Circular RNAs: A novel type of non-coding RNA and their potential implications in antiviral immunity

Emerging roles of noncoding RNAs in cardiovascular pathophysiology

This review comprehensively examines the diverse roles of noncoding RNAs (ncRNAs) in the pathogenesis and treatment of cardiovascular disease (CVD), focusing on microRNA (miRNA), long noncoding RNA (lncRNA), piwi-interacting RNA (piRNA), small-interfering RNA (siRNA), circular RNA (circRNA), and vesicle-associated RNAs. These ncRNAs are integral regulators of key cellular processes, including gene expression, inflammation, and fibrosis, and they hold great potential as both diagnostic biomarkers and therapeutic targets. The review highlights novel insights into how these RNA species, particularly miRNAs, lncRNAs, and piRNAs, contribute to various CVDs such as hypertension, atherosclerosis, and myocardial infarction. In addition, it explores the emerging role of extracellular vesicles (EVs) in intercellular communication and their therapeutic potential in cardiovascular health. The review underscores the need for continued research into ncRNAs and RNA-based therapies, with a focus on advancing delivery systems and expanding personalized medicine approaches to improve cardiovascular outcomes.

Molecular mechanism of genetic, epigenetic, and metabolic alteration in lung cancer

Lung cancer, a leading cause of cancer-related deaths worldwide, is primarily linked to smoking, tobacco use, air pollution, and exposure to hazardous chemicals. Genetic alterations, particularly in oncogenes like RAS, EGFR, MYC, BRAF, HER, and P13K, can lead to metabolic changes in cancer cells. These cells often rely on glycolysis for energy production, even in the presence of oxygen, a phenomenon known as aerobic glycolysis. This metabolic shift, along with other alterations, contributes to cancer cell growth and survival. To develop effective therapies, it's crucial to understand the genetic and metabolic changes that drive lung cancer. This review aims to identify specific genes associated with these metabolic alterations and screen phytochemicals for their potential to target these genes. By targeting both genetic and metabolic pathways, we hope to develop innovative therapeutic approaches to combat lung cancer.

Personalized medicine in colorectal cancer: a comprehensive study of precision diagnosis and treatment

Colorectal cancer is a common and fatal disease that affects many people globally. CRC is classified as the third most prevalent cancer among males and the second most frequent cancer among females worldwide. The purpose of this article is to examine how personalized medicine might be used to treat colorectal cancer. The classification of colorectal cancer based on molecular profiling, including the detection of significant gene mutations, genomic instability, and gene dysregulation, is the main topic of this discussion. Advanced technologies and biomarkers are among the detection methods that are explored, demonstrating their potential for early diagnosis and precise prognosis. In addition, the essay explores the world of treatment possibilities by providing light on FDA-approved personalized medicine solutions that provide individualized and precise interventions based on patient characteristics. This article assesses targeted treatments like cetuximab and nivolumab, looks at the therapeutic usefulness of biomarkers like microsatellite instability (MSI) and circulating tumor DNA (ctDNA), and investigates new approaches to combat resistance. Through this, our review provides a thorough overview of personalized medicine in the context of colorectal cancer, ultimately highlighting its potential to revolutionize the field and improve patient care.

Comprehensive insights into circular RNAs, miRNAs, and lncRNAs as biomarkers in retinoblastoma

Retinoblastoma (RB) is a common and potentially lethal cancer that primarily affects young children worldwide, with survival rates significantly varying between high- and low-income countries. This review aims to identify essential diagnostic markers for early diagnosis by investigating the molecular pathways associated with RB. The prevalence of RB cases is notably concentrated in Asia and Africa, contributing to a global survival rate estimate of less than 30%. Current management strategies involve complex, individualized treatment plans that consider cultural nuances, genetic abnormalities, staging, and the availability of medical resources. Recent studies suggest that circular RNAs (circRNAs) may serve as predictive and diagnostic biomarkers in the etiology of RB. This review examines the roles of long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circRNAs in RB, with the goal of improving survival rates, particularly in low- and middle-income countries. A deeper understanding of the molecular pathways of RB may facilitate the development of personalized treatment plans and targeted therapies. Elevated expression of circRNAs has been observed in most patient cases, and studies indicate that reducing specific circRNA production can inhibit tumor cell development and progression. Investigating the roles and mechanisms of circular RNAs in RB holds promise for future treatment approaches.

CircZmMED16 delays plant flowering by negatively regulating starch content through its binding to ZmAPS1

Circular RNAs (circRNAs), a type of head-to-tail closed RNA molecules, have been implicated in various aspects of plant development and stress responses through transcriptome sequencing; however, the precise functional roles of circRNAs in plants remain poorly understood. In this study, we identified a highly expressed circular RNA, circZmMED16, derived from exon 8 of the mediator complex subunit 16 (ZmMED16) across different maize (Zea mays L.) inbred lines using circRNA-seq analysis. This circRNA is predominantly expressed in maize tassels and functions in the cytoplasm. Overexpression of circZmMED16 resulted in increased expression of ZmMED16/AtMED16 and delayed flowering in both maize and Arabidopsis thaliana, compared with that in wild-type plants. In contrast, overexpression of the parent gene ZmMED16 did not alter the flowering time of transgenic plants in Arabidopsis, suggesting that circZmMED16 plays a specific role in regulating flowering, distinct from that of linear ZmMED16. To further understand the mechanisms underlying the regulation of flowering time by circZmMED16, we performed RNA pull-down, dual-luciferase, RNA interference (RNAi), and ribonuclease protection assays (RPA). These results indicate that circZmMED16 interacts with small subunit 1 of ADP-glucose pyrophosphorylase (APS1) mRNA in both maize and Arabidopsis. The knockdown of circZmMED16 increased the expression of ZmAPS1, whereas the overexpression of circZmMED16 led to the downregulation of ZmAPS1 RNA and protein. By affecting ZmAPS1 expression, circZmMED16 reduced ADP-glucose pyrophosphorylase (AGPase) activity and led to delayed flowering. These results revealed a novel regulatory mechanism for circRNAs in flowering time and shed light on their functional and regulatory roles in plants.

Circular RNAs in glioblastoma

Glioblastoma multiforme (GBM) is the most malignant and common form of brain cancer in adults. The molecular mechanisms underlying GBM progression and resistance are complex and poorly understood. Circular RNAs (circRNAs) are a new class of non-coding RNAsformed by covalently closed loopstructures with no free ends. Their circular structure makes them more stable than linear RNA and resistant to exonuclease degradation. In recent years, they have received significant attention due to their diverse functions in gene regulation and their association with various diseases, including cancer. Therefore, understanding the functions and applications of circRNAs is critical to developing targeted therapeutic interventions and advancing the field of glioblastoma cancer research. In this review, we summarized the main functions of circRNAs and their potential applications in the diagnosis, prognosis and targeted therapy of GBM.

Exosomal noncoding RNA (ncRNA) in breast cancer pathogenesis and therapy; two sides of the same coin

Over the past few years, breast cancer has become the most prevalent type of cancer globally, with the primary cause of death from the disease being metastatic cancer. This has led to the development of early detection techniques, mainly using non-invasive biomarkers in a range of body fluids. Exosomes are unique extracellular vesicles (EVs) transmitting cellular signals over great distances via various cargo. They are readily apparent in physiological fluids due to release by breast cancer cells or breast cancer-tumor microenvironment (TME) cells. In light of this, numerous biological and functional facets of human tumours, such as breast cancer, are intimately associated with exosomal noncoding RNAs (ncRNAs), containing miRNAs (microRNAs), lncRNAs (long noncoding RNAs), and circRNAs (circular RNAs). Exosomal ncRNAs serve a critical role in various steps of breast cancer development, enabling the exchange of genetic information between cancer cells and other cells (e.g., immune cells), thus regulating tumour angiogenesis, growth, metastasis, immune responses and drug resistance. They interact with multiple regulatory complexes with dissimilar enzymatic actions, which, in turn, modify the chromatin sceneries, including nucleosome modifications, DNA methylation, and histone modifications. Herein, we look into the exosomes' underlying regulatory mechanisms in breast cancer. Furthermore, we inspect the existing understanding of the functions of exosomal miRNAs, lncRNAs, and circRNAs in breast cancer to authenticate their possible significance in identifying biomarkers, deciphering their role in immune escape and drug resistance, and finally, analyzing treatment practices.

Liquid biopsy in cancer current: status, challenges and future prospects

Cancer has a high mortality rate across the globe, and tissue biopsy remains the gold standard for tumor diagnosis due to its high level of laboratory standardization, good consistency of results, relatively stable samples, and high accuracy of results. However, there are still many limitations and drawbacks in the application of tissue biopsy in tumor. The emergence of liquid biopsy provides new ideas for early diagnosis and prognosis of tumor. Compared with tissue biopsy, liquid biopsy has many advantages in the diagnosis and treatment of various types of cancer, including non-invasive, quickly and so on. Currently, the application of liquid biopsy in tumor detection has received widely attention. It is now undergoing rapid progress, and it holds significant potential for future applications. Around now, liquid biopsies encompass several components such as circulating tumor cells, circulating tumor DNA, exosomes, microRNA, circulating RNA, tumor platelets, and tumor endothelial cells. In addition, advances in the identification of liquid biopsy indicators have significantly enhanced the possibility of utilizing liquid biopsies in clinical settings. In this review, we will discuss the application, advantages and challenges of liquid biopsy in some common tumors from the perspective of diverse systems of tumors, and look forward to its future development prospects in the field of cancer diagnosis and treatment.

The implications for urological malignancies of non-coding RNAs in the the tumor microenvironment

Urological malignancies are a major global health issue because of their complexity and the wide range of ways they affect patients. There's a growing need for in-depth research into these cancers, especially at the molecular level. Recent studies have highlighted the importance of non-coding RNAs (ncRNAs) – these don't code for proteins but are crucial in controlling genes – and the tumor microenvironment (TME), which is no longer seen as just a background factor but as an active player in cancer progression. Understanding how ncRNAs and the TME interact is key for finding new ways to diagnose and predict outcomes in urological cancers, and for developing new treatments. This article reviews the basic features of ncRNAs and goes into detail about their various roles in the TME, focusing specifically on how different ncRNAs function and act in urological malignancies.

The landscape of circRNAs in gliomas temozolomide resistance: Insights into molecular pathways

As the deadliest type of primary brain tumor, gliomas represent a significant worldwide health concern. Circular RNA (circRNA), a unique non-coding RNA molecule, seems to be one of the most alluring target molecules involved in the pathophysiology of many kinds of cancers. CircRNAs have been identified as prospective targets and biomarkers for the diagnosis and treatment of numerous disorders, particularly malignancies. Recent research has established a clinical link between temozolomide (TMZ) resistance and certain circRNA dysregulations in glioma tumors. CircRNAs may play a therapeutic role in controlling or overcoming TMZ resistance in gliomas and may provide guidance for a novel kind of individualized glioma therapy. To address the biological characteristics of circRNAs and their potential to induce resistance to TMZ, this review has highlighted and summarized the possible roles that circRNAs may play in molecular pathways of drug resistance, including the Ras/Raf/ERK PI3K/Akt signaling pathway and metabolic processes in gliomas.

Circ_0015382 Regulates the miR-942-5p/NDRG1 Axis to Suppress Trophoblast Cell Functions

Circular RNAs (circRNAs) are non-coding RNAs that exert vital function in many human diseases, including preeclampsia (PE). Circ_0015382 is considered to be a key regulator of PE progression, so more molecular mechanisms need to be further studied. Real-time quantitative PCR was used to detect the mRNA levels of circ_0015382, miR-942-5p, and N-myc downstream regulated 1 (NDRG1). Western blot analysis was conducted to assess the protein levels. MTT and EdU assays were used to assess cell proliferation. Cell invasion was analyzed by transwell assay. Tube formation assay was conducted to detect cell angiogenesis. Dual-luciferase reporter assay and RNA immunoprecipitation were used to analyze the target relationship between miR-942-5p and circ_0015382 or NDRG1. Our data showed that circ_0015382 and NDRG1 were up-regulated, while miR-942-5p was down-regulated in the placental tissues of PE patients. Trophoblast cell proliferation, invasion, and angiogenesis were promoted by knockdown of circ_0015382. Circ_0015382 could sponge miR-942-5p, and NDRG1 was a target of miR-942-5p. MiR-942-5p inhibitor could reverse the promoting effects of si-circ_0015382 on trophoblast cell functions. Besides, the enhancing effects of miR-942-5p mimic on trophoblast cell proliferation, invasion, and angiogenesis could be eliminated by NDRG1 overexpression. In conclusion, our data showed that circ_0015382 inhibited trophoblast cell proliferation, invasion, and angiogenesis through regulating miR-942-5p/NDRG1 axis, providing a new mechanism for the regulation of PE progression.

Systematic identification and analysis of immune-related circRNAs of Pelteobagrus fulvidraco involved in Aeromonas veronii infection

Circular RNA (circRNA) represents a type of newly discovered non-coding RNA, distinguished by its closed loop structure formed through covalent bonds. Recent studies have revealed that circRNAs have crucial influences on host anti-pathogen responses. Yellow catfish (Pelteobagrus fulvidraco), an important aquaculture fish with great economic value, is susceptible to Aeromonas veronii, a common aquatic pathogen that can cause acute death. Here, we reported the first systematic investigation of circRNAs in yellow catfish, especially those associated with A. veronii infection at different time points. A total of 1205 circRNAs were identified, which were generated from 875 parental genes. After infection, 47 circRNAs exhibited differential expression patterns (named DEcirs). The parental genes of these DEcirs were functionally engaged in immune-related processes. Accordingly, seven DEcirs (novel_circ_000226, 278, 401, 522, 736, 843, and 975) and six corresponding parental genes (ADAMTS13, HAMP1, ANG3, APOA1, FGB, and RALGPS1) associated with immunity were obtained, and their expression was confirmed by RT-qPCR. Moreover, we found that these DEcir-gene pairs likely acted through pathways, such as platelet activation, antimicrobial humoral response, and regulation of Ral protein signal transduction, to influence host immune defenses. Additionally, integrated analysis showed that, of the 7 immune-related DEcirs, three targeted 16 miRNAs, which intertwined into circRNA-miRNA networks. These findings revealed that circRNAs, by targeting genes or miRNAs are highly involved in anti-bacterial responses in yellow catfish. Our study comprehensively illustrates the roles of circRNAs in yellow catfish immune defenses. The identified DEcirs and the circRNA-miRNA network will contribute to the further investigations on the molecular mechanisms underlying yellow catfish immune responses.

Circular RNAs in human diseases

Circular RNAs (circRNAs) are a unique class of RNA molecules formed through back-splicing rather than linear splicing. As an emerging field in molecular biology, circRNAs have garnered significant attention due to their distinct structure and potential functional implications. A comprehensive understanding of circRNAs' functions and potential clinical applications remains elusive despite accumulating evidence of their involvement in disease pathogenesis. Recent research highlights their significant roles in various human diseases, but comprehensive reviews on their functions and applications remain scarce. This review provides an in-depth examination of circRNAs, focusing first on their involvement in non-neoplastic diseases such as respiratory, endocrine, metabolic, musculoskeletal, cardiovascular, and renal disorders. We then explore their roles in tumors, with particular emphasis on exosomal circular RNAs, which are crucial for cancer initiation, progression, and resistance to treatment. By detailing their biogenesis, functions, and impact on disease mechanisms, this review underscores the potential of circRNAs as diagnostic biomarkers and therapeutic targets. The review not only enhances our understanding of circRNAs' roles in specific diseases and tumor types but also highlights their potential as novel diagnostic and therapeutic tools, thereby paving the way for future clinical investigations and potential therapeutic interventions.

Emerging Roles of Circular RNA in Macrophage Activation and Inflammatory Lung Responses

Circular RNA (circRNA) is a type of single-stranded RNA that forms a covalently closed continuous loop, unlike linear RNA. The expression of circRNAs in mammals is often conserved across species and shows tissue and cell specificity. Some circRNA serve as gene regulators. However, the biological function of most circRNAs is unclear. CircRNA does not have 5' or 3' ends. The unique structure of circRNAs provides them with a much longer half-life and more resistance to RNase R than linear RNAs. Inflammatory lung responses occur in the pathogenesis and recovery of many lung diseases. Macrophages form the first line of host defense/innate immune responses and initiate/mediate lung inflammation. For example, in bacterial pneumonia, upon pro-inflammatory activation, they release early response cytokines/chemokines that recruit neutrophils, macrophages, and lymphocytes to sites of infection and clear pathogens. The functional effects and mechanisms by which circRNAs exert physiological or pathological roles in macrophage activation and lung inflammation remain poorly understood. In this article, we will review the current understanding and progress of circRNA biogenesis, regulation, secretion, and degradation. Furthermore, we will review the current reports on the role of circRNAs in macrophage activation and polarization, as well as in the process of inflammatory lung responses.

Functional analysis of circSNYJ1/miR-142-5p/CCND1 regulatory axis in non-small cell lung cancer

Non-small cell lung cancer (NSCLC), the most prevalent form of lung cancer, accounts for approximately 85% of all lung cancer diagnoses. Circular RNAs (circRNAs) are non-coding RNAs that play an active role in gene expression regulation, influencing cell growth, migration, and apoptosis. Here, we aimed to investigate the function of circSNYJ1 in NSCLC. In the present study, we found that circSNYJ1 expression level was increased in NSCLC tissues and cell lines. Knockdown of circSNYJ1 suppressed NSCLC cell proliferation, colony formation and migration while promoting apoptosis. Mechanistically, we demonstrated that circSNYJ1 sponged miR-142-5p, thereby regulating the expression of CCND1, a well-known cell cycle regulator. In conclusion, this study uncovered a novel circSNYJ1/miR-142-5p/CCND1 axis involved in NSCLC progression, providing potential diagnostic and prognostic biomarkers for treating NSCLC.

Unveiling Novel Drug Targets and Emerging Therapies for Rheumatoid Arthritis: A Comprehensive Review

Rheumatoid arthritis (RA) is a chronic debilitating autoimmune disease, that causes joint damage, deformities, and decreased functionality. In addition, RA can also impact organs like the skin, lungs, eyes, and blood vessels. This autoimmune condition arises when the immune system erroneously targets the joint synovial membrane, resulting in synovitis, pannus formation, and cartilage damage. RA treatment is often holistic, integrating medication, physical therapy, and lifestyle modifications. Its main objective is to achieve remission or low disease activity by utilizing a "treat-to-target" approach that optimizes drug usage and dose adjustments based on clinical response and disease activity markers. The primary RA treatment uses disease-modifying antirheumatic drugs (DMARDs) that help to interrupt the inflammatory process. When there is an inadequate response, a combination of biologicals and DMARDs is recommended. Biological therapies target inflammatory pathways and have shown promising results in managing RA symptoms. Close monitoring for adverse effects and disease progression is critical to ensure optimal treatment outcomes. A deeper understanding of the pathways and mechanisms will allow new treatment strategies that minimize adverse effects and maintain quality of life. This review discusses the potential targets that can be used for designing and implementing precision medicine in RA treatment, spotlighting the latest breakthroughs in biologics, JAK inhibitors, IL-6 receptor antagonists, TNF blockers, and disease-modifying noncoding RNAs.

Non-Coding RNA as Biomarkers and Their Role in the Pathogenesis of Gastric Cancer-A Narrative Review

Non-coding RNAs (ncRNAs) represent a broad family of molecules that regulate gene expression, including microRNAs, long non-coding RNAs and circular RNAs, amongst others. Dysregulated expression of ncRNAs alters gene expression, which is implicated in the pathogenesis of several malignancies and inflammatory diseases. Gastric cancer is the fifth most frequently diagnosed cancer and the fourth most common cause of cancer-related death. Studies have found that altered expression of ncRNAs may contribute to tumourigenesis through regulating proliferation, apoptosis, drug resistance and metastasis. This review describes the potential use of ncRNAs as diagnostic and prognostic biomarkers. Moreover, we discuss the involvement of ncRNAs in the pathogenesis of gastric cancer, including their interactions with the members of major signalling pathways.

Circular RNAs and the regulation of gene expression in diabetic nephropathy (Review)

Circular RNAs (circRNAs) are non‑coding single‑stranded covalently closed RNA molecules that are considered important as regulators of gene expression at the transcriptional and post‑transcriptional levels. These molecules have been implicated in the initiation and progression of multiple human diseases, ranging from cancer to inflammatory and metabolic diseases, including diabetes mellitus and its vascular complications. The present article aimed to review the current knowledge on the biogenesis and functions of circRNAs, as well as their role in cell processes associated with diabetic nephropathy. In addition, novel potential interactions between circRNAs expressed in renal cells exposed to high‑glucose concentrations and the transcription factors c‑Jun and c‑Fos are reported.

Ferroptosis and circular RNAs: new horizons in cancer therapy

Cancer poses intricate challenges to treatment due to its complexity and diversity. Ferroptosis and circular RNAs (circRNAs) are emerging as innovative therapeutic avenues amid the evolving landscape of cancer therapy. Extensive investigations into circRNAs reveal their diverse roles, ranging from molecular regulators to pivotal influencers of ferroptosis in cancer cell lines. The results underscore the significance of circRNAs in modulating molecular pathways that impact crucial aspects of cancer development, including cell survival, proliferation, and metastasis. A detailed analysis delineates these pathways, shedding light on the molecular mechanisms through which circRNAs influence ferroptosis. Building upon recent experimental findings, the study evaluates the therapeutic potential of targeting circRNAs to induce ferroptosis. By identifying specific circRNAs associated with the etiology of cancer, this analysis paves the way for the development of targeted therapeutics that exploit vulnerabilities in cancer cells. This review consolidates the existing understanding of ferroptosis and circRNAs, emphasizing their role in cancer therapy and providing impetus for ongoing research in this dynamic field. See also the graphical abstract(Fig. 1).

CircTAOK1 regulates high glucose induced inflammation, oxidative stress, ECM accumulation, and apoptosis in diabetic nephropathy via targeting miR-142-3p/SOX6 axis

BACKGROUND

Diabetic nephropathy (DN) is a complication caused by diabetes. Circular RNAs (circRNAs) are a kind of RNA with a closed circular structure, which has high stability and is involved in many disease-related processes. The mechanism of circRNA TAO kinase 1 (circTAOK1) in the pathogenesis and development of DN is unclear.

METHODS

CircTAOK1, microRNA (miR)-142-3p, and sex-determining region Y-box transcription factor 6 (SOX6) mRNA levels were analyzed by real-time quantitative polymerase chain reaction (RT-qPCR). Cell counting kit-8 (CCK8) and 5-ethynyl-2'-deoxyuridine (EdU) assays were used to analyze cell proliferation. Cell cycle distribution was detected by flow cytometry. Western blot assay was performed to test B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X (Bax), cleaved-caspase 3, and fibronectin (FN), collagen I (Col I), and collagen IV (Col IV) protein levels. ELISA assay was used to measure interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor (TNF-α) levels. The reactive oxygen species (ROS) and malondialdehyde (MDA) levels and the superoxide dismutase (SOD) activity were assessed by the corresponding kits. And the correlation between miR-142-3p and circTAOK1 or SOX6 was confirmed by dual luciferase reporter assay, RNA immunoprecipitation assay and RNA pull down assay.

RESULTS

CircTAOK1 and SOX6 expression levels were up-regulated, while miR-142-3p expression was down-regulated in DN serum and HG-treated HK-2 cells. Knockdown of circTAOK1 could inhibit cell injury of HG-induced HK-2 cells. The inhibitory effect of circTAOK1 knockdown on HG-induced HK-2 cell injury was restored by miR-142-3p downregulation. CircTAOK1 acted as a sponge for miR-142-3p, and SOX6 was targeted by miR-142-3p. The overexpression of SOX6 could recover the effect of miR-142-3p overexpression on HG-induced HK-2 cell injury. CircTAOK1 regulated the expression of SOX6 by targeting miR-142-3p.

CONCLUSION

CircTAOK1 knockdown inhibited HG-induced HK-2 cell damage in DN by the miR-142-3p/SOX6 axis.

Exploring ncRNA-mediated pathways in sepsis-induced pyroptosis

Sepsis, a potentially fatal illness caused by an improper host response to infection, remains a serious problem in the world of healthcare. In recent years, the role of ncRNA has emerged as a pivotal aspect in the intricate landscape of cellular regulation. The exploration of ncRNA-mediated regulatory networks reveals their profound influence on key molecular pathways orchestrating pyroptotic responses during septic conditions. Through a comprehensive analysis of current literature, we navigate the diverse classes of ncRNAs, including miRNAs, lncRNAs, and circRNAs, elucidating their roles as both facilitators and inhibitors in the modulation of pyroptotic processes. Furthermore, we highlight the potential diagnostic and therapeutic implications of targeting these ncRNAs in the context of sepsis, aiming to cover the method for novel and effective strategies to mitigate the devastating consequences of septic pathogenesis. As we unravel the complexities of this regulatory axis, a deeper understanding of the intricate crosstalk between ncRNAs and pyroptosis emerges, offering promising avenues for advancing our approach to sepsis intervention. The intricate pathophysiology of sepsis is examined in this review, which explores the dynamic interaction between ncRNAs and pyroptosis, a highly regulated kind of programmed cell death.

Noncoding RNAs in hepatitis: Unraveling the apoptotic pathways

Hepatitis is a worldwide health issue that causes inflammation of the liver and is frequently brought on by viral infections, specifically those caused by the hepatitis B and C viruses. Although the pathophysiological causes of hepatitis are complex, recent research indicates that noncoding RNAs (ncRNAs) play a crucial role in regulating apoptosis, an essential process for maintaining liver homeostasis and advancing the illness. Noncoding RNAs have been linked to several biological processes, including apoptosis. These RNAs include microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs). Distinct expression patterns characterising different stages of the disease have been discovered, indicating dysregulation of these non-coding RNAs in liver tissues infected with hepatitis. The complex interplay that exists between these noncoding RNAs and apoptotic effectors, including caspases and members of the Bcl-2 family, plays a role in the precarious equilibrium that regulates cell survival and death during hepatitis. The purpose of this review is to provide an overview of ncRNA-mediated apoptosis in hepatitis, as well as insights into possible therapeutic targets and diagnostic indicators.

Deregulated miRNAs in enzalutamide resistant prostate cancer: A comprehensive review of key molecular alterations and clinical outcomes

Prostate cancer (PC) is the second most frequently diagnosed cancer and the fifth leading cause of cancer-related deaths in male population worldwide. Since the growth and progression of PC highly depend on the androgen pathway, androgen deprivation therapy (ADT) is the mainstay of systemic treatment. Enzalutamide is a second-generation antiandrogen, which is widely used for the treatment of advanced and metastatic PC. However, treatment failure and disease progression, caused by the emergence of enzalutamide resistant phenotypes, remains an important clinical challenge. MicroRNAs (miRNAs) are key regulators of gene expression and have recently emerged as potential biomarkers for being stable and easily analysed in several biological fluids. Several miRNAs that exhibit dysregulated expression patterns in enzalutamide-resistant PC have recently been identified, including miRNAs that modulate critical signalling pathways and genes involved in PC growth, survival and in the acquisition of enzalutamide phenotype. The understanding of molecular mechanisms by which miRNAs promote the development of enzalutamide resistance can provide valuable insights into the complex interplay between miRNAs, gene regulation, and treatment response in PC. Moreover, these miRNAs could serve as valuable tools for monitoring treatment response and disease progression during enzalutamide administration. This review summarises the miRNAs associated with enzalutamide resistance in PC already described in the literature, focusing on their biological roles and on their potential as biomarkers.

circ_SIRT1 upregulates ATG12 to facilitate Imatinib resistance in CML through interacting with EIF4A3

Imatinib is the current gold standard for patients with chronic myeloid leukemia (CML). However, the primary and acquired drug resistance seriously limits the efficacy. To identify novel therapeutic target in Imatinib-resistant CML is of crucial clinical significance. CircRNAs have been demonstrated the essential regulatory roles in the progression and drug resistance of cancers. In this study, we identified a novel circRNA (circ_SIRT1), derived from the SIRT1, which is up-regulated in CML. The high expression of circ_SIRT1 is correlated with drug resistance in CML. Knockdown of circ_SIRT1 regulated K562/R cells viability, invasion and apoptosis. Besides, the inhibition of circ_SIRT1 attenuated autophagy level and reduced IC50 to Imatinib of K562/R cells. Mechanistically, circ_SIRT1 directly binds to the transcription factor Eukaryotic Translation Initiation Factor 4A3(EIF4A3) and regulated EIF4A3-mediated transcription of Autophagy Related 12 (ATG12), thereby affecting Imatinib resistance and autophagy level. Overexpression of ATG12 reversed the regulative effects induced by knockdown of circ_SIRT1. Taken together, our findings revealed circ_SIRT1 acted as a potential tumor regulator in CML and unveiled the underlying mechanism on regulating Imatinib resistance. circ_SIRT1 may serve as a novel therapeutic target and provide crucial clinical implications for Imatinib-resistant CML treatment.

circNFIB decreases synthesis of arachidonic acid and inhibits breast tumor growth and metastasis

We identified circNFIB (hsa_circ_0086376) as a down-regulated circRNA in breast cancer but its effect is unclear. We aimed to explore the roles of circNFIB in breast cancer. The expression levels of circNFIB in breast cancer tissues and cells were detected. Both in vitro and in vivo experiments were used to assess the effects and mechanisms of circNFIB. circNFIB was down-regulated in 29 breast cancer tissues compared to adjacent normal tissues. circNFIB is a highly conserved circRNA and mainly located in cytoplasm of breast cancer cells. In vitro experiments showed that overexpression of circNFIB inhibited proliferation and invasion of breast cancer cells, whereas knockdown of circNFIB induced proliferation and invasion. Animal experiments indicated that circNFIB inhibited tumor growth and metastasis in vivo. Bioinformatics analysis showed that circNFIB contained an open reading frame (ORF) spanning its spliced junction, an internal ribosome entry site (IRES) and a N6-methyladenosine (m6A) site, suggesting circNFIB had the potential to encode a 56 amino acid (aa) protein, which was then confirmed by experiments. Metabonomics analysis results indicated that circNFIB may inhibit synthesis of arachidonic acid (AA) by regulating phospholipase. EIF4A3 and U2AF65 may regulate circNFIB expression by binding to the flanking sequence of circNFIB. In conclusion, circNFIB is a down-regulated circRNA in breast cancer tissues and encodes a 56 aa protein. circNFIB down-regulates AA in breast cancer cells, thus decreasing AA metabolites. Based on reported evidences of AA metabolites on cancer, we speculated that circNFIB may inhibit breast tumor growth and metastasis partly by inhibiting AA.

Identification of immune-responsive circular RNAs in shrimp (Litopenaeus vannamei) upon yellow head virus infection

Circular RNAs (circRNAs) are a subclass of non-coding RNAs (ncRNAs) formed through a process known as back-splicing. They play a crucial role in the genetic regulation of various biological processes. Currently, circRNAs have been identified as participants in the antiviral response within mammalian cells. However, circRNAs in shrimp infected with the yellow head virus (YHV) remain largely unexplored. Therefore, this study aims to identify circRNAs in the hemocytes of Litopenaeus vannamei during YHV infection. We discovered 358 differentially expressed circRNAs (DECs), with 177 of them being up-regulated and 181 down-regulated. Subsequently, eight DECs, including circ_alpha-1-inhibitor 3, circ_CDC42 small effector protein 2, circ_hemicentin 2, circ_integrin alpha V, circ_kazal-type proteinase inhibitor, circ_phenoloxidase 3, circ_related protein rab-8B, and circ_protein toll-like, were randomly selected for analysis of their expression patterns during YHV infection using qRT-PCR. Furthermore, the circRNAs' characteristics were confirmed through PCR, RNase R treatment, and Sanger sequencing, all of which were consistent with the features of circRNAs. These findings contribute to a better understanding of circRNAs' involvement in the antiviral response in shrimp.

NR1H4-mediated circRHOBTB3 modulates the proliferation, metastasis, and Warburg effects of cervical cancer through interacting with IGF2BP3

Globally, cervical cancer (CC) ranks as the fourth most common cancer and the most lethal malignancy among females of reproductive age. The incidence of CC is increasing in low-income countries, with unsatisfactory outcomes and long-term survival for CC patients. Circular RNAs (CircRNAs) are promising therapeutics that target multiple cancers. In this study, we investigated the tumorigenic role of circRHOBTB3 in CC, showing that circRHOBTB3 is highly expressed in CC cells and circRHOBTB3 knockdown also repressed CC proliferation, migration, invasion, and the Warburg effects. CircRHOBTB3 interacted with the RNA-binding protein, IGF2BP3, to stabilize its expression in CC cells and is putatively transcriptionally regulated by NR1H4. In conclusion, this novel NR1H4/circRHOBTB3/IGF2BP3 axis may provide new insights into CC pathogenesis.

Circular RNAs in tuberculosis: From mechanism of action to potential diagnostic biomarker

Tuberculosis (TB), caused by Mycobacterium tuberculosis (M. tuberculosis), continues to be a major global health concern. Understanding the molecular intricacies of TB pathogenesis is crucial for developing effective diagnostic and therapeutic approaches. Circular RNAs (circRNAs), a class of single-stranded RNA molecules characterized by covalently closed loops, have recently emerged as potential diagnostic biomarkers in various diseases. CircRNAs have been demonstrated to modulate the host's immunological responses against TB, specifically by reducing monocyte apoptosis, augmenting autophagy, and facilitating macrophage polarization. This review comprehensively explores the roles and mechanisms of circRNAs in TB pathogenesis. We also discuss the growing body of evidence supporting their utility as promising diagnostic biomarkers for TB. By bridging the gap between fundamental circRNA biology and TB diagnostics, this review offers insights into the exciting potential of circRNAs in combatting this infectious disease.

Crosstalk of NLRP3 inflammasome and noncoding RNAs in cardiomyopathies

Cardiovascular diseases (CVDs) identified as a serious public health problem. Although there is a lot of evidence that inflammatory processes play a significant role in the progression of CVDs, however, the precise mechanism is not fully understood. Nevertheless, recent studies have focused on inflammation and its related agents. Nucleotide oligomerization domain-, leucine-rich repeat-, and pyrin domain-containing protein 3 (NLRP3) is a type of pattern recognition receptor (PRR) that can recognize pathogen-associated molecular patterns and trigger innate immune response. NLRP3 is a component of the NOD-like receptor (NLR) family and have a pivotal role in detecting damage to cardiovascular tissue. It is suggested that activation of NLRP3 inflammasome leads to initiating and propagating the inflammatory response in cardiomyopathy. So, late investigations have highlighted the NLRP3 inflammasome activation in various forms of cardiomyopathy. On the other side, it was shown that noncoding RNAs (ncRNAs), particularly, microRNAs, lncRNAs, and circRNAs possess a regulatory function in the immune system's inflammatory response, implicating their involvement in various inflammatory disorders. In addition, their role in different cardiomyopathies was indicated in recent studies. This review article provides a summary of recent advancements focusing on the function of the NLRP3 inflammasome in common CVDs, especially cardiomyopathy, while also discussing the therapeutic potential of inhibiting the NLRP3 inflammasome regulated by ncRNAs.

Circular RNAs: emerging players in asthma and COPD

Circular RNAs (circRNAs) belong to a unique class of endogenously expressed non-protein-coding RNAs with a distinct circularized structure, characterized by the absence of 5'-cap and 3'-polyadenylate ends. They are generally formed through back-splicing from pre-mRNAs. They serve as regulators of transcription and splicing, and act as sponges for microRNAs (miRNAs) and RNA-binding proteins, thereby modulating the expression of target genes. As a result, they exert a substantial impact on a diverse array of cellular and biological processes, including cell proliferation, migration, inflammation, and oxidative stress. Asthma and COPD are chronic airway conditions that currently have no cure. In recent years, emerging evidence suggests that altered expression of circRNAs in airway, bronchial and immune cells is involved in asthma and COPD pathogenesis. Studies exploring circRNA dysregulation in asthma have showcased their involvement in regulating the proliferation, migration, and inflammation of airway smooth muscle and bronchial epithelial cells, as well as impacting goblet cell metaplasia, Th2 cell differentiation, and macrophage activation, primarily through interactions with miRNAs. Similarly, in COPD, circRNAs have shown altered expression patterns in the blood and lungs of patients, and these changes have been linked to modulating inflammation, oxidative stress, and airway remodeling in preclinical models. Furthermore, certain circRNAs have demonstrated promising potential as diagnostic and prognostic biomarkers for both asthma and COPD. This review delves into the current understanding of the function and molecular mechanisms of circRNAs in asthma and COPD, along with exploring their potential as biomarkers in these respiratory conditions.

Circular RNAs-mediated angiogenesis in human cancers

Circular RNAs (circRNAs) as small non-coding RNAs with cell, tissue, or organ-specific expression accomplish a broad array of functions in physiological and pathological processes such as cancer development. Angiogenesis, a complicated multistep process driving a formation of new blood vessels, speeds up tumor progression by supplying nutrients as well as energy. Abnormal expression of circRNAs reported to affect tumor development through impressing angiogenesis. Such impacts are introduced as constant with different tumorigenic features known as "hallmarks of cancer". In addition, deregulated circRNAs show possibilities to prognosis and diagnosis both in the prophecy of prognosis in malignancies and also their prejudice from healthy individuals. In the present review article, we have evaluated the angiogenic impacts and anti-angiogenic managements of circRNAs in human cancers.

Understanding crosstalk of organ tropism, tumor microenvironment and noncoding RNAs in breast cancer metastasis

Cancer metastasis is one of the major clinical challenges worldwide due to limited existing effective treatments. Metastasis roots from the host organ of origin and gradually migrates to different regional and distant organs. In different breast cancer subtypes, different organs like bones, liver, lungs and brain are targeted by the metastatic tumor cells. Cancer renders mortality to their respective metastasizing sites like bones, brain, liver, and lungs. Metastatic breast cancers are best treated and managed if detected at an early stage. Metastasis is regulated by various molecular activators and suppressors. The conventional theory of 'seed and soil' states that metastatic tumor cells move to tumor microenvironment that has favorable conditions like blood flow for them to grow just like seeds grows when planted in fertile land. Additionally, different coding as well as non-coding RNAs play a very significant role in the process of metastasis by modulating their expression levels leading to a crosstalk of various tumorigenic cascades. Treatments for metastasis is also very critical in controlling this lethal process. Detecting breast cancer metastasis at an early stage is crucial for managing and predicting metastatic progression. In this review, we have compiled several factors that can be targeted to manage the onset and gradual stages of breast cancer metastasis.

Non-coding RNAs-mediated environmental surveillance determines male fertility in plants

Plants are continuously exposed to environmental stresses leading to significant yield losses. With the changing climatic conditions, the intensity and duration of these stresses are expected to increase, posing a severe threat to crop productivity worldwide. Male gametogenesis is one of the most sensitive developmental stages. Exposure to environmental stresses during this stage leads to male sterility and yield loss. Elucidating the underlying molecular mechanism of environment-affected male sterility is essential to address this challenge. High-throughput RNA sequencing studies, loss-of-function phenotypes of sRNA biogenesis genes and functional genomics studies with non-coding RNAs have started to unveil the roles of small RNAs, long non-coding RNAs and the complex regulatory interactions between them in regulating male fertility under different growth regimes. Here, we discuss the current understanding of the non-coding RNA-mediated environmental stress surveillance and regulation of male fertility in plants. The candidate ncRNAs emerging from these studies can be leveraged to generate environment-sensitive male sterile lines for hybrid breeding or mitigate the impact of climate change on male fertility, as the situation demands.

CircRNAs in BALF exosomes and plasma as diagnostic biomarkers in patients with acute respiratory distress syndrome caused by severe pneumonia

Background

The transcriptomic studies targeting circular RNAs (circRNAs) in bronchoalveolar lavage fluid (BALF) exosomes of acute respiratory distress syndrome (ARDS) patients caused by severe pneumonia have rarely been reported. This study aimed to screen and validate abnormally expressed circRNAs in exosomes from BALF of patients with ARDS caused by severe pneumonia and then evaluate the diagnostic values of these circRNAs for ARDS.

Method

BALF was collected from four patients with ARDS caused by severe pneumonia and four healthy subjects. CircRNA expression profile was obtained by microarray analysis in BALF exosomes of the discovery cohort. The differentially expressed circRNAs in BALF exosomes were verified by real-time quantitative PCR (RT-qPCR) and underwent competitive endogenous RNA (ceRNA) network construction and functional enrichment analysis.

Results

A total of 629 circRNAs were differentially expressed in BALF exosomes between ARDS patients and healthy subjects. Nine differentially expressed circRNAs were validated by RT-qPCR, and seven were consistent with the results of microarray analysis. CeRNA network analysis was performed for hsa_circRNA_002809, hsa_circRNA_042882, and hsa_circRNA_104034. Functional enrichment analysis showed that the target genes were mainly associated with hypoxia-induced damage, inflammatory response, and the HIF-1 signaling pathway. Hsa_circRNA_042882 and hsa_circRNA_104034 can be regarded as promising diagnostic biomarkers for patients with ARDS caused by severe pneumonia, with remarkable sensitivity and specificity of the area under the curve of 0.8050 and 1 or 0.835 and 0.799, respectively.

Conclusion

This study obtained circRNA expression profiles of ARDS patients, and hsa_circRNA_042882 and hsa_circRNA_104034 were regarded as promising diagnostic biomarkers for patients with ARDS caused by severe pneumonia.

The Fate and Functionality of Alien tRNA Fragments in Culturing Medium and Cells of Escherichia coli

Numerous observations have supported the idea that various types of noncoding RNAs, including tRNA fragments (tRFs), are involved in communications between the host and its microbial community. The possibility of using their signaling function has stimulated the study of secreted RNAs, potentially involved in the interspecies interaction of bacteria. This work aimed at identifying such RNAs and characterizing their maturation during transport. We applied an approach that allowed us to detect oligoribonucleotides secreted by Prevotella copri (Segatella copri) or Rhodospirillum rubrum inside Escherichia coli cells. Four tRFs imported by E. coli cells co-cultured with these bacteria were obtained via chemical synthesis, and all of them affected the growth of E. coli. Their successive modifications in the culture medium and recipient cells were studied by high-throughput cDNA sequencing. Instead of the expected accidental exonucleolysis, in the milieu, we observed nonrandom cleavage by endonucleases continued in recipient cells. We also found intramolecular rearrangements of synthetic oligonucleotides, which may be considered traces of intermediate RNA circular isomerization. Using custom software, we estimated the frequency of such events in transcriptomes and secretomes of E. coli and observed surprising reproducibility in positions of such rare events, assuming the functionality of ring isoforms or their permuted derivatives in bacteria.

Liquid biopsy in ovarian cancer: advantages and limitations for prognosis and diagnosis

Ovarian cancer (OC) is a highly fatal gynecologic malignancy, often diagnosed at an advanced stage which presents significant challenges for disease management. The clinical application of conventional tissue biopsy methods and serological biomarkers has limitations for the diagnosis and prognosis of OC patients. Liquid biopsy is a novel sampling method that involves analyzing distinctive tumor elements secreted into the peripheral blood. Growing evidence suggests that liquid biopsy methods such as circulating tumor cells, cell-free RNA, circulating tumor DNA, exosomes, and tumor-educated platelets may improve early prognosis and diagnosis of OC, leading to enhanced therapeutic management of the disease. This study reviewed the evidence demonstrating the utility of liquid biopsy components in OC prognosis and diagnosis, and evaluated the current advantages and limitations of these methods. Additionally, the existing obstacles and crucial topics for future studies utilizing liquid biopsy in OC patients were discussed.

Functional Involvement of circRNAs in the Innate Immune Responses to Viral Infection

Effective viral clearance requires fine-tuned immune responses to minimize undesirable inflammatory responses. Circular RNAs (circRNAs) are a class of non-coding RNAs that are abundant and highly stable, formed by backsplicing pre-mRNAs, and expressed ubiquitously in eukaryotic cells, emerging as critical regulators of a plethora of signaling pathways. Recent progress in high-throughput sequencing has enabled a better understanding of the physiological and pathophysiological functions of circRNAs, overcoming the obstacle of the sequence overlap between circRNAs and their linear cognate mRNAs. Some viruses also encode circRNAs implicated in viral replication or disease progression. There is increasing evidence that viral infections dysregulate circRNA expression and that the altered expression of circRNAs is critical in regulating viral infection and replication. circRNAs were shown to regulate gene expression via microRNA and protein sponging or via encoding small polypeptides. Recent studies have also highlighted the potential role of circRNAs as promising diagnostic and prognostic biomarkers, RNA vaccines and antiviral therapy candidates due to their higher stability and lower immunogenicity. This review presents an up-to-date summary of the mechanistic involvement of circRNAs in innate immunity against viral infections, the current understanding of their regulatory roles, and the suggested applications.

CircKIF4A combines EIF4A3 to stabilize SDC1 expression to activate c-src/FAK and promotes TNBC progression

Triple-negative breast cancer (TNBC) is recognized for its poor prognosis and limited options for treatment. Circular RNA KIF4A (circKIF4A) was documented to be abnormally overexpressed in TNBC and was correlated with a poor survival rate. The objective of this study is to further examine the functional role of circKIF4A and its underlying mechanism. CircKIF4A was significantly upregulated in TNBC and the knockdown of circKIF4A suppressed TNBC cell proliferation, migration, and invasion. CircKIF4A was directly bound to EIF4A3, which interacted with SDC1. Knockdown of circKIF4A reduced interaction between EIF4A3 and SDC1 as well as SDC1 mRNA stability. SDC1 activated the c-src/FAK signaling pathways and finally promoted TNBC progression. circKIF4A induced TNBC progress in the in vivo mouse model via SDC1. CircKIF4A interacts with EIF4A3 to stabilize SDC1 mRNA, which activates the c-src/FAK signaling pathways and promotes TNBC progression. This may provide a potential therapy for TNBC treatment.

Non-Coding RNAs in Oral Cancer: Emerging Roles and Clinical Applications

Oral cancer (OC) is among the most prevalent cancers in the world. Certain geographical areas are disproportionately affected by OC cases due to the regional differences in dietary habits, tobacco and alcohol consumption. However, conventional therapeutic methods do not yield satisfying treatment outcomes. Thus, there is an urgent need to understand the disease process and to develop diagnostic and therapeutic strategies for OC. In this review, we discuss the role of various types of ncRNAs in OC, and their promising clinical implications as prognostic or diagnostic markers and therapeutic targets. MicroRNA (miRNA), long ncRNA (lncRNA), circular RNA (circRNA), PIWI-interacting RNA (piRNA), and small nucleolar RNA (snoRNA) are the major ncRNA types whose involvement in OC are emerging. Dysregulated expression of ncRNAs, particularly miRNAs, lncRNAs, and circRNAs, are linked with the initiation, progression, as well as therapy resistance of OC via modulation in a series of cellular pathways through epigenetic, transcriptional, post-transcriptional, and translational modifications. Differential expressions of miRNAs and lncRNAs in blood, saliva or extracellular vesicles have indicated potential diagnostic and prognostic importance. In this review, we have summarized all the promising aspects of ncRNAs in the management of OC.

hsa_circ_0000285 sponging miR-582-3p promotes neuroblastoma progression by regulating the Wnt/β-catenin signaling pathway

Circular RNA has been reported to play a key role in neuroblastoma (NB); however, the role of circ_0000285 in NB remains unclear. The aim of this study was to elucidate the role of circ_0000285 in NB. We studied the expression patterns of miR-582-3p and circ_0000285 in NB tissues and cells using real-time quantitative polymerase chain reaction. The expression of proteins associated with apoptosis (Bax and Bcl-2) and the proteins associated with Wnt/β-catenin (Wnt, p-Gsk-3β, Gsk-3β, β-catenin, and C-myc) were quantified by western blotting. In vivo animal models were prepared for the functional verification of circ_0000285 on tumor growth. The potential binding of circ_0000285 to miR-582-3p was ascertained using dual-luciferase reporter and RNA-binding protein immunoprecipitation experiments. Noticeable upregulation of circ_0000285 expression was observed in NB tumor samples and cell lines. In vivo and in vitro experiments indicated that the absence of circ_0000285 repressed NB cell proliferation and migration, provoked apoptosis, and impaired the activity of Wnt/β-catenin signaling. miR-582-3p is targeted by circ_0000285 and is poorly expressed in NB cells. The additional repression of miR-582-3p in NB cells after circ_0000285 silencing largely recovered circ_0000285 silencing-suppressed NB cell proliferation and migration and enhanced apoptosis. The absence of miR-582-3p restored Wnt/β-catenin signaling activity impaired by the knockdown of circ_0000285. circ_0000285 functions as an miR-582-3p sponge to strengthen Wnt/β-catenin signaling activity, thus exacerbating NB development.

Therapeutic and diagnostic applications of exosomal circRNAs in breast cancer

Circular RNAs (circRNAs) are regulatory elements that are involved in orchestrating gene expression and protein functions and are implicated in various biological processes including cancer. Notably, breast cancer has a significant mortality rate and is one of the most common malignancies in women. CircRNAs have been demonstrated to contribute to the pathogenesis of breast cancer including its initiation, progression, metastasis, and resistance to drugs. By acting as miRNA sponges, circRNAs can indirectly influence gene expression by disrupting miRNA regulation of their target genes, ultimately altering the course of cancer development and progression. Additionally, circRNAs can interact with proteins and modulate their functions including signaling pathways involved in the initiation and development of cancer. Recently, circRNAs can encode peptides that play a role in the pathophysiology of breast cancer and other diseases and their potential as diagnostic biomarkers and therapeutic targets for various cancers including breast cancer. CircRNAs possess biomarkers that differentiate, such as stability, specificity, and sensitivity, and can be detected in several biological specimens such as blood, saliva, and urine. Moreover, circRNAs play an important role in various cellular processes including cell proliferation, differentiation, and apoptosis, all of which are integral factors in the development and progression of cancer. This review synthesizes the functions of circRNAs in breast cancer, scrutinizing their contributions to the onset and evolution of the disease through their interactions with exosomes and cancer-related intracellular pathways. It also delves into the potential use of circRNA as a biomarker and therapeutic target against breast cancer. It discusses various databases and online tools that offer crucial circRNA information and regulatory networks. Lastly, the challenges and prospects of utilizing circRNAs in clinical settings associated with breast cancer are explored.

Aal-circRNA-407 regulates ovarian development of Aedes albopictus, a major arbovirus vector, via the miR-9a-5p/Foxl axis

Aedes albopictus shows a rapid global expansion and dramatic vectorial capacity for various arboviruses, thus posing a severe threat to global health. Although many noncoding RNAs have been confirmed to play functional roles in various biological processes in Ae. albopictus, the roles of circRNA remain a mystery. In the present study, we first performed high-throughput circRNA sequencing in Ae. albopictus. Then, we identified a cysteine desulfurase (CsdA) superfamily gene-originated circRNA, named aal-circRNA-407, which was the third most abundant circRNA in adult females and displayed a fat body highly expressed manifestation and blood feeding-dependent onset. SiRNA-mediated knockdown of circRNA-407 resulted in a decrease in the number of developing follicles and a reduction in follicle size post blood meal. Furthermore, we demonstrated that circRNA-407 can act as a sponge of aal-miR-9a-5p to promote the expression of its target gene Foxl and eventually regulate ovarian development. Our study is the first to report a functional circRNA in mosquitoes, expanding our current understanding of important biological roles in mosquitoes and providing an alternative genetic strategy for mosquito control.

Clinical Delivery of Circular RNA: Lessons Learned from RNA Drug Development

Circular RNAs (circRNA) represent a distinct class of covalently closed-loop RNA molecules, which play diverse roles in regulating biological processes and disease states. The enhanced stability of synthetic circRNAs compared to their linear counterparts has recently garnered considerable research interest, paving the way for new therapeutic applications. While clinical circRNA technology is still in its early stages, significant advancements in mRNA technology offer valuable insights into its potential future applications. Two primary obstacles that must be addressed are the development of efficient production methods and the optimization of delivery systems. To expedite progress in this area, this review aims to provide an overview of the current state of knowledge on circRNA structure and function, outline recent techniques for synthesizing circRNAs, highlight key delivery strategies and applications, and discuss the current challenges and future prospects in the field of circRNA-based therapeutics.

The Potential Biological Roles of Circular RNAs in the Immune Systems of Insects to Pathogen Invasion

Circular RNAs (circRNAs) are a newly discovered class of endogenously expressed non-coding RNAs (ncRNAs). They are highly stable, covalently closed molecules that frequently exhibit tissue-specific expression in eukaryotes. A small number of circRNAs are abundant and have been remarkably conserved throughout evolution. Numerous circRNAs are known to play important biological roles by acting as microRNAs (miRNAs) or protein inhibitors ('sponges'), by regulating the function of proteins, or by being translated themselves. CircRNAs have distinct cellular functions due to structural and production differences from mRNAs. Recent advances highlight the importance of characterizing circRNAs and their targets in a variety of insect species in order to fully understand how they contribute to the immune responses of these insects. Here, we focus on the recent advances in our understanding of the biogenesis of circRNAs, regulation of their abundance, and biological roles, such as serving as templates for translation and in the regulation of signaling pathways. We also discuss the emerging roles of circRNAs in regulating immune responses to various microbial pathogens. Furthermore, we describe the functions of circRNAs encoded by microbial pathogens that play in their hosts.

Circular RNA circPlce1 regulates innate immune response in miiuy croaker, Miichthys miiuy

In recent years, more and more researchers have devoted to the study of circular RNAs (circRNAs) in noncoding RNAs. As an important regulator in a variety of biological processes, circRNAs are relatively abundant in the study of mammals, while research in lower vertebrates is still lacking. In this study, we found a circRNA, circPlce1, related to innate immune response in Miichthys miiuy (miiuy croaker). The experimental results confirmed that circPlce1 could promote the production of antiviral genes and inflammatory response under the stimulation of poly (I: C) and LPS. We also confirmed that circPlce1 can promote NF-κB and IRF3 pathways through luciferase reporter assay experiment. In addition, we also found that circPlce1 can promote cell proliferation and improve cell viability. In conclusion, our results showed that circPlce1 plays an active role in regulating inflammatory response, cell proliferation and cell viability, providing a foundation for the study of the biological function of circRNAs in the innate immune response in teleost fish.

Exosomal lncRNAs in gastrointestinal cancer

Gastrointestinal cancer (GIC) remains a leading cause of morbidity and mortality worldwide. Unfortunately, these cancers are diagnosed in advanced metastatic stages due to lack of reliable biomarkers that are sufficiently specific and sensitive in early disease. There has been growing evidence that circulating exosomes can be used to diagnose cancer non-invasively with limited risks and side effects. Furthermore, exosomal long non-coding RNAs (lncRNAs) are emerging as a new class of promising biomarkers in cancer. This review provides an overview of the extraction and detection of exosomal lncRNAs with a focus on their potential role in GIC.

CircMERTK modulates the suppressive capacity of tumor-associated macrophage via targeting IL-10 in colorectal cancer

Macrophages represent the major population in the tumor microenvironment (TME). Recent studies have demonstrated circular RNAs (circRNAs) are implicated in the development and progression of different immune responses and immune diseases. However, the role of circRNAs in the development of tumor-associated macrophages (TAM) remains unknown. Here, we used the circRNA sequencing to identify the differentially expressed circRNAs (DEcircRNAs) in TAM-like cell induced by culture medium of colorectal cancer cell lines. Of note, the expression of circMERTK was remarkably overexpressed in TAMs. The ISH assay displayed that the expressions of circMERTK were mainly overlapped with macrophages marker CD68, and the abundance of circMERTK in CRC tissues was much higher than that in matched normal tissues. Functionally, circMERTK knockdown resulted in attenuated CD8⁺ T cell apoptosis in the co-culture assay, indicating that circMERTK could have an impact on the immunosuppressive activity of TAM-like cell. Mechanically, TAM-like cell could exert immunosuppressive activity via circMERTK/miR-125a-3p/IL-10 axis. These data suggested that circMERTK could play an important role in TAM activation, and may serve as a potential therapeutic target for CRC.

Transcriptome-based insights into the regulatory role of immune-responsive circular RNAs in Litopanaeus vannamei upon WSSV infection

Circular RNAs (circRNAs) are non-coding RNAs (ncRNAs) originating from a post-transcriptional modification process called back-splicing. Despite circRNAs being traditionally considered by-products rather than independently functional, circRNAs play many vital roles, such as in host immunity during viral infection. However, in shrimp, these remain largely unexplored. Therefore, this study aims to identify circRNAs in Litopenaeus vannamei in the context of WSSV infection, one of the most eradicative pathogens threatening shrimp populations worldwide. We identified 290 differentially expressed circRNAs (DECs) in L. vannamei upon WSSV infection. Eight DECs were expressed from their parental genes, including alpha-1-inhibitor-3, calpain-B, integrin-V, hemicentin-2, hemocytin, mucin-17, proPO2, and rab11-FIP4. These were examined quantitatively by qRT-PCR, which revealed the relevant expression profiles to those obtained from circRNA-Seq. Furthermore, the structural and chemical validation of the DECs conformed to the characteristics of circRNAs. One of the functional properties of circRNAs as a miRNA sponge was examined via the interaction network between DECs and WSSV-responsive miRNAs, which highlighted the targets of miRNA sponges. Our discovery could provide insight into the participation of these ncRNAs in shrimp antiviral responses.

mRNA COVID-19 Vaccines-Facts and Hypotheses on Fragmentation and Encapsulation

BACKGROUND

The adventure of the mRNA vaccine began thirty years ago in the context of influenza. This consisted in encapsulating the mRNA coding for a viral protein in a lipid particle. We show how the mRNA encoding S protein has been modified for that purpose in the context of the anti-SARS-CoV-2 vaccination.

RESULTS

by using data coming from genetic and epidemiologic databases, we show the theoretical possibility of fragmentation of this mRNA into small RNA sequences capable of inhibiting important bio-syntheses such as the production of beta-globin.

DISCUSSION

we discuss two aspects related to mRNA vaccine: (i) the plausibility of mRNA fragmentation, and (ii) the role of liposomal nanoparticles (LNPs) used in the vaccine and their impact on mRNA biodistribution.

CONCLUSION

we insist on the need to develop lipid nanoparticles allowing personalized administration of vaccines and avoiding adverse effects due to mRNA fragmentation and inefficient biodistribution. Hence, we recommend (i) adapting the mRNA of vaccines to the least mutated virus proteins and (ii) personalizing its administration to the categories of chronic patients at risk most likely to suffer from adverse effects.