Circular RNA vaccine induces potent T cell responses

CircRNA encoded-peptide: Potential stock in the transcriptomics market

The emergence of circRNA-encoded peptides has sparked significant debate in recent years as a novel mode of action for circRNAs. A mounting body of evidence suggests that these peptides play vital roles in cancer development and immune responses. This review initially elucidates the presence of circRNA-encoded peptides and delineates their specific functions across various biological processes and pathological conditions. It goes on to furnish illustrative instances to underscore the pivotal involvement of circRNA-encoded peptides in both innate and adaptive immune responses. The study sheds new light on the biological roles of circRNAs, their potential tumor-promoting and tumor-suppressing functions of circRNA-encoded peptides in specific tumor environment, and their significance in immunological contexts. Meanwhile, the limitations of existing studies on circRNA-encoded peptides are discussed in depth. In particular, circRNA-encoded peptides are critically analyzed as biomarkers and therapeutic targets. Intriguingly, the review concludes with a more organized discussion of future research on circRNA-encoded peptides.

Advancing Protein-Coding RNA Engineering: From Structural Refinement to Biomedical Implementation

Messenger RNA (mRNA), emerging as a revolutionary therapeutic tool, has shown remarkable potential in diverse fields such as vaccine development, tumor immunotherapy, gene therapy, and protein replacement therapy, attributed to its high programmability and safety. However, traditional engineered mRNA therapeutics encounter obstacles like short half-lives and limited protein expression, which impede their extensive application in the biomedical domain. In recent years, with the progress of RNA modification technologies and the advent of novel RNA techniques, including mRNA, self-amplifying RNA (saRNA), circular RNA (circRNA), and branched RNA (brRNA), researchers have achieved substantial breakthroughs in enhancing RNA stability, prolonging protein expression, and reducing immunogenicity. This article comprehensively reviews the structure, function, optimization strategies, and biomedical applications of these protein-coding RNAs.

Role of noncoding RNA and protein interaction in pancreatic cancer

ABSTRACT

Noncoding RNAs (ncRNAs) are a class of RNA molecules with little or no protein-coding potential. Emerging evidence indicates that ncRNAs are frequently dysregulated and play pivotal roles in the pathogenesis of pancreatic cancer. Their aberrant expression can arise from chromosomal abnormalities, dysregulated transcriptional control, and epigenetic modifications. ncRNAs function as protein scaffolds or molecular decoys to modulate interactions between proteins and other biomolecules, thereby regulating gene expression and contributing to pancreatic cancer progression. In this review, we summarize the mechanisms underlying ncRNA dysregulation in pancreatic cancer, emphasize the biological significance of ncRNA-protein interactions, and highlight their clinical relevance. A deeper understanding of ncRNA-protein interactions is essential to elucidate molecular mechanisms and advance translational research in pancreatic cancer.

Circular RNAs perspective: exploring the direction of immunotherapy for colorectal cancer

Circular RNAs (circRNAs) are multifaceted molecules that play a pivotal role in regulating gene expression at both transcriptional and post-transcriptional levels. Their expression is highly tissue-specific and developmentally regulated, making them critical players in various physiological processes and diseases, particularly cancer. In colorectal cancer, circRNAs exhibit significantly dysregulated expression patterns and profoundly influence disease progression through diverse molecular mechanisms. Unraveling the complex roles of circRNAs in modulating colorectal cancer immunotherapy outcomes highlights their potential as both promising biomarkers and therapeutic targets. Moving forward, advancements in circRNA-based therapeutic strategies and delivery systems are poised to transform precision medicine, enabling early colorectal cancer diagnosis and improving patient prognosis.

Mitigating Cellular Dysfunction Through Contaminant Reduction in Synthetic circRNA for High-Efficiency mRNA-Based Cell Reprogramming

Synthetic circular RNA (circRNA) holds great promise for biomedical research and therapeutic applications, but impurities introduced during synthesis trigger innate immune responses and significantly compromise its efficacy. In this study, key immunogenic byproducts, including double-stranded RNA, 5' triphosphates from uncircularized RNA, and hydrolyzed RNA fragments, are identified as impairing circRNA functionality via RNA-sensing pathways. To address this, a multi-step purification process is developed that combines enzymatic treatments and cellulose-based filtration to effectively remove these contaminants. This approach significantly reduces immune activation and increases manufacturing yields of circRNA by over 10-fold. The purified circRNA demonstrates exceptional performance in induced pluripotent stem cells (iPSCs) reprogramming, achieving over 300% reprogramming efficiency with just three OSKMLN circRNA transfection treatments. Additionally, the purified circRNA achieves high levels and persistent expression of chimeric antigen receptor (CAR) in T cells with high cytotoxicity against tumor cells, making it a promising candidate for mRNA-based CAR-T cell therapy. These findings establish the purification strategy as a scalable and reliable platform for producing therapeutic-grade RNA, with broad applications in mRNA-based cell reprogramming for regenerative medicine and cancer immunotherapy.

Circular RNAs in neurological conditions - computational identification, functional validation, and potential clinical applications

Non-coding RNAs (ncRNAs) have gained significant attention in recent years due to advancements in biotechnology, particularly high-throughput total RNA sequencing. These developments have led to new understandings of non-coding biology, revealing that approximately 80% of non-coding regions in the genome possesses biochemical functionality. Among ncRNAs, circular RNAs (circRNAs), first identified in 1976, have emerged as a prominent research field. CircRNAs are abundant in most human cell types, evolutionary conserved, highly stable, and formed by back-splicing events which generate covalently closed ends. Notably, circRNAs exhibit high expression levels in neural tissue and perform diverse biochemical functions, including acting as molecular sponges for microRNAs, interacting with RNA-binding proteins to regulate their availability and activity, modulating transcription and splicing, and even translating into functional peptides in some cases. Recent advancements in computational and experimental methods have enhanced our ability to identify and validate circRNAs, providing valuable insights into their biological roles. This review focuses on recent developments in circRNA research as they related to neuropsychiatric and neurodegenerative conditions. We also explore their potential applications in clinical diagnostics, therapeutics, and future research directions. CircRNAs remain a relatively underexplored area of non-coding biology, particularly in the context of neurological disorders. However, emerging evidence supports their role as critical players in the etiology and molecular mechanisms of conditions such as schizophrenia, bipolar disorder, major depressive disorder, Alzheimer's disease, and Parkinson's disease. These findings suggest that circRNAs may provide a novel framework contributing to the molecular dysfunctions underpinning these complex neurological conditions.

Unlocking the potential of circular RNA vaccines: a bioinformatics and computational biology perspective

Bioinformatics has significantly advanced RNA-based therapeutics, particularly circular RNAs (circRNAs), which outperform mRNA vaccines, by offering superior stability, sustained expression, and enhanced immunogenicity due to their covalently closed structure. This review highlights how bioinformatics and computational biology optimise circRNA vaccine design, elucidates internal ribosome entry sites (IRES) selection, open reading frame (ORF) optimisation, codon usage, RNA secondary structure prediction, and delivery system development. While circRNA vaccines may not always surpass traditional vaccines in stability, their production efficiency and therapeutic efficacy can be enhanced through computational strategies. The discussion also addresses challenges and future prospects, emphasizing the need for innovative solutions to overcome current limitations and advance circRNA vaccine applications.

Roles of circRNAs in viral pathogenesis

Circular RNAs (circRNAs) are a class of non-coding RNAs with a covalently closed circular structure, lacking 5'-caps or 3'-poly(A) tails. They are relatively conserved, highly stable, and often exhibit tissue- or cell-specific production in eukaryotic cells. Based on the advances in sequencing technologies and bioinformatics, multiple reports have suggested that viruses and other microorganisms may encode circRNA-like molecules, providing new insights into the physiological and pathological roles of circRNAs. The innate immune system functions as the body's primary defense mechanism against viral infections. It detects pathogen-associated molecular patterns (PAMPs) and activates signaling pathways to suppress viral replication and limit their spread. CircRNAs are involved in regulation of the host innate immune signaling pathways and play essential roles in viral pathogenesis. It has been shown that circRNAs can regulate gene expression by acting as miRNA sponges or protein sponges, or encoding small proteins in specific cases. For example, previous studies have revealed that circRNAs participate in the host antiviral immune response through the competitive endogenous RNA (ceRNA) network by acting as miRNA sponges. This review highlights research progress in the regulation and functions of host- and virus-encoded circRNAs in host-virus interactions, as well as their potential as diagnostic biomarkers and therapeutic targets in clinical applications.

Nucleic acid therapeutics: Past, present, and future

Nucleic acid therapeutics have become increasingly recognized in recent years for their capability to target both coding and non-coding sequences. Several types of nucleic acid modalities, including siRNA, mRNA, aptamer, along with antisense oligo, have been approved by regulatory bodies for therapeutic use. The field of nucleic acid therapeutics has been brought to the forefront by the rapid development of vaccines against COVID-19, followed by a number of approvals for clinical use including much anticipated CRISPR-Cas9. However, obstacles such as the difficulty of achieving efficient and targeted delivery to diseased sites remain. This review provides an overview of nucleic acid therapeutics and highlights substantial advancements, including critical engineering, conjugation, and delivery strategies, that are paving the way for their growing role in modern medicine.

Development and characterization of a miRNA-responsive circular RNA expression system with cell type specificity

Although microRNAs (miRNAs) binding to messenger RNAs (mRNAs) generally results in mRNA degradation and reduced protein expression, their interaction with the internal ribosome entry sites (IRES) of certain RNA viruses enhances viral amplification and expression. In this study, we utilized the natural hepatitis C cirus (HCV) 5' UTR region, which contains miR-122 binding sites, as the IRES of circular RNA (circRNAs) constructs. These circRNAs allowed inducible expression of downstream genes with high specificity in response to both exogenous and endogenous miR-122. Substituting the miR-122 binding sites with those for other miRNAs also resulted in the translational activation of circRNAs by their respective miRNAs in transfected cells. Furthermore, mouse models administered intravenously with lipid nanoparticle-formulated circRNAs containing miRNA binding sites (circRNA-LNP) exhibited higher expression in targeted tissues compared to those with mutated binding sites. Our research introduces a novel strategy for tissue-specific regulation of circRNA expression, potentially broadening the therapeutic applications of circRNAs and paving the way for more precise and effective treatments in gene therapy.

Recent advances and perspectives on the development of circular RNA cancer vaccines

Engineered circular RNAs (circRNAs) are emerging as promising platforms for RNA-based vaccines in cancer treatment. We summarize the recent advances of design, synthesis, and delivery of circRNA-based cancer vaccines, and highlight the applications and challenges of circRNA vaccines in cancer therapy. Further enhancements are required in areas such as antigen selection, targeted delivery, multidimensional crosstalks, and clinical trial assessments to advance the efficacy and safety of circRNA vaccines in cancer.

A review of RNA nanoparticles for drug/gene/protein delivery in advanced therapies: Current state and future prospects

Nanotechnology involves the utilization of materials with exceptional properties at the nanoscale. Over the past few years, nanotechnologies have demonstrated significant potential in improving human health, particularly in medical treatments. The self-assembly characteristic of RNA is a highly effective method for designing and constructing nanostructures using a combination of biological, chemical, and physical techniques from different fields. There is great potential for the application of RNA nanotechnology in therapeutics. This review explores various nano-based drug delivery systems and their unique features through the impressive progress of the RNA field and their significant therapeutic promises due to their unique performance in the COVID-19 pandemic. However, a significant hurdle in fully harnessing the power of RNA drugs lies in effectively delivering RNA to precise organs and tissues, a critical factor for achieving therapeutic effectiveness, minimizing side effects, and optimizing treatment outcomes. There have been many efforts to pursue targeting, but the clinical translation of RNA drugs has been hindered by the lack of clear guidelines and shared understanding. A comprehensive understanding of various principles is essential to develop vaccines using nucleic acids and nanomedicine successfully. These include mechanisms of immune responses, functions of nucleic acids, nanotechnology, and vaccinations. Regarding this matter, the aim of this review is to revisit the fundamental principles of the immune system's function, vaccination, nanotechnology, and drug delivery in relation to the creation and manufacturing of vaccines utilizing nanotechnology and nucleic acids. RNA drugs have demonstrated significant potential in treating a wide range of diseases in both clinical and preclinical research. One of the reasons is their capacity to regulate gene expression and manage protein production efficiently. Different methods, like modifying chemicals, connecting ligands, and utilizing nanotechnology, have been essential in enabling the effective use of RNA-based treatments in medical environments. The article reviews stimuli-responsive nanotechnologies for RNA delivery and their potential in RNA medicines. It emphasizes the notable benefits of these technologies in improving the effectiveness of RNA and targeting specific cells and organs. This review offers a comprehensive analysis of different RNA drugs and how they work to produce therapeutic benefits. Recent progress in using RNA-based drugs, especially mRNA treatments, has shown that targeted delivery methods work well in medical treatments.

Vax-Innate: improving therapeutic cancer vaccines by modulating T cells and the tumour microenvironment

T cells have a critical role in mediating antitumour immunity. The success of immune checkpoint inhibitors (ICIs) for cancer treatment highlights how enhancing endogenous T cell responses can mediate tumour regression. However, mortality remains high for many cancers, especially in the metastatic setting. Based on advances in the genetic characterization of tumours and identification of tumour-specific antigens, individualized therapeutic cancer vaccines targeting mutated tumour antigens (neoantigens) are being developed to generate tumour-specific T cells for improved therapeutic responses. Early clinical trials using individualized neoantigen vaccines for patients with advanced disease had limited clinical efficacy despite demonstrated induction of T cell responses. Therefore, enhancing T cell activity by improving the magnitude, quality and breadth of T cell responses following vaccination is one current goal for improving outcome against metastatic tumours. Another major consideration is how T cells can be further optimized to function within the tumour microenvironment (TME). In this Perspective, we focus on neoantigen vaccines and propose a new approach, termed Vax-Innate, in which vaccination through intravenous delivery or in combination with tumour-targeting immune modulators may improve antitumour efficacy by simultaneously increasing the magnitude, quality and breadth of T cells while transforming the TME into a largely immunostimulatory environment for T cells.

Internal cap-initiated translation for efficient protein production from circular mRNA

Circular mRNA faces challenges in enhancing its translation potential as an RNA therapeutic. Here we introduce two molecular designs that bolster circular mRNA translation through an internal cap-initiated mechanism. The first consists of a circular mRNA with a covalently attached N7-methylguanosine (m7G) cap through a branching structure (cap-circ mRNA). This modification allows circular mRNA to recruit translation machinery and produce proteins more efficiently than internal ribosome entry site (IRES)-containing circular mRNAs. Combining with an N1-methylpseudouridine (m1Ψ) modification, cap-circ mRNA exhibits a lower acute immunostimulatory effect, maintaining high translation in mice. The second design features the non-covalent attachment of an m7G cap to a circular mRNA through hybridization with an m7G cap-containing oligonucleotide, enhancing translation by more than 50-fold. This setup allows circular mRNAs to synthesize reporter proteins upon hybridizing with capped mRNAs or long non-coding RNAs and to undergo rolling circle-type translation. These advancements broaden the therapeutic applications of circular mRNAs by minimizing their molecular size, elevating translation efficiency and facilitating cell-type-selective translation.

The circRNA cEMSY Induces Immunogenic Cell Death and Boosts Immunotherapy Efficacy in Lung Adenocarcinoma

Immunogenic cell death (ICD) induces an active immune response. Activating ICD represents a potential approach to boost the antitumor activity of immunotherapy, highlighting the need to identify effective and safe ICD inducers. In this study, we identified a conserved, ICD-related circular RNA cEMSY by systematically screening ICD models induced by multiple cell stressors in lung adenocarcinoma. cEMSY triggered ICD in lung adenocarcinoma cells both in vitro and in vivo, leading to the release of damage-associated molecular patterns and promoting T-cell cross-priming by dendritic cells. Notably, the intratumoral delivery of lipid nanoparticle-encapsulated cEMSY induced a potent antitumor immune response in an immunosuppressed tumor model, which synergized with PD-1 blockade to facilitate long-term antitumor immunity with no apparent toxicities. Mechanistically, cEMSY mediated mitochondrial aggregation of the RNA-binding protein TDP-43 that enabled leakage of mitochondrial DNA to stimulate the cGAS-STING pathway, activating the antiviral immune response. Clinically, elevated expression of cEMSY correlated with enhanced infiltration of dendritic cells and CD8+ T cells and favorable immunotherapy response in lung adenocarcinoma. Together, these findings support the dual potential of cEMSY as a target and biomarker for improving immune checkpoint inhibitor responses in lung adenocarcinoma. Significance: cEMSY is a safe and effective immunogenic cell death inducer that synergizes with PD-1 blockade in lung adenocarcinoma, providing a potential strategy to enhance the efficacy of tumor immunotherapy.

mRNA vaccines in the context of cancer treatment: from concept to application

Immuno-oncology has witnessed remarkable advancements in the past decade, revolutionizing the landscape of cancer therapeutics in an encouraging manner. Among the diverse immunotherapy strategies, mRNA vaccines have ushered in a new era for the therapeutic management of malignant diseases, primarily due to their impressive impact on the COVID-19 pandemic. In this comprehensive review, we offer a systematic overview of mRNA vaccines, focusing on the optimization of structural design, the crucial role of delivery materials, and the administration route. Additionally, we summarize preclinical studies and clinical trials to provide valuable insights into the current status of mRNA vaccines in cancer treatment. Furthermore, we delve into a systematic discussion on the significant challenges facing the current development of mRNA tumor vaccines. These challenges encompass both intrinsic and external factors that are closely intertwined with the successful application of this innovative approach. To pave the way for a more promising future in cancer treatments, a deeper understanding of immunological mechanisms, an increasing number of high-quality clinical trials, and a well-established manufacturing platform are crucial. Collaborative efforts between scientists, clinicians, and industry engineers are essential to achieving these goals.

Expanding the Potential of Circular RNA (CircRNA) Vaccines: A Promising Therapeutic Approach

In recent years, circular RNAs (circRNAs) have garnered significant attention due to their unique structure and function, positioning them as promising candidates for next-generation vaccines. The circRNA vaccine, as an RNA vaccine, offers significant advantages in preventing infectious diseases by serving as a vector for protein expression through non-canonical translation. Notably, circRNA vaccines have demonstrated enduring antigenic expression and generate a larger percentage of neutralizing antibodies compared to mRNA vaccines administered at the same dosage. Furthermore, circRNA vaccines can elicit robust cellular and humoral immunity, indicating their potential for tumor vaccine development. However, certain challenges must be addressed to facilitate the widespread use of circRNA vaccines in both infectious disease prevention and tumor treatment. These challenges include the low efficiency of linear RNA circularization, the suboptimal targeting of delivery systems, and the assessment of potential side effects. This work aims to describe the characteristics and functions of circRNAs, elucidate the mechanism behind circRNA vaccines, and discuss their applications in the prevention of infectious diseases and the treatment of tumors, along with their potential future applications.

Optimized circular RNA vaccines for superior cancer immunotherapy

Rationale: Circular RNA (circRNA) has gained attention as a promising platform for mRNA vaccines due to its stability, sustained protein expression, and intrinsic immunostimulatory properties. This study aimed to design and optimize a circRNA cancer vaccine platform by screening for efficient internal ribosome entry sites (IRES) and enhancing circRNA translation efficiency for improved cancer immunotherapy. Methods: We screened 29 IRES elements to identify the most efficient one for immune cell translation, ultimately discovering the Enterovirus A (EV-A) IRES. Using SHAPE-MaP technology, we analyzed the secondary structure of circRNA and introduced targeted mutations and deletions to optimize translation efficiency. Additionally, we investigated the regulatory roles of spacer sequences and microRNA recognition sites in circRNA design and examined the mechanisms behind IRES-mediated translation initiation. Results: The EV-A IRES was identified as the most efficient for immune cell translation. Structural modifications and optimization of spacer sequences enhanced the translation efficiency of circRNA. Comparative studies demonstrated that circRNA vaccines induced stronger T cell immune responses and exhibited superior tumor prevention and therapeutic efficacy compared to traditional linear mRNA vaccines. Conclusion: The optimized tumor antigen circRNA vaccine platform offers a stable, efficient alternative to conventional mRNA vaccines for cancer immunotherapy, with enhanced immune responses and improved therapeutic outcomes. This work lays the foundation for developing circRNA-based vaccines as a novel strategy for cancer treatment.

A Review on Circular RNA Translation and Its Implications in Disease

The mRNA vaccine has emerged as a powerful tool against viral infection during the coronavirus disease 2019 (COVID-19) pandemic. In the post-COVID-19 era, the applications of mRNA-based therapy continue to expand and evolve. Circular RNA (circRNA), long assumed to be a noncoding RNA, has been proven to be translatable and subsequently developed as a next-generation mRNA modality due to its higher stability and wider therapeutic window. Nonetheless, the studies of circRNA translation and its application in diseases still present numerous technical features and challenges. In this chapter, we provide a summary and discussion on the mechanisms of circRNA translation and its applications in medicine development, aiming to serve as a reference and inspiration for readers interested in circRNA-based therapy.

Quantitative Real-Time PCR for Circular RNA Detection and Analysis

In eukaryotes, nearly 2% of the genome represented by the coding proteins. However, emerging evidence suggest more than 75% of the human genome referred to as noncoding part also plays a crucial role in governing major regulatory pathways. Noncoding RNAs can be categorized into several groups, such as microRNAs (miRNAs), small nuclear RNA (snRNAs), small nucleolar RNA (snoRNAs), transfer RNA (tRNA), and circular RNA (circRNAs), which contribute to this regulatory landscape. Circular RNAs (circRNAs) are identified as a new class of regulatory noncoding RNAs with gene regulatory roles by acting as miRNA or RNA binding protein sponges or interacting with proteins. Researchers employ quantitative real-time PCR methods to examine circular RNA expression utilizing divergent primers for identification and quantification.

Recent progress in mRNA cancer vaccines

The research and development of messenger RNA (mRNA) cancer vaccines have gradually overcome numerous challenges through the application of personalized cancer antigens, structural optimization of mRNA, and the development of alternative RNA-based vectors and efficient targeted delivery vectors. Clinical trials are currently underway for various cancer vaccines that encode tumor-associated antigens (TAAs), tumor-specific antigens (TSAs), or immunomodulators. In this paper, we summarize the optimization of mRNA and the emergence of RNA-based expression vectors in cancer vaccines. We begin by reviewing the advancement and utilization of state-of-the-art targeted lipid nanoparticles (LNPs), followed by presenting the primary classifications and clinical applications of mRNA cancer vaccines. Collectively, mRNA vaccines are emerging as a central focus in cancer immunotherapy, offering the potential to address multiple challenges in cancer treatment, either as standalone therapies or in combination with current cancer treatments.

Circular RNAs in Viral Infection and Antiviral Treatment

Circular RNAs (circRNAs) are a class of noncoding RNAs that lack the 5'-cap structure and the 3' poly(A) tail. Their distinguishing feature is that the 3' and 5' ends are covalently linked to form a closed circular structure. CircRNAs have a longer half-life and stronger ribonuclease resistance compared with linear RNA. Viral infections lead to the production of circRNA molecules through the transcription and splicing mechanisms of host cells. circRNAs are produced from the transcription and splicing of the viral genome or from the splicing reactions of the host cell gene. They participate in regulating the replication of many viruses, including coronaviruses, human herpesviruses, human immunodeficiency virus, and cytomegalovirus. CircRNAs regulate the infection process by modulating circRNA expression in host cells and affect cellular biological processes. Some circRNAs have been proposed as diagnostic markers for viral infections. In this review, we discussed the properties of virus-derived circRNAs, the biological functions of diverse viruses-derived and host circRNAs during viral infections, and the critical role of circRNAs in the host's antiviral immune defense. Extensive research on the applications of circRNAs can help us better understand gene regulatory networks and disease mechanisms.

The current therapeutic cancer vaccines landscape in non-small cell lung cancer

Currently, conventional immunotherapies for the treatment of non-small cell lung cancer (NSCLC) have low response rates and benefit only a minority of patients, particularly those with advanced disease, so novel therapeutic strategies are urgent deeded. Therapeutic cancer vaccines, a form of active immunotherapy, harness potential to activate the adaptive immune system against tumor cells via antigen cross-presentation. Cancer vaccines can establish enduring immune memory and guard against recurrences. Vaccine-induced tumor cell death prompts antigen epitope spreading, activating functional T cells and thereby sustaining a cancer-immunity cycle. The success of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rendered cancer vaccines a promising avenue, especially when combined with immunotherapy or chemoradiotherapy for NSCLC. This review delves into the intricate antitumor immune mechanisms underlying therapeutic cancer vaccines, enumerates the tumor antigen spectrum of NSCLC, discusses different cancer vaccines progress and summarizes relevant clinical trials. Additionally, we analyze the combination strategies, current limitations, and future prospects of cancer vaccines in NSCLC treatment, aiming to offer fresh insights for their clinical application in managing NSCLC. Overall, cancer vaccines offer promising potential for NSCLC treatment, particularly combining with chemoradiotherapy or immunotherapy could further improve survival in advanced patients. Exploring inhaled vaccines or prophylactic vaccines represents a crucial research avenue.

A previously unidentified circRNA inhibits virus replication by regulating the miR-24-3p/KEAP1 axis

Circular RNAs (circRNAs) exert diverse biological functions in different processes. However, the role of circRNAs during virus infection is mostly unknown. Herein, we explored the characteristics of host circRNAs using alphaherpesvirus pseudorabies virus (PRV) as a model. PRV infection upregulated the expression of circRNA circ29164, which does not encode a protein. RNA pulldown assays identified that circ29164 interacts with the microRNA ssc-miRNA-24-3p. Further analysis indicated that ssc-miR-24-3p targets the mRNA encoding kelch-like ECH-associated protein 1 (KEAP1), and circ29164 competitively binds to ssc-miR-24-3p to prevent it binding to Keap1. Apoptosis detection demonstrated that circ29164 or Keap1 overexpression, but not knockdown, induced caspase 3 activity and the release of cytochrome C from mitochondria, and inhibited PRV replication. Taken together, these data identified a previously undiscovered circRNA, circ29164, which inhibits PRV replication by competitively binding to ssc-24-3p to maintain KEAP1 levels.

Advancing the next generation of cancer treatment with circular RNAs in CAR-T cell therapy

Chimeric Antigen Receptor T-cell (CAR-T) therapy has revolutionized the treatment of hematological malignancies. However, its effectiveness against solid tumors remains constrained by challenges such as T-cell exhaustion, limited persistence, and off-target effects. These challenges highlight critical gaps in current CAR-T cell therapeutic strategies, particularly for solid tumor applications. Circular RNAs (circRNAs) represent a transformative class of non-coding RNAs, known for their exceptional stability and precise regulatory functions, positioning them as promising candidates for enhancing next-generation CAR-T cell therapies. Notably, circRNAs can bridge the gap between preclinical research and clinical application by offering innovative solutions to overcome technical hurdles and improve therapeutic outcomes. Despite their potential, circRNAs remain underexplored in clinical application of CAR-T cell therapies for solid tumors, presenting a significant opportunity for innovation. The mechanisms through which circRNAs modulate CAR-T cell exhaustion, persistence, and tumor specificity are not yet fully understood, and technical challenges, such as achieving efficient and targeted circRNA delivery, which still need to be addressed. This review highlights the importance of integrating circRNAs into CAR-T cell therapy to enhance specificity, minimize off-target effects, and improve therapeutic durability. By emphasizing the innovative potential of circRNAs and identifying key research gaps, this review provides a roadmap for advancing CAR-T cell therapy and setting the stage for the next generation of personalized cancer treatments.

Advanced technologies for the development of infectious disease vaccines

Vaccines play a critical role in the prevention of life-threatening infectious disease. However, the development of effective vaccines against many immune-evading pathogens such as HIV has proven challenging, and existing vaccines against some diseases such as tuberculosis and malaria have limited efficacy. The historically slow rate of vaccine development and limited pan-variant immune responses also limit existing vaccine utility against rapidly emerging and mutating pathogens such as influenza and SARS-CoV-2. Additionally, reactogenic effects can contribute to vaccine hesitancy, further undermining the ability of vaccination campaigns to generate herd immunity. These limitations are fuelling the development of novel vaccine technologies to more effectively combat infectious diseases. Towards this end, advances in vaccine delivery systems, adjuvants, antigens and other technologies are paving the way for the next generation of vaccines. This Review focuses on recent advances in synthetic vaccine systems and their associated challenges, highlighting innovation in the field of nano- and nucleic acid-based vaccines.

The role of polypeptides encoded by ncRNAs in cancer

It was previously thought that ncRNA could not encode polypeptides, but recent reports have challenged this notion. As research into ncRNA progresses, it is increasingly clear that it serves roles beyond traditional mechanisms, playing significant regulatory roles in various diseases, notably cancer, which is responsible for 70% of human deaths. Numerous studies have highlighted the diverse regulatory mechanisms of ncRNA that are pivotal in cancer initiation and progression. The role of ncRNA-encoded polypeptides in cancer regulation has gained prominence. This article explores the newly identified regulatory functions of these polypeptides in three types of ncRNA-lncRNA, pri-miRNA, and circRNA. These polypeptides can interact with proteins, influence signaling pathways, enhance miRNA stability, and regulate cancer progression, malignancy, resistance, and other clinical challenges. Furthermore, we discuss the evolutionary significance of these polypeptides in the transition from RNA to protein, examining their emergence and conservation throughout evolution.

Vaccine Strategies Against RNA Viruses: Current Advances and Future Directions

The development of vaccines against RNA viruses has undergone a rapid evolution in recent years, particularly driven by the COVID-19 pandemic. This review examines the key roles that RNA viruses, with their high mutation rates and zoonotic potential, play in fostering vaccine innovation. We also discuss both traditional and modern vaccine platforms and the impact of new technologies, such as artificial intelligence, on optimizing immunization strategies. This review evaluates various vaccine platforms, ranging from traditional approaches (inactivated and live-attenuated vaccines) to modern technologies (subunit vaccines, viral and bacterial vectors, nucleic acid vaccines such as mRNA and DNA, and phage-like particle vaccines). To illustrate these platforms' practical applications, we present case studies of vaccines developed for RNA viruses such as SARS-CoV-2, influenza, Zika, and dengue. Additionally, we assess the role of artificial intelligence in predicting viral mutations and enhancing vaccine design. The case studies underscore the successful application of RNA-based vaccines, particularly in the fight against COVID-19, which has saved millions of lives. Current clinical trials for influenza, Zika, and dengue vaccines continue to show promise, highlighting the growing efficacy and adaptability of these platforms. Furthermore, artificial intelligence is driving improvements in vaccine candidate optimization and providing predictive models for viral evolution, enhancing our ability to respond to future outbreaks. Advances in vaccine technology, such as the success of mRNA vaccines against SARS-CoV-2, highlight the potential of nucleic acid platforms in combating RNA viruses. Ongoing trials for influenza, Zika, and dengue demonstrate platform adaptability, while artificial intelligence enhances vaccine design by predicting viral mutations. Integrating these innovations with the One Health approach, which unites human, animal, and environmental health, is essential for strengthening global preparedness against future RNA virus threats.

IL-7 promotes mRNA vaccine-induced long-term immunity

Messenger RNA (mRNA) vaccines are a key technology in combating existing and emerging infectious diseases. However, improving the immunogenicity and durability of mRNA vaccines remains a challenge. To elicit optimal immune responses, integrating antigen-encoded mRNA and immunostimulatory adjuvants into a single formulation is a promising approach to enhancing the efficacy of mRNA vaccines. Here, we report an adjuvant strategy to enhance the efficacy of mRNA vaccines by co-loading mRNA encoding the antigen (rabies virus glycoprotein, RABV-G) and mRNA encoding IL-7 into lipid nanoparticles, achieving co-delivery to the same antigen-presenting cells. A single immunization with G&IL-7 mRNA vaccine elicited robust humoral immune responses in mice and conferred complete protection against RABV challenge. Notably, the high levels of neutralizing antibody induced by the G&IL-7 mRNA vaccine were maintained for at least 6 months, providing mice with long-term significant and complete protection against RABV. Additionally, IL-7 also enhanced antibody responses against the SARS-CoV-2. These data demonstrate that IL-7 is a potent mRNA vaccine adjuvant that can provide the required immune stimulation in various mRNA vaccine formulations.

Synthetic circRNA therapeutics: innovations, strategies, and future horizons

Small molecule drugs are increasingly emerging as innovative and effective treatments for various diseases, with mRNA therapeutics being a notable representative. The success of COVID-19 vaccines has underscored the transformative potential of mRNA in RNA therapeutics. Within the RNA family, there is another unique type known as circRNA. This single-stranded closed-loop RNA molecule offers notable advantages over mRNA, including enhanced stability and prolonged protein expression, which may significantly impact therapeutic strategies. Furthermore, circRNA plays a pivotal role in the pathogenesis of various diseases, such as cancers, autoimmune disorders, and cardiovascular diseases, making it a promising clinical intervention target. Despite these benefits, the application of circRNA in clinical settings remains underexplored. This review provides a comprehensive overview of the current state of synthetic circRNA therapeutics, focusing on its synthesis, optimization, delivery, and diverse applications. It also addresses the challenges impeding the advancement of circRNA therapeutics from bench to bedside. By summarizing these aspects, the review aims to equip researchers with insights into the ongoing developments and future directions in circRNA therapeutics. Highlighting both the progress and the existing gaps in circRNA research, this review offers valuable perspectives for advancing the field and guiding future investigations.

CircRNAs as upstream regulators of miRNA//HMGA2 axis in human cancer

High mobility group protein A2 (HMGA2) is widely recognized as a chromatin-binding protein, whose overexpression is observed in nearly all human cancers. It exerts its oncogenic effects by influencing various cellular processes such as the epithelial-mesenchymal transition, cell differentiation, and DNA damage repair. MicroRNA (miRNA) serves as a pivotal gene expression regulator, concurrently modulating multiple genes implicated in cancer progression, including HMGA2. It also serves as a significant biomarker for cancer. Circular RNA (circRNA) plays a crucial role in gene regulation primarily by sequestering miRNAs and impeding their ability to enhance the expression of other genes, including HMGA2. Increasingly, studies have underscored the vital role of miRNA/HMGA2 interactions in cancer. Given the significance of circRNA as an upstream regulatory mediator and the complexity of regulatory mechanisms, we hereby present a comprehensive overview of the pivotal role of circRNAs as upstream regulators of the miRNA//HMGA2 axis in human cancers. This insight may herald a novel direction for future cancer research.

CXCL13 promotes broad immune responses induced by circular RNA vaccines

Antibody responses induced by current vaccines for influenza and SARS-CoV-2 often lack robust cross-reactivity. As hubs where diverse immune cells converge and interact, the alterations in the immune microenvironment within lymph nodes (LNs) are intricately linked to immune responses. Herein, we designed a lipid nanoparticle (LNP) loaded with circular RNA (circRNA) and targeted to LNs, in which CXCL13 was directly integrated into antigen-encoding circRNA strands. We demonstrated that CXCL13 alters the transcriptomic profiles of LNs, especially the upregulation of IL-21 and IL-4. Meanwhile, CXCL13 promotes the formation of germinal center and elicits robust antigen-specific T cell responses. With the codelivery of CXCL13 and the antigen, CXCL13 enhances cross-reactive antibodies against influenza virus and SARS-CoV-2, achieving protection against both homologous and heterologous influenza virus challenges in a mouse model. Notably, the targeted modification of LNP surfaces with antibodies helps address some of the challenges associated with lyophilized LNP vaccines, which is crucial for the long-term storage of LNP-circRNA vaccines. Overall, the circRNA-based antigen-CXCL13 coexpression system developed herein provides a simple and robust platform that enhances the magnitude and breadth of antibody responses against multiple viral glycoproteins, highlighting the potential utility of CXCL13 in inducing broad immune responses.

Advances and applications of RNA vaccines in tumor treatment

Compared to other types of tumor vaccines, RNA vaccines have emerged as promising alternatives to conventional vaccine therapy due to their high efficiency, rapid development capability, and potential for low-cost manufacturing and safe drug delivery. RNA vaccines mainly include mRNA, circular RNA (circRNA), and Self-amplifying mRNA(SAM). Different RNA vaccine platforms for different tumors have shown encouraging results in animal and human models. This review comprehensively describes the advances and applications of RNA vaccines in antitumor therapy. Future directions for extending this promising vaccine platform to a wide range of therapeutic uses are also discussed.

Circular RNAs: Novel Players in Cancer Mechanisms and Therapeutic Strategies

Circular RNAs (circRNAs) are a novel class of noncoding RNAs that have emerged as pivotal players in gene regulation. Our understanding of circRNAs has greatly expanded over the last decade, with studies elucidating their biology and exploring their therapeutic applications. In this review, we provide an overview of the current understanding of circRNA biogenesis, outline their mechanisms of action in cancer, and assess their clinical potential as biomarkers. Furthermore, we discuss circRNAs as a potential therapeutic strategy, including recent advances in circRNA production and translation, along with proof-of-concept preclinical studies of cancer vaccines.

CircRNA based multivalent neuraminidase vaccine induces broad protection against influenza viruses in mice

Developing broad-spectrum influenza vaccines is crucial for influenza control and potential pandemic preparedness. Here, we reported a novel vaccine design utilizing circular RNA (circRNA) as a delivery platform for multi-subtype neuraminidases (NA) (influenza A N1, N2, and influenza B Victoria lineage NA) immunogens. Individual NA circRNA lipid nanoparticles (LNP) elicited robust NA-specific antibody responses with neuraminidase inhibition activity (NAI), preventing the virus from egressing and infecting neighboring cells. Additionally, the administration of circRNA LNP induced cellular immunity in mice. To achieve a universal influenza vaccine, we combined all three subtypes of NA circRNA-LNPs to generate a trivalent circRNA vaccine. The trivalent vaccine elicited a balanced antibody response against all three NA subtypes and a Th1-biased immune response in mice. Moreover, it protected mice against the lethal challenge of matched and mismatched H1N1, H3N2, and influenza B viruses, encompassing circulating and ancestral influenza virus strains. This study highlights the potential of delivering multiple NA antigens through circRNA-LNPs as a promising strategy for effectively developing a universal influenza vaccine against diverse influenza viruses.

Circular RNA in cancer

Over the past decade, circular RNA (circRNA) research has evolved into a bona fide research field shedding light on the functional consequence of this unique family of RNA molecules in cancer. Although the method of formation and the abundance of circRNAs can differ from their cognate linear mRNA, the spectrum of interacting partners and their resultant cellular functions in oncogenesis are analogous. However, with 10 times more diversity in circRNA variants compared with linear RNA variants, combined with their hyperstability in the cell, circRNAs are equipped to influence every stage of oncogenesis. This is an opportune time to address the breadth of circRNA in cancer focused on their spatiotemporal expression, mutations in biogenesis factors and contemporary functions through each stage of cancer. In this Review, we highlight examples of functional circRNAs in specific cancers, which satisfy critical criteria, including their physical co-association with the target and circRNA abundance at stoichiometrically valid quantities. These considerations are essential to develop strategies for the therapeutic exploitation of circRNAs as biomarkers and targeted anticancer agents.

The circular RNA circSLC16A10 alleviates diabetic retinopathy by improving mitochondrial function via the miR-761-5p/MFN2 axis

It has been demonstrated that circular RNAs (circRNAs) are associated with the development of diabetic retinopathy (DR). Nevertheless, the function of circSLC16A10 in the development of DR remains unclear. In order to investigate the role of circSLC16A10, we employed cell and animal models of DR. An analysis of a public database revealed that hsa_circSLC16A10 was expressed at lower levels in DR patients than in diabetic patients without DR or healthy controls. Additionally, the level of hsa_circSLC16A10 was lower in high glucose (HG)-exposed ARPE-19 cells and diabetic mice. hsa_circSLC16A10 was observed to be mainly distributed in the cytoplasm. Moreover, overexpression of hsa_circSLC16A10 alleviated HG-induced endoplasmic reticulum stress and cell apoptosis in vitro. Furthermore, overexpression of hsa_circSLC16A10 ameliorated HG-induced mitochondrial dysfunction, as evidenced by improvements in mitochondrial structure and function. hsa_circSLC16A10 acted as a hsa-miR-761-5p sponge to increase MFN2 expression. MFN2 knockdown or hsa-miR-761-5p overexpression partially reversed the protective effect of hsa_circSLC16A10 in vitro. The protective effect of mmu_circSLC16A10 against DR was confirmed in an animal model of DR. These findings indicate that circSLC16A10 may regulate DR progression by improving mitochondrial function via the miR-761-5p/MFN2 axis.

In Vitro Self-Circularization Methods Based on Self-Splicing Ribozyme

In vitro circular RNA (circRNA) preparation methods have been gaining a lot of attention recently as several reports suggest that circRNAs are more stable, with better performances in cells and in vivo, than linear RNAs in various biomedical applications. Self-splicing ribozymes are considered a major in vitro circRNA generation method for biomedical applications due to their simplicity and efficiency in the circularization of the gene of interest. This review summarizes, updates, and discusses the recently developed self-circularization methods based on the self-splicing ribozyme, such as group I and II intron ribozymes, and the pros and cons of each method in preparing circRNA in vitro.

Advances in Engineering Circular RNA Vaccines

Engineered circular RNAs (circRNAs) are a class of single-stranded RNAs with head-to-tail covalently linked structures that integrate open reading frames (ORFs) and internal ribosome entry sites (IRESs) with the function of coding and expressing proteins. Compared to mRNA vaccines, circRNA vaccines offer a more improved method that is safe, stable, and simple to manufacture. With the rapid revelation of the biological functions of circRNA and the success of Severe Acute Respiratory Coronavirus Type II (SARS-CoV-2) mRNA vaccines, biopharmaceutical companies and researchers around the globe are attempting to develop more stable circRNA vaccines for illness prevention and treatment. Nevertheless, research on circRNA vaccines is still in its infancy, and more work and assessment are needed for their synthesis, delivery, and use. In this review, based on the current understanding of the molecular biological properties and immunotherapeutic mechanisms of circRNA, we summarize the current preparation methods of circRNA vaccines, including design, synthesis, purification, and identification. We discuss their delivery strategies and summarize the challenges facing the clinical application of circRNAs to provide references for circRNA vaccine-related research.

Circular RNA circNIPBL regulates TP53-H179R mutations in NNK-induced bronchial epithelial carcinogenesis

Exposure to environmental carcinogens is a significant contributor to cancer development, with genetic and epigenetic alterations playing pivotal roles in the carcinogenic process. However, the interplay between epigenetic regulation and genetic changes in carcinogenesis has yet to receive comprehensive attention. This study investigates the impact of continuous exposure to the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) on bronchial epithelial cells, leading to malignant transformation. Our findings reveal the down-regulation of the tumor suppressor-like circular RNA circNIPBL during oncogenic processes concomitant with the accumulation of the TP53-H179R, a single nucleotide variant. Diminished circNIPBL expression enhances the proliferative, distant metastatic, and tumor-forming capabilities of NNK-induced cancerous cells and lung cancer cell lines (A549, H1299), while also promoting the accumulation of TP53-H179R during NNK-induced carcinogenesis. Mechanistic investigations demonstrate that circNIPBL interacts with HSP90α to regulate the translocation of AHR into the nucleus, which may be a potential regulatory mechanism for NNK-induced carcinogenesis and TP53-H179R accumulation. This study introduces a novel perspective on the interplay between genetic alterations and epigenetic regulation in chemical carcinogenesis, which provides novel insight into the etiology of cancer.

Circular RNA-based neoantigen vaccine for hepatocellular carcinoma immunotherapy

mRNA vaccines are regarded as a highly promising avenue for next-generation cancer therapy. Nevertheless, the intricacy of production, inherent instability, and low expression persistence of linear mRNA significantly restrict their extensive utilization. Circular RNAs (circRNAs) offer a novel solution to these limitations due to their efficient protein expression ability, which can be rapidly generated in vitro without the need for extra modifications. Here, we present a novel neoantigen vaccine based on circRNA that induces a potent anti-tumor immune response by expressing hepatocellular carcinoma-specific tumor neoantigens. By cyclizing linearRNA molecules, we were able to enhance the stability of RNA vaccines and form highly stable circRNA molecules with the capacity for sustained protein expression. We confirmed that neoantigen-encoded circRNA can promote dendritic cell (DC) activation and enhance DC-induced T-cell activation in vitro, thereby enhancing T-cell killing of tumor cells. Encapsulating neoantigen-encoded circRNA within lipid nanoparticles for in vivo expression has enabled the creation of a novel circRNA vaccine platform. This platform demonstrates superior tumor treatment and prevention in various murine tumor models, eliciting a robust T-cell immune response. Our circRNA neoantigen vaccine offers new options and application prospects for neoantigen immunotherapy in solid tumors.

Isoprenoid CARTs: In Vitro and In Vivo mRNA Delivery by Charge-Altering Releasable Transporters Functionalized with Archaea-inspired Branched Lipids

The delivery of oligonucleotides across biological barriers is a challenge of unsurpassed significance at the interface of materials science and medicine, with emerging clinical utility in prophylactic and therapeutic vaccinations, immunotherapies, genome editing, and cell rejuvenation. Here, we address the role of readily available branched lipids in the design, synthesis, and evaluation of isoprenoid charge-altering releasable transporters (CARTs), a pH-responsive oligomeric nanoparticle delivery system for RNA. Systematic variation of the lipid block reveals an emergent relationship between the lipid block and the neutralization kinetics of the polycationic block. Unexpectedly, iA21A11, a CART with the smallest lipid side chain, isoamyl-, was identified as the lead isoprenoid CART for the in vitro transfection of immortalized lymphoblastic cell lines. When administered intramuscularly in a murine model, iA21A11-mRNA complexes induce higher protein expression levels than our previous lead CART, ONA. Isoprenoid CARTs represent a new delivery platform for RNA vaccines and other polyanion-based therapeutics.

Engineering circular RNA for molecular and metabolic reprogramming

The role of messenger RNA (mRNA) in biological systems is extremely versatile. However, it's extremely short half-life poses a fundamental restriction on its application. Moreover, the translation efficiency of mRNA is also limited. On the contrary, circular RNAs, also known as circRNAs, are a common and stable form of RNA found in eukaryotic cells. These molecules are synthesized via back-splicing. Both synthetic circRNAs and certain endogenous circRNAs have the potential to encode proteins, hence suggesting the potential of circRNA as a gene expression machinery. Herein, we aim to summarize all engineering aspects that allow exogenous circular RNA (circRNA) to prolong the time that proteins are expressed from full-length RNA signals. This review presents a systematic engineering approach that have been devised to efficiently assemble circRNAs and evaluate several aspects that have an impact on protein production derived from. We have also reviewed how optimization of the key components of circRNAs, including the topology of vector, 5' and 3' untranslated sections, entrance site of the internal ribosome, and engineered aptamers could be efficiently impacting the translation machinery for molecular and metabolic reprogramming. Collectively, molecular and metabolic reprogramming present a novel way of regulating distinctive cellular features, for instance growth traits to neoplastic cells, and offer new possibilities for therapeutic inventions.

CircRNA Regulation of T Cells in Cancer: Unraveling Potential Targets

T lymphocytes play a critical role in antitumor immunity, but their exhaustion poses a significant challenge for immune evasion by malignant cells. Circular RNAs (circRNAs), characterized by their covalently closed looped structure, have emerged as pivotal regulators within the neoplastic landscape. Recent studies have highlighted their multifaceted roles in cellular processes, including gene expression modulation and protein function regulation, which are often disrupted in cancer. In this review, we systematically explore the intricate interplay between circRNAs and T cell modulation within the tumor microenvironment. By dissecting the regulatory mechanisms through which circRNAs impact T cell exhaustion, we aim to uncover pathways crucial for immune evasion and T cell dysfunction. These insights can inform innovative immunotherapeutic strategies targeting circRNA-mediated molecular pathways. Additionally, we discuss the translational potential of circRNAs as biomarkers for therapeutic response prediction and as intervention targets. Our comprehensive analysis aims to enhance the understanding of immune evasion dynamics in the tumor microenvironment by facilitating the development of precision immunotherapy.

Pathways for macrophage uptake of cell-free circular RNAs

Circular RNAs (circRNAs) are stable RNAs present in cell-free RNA, which may comprise cellular debris and pathogen genomes. Here, we investigate the phenomenon and mechanism of cellular uptake and intracellular fate of exogenous circRNAs. Human myeloid cells and B cells selectively internalize extracellular circRNAs. Macrophage uptake of circRNA is rapid, energy dependent, and saturable. CircRNA uptake can lead to translation of encoded sequences and antigen presentation. The route of internalization influences immune activation after circRNA uptake, with distinct gene expression programs depending on the route of RNA delivery. Genome-scale CRISPR screens and chemical inhibitor studies nominate macrophage scavenger receptor MSR1, Toll-like receptors, and mTOR signaling as key regulators of receptor-mediated phagocytosis of circRNAs, a dominant pathway to internalize circRNAs in parallel to macropinocytosis. These results suggest that cell-free circRNA serves as an "eat me" signal and danger-associated molecular pattern, indicating orderly pathways of recognition and disposal.

Organ- and Cell-Selective Delivery of mRNA In Vivo Using Guanidinylated Serinol Charge-Altering Releasable Transporters

Selective RNA delivery is required for the broad implementation of RNA clinical applications, including prophylactic and therapeutic vaccinations, immunotherapies for cancer, and genome editing. Current polyanion delivery relies heavily on cationic amines, while cationic guanidinium systems have received limited attention due in part to their strong polyanion association, which impedes intracellular polyanion release. Here, we disclose a general solution to this problem in which cationic guanidinium groups are used to form stable RNA complexes upon formulation but at physiological pH undergo a novel charge-neutralization process, resulting in RNA release. This new delivery system consists of guanidinylated serinol moieties incorporated into a charge-altering releasable transporter (GSer-CARTs). Significantly, systematic variations in structure and formulation resulted in GSer-CARTs that exhibit highly selective mRNA delivery to the lung (∼97%) and spleen (∼98%) without targeting ligands. Illustrative of their breadth and translational potential, GSer-CARTs deliver circRNA, providing the basis for a cancer vaccination strategy, which in a murine model resulted in antigen-specific immune responses and effective suppression of established tumors.

The biogenesis, identification, and functionality of circWWP2 in lipopolysaccharide stimulated macrophages

CircRNA, a non-coding RNA, is an ideal biomarker and a suitable potential therapeutic target for various disease due to its high stability, species conservation and cell/tissue specificity. Our previous study has found a circular RNA WWP2 (circWWP2) was significantly decreased in chicken macrophages during bacterial infection. However, the function of circWWP2 in chicken macrophages remains unclear. In this study, it was demonstrated that circWWP2 was a stable circular RNA created by back-splicing of exons 2 to 4 of WWP2 via PCR amplification, Sanger sequencing, RNase R exonuclease digestion, and RT-qPCR. Moreover, bioinformatics analysis showed circWWP2 could interact with 13 miRNAs and target 3,264 genes, which were significantly enriched in lysosomes, IgA-producing intestinal immune networks for IgA production, and Notch signaling pathway. Furthermore, CCK8 and RT-qPCR indicated that overexpression of circWWP2 could promote lipopolysaccharide (LPS)-induced cellular injury by decreasing cell viability and increasing the expression levels of pro-inflammatory cytokines and pro-apoptosis genes, and NO production. CircWWP2 may exert a potential target for the treatment of bacterial infection. Further experiments are necessary to validate the specific mechanism that circWWP2 regulates LPS induced cellular immune responses.

CircRNA: a rising therapeutic strategy for lung injury induced by pulmonary toxicants

Lung injury has been a serious medical problem that requires new therapeutic approaches and biomarkers. Circular RNAs (circRNAs) are non-coding RNAs (ncRNAs) that exist widely in eukaryotes. CircRNAs are single-stranded RNAs that form covalently closed loops. CircRNAs are significant gene regulators that have a role in the development, progression, and therapy of lung injury by controlling transcription, translating into protein, and sponging microRNAs (miRNAs) and proteins. Although the study of circRNAs in lung injury caused by pulmonary toxicants is just beginning, several studies have revealed their expression patterns. The function that circRNAs perform in relation to pulmonary toxicants (severe acute respiratory distress syndrome coronavirus-2 (SARS-CoV-2), drug abuse, PM2.5, and cigarette smoke) is the main topic of this review. A variety of circRNAs can serve as potential biomarkers of lung injury. In this review, the biogenesis, properties, and biological functions of circRNAs were concluded, and the relationship between circRNAs and pulmonary toxicants was discussed. It is expected that the new ideas and potential treatment targets that circRNAs provide would be beneficial to research into the molecular mechanisms behind lung injury.

Potential therapeutic strategy for cancer: Multi-dimensional cross-talk between circRNAs and parental genes

In many ways, circular RNAs (circRNAs) have been demonstrated to be crucial in the onset and advancement of cancer throughout the last ten years and have become a new focus of intense research in the field of RNAs. Accumulating studies have demonstrated that circRNAs can regulate parental gene expression via a variety of biological pathways. Furthermore, research into the complex interactions between circRNAs and their parental genes will shed light on their biological roles and open up new avenues for circRNAs' potential clinical translational uses. However, to date, multi-dimensional cross-talk between circRNAs and parental genes have not been systematically elucidated. Particularly intriguing is circRNA's exploration of tumor targeting, and potential therapeutic uses based on the parental gene regulation perspective. Here, we discuss their biogenesis, take a fresh look at the molecular mechanisms through which circRNAs control the expression of their parental genes in cancer. We further highlight We further highlight the latest circRNA clinical translational applications, including prognostic diagnostic markers, cancer vaccines, gDNA, and so on. Demonstrating the potential benefits and future applications of circRNA therapy.

Translational adaptation in breast cancer metastasis and emerging therapeutic opportunities

Breast cancer's tendency to metastasize poses a critical barrier to effective treatment, making it a leading cause of mortality among women worldwide. A growing body of evidence is showing that translational adaptation is emerging as a key mechanism enabling cancer cells to thrive in the dynamic tumor microenvironment (TME). Here, we systematically summarize how breast cancer cells utilize translational adaptation to drive metastasis, highlighting the intricate regulation by specific translation machinery and mRNA attributes such as sequences and structures, along with the involvement of tRNAs and other trans-acting RNAs. We provide an overview of the latest findings and emerging concepts in this area, discussing their potential implications for therapeutic strategies in breast cancer.