNAs are vastly studied and found to play role in various human physiologic as well as pathological conditions. A huge number of miRNAs have been identified in human cells whose expression is straightly regulated with crucial biological functions, while this number is constantly increasing. miRNAs are particularly studied in cancers, where they either can act with oncogenic function (oncomiRs) or tumor-suppressors role (referred as tumor-suppressor/oncorepressor miRNAs). miR-382 is a well-studied miRNA, which is revealed to play regulatory roles in physiological processes like osteogenic differentiation, hematopoietic stem cell differentiation and normal hematopoiesis, and liver progenitor cell differentiation. Notably, miR-382 deregulation is reported in pathologic conditions, such as renal fibrosis, muscular dystrophies, Rett syndrome, epidural fibrosis, atrial fibrillation, amelogenesis imperfecta, oxidative stress, human immunodeficiency virus (HIV) replication, and various types of cancers. The majority of oncogenesis studies have claimed miR-382 downregulation in cancers and suppressor impact on malignant phenotype of cancer cells in vitro and in vivo, while a few studies suggest opposite findings. Given the putative role of this miRNA in regulation of oncogenesis, assessment of miR-382 expression is suggested in a several clinical investigations as a prognostic/diagnostic biomarker for cancer patients. In this review, we have an overview to recent studies evaluated the role of miR-382 in oncogenesis as well as its clinical potential.

The origin of brain malignancies at the blood-brain barrier

Despite improvements in extracranial therapy, survival rate for patients suffering from brain metastases remains very poor. This is coupled with the incidence of brain metastases continuing to rise. In this review, we focus on core contributions of the blood-brain barrier to the origin of brain metastases. We first provide an overview of the structure and function of the blood-brain barrier under physiological conditions. Next, we discuss the emerging idea of a pre-metastatic niche, namely that secreted factors and extracellular vesicles from a primary tumor site are able to travel through the circulation and prime the neurovasculature for metastatic invasion. We then consider the neurotropic mechanisms that circulating tumor cells possess or develop that facilitate disruption of the blood-brain barrier and survival in the brain's parenchyma. Finally, we compare and contrast brain metastases at the blood-brain barrier to the primary brain tumor, glioma, examining the process of vessel co-option that favors the survival and outgrowth of brain malignancies.

Validation of a microRNA liquid biopsy assay for diagnosis and risk stratification of invasive cutaneous melanoma

BACKGROUND

Noninvasive molecular biomarkers are needed to improve the early, accurate and precise diagnosis of invasive cutaneous melanoma.

OBJECTIVES

To independently validate a previously identified circulating microRNA signature of melanoma (MEL38), and, secondly, to develop a complementary microRNA signature, optimized for prognostication.

PATIENTS AND METHODS

MicroRNA expression profiling was performed on plasma samples from a multicentre observational case-control study, involving patients with primary or metastatic melanoma, melanoma in situ, nonmelanoma skin cancer, or benign naevi. MicroRNA profiles from patients with length of survival, treatment and sentinel lymph node biopsy (SLNB) data were used to develop the prognostic signature. The primary outcome of interest for MEL38 was its association with melanoma status, including area under the curve, binary diagnostic sensitivity and specificity, and incidence-adjusted positive and negative predictive values. The prognostic signature was assessed using rates of survival per risk group and relationship to conventional predictors of outcome.

RESULTS

Circulating microRNA profiles of 372 patients with invasive melanoma and 210 control individuals were generated. The average age of all participants was 59 years; 49% were male. A MEL38 score > 5.5 indicated the presence of invasive melanoma. Overall, 551/582 (95%) of patients were correctly diagnosed, with 93% sensitivity and 98% specificity. MEL38 score ranged from 0 to 10 with an area under the curve of 0.98 (95% confidence interval 0.97-0.99, P < 0.001). A novel prognostic 12-microRNA signature (MEL12) developed from 232 patients identified low-, standard- or high-risk groups, with 94%, 78% and 58% rates of 10-year melanoma-specific survival, respectively (log-rank P < 0.001). MEL12 prognostic risk groups were significantly associated with clinical staging (χ2, P < 0.001) and SLNB status (P = 0.027). Patients who were classified as high risk by MEL12 were approximately three times more likely to have melanoma detected in their sentinel lymph nodes compared to low-risk patients.

CONCLUSIONS

The circulating MEL38 signature may assist in diagnosing patients with invasive melanoma vs. other conditions associated with a lower - or negligible - risk of mortality. A complementary and prognostic MEL12 signature is predictive of SLNB status, clinical stage and probability of survival. Plasma microRNA profiling may help to optimize existing diagnostic pathways as well as enable personalized, risk-informed melanoma treatment decisions.

Let-7a/cMyc/CCAT1/miR-17-5p Circuit Re-sensitizes Atezolizumab Resistance in Triple Negative Breast Cancer through Modulating PD-L1

BACKGROUND

Triple negative breast cancer (TNBC) is an immunogenically hot tumor. The immune checkpoint blockades (ICBs) have been recently emerged as promising therapeutic candidates for several malignancies including TNBC. Yet, the development of innate and/or adaptive resistance by TNBC patients towards ICBs such as programmed death-ligand 1 (PD-L1) inhibitors (e.g. Atezolizumab) shed the light on importance of identifying the underlying mechanisms regulating PD-L1 in TNBC. Recently, it was reported that non-coding RNAs (ncRNAs) perform a fundamental role in regulating PD-L1 expression in TNBC. Hence, this study aims to explore a novel ncRNA axis tuning PD-L1 in TNBC patients and investigate its possible involvement in fighting Atezolizumab resistance.

METHODS

In-silico screening was executed to identify ncRNAs that could potentially target PD-L1. Screening of PD-L1 and the nominated ncRNAs (miR-17-5p, let-7a and CCAT1 lncRNA) was performed in BC patients and cell lines. Ectopic expression and/or knockdown of respective ncRNAs were performed in MDA-MB-231. Cellular viability, migration and clonogenic capacities were evaluated using MTT, scratch assay and colony-forming assay, respectively.

RESULTS

PD-L1 was upregulated in BC patients, especially in TNBC patients. PD-L1 is positively associated with lymph node metastasis and high Ki-67 in recruited BC patients. Let-7a and miR-17-5p were nominated as potential regulators of PD-L1. Ectopic expression of let-7a and miR-17-5p caused a noticeable reduction in PD-L1 levels in TNBC cells. In order to investigate the whole ceRNA circuit regulating PD-L1 in TNBC, intensive bioinformatic studies were performed. The lncRNA, Colon Cancer-associated transcript 1 (CCAT1), was reported to target PD-L1 regulating miRNAs. Results showed that CCAT1 is an upregulated oncogenic lncRNA in TNBC patients and cell lines. CCAT1 siRNAs induced a noticeable reduction in PD-L1 levels and a marked increase in miR-17-5p level, building up a novel regulatory axis CCAT1/miR-17-5p/PD-L1 in TNBC cells that was tuned by the let-7a/c-Myc engine. On the functional level, co-treatment of CCAT-1 siRNAs and let-7a mimics efficiently relieved Atezolizumab resistance in MDA-MB-231 cells.

CONCLUSION

The present study revealed a novel PD-L1 regulatory axis via targeting let-7a/c-Myc/CCAT/miR-17-5p. Additionally, it sheds the light on the potential combinational role of CCAT-1 siRNAs and Let-7a mimics in relieving Atezolizumab resistance in TNBC patients.

DICER1 Syndrome: A Multicenter Surgical Experience and Systematic Review

DICER1 syndrome is a rare genetic disorder that predisposes patients to the development of malignant and non-malignant diseases. Presently, DICER1 syndrome diagnosis still occurs late, usually following surgical operations, affecting patients' outcomes, especially for further neoplasms, which are entailed in this syndrome. For this reason, herein we present a multicenter report of DICER1 syndrome, with the prospective aim of enhancing post-surgical surveillance. A cohort of seven patients was collected among the surgical registries of Pediatric Surgery at the University of Pisa with the General and Oncologic Surgery of Federico II, University of Naples, and the Pediatric Surgery, Regina Margherita Hospital, University of Turin. In each case, the following data were analyzed: sex, age at diagnosis, age at first surgery, clinical features, familial, genetic investigations, and follow-up. A comprehensive literature review of DICER1 cases, including case reports and multicenter studies published from 1996 to June 2022, was performed. Eventually, the retrieved data from the literature were compared with the data emerging from our cohort of patients.

MicroRNAs as clinical tools for diagnosis, prognosis, and therapy in prostate cancer

Prostate cancer (PCa) is one of the most commonly diagnosed cancers among men worldwide. Despite the presence of accumulated clinical strategies for PCa management, limited prognostic/sensitive biomarkers are available to follow up on disease occurrence and progression. MicroRNAs (miRNAs) are small non-coding RNAs that control gene expression through post-transcriptional regulation of their complementary target messenger RNA (mRNA). MiRNAs modulate fundamental biological processes and play crucial roles in the pathology of various diseases, including PCa. Multiple evidence proved an aberrant miRNA expression profile in PCa, which is actively involved in the carcinogenic process. The robust and pleiotropic impact of miRNAs on PCa suggests them as potential candidates to help more understand the molecular landscape of the disease, which is likely to provide tools for early diagnosis and prognosis as well as additional therapeutic strategies to manage prostate tumors. Here, we emphasize the most consistently reported dysregulated miRNAs and highlight the contribution of their altered downstream targets with PCa hallmarks. Also, we report the potential effectiveness of using miRNAs as diagnostic/prognostic biomarkers in PCa and the high-throughput profiling technologies that are being used in their detection. Another key aspect to be discussed in this review is the promising implication of miRNAs molecules as therapeutic tools and targets for fighting PCa.

[Identification of key molecules in miRNA-mRNA regulatory network associated with high-grade serous ovarian cancer recurrence using bioinformatic analysis]

OBJECTIVE

To investigate the correlation of the potential functional microRNA (miRNA)-mRNA regulatory network with recurrence of high-grade serous ovarian carcinoma (HGSOC) and its biological significance.

METHODS

This study was performed based on the data of 354 patients with HGSOC from the Cancer Genome Atlas database. In these patients, HGSOC was divided into different subtypes based on the pathways identified by GO analysis, and the correlations of the subtypes with HGSOC recurrence and differentially expressed miRNAs and mRNAs were assessed. Two relapse-related datasets were identified using the Gene Set Enrichment (GSE) database, from which the differentially expressed miRNAs were identified by intersection with the TCGA data. The target genes of these miRNAs were predicted using miRWalk 2.0 database, and these common differentially expressed miRNAs and mRNAs were used to construct the key miRNA-mRNA network associated with HGSOC recurrence. The expression of miR-506-3p and SNAI2 in two ovarian cancer cell lines was detected using RT-qPCR and Western blotting, and their targeted binding was verified using a double luciferase assay. The effect of miR-506-3p expression modulation on ovarian cancer cell migration was detected using scratch assay and Transwell assay.

RESULTS

We screened 303 GO terms of HGSOC-related pathways and identified two HGSOC subtypes (C1 and C2). The subtype C1 was associated with a significantly higher recurrence rate than C2. The differentially expressed genes between C1 and C2 subtypes were mainly enriched in epithelial-mesenchymal transition (EMT). Five miRNAs were identified as potential regulators of EMT, and a total of 41 target genes were found to be involved in the differential expressions of EMT pathway between C1 and C2 subtypes. The key miRNA-mRNA network associated with HGSOC recurrence was constructed based on these 5 miRNAs and 41 mRNAs. MiR-506-3p was confirmed to bind to SNAI2, and up-regulation of miR-506-3p significantly inhibited SNAI2 expression and reduced migration and invasion of SKOV3 and CAOV3 cells (P < 0.05), while miR-506-3p knockdown produced the opposite effects (P < 0.05).

CONCLUSION

MiR-506-3p and SNAI2 are the key molecules associated with HGSOC recurrence. MiR-506-3p may affect EMT of ovarian cancer cells by regulating cell migration and invasion via SNAI2, and its expression level has predictive value for HGSOC recurrence.

Tumor-derived miRNAs as tumor microenvironment regulators for synergistic therapeutic options

MicroRNAs (miRNAs) are a class of non-coding RNAs that perform post-transcriptional gene regulation. This review focuses on the role of tumor cell-derived miRNAs in the regulation of the tumor microenvironment (TME) via receptor cell recoding, including angiogenesis, expression of immunosuppressive molecules, formation of radiation resistance, and chemoresistance. Furthermore, we discuss the potential of these molecules as adjuvant therapies in combination with chemotherapy, radiotherapy, or immunotherapy, as well as their advantages as efficacy predictors for personalized therapy. MiRNA-based therapeutic agents for tumors are currently in clinical trials, and while challenges remain, additional research on tumor-derived miRNAs is warranted, which may provide significant clinical benefits to cancer patients.

An Overview of Epigenetics in Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) represents a heterogenous group of cancers with complex genetic background and histological varieties, which require various clinical therapies. Clear cell RCC represents the most common form of RCC that accounts for 3 out of 4 RCC cases. Screening methods for RCC lack sensitivity and specificity, and thus biomarkers that will allow early diagnosis are crucial. The impact of epigenetics in the development and progression of cancer, including RCC, is significant. Noncoding RNAs, histone modifications and DNA methylation represent fundamental epigenetic mechanisms and have been proved to be promising biomarkers. MicroRNAs have advantageous properties that facilitate early diagnosis of RCC, while their expression profiles have been assessed in renal cancer samples (tissue, blood, and urine). Current literature reports the up-regulation of mir122, mir1271 and mir15b in RCC specimens, which induces cell proliferation via FOXP-1 and PTEN genes. However, it should be noted that conflicting results are found in urine and serum patient samples. Moreover, promoters of at least 200 genes are methylated in renal cancers leading to epigenetic dysregulation. In this review, we analyze the vast plethora of studies that have evaluated the role of epigenetic mechanisms in RCC patients and their clinical importance.

MicroRNA Expression Profile Separates Squamous Cell Carcinoma by Mode of Differentiation

BACKGROUND

Squamous cell carcinoma (SCC) is a non-melanoma skin cancer with several risk factors including age and sun exposure. The degree of histological differentiation is considered an independent predictor of recurrence, metastasis, and survival. MicroRNAs (miRNAs) are small non-coding RNAs that play an important role in regulating gene expression, culminating in the initiation and progression of multiple tumors. The aim of this study was to determine changes in miRNA expression as a result of the mode of differentiation in SCC.

METHODS

We analyzed 29 SCC samples that were separated by mode of differentiation into well (n=4), moderate (n=20) and poor (n=5). Of the 29 samples, five had matched normal tissues, which were used as controls. Total RNA was extracted using the RNeasy FFPE kit, and miRNAs were quantified using Qiagen MiRCURY LNA miRNA PCR Assays. Ten miRNAs (hsa-miR-21, hsa-miR-146b-3p, hsa-miR-155-5p, hsa-miR-451a, hsa-miR-196-5p, hsa-miR-221-5p, hsa-miR-375, hsa-miR-205-5p, hsa-let-7d-5p and hsa-miR-491-5p) that have been previously differentiated in cancer, were quantified. A fold regulation above 1 indicated upregulation and below 1, downregulation.

RESULTS

Hierarchical clustering showed that the miRNA expression profile in the moderately differentiated group was similar to the well-differentiated group. The miRNA with the greatest upregulation in the moderate group was hsa-miR-375, while in the well group, hsa-miR-491-5p showed the greatest downregulation.

CONCLUSION

In conclusion, this study observed that the well and moderate groups had similar microRNA expression patterns compared to the poorly differentiated group. MicroRNA expression profiling may be used to better understand the factors underpinning mode of differentiation in SCC.

Role of miRNA in Melanoma Development and Progression

Melanoma is one of the most aggressive and progressive skin cancers. It develops from normal pigment-producing cells known as melanocytes, so it is important to know the mechanism behind such transformations. The study of metastasis mechanisms is crucial for a better understanding the biology of neoplastic cells. Metastasis of melanoma, or any type of cancer, is a multi-stage process in which the neoplastic cells leave the primary tumour, travel through the blood and/or lymphatic vessels, settle in distant organs and create secondary tumours. MicroRNA (miRNA) can participate in several steps of the metastatic process. This review presents the role of miRNA molecules in the development and progression as well as the immune response to melanoma.

Non-coding RNAs and glioma: Focus on cancer stem cells

Glioblastoma and gliomas can have a wide range of histopathologic subtypes. These heterogeneous histologic phenotypes originate from tumor cells with the distinct functions of tumorigenesis and self-renewal, called glioma stem cells (GSCs). GSCs are characterized based on multi-layered epigenetic mechanisms, which control the expression of many genes. This epigenetic regulatory mechanism is often based on functional non-coding RNAs (ncRNAs). ncRNAs have become increasingly important in the pathogenesis of human cancer and work as oncogenes or tumor suppressors to regulate carcinogenesis and progression. These RNAs by being involved in chromatin remodeling and modification, transcriptional regulation, and alternative splicing of pre-mRNA, as well as mRNA stability and protein translation, play a key role in tumor development and progression. Numerous studies have been performed to try to understand the dysregulation pattern of these ncRNAs in tumors and cancer stem cells (CSCs), which show robust differentiation and self-regeneration capacity. This review provides recent findings on the role of ncRNAs in glioma development and progression, particularly their effects on CSCs, thus accelerating the clinical implementation of ncRNAs as promising tumor biomarkers and therapeutic targets.

The microRNA Lifecycle in Health and Cancer

MicroRNAs (miRNAs) are small non-coding RNAs of ~22 nucleotides that regulate gene expression at the post-transcriptional level. They can bind to around 60% of all protein-coding genes with an average of 200 targets per miRNA, indicating their important function within physiological and pathological cellular processes. miRNAs can be quickly produced in high amounts through canonical and non-canonical pathways that involve a multitude of steps and proteins. In cancer, miRNA biogenesis, availability and regulation of target expression can be altered to promote tumour progression. This can be due to genetic causes, such as single nucleotide polymorphisms, epigenetic changes, differences in host gene expression, or chromosomal remodelling. Alternatively, post-transcriptional changes in miRNA stability, and defective or absent components and mediators of the miRNA-induced silencing complex can lead to altered miRNA function. This review provides an overview of the current knowledge on the lifecycle of miRNAs in health and cancer. Understanding miRNA function and regulation is fundamental prior to potential future application of miRNAs as cancer biomarkers.

Deregulated miRNA clusters in ovarian cancer: Imperative implications in personalized medicine

Ovarian cancer (OC) is one of the most common and fatal types of gynecological cancer. OC is usually detected at the advanced stages of the disease, making it highly lethal. miRNAs are single-stranded, small non-coding RNAs with an approximate size ranging around 22 nt. Interestingly, a considerable proportion of miRNAs are organized in clusters with miRNA genes placed adjacent to one another, getting transcribed together to result in miRNA clusters (MCs). MCs comprise two or more miRNAs that follow the same orientation during transcription. Abnormal expression of the miRNA cluster has been identified as one of the key drivers in OC. MC exists both as tumor-suppressive and oncogenic clusters and has a significant role in OC pathogenesis by facilitating cancer cells to acquire various hallmarks. The present review summarizes the regulation and biological function of MCs in OC. The review also highlights the utility of abnormally expressed MCs in the clinical management of OC.

Garmultin-A Incites Apoptosis in CB3 Cells Through miR-17-5p by Attenuating Poly (ADP-Ribose) Polymerase-1

Background

Leukemia accounts for a large number of deaths, worldwide, every year. Treating this ailment is always a challenging job. Recently, oncogenic miRNA leading to apoptosis are highly promising targets of many natural products. In this study, Garmultin-A (GA), isolated from the bark of Garcinia multiflora, was elucidated for its anti-leukemic effect in CB3 cells.

Methods

The effect of the compound on CB3 cell viability was detected by MTT assay and apoptosis by FITC Annexin V/PI and Hochest 33258 staining. The western blot analysis assessed the BAX, BCL2, cMYC, pERK, and PARP-1 protein levels. Autodock analysis predicted the ligand–protein interactions. q-RT-PCR quantified the miR-17-5p expression. Luciferase assay confirmed the interaction between PARP-1 and miR-17-5p.

Results

We uncover that GA leads to apoptosis by inducing overexpression of miR-17-5p and significantly downregulate PARP-1 protein levels in CB3 cells. The overexpression of miR-17-5p promotes apoptosis, and the miR-17-5p antagomirs restore GA-triggered apoptosis. Notably, we disclose that PARP-1 is a direct target of miR-17-5p. Increased pro-apoptotic and reduced anti-apoptosis protein levels were also observed in GA-treated CB3 cells.

Conclusion

These results provide critical insights that GA could induce apoptosis in CB3 cells through targeting miR-17-5p by attenuating PARP-1. Thus, GA could act as a novel therapeutic agent for erythroleukemia.

The reversion of DNA methylation-induced miRNA silence via biomimetic nanoparticles-mediated gene delivery for efficient lung adenocarcinoma therapy

Background

Lung cancer is one of the fatal cancers worldwide, and over 60% of patients are lung adenocarcinoma (LUAD). Our clinical data demonstrated that DNA methylation of the promoter region of miR-126-3p was upregulated, which led to the decreased expression of miR-126-3p in 67 cases of lung cancer tissues, implying that miR-126-3p acted as a tumor suppressor. Transduction of miR-126-3p is a potential therapeutic strategy for treating LUAD, yet the physiological environment and properties of miRNA challenge current transduction approaches.

Methods

We evaluated the expression of miR-126-3p in 67 pairs of lung cancer tissues and the corresponding adjacent non-tumorous tissues by Reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The relationship between the overall survival of lung cancer patients and miR-126-3p was analyzed by the Cancer Genome Atlas cohort database (Oncolnc, http://www.oncolnc.org). We analyzed DNA methylation Methylation-specific PCR (MSP) analysis. To determine whether ADAM9 is the direct target of miR-126-3p, we performed the 3′-UTR luciferase reporter assay. The protein levels in the cells or tissues were evaluated with western blotting (WB) analysis. The biodistribution of nanoparticles were monitored by in vivo tracking system.

Results

We describe the development of novel stealth and matrix metalloproteinase 2 (MMP2)-activated biomimetic nanoparticles, which are constructed using MMP2-responsive peptides to bind the miR-126-3p (known as MAIN), and further camouflaged with red blood cell (RBC) membranes (hence named REMAIN). REMAIN was able to effectively transduce miRNA into lung cancer cells and release them via MMP2 responsiveness. Additionally, REMAIN possessed the advantages of the natural RBC membrane, including extended circulation time, lower toxicity, better biocompatibility, and immune escape. Moreover, in vitro and in vivo results demonstrated that REMAIN effectively induced apoptosis of lung cancer cells and inhibited LUAD development and progression by targeting ADAM9.

Conclusion

The novel style of stealth and MMP2-activated biomimetic nanoparticles show great potential in miRNA delivery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-022-01651-4.

OncomiRs as noncoding RNAs having functions in cancer: Their role in immune suppression and clinical implications

Currently, microRNAs have been established as central players in tumorigenesis, but above all, they have opened an important door for our understanding of immune and tumor cell communication. This dialog is largely due to onco-miR transfer from tumor cells to cells of the tumor microenvironment by exosome. This review outlines recent advances regarding the role of oncomiRs in enhancing cancer and how they modulate the cancer-related immune response in the tumor immune microenvironment.

MicroRNAs (miRNAs) are a type of noncoding RNA that are important posttranscriptional regulators of messenger RNA (mRNA) translation into proteins. By regulating gene expression, miRNAs enhance or inhibit cancer development and participate in several cancer biological processes, including proliferation, invasion metastasis, angiogenesis, chemoresistance and immune escape. Consistent with their widespread effects, miRNAs have been categorized as oncogenes (oncomiRs) or tumor suppressor (TS) miRNAs. MiRNAs that promote tumor growth, called oncomiRs, inhibit messenger RNAs of TS genes and are therefore overexpressed in cancer. In contrast, TS miRNAs inhibit oncogene messenger RNAs and are therefore underexpressed in cancer. Endogenous miRNAs regulate different cellular pathways in all cell types. Therefore, they are not only key modulators in cancer cells but also in the cells constituting their microenvironments. Recently, it was shown that miRNAs are also involved in intercellular communication. Indeed, miRNAs can be transferred from one cell type to another where they regulate targeted gene expression. The primary carriers for the transfer of miRNAs from one cell to another are exosomes. Exosomes are currently considered the primary carriers for communication between the tumor and its surrounding stromal cells to support cancer progression and drive immune suppression. Exosome and miRNAs are seen by many as a hope for developing a new class of targeted therapy. This review outlines recent advances in understanding the role of oncomiRs in enhancing cancer and how they promote its aggressive characteristics and deeply discusses the role of oncomiRs in suppressing the anticancer immune response in its microenvironment. Additionally, further understanding the mechanism of oncomiR-related immune suppression will facilitate the use of miRNAs as biomarkers for impaired antitumor immune function, making them ideal immunotherapy targets.

Association between microRNA 671 polymorphisms and the susceptibility to soft tissue sarcomas in a Chinese population

This study evaluated the association between the microRNA (miRNA) gene polymorphisms and the susceptibility to soft tissue sarcomas (STSs). In this case–control study, DNA was extracted from leukocytes in peripheral blood, which was collected from 169 STSs patients and 170 healthy controls. Three SNPs for miR-210, five SNPs for miR-206, two SNPs for miR-485, two SNPs for miR-34b, two SNPs for miR-671, and three SNPs for miR-381 were investigated and genotyped using a Sequenom Mass ARRAY matrix-assisted laser desorption/ionization-time of flight mass spectrometry platform. Unconditional logistic regression analysis was used to analyze the association between miRNA gene polymorphisms and the susceptibility to STSs. The results showed that miR-671 rs1870238 GC + CC (OR = 1.963, 95% CI = 1.258–3.064, P = 0.003) and miR-671 rs2446065 CG + GG (OR =1.838, 95% CI = 1.178–2.868, P = 0.007) may be genetic risk factors for STSs after adjustment for age and smoking. Therefore, this study suggests that individuals carrying the GC + CC genotype for miR-671 rs1870238 or the CG + GG genotype for miR-671 rs2446065 are susceptible to STSs.

MiRNAs in Lung Cancer: Diagnostic, Prognostic, and Therapeutic Potential

Lung cancer is the dominant emerging factor in cancer-related mortality around the globe. Therapeutic interventions for lung cancer are not up to par, mainly due to reoccurrence/relapse, chemoresistance, and late diagnosis. People are currently interested in miRNAs, which are small double-stranded (20–24 ribonucleotides) structures that regulate molecular targets (tumor suppressors, oncogenes) involved in tumorigeneses such as cell proliferation, apoptosis, metastasis, and angiogenesis via post-transcriptional regulation of mRNA. Many studies suggest the emerging role of miRNAs in lung cancer diagnostics, prognostics, and therapeutics. Therefore, it is necessary to intensely explore the miRNOME expression of lung tumors and the development of anti-cancer strategies. The current review focuses on the therapeutic, diagnostic, and prognostic potential of numerous miRNAs in lung cancer.

Beyond Proteolysis-Targeting Chimeric Molecules: Designing Heterobifunctional Molecules Based on Functional Effectors

In recent years, with the successful development of proteolysis-targeting chimeric molecules (PROTACs), the potential of heterobifunctional molecules to contribute to reenvisioning drug design, especially small-molecule drugs, has been increasingly recognized. Inspired by PROTACs, diverse heterobifunctional molecules have been reported to simultaneously bind two or more molecules and bring them into proximity to interaction, such as ribonuclease-recruiting, autophagy-recruiting, lysosome-recruiting, kinase-recruiting, phosphatase-recruiting, glycosyltransferase-recruiting, and acetyltransferase-recruiting chimeras. On the basis of the heterobifunctional principle, more opportunities for advancing drug design by linking potential effectors to a protein of interest (POI) have emerged. Herein, we introduce heterobifunctional molecules other than PROTACs, summarize the limitations of existing molecules, list the main challenges, and propose perspectives for future research directions, providing insight into alternative design strategies based on substrate-proximity-based targeting.

The New Face of a Well-Known Antibiotic: A Review of the Anticancer Activity of Enoxacin and Its Derivatives

Simple Summary

Enoxacin is a second-generation quinolone with promising anticancer activity. In contrast to other members of the quinolone group, it exhibits an extraordinary cytotoxic mechanism of action. Enoxacin enhances RNA interference and promotes microRNA processing, as well as the production of free radicals. Interestingly, apart from its proapoptotic, cell cycle arresting and cytostatic effects, enoxacin manifests a limitation of cancer invasiveness. The underlying mechanisms are the competitive inhibition of vacuolar H⁺-ATPase subunits and c-Jun N-terminal kinase signaling pathway suppression. The newly synthesized enoxacin derivatives have shown a magnified cytotoxic effect with an emphasis on prooxidative, proapoptotic and microRNA interference actions. The mentioned mechanisms seem to contribute to a safer, more selective and more effective anticancer therapy.

Abstract

Enoxacin as a second-generation synthetic quinolone is known for its antibacterial action; however, in recent years there have been studies focusing on its anticancer potential. Interestingly, it turns out that compared to other fluoroquinolones, enoxacin exhibits uncommon cytotoxic properties. Besides its influence on apoptosis, the cell cycle and cell growth, it exhibits a regulatory action on microRNA biogenesis. It was revealed that the molecular targets of the enoxacin-mediated inhibition of osteoclastogenesis are vacuolar H⁺-ATPase subunits and the c-Jun N-terminal kinase signaling pathway, causing a decrease in cell invasiveness. Interestingly, the prooxidative nature of the subjected fluoroquinolone enhanced the cytotoxic effect. Crucial for the anticancer activity were the carboxyl group at the third carbon atom, fluorine at the seventh carbon atom and nitrogen at the eighth position of naphyridine. Modifications of the parent drug improved the induction of oxidative stress, cell cycle arrest and the dysregulation of microRNA. The inhibition of V-ATPase–microfilament binding was also observed. Enoxacin strongly affected various cancer but not normal cells, excluding keratinocytes, which suffered from phototoxicity. It seems to be an underestimated anticancer drug with pleiotropic action. Furthermore, its usage as a safe antibiotic with well-known pharmacokinetics and selectivity will enhance the development of anticancer treatment strategies. This review covers articles published within the years 2000–2021, with a strong focus on the recent years (2016–2021). However, some canonical papers published in twentieth century are also mentioned.

PTEN in cancer associated fibroblasts

Decades of research have concluded that disruptions to Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) have profound effects on cancer progression. However, as our understanding of the tumor stroma has evolved, we can appreciate that disruptions to tumor suppressors such as PTEN should not be studied solely in an epithelial context. Inactivation of PTEN in the stroma is associated with worse outcomes in human cancers, therefore, it is important to understand activities regulated downstream of PTEN in stromal compartments. Studies reviewed herein provide evidence for important mechanistic targets downstream of PTEN signaling in cancer-associated fibroblasts (CAFs), a major component of the tumor stroma. We also discuss the potential clinical implications for these findings.

pH-Responsive Polymer Nanomaterials for Tumor Therapy

The complexity of the tumor microenvironment presents significant challenges to cancer therapy, while providing opportunities for targeted drug delivery. Using characteristic signals of the tumor microenvironment, various stimuli-responsive drug delivery systems can be constructed for targeted drug delivery to tumor sites. Among these, the pH is frequently utilized, owing to the pH of the tumor microenvironment being lower than that of blood and healthy tissues. pH-responsive polymer carriers can improve the efficiency of drug delivery in vivo, allow targeted drug delivery, and reduce adverse drug reactions, enabling multifunctional and personalized treatment. pH-responsive polymers have gained increasing interest due to their advantageous properties and potential for applicability in tumor therapy. In this review, recent advances in, and common applications of, pH-responsive polymer nanomaterials for drug delivery in cancer therapy are summarized, with a focus on the different types of pH-responsive polymers. Moreover, the challenges and future applications in this field are prospected.

Computing microRNA-gene interaction networks in pan-cancer using miRDriver

DNA copy number aberrated regions in cancer are known to harbor cancer driver genes and the short non-coding RNA molecules, i.e., microRNAs. In this study, we integrated the multi-omics datasets such as copy number aberration, DNA methylation, gene and microRNA expression to identify the signature microRNA-gene associations from frequently aberrated DNA regions across pan-cancer utilizing a LASSO-based regression approach. We studied 7294 patient samples associated with eighteen different cancer types from The Cancer Genome Atlas (TCGA) database and identified several cancer-specific and common microRNA-gene interactions enriched in experimentally validated microRNA-target interactions. We highlighted several oncogenic and tumor suppressor microRNAs that were cancer-specific and common in several cancer types. Our method substantially outperformed the five state-of-art methods in selecting significantly known microRNA-gene interactions in multiple cancer types. Several microRNAs and genes were found to be associated with tumor survival and progression. Selected target genes were found to be significantly enriched in cancer-related pathways, cancer hallmark and Gene Ontology (GO) terms. Furthermore, subtype-specific potential gene signatures were discovered in multiple cancer types.

Towards an integrative understanding of cancer mechanobiology: calcium, YAP, and microRNA under biophysical forces

An increasing number of studies have demonstrated the significant roles of the interplay between microenvironmental mechanics in tissues and biochemical-genetic activities in resident tumor cells at different stages of tumor progression. Mediated by molecular mechano-sensors or -transducers, biomechanical cues in tissue microenvironments are transmitted into the tumor cells and regulate biochemical responses and gene expression through mechanotransduction processes. However, the molecular interplay between the mechanotransduction processes and intracellular biochemical signaling pathways remains elusive. This paper reviews the recent advances in understanding the crosstalk between biomechanical cues and three critical biochemical effectors during tumor progression: calcium ions (Ca²⁺), yes-associated protein (YAP), and microRNAs (miRNAs). We address the molecular mechanisms underpinning the interplay between the mechanotransduction pathways and each of the three effectors. Furthermore, we discuss the functional interactions among the three effectors in the context of soft matter and mechanobiology. We conclude by proposing future directions on studying the tumor mechanobiology that can employ Ca²⁺, YAP, and miRNAs as novel strategies for cancer mechanotheraputics. This framework has the potential to bring insights into the development of novel next-generation cancer therapies to suppress and treat tumors.

Exploring the Mechanism of Baicalin Intervention in Breast Cancer Based on MicroRNA Microarrays and Bioinformatics Strategies

Objective

To explore the mechanism of baicalin intervention in breast cancer based on microRNA microarrays.

Methods

The inhibitory rate of baicalin intervention in MCF-7 breast cancer cells was determined by MTT. Then, the miRNA microarrays were used to validate the key microRNAs. After that, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to validate microRNA, hsa-miR-15a, hsa-miR-100, hsa-miR-16, and hsa-miR-7t. Finally, the potential targets of these key microRNAs are predicted by miRWalk, and DAVID was utilized for gene ontology (GO) enrichment analysis and pathway enrichment analysis.

Results

Baicalin may inhibit the proliferation of MCF-7 cells in a dose-dependent and time-dependent manner. The concentration of baicalin 150 μmol/L was determined for the subsequent miRNA chip research. A total of 92 upregulated microRNAs and 35 downregulated microRNAs were obtained. The upregulated miRNAs include hsa-miR-6799-5p, hsa-miR-6126, hsa-miR-4792, hsa-miR-6848-5p, hsa-miR-3197, hsa-miR-6779-5p, and hsa-miR -654-5p. The downregulated miRNAs include hsa-miR-3911, hsa-miR-504-5p, hsa-miR-30a-3p, hsa-miR-193b-3p, and hsa-miR-181b-5p. Then, differentially expressed miRNA was verified by qRT-PCR. The results showed that the expression of hsa-miR-15a, hsa-miR-100, hsa-miR-16, and hsa-let-7c was upregulated (P < 0.05), which was consistent with the results of the miRNA microarray. The enrichment analysis showed that baicalin might regulate the DNA-templated proliferation, DNA-templated transcription, p53 signaling pathway, etc., of MCF-7 breast cancer cells through miRNA.

Conclusion

Baicalin inhibits the proliferation of breast cancer cells. It may achieve antitumor effects through regulating microRNAs so as to affect the DNA replication (such as cellular response to DNA damage stimulus and DNA binding), RNA transcription (such as regulation of transcription, DNA-templated, transcription from RNA polymerase II promoter, and transcription factor binding), protein synthesis (such as mRNA binding, Golgi apparatus, and protein complex), endocytosis, pathways in cancer, p53 signaling pathway, and so on.

Role of MicroRNAs in the Development and Progression of the Four Medulloblastoma Subgroups

Medulloblastoma is the most frequent malignant brain tumour in children. Medulloblastoma originate during the embryonic stage. They are located in the cerebellum, which is the area of the central nervous system (CNS) responsible for controlling equilibrium and coordination of movements. In 2012, medulloblastoma were divided into four subgroups based on a genome-wide analysis of RNA expression. These subgroups are named Wingless, Sonic Hedgehog, Group 3 and Group 4. Each subgroup has a different cell of origin, prognosis, and response to therapies. Wingless and Sonic Hedgehog medulloblastoma are so named based on the main mutation originating these tumours. Group 3 and Group 4 have generic names because we do not know the key mutation driving these tumours. Gene expression at the post-transcriptional level is regulated by a group of small single-stranded non-coding RNAs. These microRNA (miRNAs or miRs) play a central role in several cellular functions such as cell differentiation and, therefore, any malfunction in this regulatory system leads to a variety of disorders such as cancer. The role of miRNAs in medulloblastoma is still a topic of intense clinical research; previous studies have mostly concentrated on the clinical entity of the single disease rather than in the four molecular subgroups. In this review, we summarize the latest discoveries on miRNAs in the four medulloblastoma subgroups.