m6A methyltransferase METTL3 maintains colon cancer tumorigenicity by suppressing SOCS2 to promote cell proliferation

The landscape of N 6-methyladenosine RNA methylation in skin diseases

Skin diseases encompass a diverse range of conditions with significant psychological and physiological impacts. N6-methyladenosine (m6A) RNA methylation is a key epitranscriptomic modification that regulates gene expression by influencing RNA stability, splicing, translation, export and degradation. Recent studies have highlighted the crucial role of m6A modification in the pathogenesis and progression of various skin diseases. m6A modification affects critical biologic processes of the skin, such as inflammation, immune response and cellular ageing. This review systematically explores the landscape of m6A modification in nontumour skin diseases, elucidating its regulatory roles and therapeutic implications, including wound healing, scar and keloid, skin ageing, psoriasis, systemic lupus erythematosus, acne vulgaris, rosacea, chronic actinic dermatitis and scleroderma. The intricate mechanisms of m6A modification can lead to the development of novel diagnostic biomarkers and therapeutic strategies, ultimately improving patient outcomes.

CRISPR-based genetically modified scaffold-free biomaterials for tissue engineering and regenerative medicine

CRISPR-based genetically modified scaffold-free biomaterials, including extracellular vehicles, cell sheets, cell aggregates, organoids and organs, have attracted significant attention in the fields of regenerative medicine and tissue engineering in recent years. With a wide range of applications in gene therapy, modeling disease, tissue regeneration, organ xenotransplantation, modeling organogenesis as well as gene and drug screening, they are at a critical juncture from clinical trials to therapeutic applications. Xenografts have already been tested on non-human primates and humans. However, we have to admit that a series of obstacles still need to be addressed, such as immune response, viral infection, off-target effects, difficulty in mass production, and ethical issues. Therefore, future research should pay more attention to improving their safety, accuracy of gene editing, flexibility of production, and ethical rationality. This review summarizes various types of CRISPR-based genetically modified scaffold-free biomaterials, including their preparation procedures, applications, and possible improvements.

CEBPA Restrains the Malignant Progression of Breast Cancer by Prompting the Transcription of SOCS2

The suppressor of cytokine signaling 2 (SOCS2) has been identified to act as a tumor suppressor in breast cancer (BC) progression. However, the action of SOCS2 in macrophage polarization in BC cells has not been reported yet. The qRT-PCR and western blotting were adopted for detecting the levels of mRNAs and proteins. The macrophage M2 polarization was analyzed by flow cytometry. Analyses of cell oncogenic phenotypes and tumor growth were conducted using 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, scratch, Transwell, tube formation assays in vitro, and tumor xenograft assay in vivo, respectively. The interaction between CEBPA (CCAAT Enhancer Binding Protein Alpha) and SOCS2 was confirmed using bioinformatics analysis and dual-luciferase reporter assay. SOCS2 was lowly expressed in BC tissues and cells. Functionally, overexpression of SOCS2 inhibited macrophage M2 polarization, and impaired BC cell proliferation, angiogenesis, and metastasis. Mechanistically, CEBPA bound to the promoter region of SOCS2, and promoted its transcription. A low CEBPA expression was observed in BC tissues and cells. Forced expression of CEBPA also suppressed macrophage M2 polarization, BC cell proliferation, angiogenesis, and metastasis. Moreover, the anticancer effects mediated by CEBPA were abolished by SOCS2 knockdown. In addition, CEBPA overexpression impeded BC growth in nude mice by regulating SOCS2. CEBPA suppressed macrophage M2 polarization, BC cell proliferation, angiogenesis, and metastasis by promoting SOCS2 transcription in a targeted manner.

HDAC2-Mediated METTL3 Delactylation Promotes DNA Damage Repair and Chemotherapy Resistance in Triple-Negative Breast Cancer

The current treatment of triple-negative breast cancer (TNBC) is still primarily based on platinum-based chemotherapy. However, TNBC cells frequently develop resistance to platinum and experience relapse after drug withdrawal. It is crucial to specifically target and eliminate cisplatin-tolerant cells after platinum administration. Here, it is reported that upregulated N 6-methyladenosine (m6A) modification drives the development of resistance in TNBC cells during cisplatin treatment. Mechanistically, histone deacetylase 2 (HDAC2) mediates delactylation of methyltransferase-like 3 (METTL3), facilitating METTL3 interaction with Wilms'-tumor-1-associated protein and subsequently increasing m6A of transcript-associated DNA damage repair. This ultimately promotes cell survival under cisplatin. Furthermore, pharmacological inhibition of HDAC2 using Tucidinostat can enhance the sensitivity of TNBC cells to cisplatin therapy. This study not only elucidates the biological function of lactylated METTL3 in tumor cells but also highlights its negative regulatory effect on cisplatin resistance. Additionally, it underscores the nonclassical functional mechanism of Tucidinostat as a HDAC inhibitor for improving the efficacy of cisplatin against TNBC.

The METTL3/TRAP1 axis as a key regulator of 5-fluorouracil chemosensitivity in colorectal cancer

Colorectal cancer (CRC) remains a significant clinical challenge, with 5-Fluorouracil (5-FU) being the frontline chemotherapy. However, chemoresistance remains a major obstacle to effective treatment. METTL3, a key methyltransferase involved in RNA methylation processes, has been implicated in CRC carcinogenesis. However, its role in modulating CRC sensitivity to 5-FU remains elusive. In this study, we aimed to investigate the role and mechanisms of METTL3 in regulating 5-FU chemosensitivity in CRC cells. Initially, we observed that 5-FU treatment inhibited cell viability and induced apoptosis, accompanied by a reduction in METTL3 expression in HCT-116 and HCT-8 cells. Subsequent assays including drug sensitivity, EdU, colony formation, TUNEL staining, and flow cytometry revealed that METTL3 depletion enhanced 5-FU sensitivity and increased apoptosis induction both in vitro and in vivo. Conversely, METTL3 overexpression conferred resistance to 5-FU in both cell lines. Moreover, knockdown of METTL3 in 5-FU-resistant CRC cell lines HCT-116/FU and HCT-15/FU significantly decreased 5-FU tolerance and induced apoptosis upon 5-FU treatment. Mechanistically, we found that METTL3 regulated 5-FU sensitivity and apoptosis induction by modulating TRAP1 expression. Further investigations using m6A colorimetric ELISA, dot blot, MeRIP-qPCR and RNA stability assays demonstrated that METTL3 regulated TRAP1 mRNA stability in an m6A-dependent manner. Additionally, overexpression of TRAP1 mitigated the cytotoxic effects of 5-FU on CRC cells. In summary, our study uncovers the pivotal role of the METTL3/TRAP1 axis in modulating 5-FU chemosensitivity in CRC. These findings provide new insights into the mechanisms underlying CRC resistance to 5-FU and may offer potential targets for future therapeutic interventions.

Research progress on N6-Methyladenosine modification in angiogenesis, vasculogenic mimicry, and therapeutic implications in breast cancer

N6-methyladenosine (m6A) modification is the most common epitranscriptomic modification in eukaryotic RNA and has garnered extensive attention in the context of breast cancer research. The m6A modification significantly impacts tumorigenesis and tumor progression by regulating RNA stability, splicing, translation, and degradation. In this review we summarize recent advances in understanding the roles of m6A modification in the mechanisms underlying angiogenesis and vasculogenic mimicry in breast cancer. We review how m6A modification and associated transcripts influence relevant factors by affecting key factors and signaling pathways, highlighting the interactions among m6A "writers," "erasers," and "readers," and their overall impact on tumor angiogenesis and vasculogenic mimicry, as well as potential new therapeutic targets.

Gold Nanoparticle Inhibits the Tumor-Associated Macrophage M2 Polarization by Inhibiting m6A Methylation-Dependent ATG5/Autophagy in Prostate Cancer

Background: This study aims to study how gold nanoparticles (AuNPs) function in the recruitment and polarization of tumor-associated macrophages (TAMs) in hormone-sensitive prostate cancer (HSPC) and castration-resistant prostate cancer (CRPC). Methods: Phorbol ester (PMA)-treated THP-1 cells were cocultured with LNCaP or PC3 cells to simulate TAMs. Macrophage M2 polarization levels were detected using flow cytometry and M2 marker determination. ATG5 expression was detected by western blotting. Luciferase reporter assay was used to analyze the N6-methyladenosine (m6A) site activity of ATG5 3' untranslated regions (3'-UTRs). Methylated RNA immune precipitation (MeRIP)-quantitative polymerase chain reaction (qPCR) was performed to determine the m6A levels at ATG5 3'-UTR. Xenograft mouse models were used to determine the function of AuNPs in vivo. Results: Macrophages exhibited reduced M2 polarization in both HSPC and CRPC cells after AuNP treatment which was prevented by induction of autophagy. AuNP treatment decreased the m6A levels in the 3'-UTR of ATG5. Mutational analysis of potential m6A sites within ATG5 3'-UTR revealed that these sites were required for AuNP regulation, indicating that AuNPs inhibited ATG5 levels in an m6A-dependent manner. The mouse model revealed that AuNPs significantly reduced the M2 polarization of TAMs in an autophagy-dependent manner in vivo. This suggests that AuNPs inhibit tumor growth in vivo partially through targeting M2 TAM. Conclusion: The ATG5/autophagy pathway is inhibited by AuNP treatment in an METTL3/m6A-dependent manner. AuNPs inhibit the TAM M2 polarization in HSPC and CRPC by inhibiting ATG5/autophagy.

Epigenetic modification of hepatitis B virus infection and related hepatocellular carcinoma

Hepatitis B virus (HBV) infection poses a challenge to global public health. Persistent liver infection with HBV is associated with an increased risk of developing severe liver disease. The complex interaction between the virus and the host is the reason for the persistent presence of HBV and the risk of tumor development. Chronic liver inflammation, integration of viral genome with host genome, expression of HBx protein, and viral genotype are all key participants in the pathogenesis of hepatocellular carcinoma (HCC). Epigenetic regulation in HBV-associated HCC involves complex interactions of molecular mechanisms that control gene expression and function without altering the underlying DNA sequence. These epigenetic modifications can significantly affect the onset and progression of HCC. This review summarizes recent research on the epigenetic regulation of HBV persistent infection and HBV-HCC development, including DNA methylation, histone modification, RNA modification, non-coding RNA, etc. Enhanced knowledge of these mechanisms will offer fresh perspectives and potential targets for intervention tactics in HBV-HCC.

Current insights on m6A RNA modification in acute leukemia: therapeutic targets and future prospects

RNA modification is the critical mechanism for regulating post-transcriptional processes. There are more than 150 RNA modifications reported so far, among which N6-Methyladenosine is the most prevalent one. M6A RNA modification complex consists of 'writers', 'readers' and 'erasers' which together in a group catalyze, recognize and regulate the methylation process of RNA and thereby regulate the stability and translation of mRNA. The discovery of erasers also known as demethylases, revolutionized the research on RNA modifications as it revealed that this modification is reversible. Since then, various studies have focused on discovering the role of m6A modification in various diseases especially cancers. Aberrant expression of these 'readers', 'writers', and 'erasers' is found to be altered in various cancers resulting in disturbance of cellular homeostasis. Acute leukemias are the most common cancer found in pediatric patients and account for 20% of adult cases. Dysregulation of the RNA modifying complex have been reported in development and progression of hematopoietic malignancies. Further, targeting m6A modification is the new approach for cancer immunotherapy and is being explored extensively. This review provides detailed information about current information on the role of m6A RNA modification in acute leukemia and their therapeutic potential.

Unraveling the landscape of m6A RNA methylation in wound healing and scars

Wound healing is a complex process involving sequential stages of hemostasis, inflammation, proliferation, and remodeling. Multiple cell types and factors, including underlying conditions like diabetes and bacterial colonization, can influence healing outcomes and scar formation. N6-methyladenosine (m6A), a predominant RNA modification, plays crucial roles in gene expression regulation, impacting various biological processes and diseases. m6A regulates embryonic skin morphogenesis, wound repair, and pathophysiological processes like inflammation and angiogenesis. Recent studies have highlighted the role of m6A in wound healing, scar formation, and tissue remodeling. Additionally, m6A presents a unique expression pattern in pathological wounds and scars, potentially influencing wound healing and scar formation through modulating gene expression and cellular signaling, thereby serving as potential biomarkers or therapeutic targets. Targeting m6A modifications are potential strategies to enhance wound healing and reduce scar formation. This review aims to explore the roles and mechanisms of m6A RNA methylation in wound healing and scars, and discuss current challenges and perspectives. Continued research in this field will provide significant value for optimal wound repair and scar treatment.

m6A epitranscriptomic and epigenetic crosstalk in liver fibrosis: Special emphasis on DNA methylation and non-coding RNAs

Liver fibrosis is a pathological process caused by a variety of chronic liver diseases. Currently, therapeutic options for liver fibrosis are very limited, highlighting the urgent need to explore new treatment approaches. Epigenetic modifications and epitranscriptomic modifications, as reversible regulatory mechanisms, are involved in the development of liver fibrosis. In recent years, researches in epitranscriptomics and epigenetics have opened new perspectives for understanding the pathogenesis of liver fibrosis. Exploring the epigenetic mechanisms of liver fibrosis may provide valuable insights into the development of new therapies for chronic liver diseases. This review primarily focus on the regulatory mechanisms of N6-methyladenosine (m6A) modification, non-coding RNA, and DNA methylation in organ fibrosis. It discusses the interactions between m6A modification and DNA methylation, as well as between m6A modification and non-coding RNA, providing a reference for understanding the interplay between epitranscriptomics and epigenetics.

Unveiling the pathological functions of SOCS in colorectal cancer: Current concepts and future perspectives

Colorectal cancer (CRC) remains a significant global health challenge, marked by increasing incidence and mortality rates in recent years. The pathogenesis of CRC is complex, involving chronic inflammation of the intestinal mucosa, heightened immunoinflammatory responses, and resistance to apoptosis. The suppressor of cytokine signaling (SOCS) family, comprised of key negative regulators within cytokine signaling pathways, plays a crucial role in cell proliferation, growth, and metabolic regulation. Deficiencies in various SOCS proteins can trigger the activation of the Janus kinase (JAK) and signal transducers and activators of transcription (STAT) pathways, following the binding of cytokines and growth factors to their receptors. Mounting evidence indicates that SOCS proteins are integral to the development and progression of CRC, positioning them as promising targets for novel anticancer therapies. This review delves into the structure, function, and molecular mechanisms of SOCS family members, examining their roles in cell proliferation, apoptosis, migration, epithelial-mesenchymal transition (EMT), and immune modulation. Additionally, it explores their potential impact on the regulation of CRC immunotherapy, offering new insights and perspectives that may inform the development of innovative therapeutic strategies for CRC.

Review of METTL3 in colorectal cancer: From mechanisms to the therapeutic potential

N6-methyladenosine (m6A), the most abundant modification in mRNAs, affects the fate of the modified RNAs at the post-transcriptional level and participants in various biological and pathological processes. Increasing evidence shows that m6A modification plays a role in the progression of many malignancies, including colorectal cancer (CRC). As the only catalytic subunit in methyltransferase complex, methyltransferase-like 3 (METTL3) is essential to the performance of m6A modification. It has been found that METTL3 is associated with the prognosis of CRC and significantly influences various aspects of CRC, such as cell proliferation, invasion, migration, metastasis, metabolism, tumor microcirculation, tumor microenvironment, and drug resistance. The relationship between METTL3 and gut-microbiota is also involved into the progression of CRC. Furthermore, METTL3 might be a viable target for CRC treatment to prolong survival. In this review, we comprehensively summarize the function of METTL3 in CRC and the underlying molecular mechanisms. We aim to deepen understanding and offer new ideas for diagnostic biomarkers and therapeutic targets for colorectal cancer.

The m6A methyltransferase METTL3 modifies Kcnk6 promoting on inflammation associated carcinogenesis is essential for colon homeostasis and defense system through histone lactylation dependent YTHDF2 binding

Inflammation induces tumor formation and plays a crucial role in tumor progression and prognosis. KCNK6, by regulating K(+) efflux to reduce NLRP3 Inflammasome-induced lung injury, relaxes the aorta. This study aims to elucidate the effects and biological mechanism of KCNK6 in inflammation-associated carcinogenesis, which may be essential for colon homeostasis and the defense system. To induce colitis, mice were given 3.0% Dextran Sodium Sulfate (DSS) in their drinking water for 7 days. The Azoxymethane (AOM) +DSS method was used to induce colon cancer in the mice model. Bone marrow-derived macrophages (BMDM) from Kcnk6-/- mice, AW264.7 cells, and human colon cancer HCT116 and Caco2 cells were used as in vitro models. The loss of Kcnk6 prevented spontaneous colitis and restored mucosal integrity and homeostatic molecules. Additionally, the loss of Kcnk6 reduced the severity of AOM/DSS-induced carcinogenesis. Kcnk6 promoted cell viability and proliferation in HCT-116 or Caco-2 cells. The loss of Kcnk6 inhibited the levels of inflammatory factors in BMDM cells. Kcnk6 accelerated potassium channel activity, inducing NLRP3 inflammasome activation. METTL3-mediated m6A modification increased Kcnk6 stability in a YTHDF2-dependent manner. Histone lactylation activated the transcription of YTHDF2/Kcnk6. Our study revealed the important role of Kcnk6 in inflammation-associated carcinogenesis progression. The m6A methyltransferase METTL3 and histone lactylation increased Kcnk6 stability in a YTHDF2-dependent manner, providing a potential strategy for inflammation-associated carcinogenesis or colorectal cancer therapy.

Modulating mitochondrial dynamics ameliorates left ventricular dysfunction by suppressing diverse cell death pathways after diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) triggers a detrimental shift in mitochondrial dynamics, characterized by increased fission and decreased fusion, contributing to cardiomyocyte apoptosis and cardiac dysfunction. This study investigated the impact of modulating mitochondrial dynamics on DCM outcomes and underlying mechanisms in a mouse model. DCM induction led to upregulation of fission genes (Drp1, Mff, Fis1) and downregulation of fusion genes (Mfn1, Mfn2, Opa1). Inhibiting fission with Mdivi-1 or promoting fusion with Ginsenoside Rg1 preserved cardiac function, as evidenced by improved left ventricular ejection fraction (LVEF), fractional shortening (FS), and E/A ratio. Both treatments also reduced infarct size and attenuated cardiomyocyte apoptosis, indicated by decreased caspase-3 activity. Mechanistically, Mdivi-1 enhanced mitochondrial function by improving mitochondrial membrane potential, reducing reactive oxygen species (ROS) production, and increasing ATP generation. Ginsenoside Rg1 also preserved mitochondrial integrity and function under hypoxic conditions in HL-1 cardiomyocytes. These findings suggest that restoring the balance of mitochondrial dynamics through pharmacological interventions targeting either fission or fusion may offer a promising therapeutic strategy for mitigating MI-induced cardiac injury and improving patient outcomes.

Programmable protein expression using a genetically encoded m6A sensor

The N6-methyladenosine (m6A) modification is found in thousands of cellular mRNAs and is a critical regulator of gene expression and cellular physiology. m6A dysregulation contributes to several human diseases, and the m6A methyltransferase machinery has emerged as a promising therapeutic target. However, current methods for studying m6A require RNA isolation and do not provide a real-time readout of mRNA methylation in living cells. Here we present a genetically encoded m6A sensor (GEMS) technology, which couples a fluorescent signal with cellular mRNA methylation. GEMS detects changes in m6A caused by pharmacological inhibition of the m6A methyltransferase, giving it potential utility for drug discovery efforts. Additionally, GEMS can be programmed to achieve m6A-dependent delivery of custom protein payloads in cells. Thus, GEMS is a versatile platform for m6A sensing that provides both a simple readout for m6A methylation and a system for m6A-coupled protein expression.

Mitochondrial ATP Synthesis and Proton Transport Synergistically Mitigate Oligodendrocyte Progenitor Cell Dysfunction Following Transient Middle Cerebral Artery Occlusion via the Pbx3/Dguok/Kif21b Signaling Pathway

In the realm of this study, obtaining a comprehensive understanding of ischemic brain injury and its molecular foundations is of paramount importance. Our study delved into single-cell data analysis, with a specific focus on sub-celltypes and differentially expressed genes in the aftermath of ischemic injury. Notably, we observed a significant enrichment of the "ATP METABOLIC PROCESS" and "ATP HYDROLYSIS ACTIVITY" pathways, featuring pivotal genes such as Pbx3, Dguok, and Kif21b. A remarkable finding was the consistent upregulation of genes like Fabp7 and Bcl11a within the MCAO group, highlighting their crucial roles in regulating the pathway of mitochondrial ATP synthesis coupled proton transport. Furthermore, our network analysis unveiled pathways like "Neuron differentiation" and "T cell differentiation" as central in the regulatory processes of sub-celltypes. These findings provide valuable insights into the intricate molecular responses and regulatory mechanisms that govern brain injury. The shared differentially expressed genes among sub-celltypes emphasize their significance in orchestrating responses post-ischemic injury. Our research, viewed from the perspective of a medical researcher, contributes to the evolving understanding of the molecular landscape underlying ischemic brain injury, potentially paving the way for targeted therapeutic strategies and improved patient outcomes.

Nicotinamide Riboside-Driven Modulation of SIRT3/mtROS/JNK Signaling Pathways Alleviates Myocardial Ischemia-Reperfusion Injury

Myocardial ischemia-reperfusion (I/R) injury exacerbates cellular damage upon restoring blood flow to ischemic cardiac tissue, causing oxidative stress, inflammation, and apoptosis. This study investigates Nicotinamide Riboside (NR), a precursor of nicotinamide adenine dinucleotide (NAD+), for its cardioprotective effects. Administering NR to mice before I/R injury and evaluating heart function via echocardiography showed that NR significantly improved heart function, increased left ventricular ejection fraction (LVEF) and fractional shortening (FS), and reduced left ventricular end-diastolic (LVDd) and end-systolic diameters (LVSd). NR also restored E/A and E/e' ratios. It reduced cardiomyocyte apoptosis both in vivo and in vitro, inhibiting elevated caspase-3 activity and returning Bax protein levels to normal. In vitro, NR reduced the apoptotic rate in hydrogen peroxide (H2O2)-treated HL-1 cells from 30% to 10%. Mechanistically, NR modulated the SIRT3/mtROS/JNK pathway, reversing H2O2-induced SIRT3 downregulation, reducing mitochondrial reactive oxygen species (mtROS), and inhibiting JNK activation. Using SIRT3-knockout (SIRT3-KO) mice, we confirmed that NR's cardioprotective effects depend on SIRT3. Echocardiography showed that NR's benefits were abrogated in SIRT3-KO mice. In conclusion, NR provides significant cardioprotection against myocardial I/R injury by enhancing NAD+ levels and modulating the SIRT3/mtROS/JNK pathway, suggesting its potential as a novel therapeutic agent for ischemic heart diseases, meriting further clinical research.

Recent advances in CRISPR-Cas systems for colorectal cancer research and therapeutics

INTRODUCTION

Colon cancer, ranked as the fourth leading global cause of cancer death, exhibits a complex progression marked by genetic variations. Over the past decade, the utilization of diverse CRISPR systems has propelled accelerated research into colorectal cancer (CRC) treatment.

AREAS COVERED

CRISPR/Cas9, a key player in this research, identifies new oncogenes, tumor suppressor genes (TSGs), and drug-resistance genes. Additionally, it facilitates the construction of experimental models, conducts genome-wide library screening, and develops new therapeutic targets, especially for targeted knockout in vivo or molecular targeted drug delivery, contributing to personalized treatments and significantly enhancing the care of colon cancer patients. In this review, we provide insights into the mechanism of the CRISPR/Cas9 system, offering a comprehensive exploration of its applications in CRC, spanning screening, modeling, gene functions, diagnosis, and gene therapy. While acknowledging its transformative potential, the article  highlights the challenges and limitations of CRISPR systems.

EXPERT OPINION

The application of CRISPR/Cas9 in CRC research provides a promising avenue for personalized treatments. Its potential for identifying key genes and enabling experimental models and genome-wide screening enhances patient care. This review underscores the significance of CRISPR-Cas9 gene editing technology across basic research, diagnosis, and the treatment landscape of colon cancer.

Current landscape of exosomes in tuberculosis development, diagnosis, and treatment applications

Tuberculosis (TB), caused by the bacterial pathogen Mycobacterium tuberculosis (MTB), remains one of the most prevalent and deadly infectious diseases worldwide. Currently, there are complex interactions between host cells and pathogens in TB. The onset, progression, and regression of TB are correlated not only with the virulence of MTB but also with the immunity of TB patients. Exosomes are cell-secreted membrane-bound nanovesicles with lipid bilayers that contain a variety of biomolecules, such as metabolites, lipids, proteins, and nucleic acids. Exosome-mediated cell-cell communication and interactions with the microenvironment represent crucial mechanisms through which exosomes exert their functional effects. Exosomes harbor a wide range of regulatory roles in physiological and pathological conditions, including MTB infection. Exosomes can regulate the immune response, metabolism, and cellular death to remodel the progression of MTB infection. During MTB infection, exosomes display distinctive profiles and quantities that may act as diagnostic biomarkers, suggesting that exosomes provide a revealing glimpse into the evolving landscape of MTB infections. Furthermore, exosomes derived from MTB and mesenchymal stem cells can be harnessed as vaccine platforms and drug delivery vehicles for the precise targeting and treatment of TB. In this review, we highlight the functions and mechanisms through which exosomes influence the progression of TB. Additionally, we unravel the critical significance of exosomal constituents in the diagnosis and therapeutic applications of TB, aiming to offer novel perspectives and strategies for combating TB.

Stem Cell-Derived Extracellular Vesicles: Promising Therapeutic Opportunities for Diabetic Wound Healing

Wound healing is a sophisticated and orderly process of cellular interactions in which the body restores tissue architecture and functionality following injury. Healing of chronic diabetic wounds is difficult due to impaired blood circulation, a reduced immune response, and disrupted cellular repair mechanisms, which are often associated with diabetes. Stem cell-derived extracellular vesicles (SC-EVs) hold the regenerative potential, encapsulating a diverse cargo of proteins, RNAs, and cytokines, presenting a safe, bioactivity, and less ethical issues than other treatments. SC-EVs orchestrate multiple regenerative processes by modulating cellular communication, increasing angiogenesis, and promoting the recruitment and differentiation of progenitor cells, thereby potentiating the reparative milieu for diabetic wound healing. Therefore, this review investigated the effects and mechanisms of EVs from various stem cells in diabetic wound healing, as well as their limitations and challenges. Continued exploration of SC-EVs has the potential to revolutionize diabetic wound care.

Intranuclear assembly of leucine-rich peptides for selective death of osteosarcoma cells

Herein, we show a pair of leucine-rich L- and D-phosphopeptides which self-assemble into twisting nanofibers, whose secondary structures contain a strong β-sheet component after being dephosphorylated by alkaline phosphatase (ALP). While being incubated with ALP overexpressing osteosarcoma cells, both of the peptides self-assemble in the nuclei and induce cell death. The cell death involves multiple cell death modalities and occurs along with the disruption of cell membranes. Enzyme-instructed self-assembly (EISA) inhibits osteosarcoma cells and shows no side effect to other cells. In addition, the cancer cells hardly gain drug resistance after repeated treatment. This work reports a pair of EISA-based nanofibers to target cell nuclei, and also provides a novel chemotherapeutic agent to inhibit osteosarcoma cells without side effects and drug resistance.

Association of a novel frameshift variant and a known deleterious variant in MMR genes with Lynch syndrome in Chinese families

BACKGROUND

Lynch syndrome (LS) is the most common hereditary colorectal cancer (CRC) syndrome. This condition is characterized by germline variants in DNA mismatch repair (MMR) genes, including MLH1, MSH2, MSH6, and PMS2. In this study, we analyzed the molecular defects and clinical manifestations of two families affected with CRC and proposed appropriate individual preventive strategies for all carriers of the variant.

METHODS

We recruited two families diagnosed with CRC and combined their family history and immunohistochemical results to analyze the variants of probands and those of other family members by using whole exome sequencing. Subsequently, gene variants in each family were screened by comparing them with the variants available in the public database. Sanger sequencing was performed to verify the variant sites. An online platform ( https://www.uniprot.org ) was used to analyze the functional domains of mutant proteins.

RESULTS

A novel frameshift variant (NM_001281492, c.1129_1130del, p.R377fs) in MSH6 and a known deleterious variant (NM_000249.4:c.1731G > A, p.S577S) in MLH1 were identified in the two families with CRC. Using bioinformatics tools, we noted that the frameshift variant reduced the number of amino acids in the MSH6 protein from 1230 to 383, thereby leading to no MSH6 protein expression. The silent variant caused splicing defects and was strongly associated with LS. 5-Fluorouracil-based adjuvant chemotherapy is not recommended for patients with LS.

CONCLUSIONS

The novel frameshift variant (MSH6, c.1129_1130del, p.R377fs) is likely pathogenic to LS, and the variant (MLH1, c.1731G > A, p.S577S) has been further confirmed to be pathogenic to LS. Our findings underscore the significance of genetic testing for LS and recommend that genetic consultation and regular follow-ups be conducted to guide individualized treatment for cancer-afflicted families, especially those with a deficiency in MMR expression.

Regulation of m6A Methylome in Cancer: Mechanisms, Implications, and Therapeutic Strategies

Reversible N6-adenosine methylation of mRNA, referred to as m6A modification, has emerged as an important regulator of post-transcriptional RNA processing. Numerous studies have highlighted its crucial role in the pathogenesis of diverse diseases, particularly cancer. Post-translational modifications of m6A-related proteins play a fundamental role in regulating the m6A methylome, thereby influencing the fate of m6A-methylated RNA. A comprehensive understanding of the mechanisms that regulate m6A-related proteins and the factors contributing to the specificity of m6A deposition has the potential to unveil novel therapeutic strategies for cancer treatment. This review provides an in-depth overview of our current knowledge of post-translational modifications of m6A-related proteins, associated signaling pathways, and the mechanisms that drive the specificity of m6A modifications. Additionally, we explored the role of m6A-dependent mechanisms in the progression of various human cancers. Together, this review summarizes the mechanisms underlying the regulation of the m6A methylome to provide insight into its potential as a novel therapeutic strategy for the treatment of cancer.

N6-methyladenosine methylation regulatory pattern of pulmonary lymphoepithelioma-like carcinoma based on exosomal transcriptome analysis

Pulmonary lymphoepithelioma-like carcinoma (pLELC) is a rare malignancy that lacks specific biomarkers. N6-methyladenosine (m6 A) is the most widespread internal modification of messenger RNA (mRNA), and its dysregulation is involved in the development of many cancers. However, the expression of m6 A genes in pLELC and their roles are unknown. We obtained an exosomal transcriptome data set of patients diagnosed with pLELC and healthy controls using RNA sequencing and identified differentially expressed genes (DEGs) in the two groups using R software. The differential expression of the 37 m6 A genes in the two sets of samples was further analyzed, and receiver operating characteristic (ROC) curves were plotted for each gene to identify their grouping ability. The STRING database was used to construct a protein-protein interaction network for m6 A genes. An mRNA-miRNA regulatory network of m6 A-related DEGs was constructed using the miRNet database, and a prediction score formula was established. A nomogram was constructed based on the candidate m6 A genes and prediction scores. The expression of key genes was determined through the immunohistochemical (IHC) staining of clinical tissue sections. Using ROC curves, nine m6 A genes were revealed to have classification efficacy in both groups of samples. We screened seven m6 A-related DEGs (MAN2C1, HNRNPCL1, FUS, EIF6, DIP2A, COA3, and BUD13) that were beneficial for grouping and constructed nomogram models. Through IHC, we identified FUS and EIF6 as being possibly involved in the occurrence and development of pLELC. The m6 A gene expression patterns in pLELC-derived exosomes were significantly different from those in healthy controls. We screened several key genes to facilitate the development of diagnostic markers for pulmonary lymphoepithelioma.

Research progress of N6-methyladenosine in colorectal cancer: A review

Colorectal cancer is the third most common malignant tumor worldwide, causing serious harm to human health. Epigenetic modification, especially RNA methylation modification, plays a critical role in the occurrence and development of colorectal cancer via post-transcriptional regulation of mRNA and non-coding RNA expression. Among these, N6-methyladenosine (m6A) is the most common chemical modification in mammals, which plays an important role in the progress of cancer, including colorectal cancer. m6A is a dynamic and reversible process and is mainly regulated by m6A methyltransferase ("writers"), m6A demethylases ("erasers"), and m6A binding proteins ("readers"). Herein, we reviewed recent advances in the role of m6A modification in colorectal cancer and focused on the factors affecting m6A modification. Furthermore, we discussed the clinical application of m6A modifications for colorectal cancer diagnosis, prognosis, and treatment and provided guides in clinical practice. m6A modification and m6A regulators play significant roles in the occurrence and development of colorectal cancer by regulating the stability and translation of mRNAs, the maturation of miRNAs, and the function of lncRNAs. m6A regulators can play biological roles in colorectal cancer through m6A-dependent manner or m6A-independent manner. Multiplies of internal factors, including miRNAs and lncRNAs, and external factors can also regulate the m6A modification by completing with m6A regulators in a base complement manner, regulating the expression of m6A and mutating the m6A site. m6A regulators and m6A modificantion are diagnostic and prognostic markers for CRC. Therefore, m6A regulators and m6A modificantion may be potential therapeutic target for CRC in the future.

The potential role of RNA modification in skin diseases, as well as the recent advances in its detection methods and therapeutic agents

RNA modification is considered as an epigenetic modification that plays an indispensable role in biological processes such as gene expression and genome editing without altering nucleotide sequence, but the molecular mechanism of RNA modification has not been discussed systematically in the development of skin diseases. This article mainly presents the whole picture of theoretical achievements on the potential role of RNA modification in dermatology. Furthermore, this article summarizes the latest advances in clinical practice related with RNA modification, including its detection methods and drug development. Based on this comprehensive review, we aim to illustrate the current blind spots and future directions of RNA modification, which may provide new insights for researchers in this field.

Interaction between N6-methyladenosine modification and the tumor microenvironment in colorectal cancer

The incidence and mortality of colorectal cancer (CRC) are rapidly increasing worldwide. Recently, there has been significant attention given to N6-methyladenosine (m6A), the most common mRNA modification, especially for its effects on CRC development. It is important to note that the progression of CRC would be greatly hindered without the tumor microenvironment (TME). The interaction between CRC cells and their surroundings can activate and influence complex signaling mechanisms of epigenetic changes to affect the survival of tumor cells with a malignant phenotype. Additionally, the TME is influenced by m6A regulatory factors, impacting the progression and prognosis of CRC. In this review, we describe the interactions and specific mechanisms between m6A modification and the metabolic, hypoxia, inflammatory, and immune microenvironments of CRC. Furthermore, we summarize the therapeutic role that m6A modification can play in the CRC microenvironment, and discuss the current status, limitations, and potential future directions in this field. This review aims to provide new insights into the molecular targets and theoretical foundations for the treatment of CRC.

Ultrasound coupled RES-loaded ultrasound microbubble inhibits the proliferation of ovarian cancer cells by expression of long non-coding RNA (lncRNA) involved in apoptosis using real-time PCR

The primary objective of this study was to evaluate the effect of low-frequency ultrasound combined with RES-loaded ultrasound microbubble contrast agents on the transcriptional and translational activities of ovarian cancer cells. After being cultures, ovarian cancer cells (OVCAR-3) and human umbilical cord endothelial cells (HUCEC) were transfected with siRNA, which was followed by RNA extraction and real-time PCR to evaluate transcriptional activity. Translational activity was determined by western blotting, which was followed by RNA interference. Proliferative and invasive activity was measured using cell proliferation, colony formation, and immunofluorescence assays. Lastly, RNA sequencing was performed. Our findings indicated that ultrasound combined with RES microbubbles inhibited cell proliferation and invasion. The expression of ING5 was enhanced, while the expression of EMT was suppressed in ovarian cancer cells. A negative correlation was observed between of the expression of ING5 and cell proliferation/migration, which were enhanced upon inhibition of ING5, suggesting dysregulation of transcriptional and translational cellular processes which could be of diagnostic and therapeutic value in ovarian cancer. Additionally, the dysregulation of lncRNAs can alter cellular homeostasis and promote ovarian cancer progression. A combination of low-frequency and RES-loaded ultrasound microbubbles was found to effectively inhibit the proliferation of OVCAR-3 ovarian cancer cells and induce apoptosis. This approach was more effective than low-frequency ultrasound combined with RES alone.

Expression and clinical significance of METTL3 in colorectal cancer

Methyltransferase-like 3 (METTL3) belongs to the class I MTase family, and it has been proved that METTL3 is highly expressed in a variety of tumors and promotes tumor progression. Our previous studies have shown that METTL3 is highly expressed in gastric cancer tissues compared with para-cancer tissues, and its expression level is negatively correlated with good postoperative prognosis of patients. To explore the expression of METTL3 in colorectal cancer (CRC) tissue and the relationship between METTL3 and the clinicopathologic features and prognosis of CRC patients. The expression of METTL3 in cancer tissues and adjacent tissues of 180 patients with colorectal cancer was analyzed by tissue microarray and immunohistochemistry. The clinicopathologic features of patients with different METTL3 expression levels were analyzed. The expression level of METTL3 in colorectal cancer tissues was higher than that in adjacent tissues (P < .05). There were statistically significant differences in the expression of METTL3 in clinical stage, survival time and distant metastasis (all P < .05). The expression level of METTL3 in colorectal cancer tissues with tumor-node-metastasis stage III and IV and distant metastasis was higher than that in clinical stage I and II and without distant metastasis (P < .05). Patients with high METTL3 expression had a higher overall mortality rate compared to patients with low METTL3 expression, and the difference was statistically significant (P < .05). Univariate Cox regression analysis suggested that tumor distant metastasis, vascular invasion, pathological grade, lymph node metastasis and METTL3 expression level were risk factors for overall survival in CRC patients (all P < .05). Multivariate Cox regression analysis suggested that low pathological grade (hazard ratio = 1.695, 95% confidence interval: 1.116-2.274, P = .005) and high METTL3 expression (hazard ratio = 2.156, 95% confidence interval: 1.587-2.725, P < .001) could be used as independent risk factors for prognosis assessment. The expression of METTL3 was increased in colorectal cancer, and METTL3 was closely related to clinical stage, distant metastasis and prognosis of colorectal cancer.

METTL3 regulates N6-methyladenosine modification of ANGPTL3 mRNA and potentiates malignant progression of stomach adenocarcinoma

BACKGROUND

N6-methyladenosine (m6A) is associated with mammalian mRNA biogenesis, decay, translation and metabolism, and also contributes greatly to gastrointestinal tumor formation and development. Therefore, the specific mechanisms and signaling pathways mediated by methyltransferase-like 3 (METTL3), which catalyzes the formation of m6A chemical labeling in stomach adenocarcinoma (STAD), are still worth exploring.

METHODS

Quantitative real-time PCR (qRT-PCR) was constructed to detect the expression of METTL3 in gastric cancer cell lines and patient tissues. The biological function of METTL3 was investigated in vitro/in vivo by Cell Counting Kit-8, colony formation assay, Transwell assay and nude mouse tumorigenesis assay. Based on the LinkedOmics database, the genes co-expressed with METTL3 in the TCGA STAD cohort were analyzed to clarify the downstream targets of METTL3. Methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) and RNA stability analysis were employed to explore the mechanism of METTL3 in gastric cancer progression.

RESULTS

We analyzed TCGA data and found that METTL3 was frequently elevated in STAD, and demonstrated that METTL3 was present at high levels in clinical STAD tissues and cells. High METTL3 expression was more likely to have advanced TNM tumors and distant metastasis. On the other hand, METTL3 silencing effectively impeded the higher oncogenic capacity of AGS and HGC27 cells in vivo and in vitro, as reflected by slowed cell growth and diminished migration and invasion capacities. Continued mining of the TCGA dataset identified the co-expression of angiopoietin-like 3 (ANGPTL3) and METTL3 in STAD. Lower level of ANGPTL3 was related to increased level of METTL3 in STAD samples and shorter survival times in STAD patients. ANGPTL3 enrichment limited the growth and metastasis of STAD cells. Besides, ANGPTL3 mRNA levels could be decreased by METTL3-dominated m6A modifications, a result derived from a combination of MeRIP-qPCR and RNA half-life experiments. Importantly, the inhibitory effect of METTL3 silencing on cancer could be reversed to some extent by ANGPTL3 inhibition.

CONCLUSIONS

Overall, our findings suggested that METTL3 functioned an oncogenic role in STAD by reducing ANGPTL3 expression in an m6A-dependent manner. The discovery of the METTL3-ANGPTL3 axis and its effect on STAD tumor growth will contribute to further studies on the mechanisms of gastric adenocarcinoma development.

CSNK1D-mediated phosphorylation of HNRNPA2B1 induces miR-25-3p/miR-93-5p maturation to promote prostate cancer cell proliferation and migration through m6A-dependent manner

It has been reported that heterogeneous nuclear ribonucleoprotein A2/B1 (HNRNPA2B1) is highly expressed in prostate cancer (PCa) and associated with poor prognosis of patients with PCa. Nevertheless, the specific mechanism underlying HNRNPA2B1 functions in PCa remains not clear. In our study, we proved that HNRNPA2B1 promoted the progression of PCa through in vitro and in vivo experiments. Further, we found that HNRNPA2B1 induced the maturation of miR-25-3p/miR-93-5p by recognizing primary miR-25/93 (pri-miR-25/93) through N6-methyladenosine (m6A)-dependent manner. In addition, both miR-93-5p and miR-25-3p were proven as tumor promoters in PCa. Interestingly, by mass spectrometry analysis and mechanical experiments, we found that casein kinase 1 delta (CSNK1D) could mediate the phosphorylation of HNRNPA2B1 to enhance its stability. Moreover, we further proved that miR-93-5p targeted BMP and activin membrane-bound inhibitor (BAMBI) mRNA to reduce its expression, thereby activating transforming growth factor β (TGF-β) pathway. At the same time, miR-25-3p targeted forkhead box O3 (FOXO3) to inactivate FOXO pathway. These results collectively indicated that CSNK1D stabilized HNRNPA2B1 facilitates the processing of miR-25-3p/miR-93-5p to regulate TGF-β and FOXO pathways, resulting in PCa progression. Our findings supported that HNRNPA2B1 might be a promising target for PCa treatment.

MiR-532-3p inhibited the methylation of SOCS2 to suppress the progression of PC by targeting DNMT3A

Pancreatic cancer (PC) is one of the deadliest malignancies, with poor diagnosis and prognosis. miR-532-3p has been reported to be a tumor suppressor in various cancers, whereas the mechanism of miR-532-3p in the progression of PC remains poorly understood. In this study, it was found that miR-532-3p and SOCS2 were down-regulated, whereas DNMT3A was up-regulated in PC. Knockdown of DNMT3A or overexpression of miR-532-3p suppressed PC cell proliferation, invasion, and migration, as well as tumor formation in nude mice. DNMT3A induced the methylation of SOCS2 promoter. SOCS2 knockdown reversed the inhibiting effect of DNMT3A silencing on PC cell growth. miR-532-3p directly bound to DNMT3A and negatively regulated its expression while up-regulating SOCS2 levels. DNMT3A overexpression reversed the inhibiting effect of miR-532-3p overexpression on PC cell growth. In conclusion, the overexpression of miR-532-3p could suppress proliferation, invasion, and migration of PC cells, as well as tumor formation in nude mice through inhibiting the methylation of SOCS2 by targeting DNMT3A.

Effect of circular RNAs and N6-methyladenosine (m6A) modification on cancer biology

N6-methyladenosine (m6A), as the most abundant and well-known RNA modification, has been found to play an important role in cancer. Circular RNAs (circRNAs) are a class of single-stranded covalently closed RNA molecules generated by the reverse splicing process. Recent studies have revealed the vital roles of circRNAs in many diseases, including tumorigenesis. Accumulating evidence also shows an association between m6A modification and circRNAs. This study aimed to review the interactions between m6A modification and circRNAs and illustrate their roles in tumorigenesis. m6A modification can modulate the biogenesis, translation, cytoplasmic export, degradation, and other functions of circRNAs in different tumors. circRNAs can also modulate m6A modification by affecting writers, erasers, and readers. We focused on the potential regulatory mechanisms and the biological consequences of m6A modification of circRNAs, as well as the interactions in tumors of different systems. Finally, we listed the possible development directions of m6A modification and circRNAs, which might facilitate the clinical application of tumor therapy. AVAILABILITY OF DATA AND MATERIALS: Not applicable. Keywords.

METTL3-mediated Hsa_circ_0000390 downregulation enhances the proliferation, migration, and invasion of colorectal cancer cells by increasing Notch1 expression

Circular RNAs (circRNAs), as noncoding RNAs, have gained widespread attention in cancers. Circ_0000390 has been verified to be downregulated in gastric cancer, while its function and regulatory mechanism in cancer is largely unknown. The purpose of this study is to investigate the expression, functions, and potential mechanism of circ_0000390 in colorectal cancer (CRC). Circ_0000390 expression in CRC tissues was first identified with RT-qPCR. Besides, the function of circ_0000390 was assessed through gain-of-function and rescued experiments in CRC cells and mouse xenograft models. Our results showed that circ_0000390 was lowly expressed in CRC tissues, and circ_0000390 could downregulate Notch1 and be downregulated by METTL3. Functionally, results showed circ_0000390 overexpression suppressed the proliferation, cell migration, and invasion of CRC cells, which also could be reversed by Notch1 overexpression. Additionally, METTL3 overexpression could accelerate the proliferation, cell migration, and invasion of CRC cells, which also was weakened by circ_0000390 overexpression in CRC cells in vitro and in vivo. This study suggested that circ_0000390 might be anti-tumor factor in CRC and METTL3/Notch1 might be a therapeutic targets for CRC.

Role of NAT10-mediated ac4C-modified HSP90AA1 RNA acetylation in ER stress-mediated metastasis and lenvatinib resistance in hepatocellular carcinoma

Emerging evidence showed that epigenetic regulation plays important role in the pathogenesis of HCC. N4-acetocytidine (ac4C) was an acetylation chemical modification of mRNA, and NAT10 is reported to regulate ac4C modification and enhance endoplasmic reticulum stress (ERS) in tumor metastasis. Here, we report a novel mechanism by which NAT10-mediated mRNA ac4C-modified HSP90AA1 regulates metastasis and tumor resistance in ERS of HCC. Immunohistochemical, bioinformatics analyses, and in vitro and in vivo experiments, e.g., acRIP-Seq, RNA-Seq, and double luciferase reporter experiment, were employed to investigate the effect of NAT10 on metastasis and drug resistance in HCC. The increased expression of NAT10 was associated with HCC risk and poor prognosis. Cell and animal experiments showed that NAT10 enhanced the metastasis ability and apoptosis resistance of HCC cells in ERS and ERS state. NAT10 could upregulate the modification level of HSP90AA1 mRNA ac4C, maintain the stability of HSP90AA1, and upregulate the expression of HSP90AA1, which further promotes the metastasis of ERS hepatoma cells and the resistance to apoptosis of Lenvatinib. This study proposes a novel mechanism by which NAT10-mediated mRNA ac4C modification regulates tumor metastasis. In addition, we demonstrated the regulatory effect of NAT10-HSP90AA1 on metastasis and drug resistance of ERS in HCC cells.

Application of CRISPR-Cas9 gene editing technology in basic research, diagnosis and treatment of colon cancer

Colon cancer is the fourth leading cause of cancer death worldwide, and its progression is accompanied by a complex array of genetic variations. CRISPR/Cas9 can identify new drug-resistant or sensitive mutations in colon cancer, and can use gene editing technology to develop new therapeutic targets and provide personalized treatments, thereby significantly improving the treatment of colon cancer patients. CRISPR/Cas9 systems are driving advances in biotechnology. RNA-directed Cas enzymes have accelerated the pace of basic research and led to clinical breakthroughs. This article reviews the rapid development of CRISPR/Cas in colon cancer, from gene editing to transcription regulation, gene knockout, genome-wide CRISPR tools, therapeutic targets, stem cell genomics, immunotherapy, metabolism-related genes and inflammatory bowel disease. In addition, the limitations and future development of CRISPR/Cas9 in colon cancer studies are reviewed. In conclusion, this article reviews the application of CRISPR-Cas9 gene editing technology in basic research, diagnosis and treatment of colon cancer.

m6A modification on the fate of colorectal cancer: functions and mechanisms of cell proliferation and tumorigenesis

N6-methyladenosine (m6A) is the most pervasive RNA modification in eukaryotic cells. The dynamic and reversible m6A modification of RNA plays a critical role in the occurrence and progression of tumors by regulating RNA metabolism, including translocation, mRNA stability or decay, pre-mRNA splicing, and lncRNA processing. Numerous studies have shown that m6A modification is involved in the development of various cancers. This review aims to summarize the significant role of m6A modification in the proliferation and tumorigenesis of CRC, as well as the potential of modulating m6A modification for tumor treatment. These findings may offer new therapeutic strategies for clinical implementation of m6A modification in CRC in the near future.

Increased expression of miR-194-5p through the circPVRL3/miR-194-5p/SOCS2 axis promotes proliferation and metastasis in pancreatic ductal adenocarcinoma by activating the PI3K/AKT signaling pathway

BACKGROUND

MicroRNAs (miRNAs), as an indispensable type of non-coding RNA (ncRNA), participate in diverse biological processes. However, the specific regulatory mechanism of certain miRNAs in pancreatic ductal adenocarcinoma (PDAC) remains unclear.

METHODS

The expression of miR-194-5p in PDAC tissue microarray and cell lines were detected by RNA-scope and real-time quantitative PCR (RT-qPCR). The function of proliferation and migration carried by miR-194-5p in vitro and vivo was observed by several functional experiments. Informatics methods and RNA sequencing data were applied to explore the target of miR-194-5p and the upstream circular RNA (circRNA) of miR-194-5p. RNA-binding protein immunoprecipitation (RIP) assay and dual-luciferase reporter assay confirmed the relationships between miR-194-5p and SOCS2 or miR-194-5p and circPVRL3. The proliferation and migration abilities of SOCS2 and circPVRL3 were accessed by rescue experiments.

RESULTS

In this study, we aimed to clarify the molecular mechanisms of miR-194-5p, which has critical roles during PDAC progression. We found that the expression of miR-194-5p was significantly upregulated in PDAC tissue compared to tumor-adjacent tissue and was highly related to age and nerve invasion according to RNAscope and RT‒qPCR. Overexpression of miR-194-5p accelerated the cell cycle and enhanced the proliferation and migration processes according to several functional experiments in vitro and in vivo. Specifically, circPVRL3, miR-194-5p, and SOCS2 were confirmed to work as competing endogenous RNAs (ceRNAs) according to informatics methods, RIP, and dual-luciferase reporter assays. Additionally, the rescue experiments confirmed the relationship among miR-194-5p, circPVRL3, and SOCS2 mRNA. Finally, the circPVRL3/miR-194-5p/SOCS2 axis activates the PI3K/AKT signaling pathway to regulate the proliferation and metastasis of PDAC.

CONCLUSION

Our findings indicated that an increase of miR-194-5p caused by circPVRL3 downregulation stimulates the PI3K/AKT signaling pathway to promote PDAC progression via the circPVRL3/miR-194-5p/SOCS2 axis, which suggests that the circPVRL3/miR-194-5p/SOCS2 axis may be a potential therapeutic target for PDAC patients.

The Role of N6-Methyladenosine in Inflammatory Diseases

N⁶-Methyladenosine (m⁶A) is the most abundant epigenetic RNA modification in eukaryotes, regulating RNA metabolism (export, stability, translation, and decay) in cells through changes in the activity of writers, erasers, and readers and ultimately affecting human life or disease processes. Inflammation is a response to infection and injury in various diseases and has therefore attracted significant attention. Currently, extensive evidence indicates that m⁶A plays an essential role in inflammation. In this review, we focus on the mechanisms of m⁶A in inflammatory autoimmune diseases, metabolic disorder, cardio-cerebrovascular diseases, cancer, and pathogen-induced inflammation, as well as its possible role as targets for clinical diagnosis and treatment.

METTL3 contributes to slow transit constipation by regulating miR-30b-5p/PIK3R2/Akt/mTOR signaling cascade through DGCR8

BACKGROUND

N6-methyladenosine (m6A) is the most prevalent methylation modification of eukaryotic RNA, and methyltransferase-like 3 (METTL3) plays a vital role in multiple cell functions. This study aimed to investigate the role of m6A methylase METTL3 in slow transit constipation (STC).

MATERIAL AND METHOD

The expression of METTL3 and DGCR8 was measured in STC tissues and glutamic acid-induced interstitial cells of Cajal (ICCs). The effects of METTL3, miR-30b-5p, and DGCR8 on the biological characteristics of ICCs were investigated on the basis of loss-of-function analyses. Luciferase reporter assay was used to identify the direct binding sites of miR-30b-5p with PIK3R2.

RESULTS

The results showed that the METTL3, DGCR8, miR-30b-5p, and the methylation level of m6A were significantly increased in STC tissues and glutamic acid-induced ICCs. Silencing of METTL3 and miR-30b-5p inhibited apoptosis, autophagy, and pyroptosis of glutamic acid-induced ICCs. Moreover, overexpression of miR-30b-5p reversed the cytoprotection of METTL3 knockdown in glutamic acid-induced ICCs. Besides, DGCR8 knockdown could facilitate cell growth and decrease apoptotic glutamic acid-induced ICCs. Mechanically, we illustrated that METTL3 in glutamic acid-induced ICCs significantly accelerated the maturation of pri-miR-30b-5p by m6A methylation modification, resulting in the reduction of PIK3R2, which results in the inhibition of PI3K/Akt/mTOR pathway and ultimately leads to the cell death of STC.

CONCLUSIONS

Collectively, these data demonstrated that METTL3 promoted the apoptosis, autophagy, and pyroptosis of glutamic acid-induced ICCs by interacting with the DGCR8 and successively modulating the miR-30b-5p/PIK3R2 axis in an m6A-dependent manner, and METTL3 may be a potential therapeutic target for STC.

Analysis of m6A modulator-mediated methylation modification patterns and the tumor microenvironment in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is the most common histological subtype of lung cancer. In the development and progression of LUAD, epigenetic aberration plays a crucial role. However, the function of RNA N6-methyladenosine (m⁶A) modifications in the LUAD progression is unknown. The m6A regulator modification patterns in 955 LUAD samples were analyzed comprehensively. Patterns were systematically correlated with the tumor microenvironment (TME) cell-infiltration characteristics. Using principal component analysis algorithms, the m6Ascore was generated to quantify m⁶A modification patterns in individual tumors. Then, their values for predicting prognoses and therapeutic response in LUAD patients were assessed. Three distinct m⁶A modification patterns in LUAD were identified. Among them, the prognosis of m6Acluster C was the best, while the prognosis of m⁶Acluster A was the worst. Interestingly, the characterization of TME cell infiltration and biological behavior differed among the three patterns. To evaluate m⁶A modification patterns within individual tumors, an m⁶Ascore signature was constructed. The results showed that the high m⁶Ascore group was associated with a better prognosis; tumor somatic mutations and tumor microenvironment differed significantly between the high- and low- m⁶Ascore groups. Furthermore, in the cohort with anti-CTLA-4 treatment alone, patients with a high m⁶Ascore had higher ICI scores, which indicated significant therapeutic advantage and clinical benefits.

MEX3C-Mediated Decay of SOCS3 mRNA Promotes JAK2/STAT3 Signaling to Facilitate Metastasis in Hepatocellular Carcinoma

Tumor metastasis is one of the major causes of high mortality in patients with hepatocellular carcinoma (HCC). Sustained activation of STAT3 signaling plays a critical role in HCC metastasis. RNA binding protein (RBP)-mediated posttranscriptional regulation is involved in the precise control of signal transduction, including STAT3 signaling. In this study, we investigated whether RBPs are important regulators of HCC metastasis. The RBP MEX3C was found to be significantly upregulated in highly metastatic HCC and correlated with poor prognosis in HCC. Mechanistically, MEX3C increased JAK2/STAT3 pathway activity by downregulating SOCS3, a major negative regulator of JAK2/STAT3 signaling. MEX3C interacted with the 3'UTR of SOCS3 and recruited CNOT7 to ubiquitinate and accelerate decay of SOCS3 mRNA. Treatment with MEX3C-specific antisense oligonucleotide significantly inhibited JAK2/STAT3 pathway activation, suppressing HCC migration in vitro and metastasis in vivo. These findings highlight a novel mRNA decay-mediated mechanism for the disruption of SOCS3-driven negative regulation of JAK2/STAT3 signaling, suggesting MEX3C may be a potential prognostic biomarker and promising therapeutic target in HCC.

SIGNIFICANCE

This study reveals that RNA-binding protein MEX3C induces SOCS3 mRNA decay to promote JAK2/STAT3 activation and tumor metastasis in hepatocellular carcinoma, identifying MEX3C targeting as a potential approach for treating metastatic disease.

Oxymatrine suppresses oral squamous cell carcinoma progression by suppressing CXC chemokine receptor 4 in an m6A modification decrease dependent manner

Oxymatrine has been revealed to exert antitumor activity; however, its role in oral squamous cell carcinoma (OSCC) remains unclear. In the present study, the effects and underlying molecular mechanisms of oxymatrine in OSCC were explored. The antineoplastic effects of oxymatrine were measured using Cell Counting Kit‑8, apoptosis and Transwell assays. The inhibitory effect of oxymatrine on tumor growth was evaluated in vivo. The regulation of oxymatrine on the CXC chemokine receptor 4 (CXCR4) was analyzed using western blotting, reverse transcription‑quantitative PCR, RNA stability and methylated RNA immunoprecipitation assays. The present results revealed that oxymatrine inhibited the proliferation and migration of OSCC cells and promoted cell apoptosis. Furthermore, oxymatrine reduced CXCR4 mRNA and protein expression levels by promoting CXCR4 mRNA degradation. Mechanistically, oxymatrine inhibited the methylation at the N6‑position of adenosine (m⁶A modification) of CXCR4 mRNA by decreasing the expression of the methyltransferase‑like 3 (METTL3) gene. In addition, oxymatrine inhibited tumor growth in vivo. Taken together, our findings demonstrated the antitumor effect of oxymatrine on OSCC. Mechanistically, oxymatrine inhibited the progression of OSCC by downregulating METTL3 and degrading CXCR4 mRNA by decreasing the level of m⁶A modification.

WTAP promotes oesophageal squamous cell carcinoma development by decreasing CPSF4 expression in an m6A-dependent manner

m⁶A is a widespread RNA modification. However, the mechanism through which m⁶A regulated the progress of oesophageal squamous cell carcinoma (ESCC) remains undetermined. The levels and prognosis of WTAP were analysed using an ESCC tissue microarray (87 ESCC and 44 paracancerous tissues). TCGA and Oncolnc databases validate WTAP expression and prognosis. CCK8, colony formation (CF), wound healing, transwell cell invasion (CI), and migration (CM) assays were employed for the detection of the biological impacts of WTAP. Expression of tumour stemness-related genes was assessed via qRT-PCR and western blotting. The m⁶A RNA methylation (m⁶AMe) quantitative kit was employed for cellular methylation level detection. Arraystar m⁶A-mRNA and lncRNA epitranscriptomic microarray analyses were used to screen low methylation, high expression, and prognosis-related candidate gene CPSF4. KEGG enrichment analysis was used to screen the downstream signalling pathways of CPSF4. WTAP, a methyltransferase "writer", was markedly enhanced in ESCC and was strongly correlated with poor patient outcome. WTAP knockdown inhibited the cell proliferation (CP), CI, CM, and stemness of ESCC cells in vitro and reduced the overall m⁶A modification (m⁶AMo) percentage of ESCC cells. CPSF4 is a target of WTAP-based m⁶AMo. WTAP-based m⁶AMo of CPSF4 transcript reduced the stability of CPSF4 by relying on YTHDF2. We identified the significant role of WTAP-catalysed m⁶AMo in ESCC tumourigenesis, wherein it facilitates ESCC tumour growth and metastasis through decreasing CPSF4 expression in an m⁶A-dependent manner.

The functions of N6-methyladenosine (m6A) RNA modifications in colorectal cancer

Colorectal cancers (CRC), which includes colon cancer (CC) and rectal cancer (RC), are some of the most common malignant tumors that are prone to distant metastasis. Its high incidence rate and high mortality rate have attracted much attention. In recent years, epigenetics has attracted increasing attention and has been the focus of many research studies. N6-methyladenosine(m6A) RNA modifications can modify eukaryotic mRNA to impact metabolism. The changes in the m6A regulatory genes are related to the occurrence and development of CRC and play an important role in the pathogenesis of CRC. The effect of m6A RNA modification is regulated by its related regulatory factors ("writer", "eraser", "reader"). In this review, we comprehensively analyzed the effect of m6A methylation on CRC and the relationship between the expression of related regulatory factors and the development and occurrence of CRC. Then, we summarized the roles of m6A and its regulatory factors in CRC and its potential clinical value, which provides a basis for further research on the mechanism of m6A methylation in CRC.

WTAP mediates FOXP3 mRNA stability to promote SMARCE1 expression and augment glycolysis in colon adenocarcinoma

N6-methyladenosine (m6A) is the most abundant mRNA internal modification and has reportedly been linked to aerobic glycolysis, a hallmark event in tumor development. This work focuses on the role of the m6A methyltransferase WT1-associated protein (WTAP) in metabolic reprogramming and development of colon adenocarcinoma (COAD) and the molecules involved. The WTAP expression in COAD tissues and cells was detected. WTAP was knocked down in two COAD cell lines to figure out its role in the glycolytic activity and malignant phenotype of cancer cells. Cancer cells were further injected into nude mice subcutaneously or via tail vein to evaluate tumor growth and metastasis. The downstream molecules involved were explored using bioinformatics tools, and the molecular interactions were confirmed by immunoprecipitation, luciferase assays, and rescue experiments. WTAP was abundantly expressed in COAD samples. Knockdown of WTAP suppressed glucose consumption, lactate production, and glycolysis, which consequently suppressed cancer cell growth and dissemination in vitro and in vivo. WTAP promoted m6A methylation and stabilized forkhead box P3 (FOXP3) mRNA with the participation of the m6A "reader" YTHDF1. FOXP3 could further bind to SMARCE1 promoter for transcriptional activation. Rescue experiments showed that upregulation of FOXP3 or SMARCE1 restored the glycolytic activity in COAD cells and augmented the growth and mobility of cells both in vitro and in vivo. This study demonstrates that WTAP grants glycolytic activity to COAD and promotes tumor malignant development via the m6A modification of FOXP3 mRNA and the upregulation of SMARCE1.

The emerging therapeutic target of dynamic and reversible N6-methyladenosine modification during cancer development

As a reversible and dynamic epigenetic modification, N6-methyladenosine (m6A) modification is ubiquitous in eukaryotic cells. m6A methylation is prevalent in almost all RNA metabolism processes that affect the fate of cells, including cancer development. As indicated by the available evidence, targeting m6A regulators may play a crucial role in tumor therapy and multidrug resistance. Currently, many questions remain uncovered. Here, we review recent studies on m6A modification in various aspects of tumor progression, tumor immunity, multidrug resistance, and therapeutic targets to provide new insight into the m6A methylation process.

N6-methyladenosine-mediated upregulation of LINC00520 accelerates breast cancer progression via regulating miR-577/POSTN axis and downstream ILK/AKT/mTOR signaling pathway

Various lncRNAs have been reported to be closely associated with cancer initiation and progression in breast cancer (BC), including LINC00520. However, the role and underlying mechanisms by which LINC00520 affects BC aggressiveness have not been fully delineated, and this study aimed to explore this issue. Through performing qRT-PCR analysis, we proved that LINC00520 was significantly upregulated in BC tissues and cells, compared with normal tissues and cells. Higher expression of LINC00520 was closely related to higher tumor grade, poor differentiation and shorter survival in BC patients. Next, the loss-of-function experiments evidenced that silencing LINC00520 suppressed BC cell proliferation, migration and epithelial-mesenchymal transition (EMT) in vitro, and inhibited tumorigenesis in vivo. Interestingly, we found that LINC00520 expression was positively regulated by METTL3-mediated N6-methyladenosine(m⁶A) modification in BC. Furthermore, we identified the tumor-suppressor miR-577 as the binding target of LINC00520 in BC. Mechanistically, LINC00520 elevated POSTN level via sponging miR-577, resulting in the activation of the downstream tumor-promoting ILK/Akt/mTOR pathway. Finally, the rescuing experiments evidenced that both POSTN knockdown and ILK/Akt/mTOR pathway inhibitor OSU-T315 abrogated the promoting effects of miR-577 ablation on the malignant phenotypes in BC. Collectively, this study firstly verified that LINC00520 acted as a ceRNA of miR-577 to advance BC aggressiveness in a m⁶A-dependent manner, providing novel biomarkers for BC diagnosis and therapy.

Methyltransferase-like 3 facilitates lung cancer progression by accelerating m6A methylation-mediated primary miR-663 processing and impeding SOCS6 expression

OBJECTIVE

Lung cancer (LC) remains a threatening health issue worldwide. Methyltransferase-like protein 3 (METTL3) is imperative in carcinogenesis via m6A modification of microRNAs (miRNAs). This study estimated the effect of METTL3 in LC by regulating m6A methylation-mediated pri-miR-663 processing.

METHODS

miR-663 expression in 4 LC cell lines and normal HBE cells was determined using RT-qPCR. A549 and PC9 LC cells selected for in vitro studies were transfected with miR-663 mimics or inhibitor. Cell viability, migration, invasion, proliferation, and apoptosis were detected by CCK-8, Transwell, EdU, and flow cytometry assays. The downstream target genes and binding sites of miR-663 were predicted via Starbase database and validated by dual-luciferase assay. LC cells were delivered with oe-METTL3/sh-METTL3. Crosslinking between METTL3 and DGCR8 was verified by co-immunoprecipitation. Levels of m6A, miR-663, and pri-miR-663 were measured by m6A dot blot assay and RT-qPCR. m6A modification of pri-miR-663 was verified by Me-RIP assay. Finally, the effects of METTL3 in vivo were ascertained by tumor xenograft in nude mice.

RESULTS

miR-663 was upregulated in LC cells, and miR-663 overexpression promoted cell proliferation, migration, invasion, and inhibited apoptosis, but miR-663 knockdown exerted the opposite effects. miR-663 repressed SOCS6 expression. SOCS6 overexpression annulled the promotion of miR-663 on LC cell growth. METTL3 bound to DGCR8, and METTL3 silencing elevated the levels of pri-miR-663 and m6A methylation-modified pri-miR-663, and suppressed miR-663 maturation and miR-663 expression. METTL3 facilitated tumor growth in mice through the miR-663/SOCS6 axis.

CONCLUSION

METTL3 promotes LC progression by accelerating m6A methylation-mediated pri-miR-663 processing and repressing SOCS6.