N6-methyladenosine-modified circIGF2BP3 inhibits CD8+ T-cell responses to facilitate tumor immune evasion by promoting the deubiquitination of PD-L1 in non-small cell lung cancer

Circular RNAs: key players in tumor immune evasion

Immune responses against tumor antigens play a role in confining tumor growth. In response, cancer cells developed several mechanisms to bypass or defeat these anti-tumor immune responses-collectively referred to as "tumor immune evasion". Recent studies have shown that a group of non-coding RNAs, namely circRNAs affect several aspects of tumor immune evasion through regulation of activity of CD8 + T cells, regulatory T cells, natural killer cells, cytokine-induced killer cells or other immune cells. Understanding the role of circRNAs in this process facilitate design of novel therapies for enhancing the anti-tumor capacity of immune system. This review provides an outline of different roles of circRNAs in the tumor immune evasion.

Biological roles of enhancer RNA m6A modification and its implications in cancer

Enhancers, as distal cis-regulatory elements in the genome, have a pivotal influence on orchestrating precise gene expression. Enhancer RNAs (eRNAs), transcribed from active enhancer regions, are increasingly recognized as key regulators of transcription. N6-methyladenosine (m6A), the most plentiful internal modification in eukaryotic mRNAs, has garnered significant research interest in recent years. With advancements in high-throughput sequencing technologies, it has been established that m6A modifications are also present on eRNAs. An accumulative body of evidence demonstrates that aberrant enhancers, eRNAs, and m6A modifications are intimately connected with carcinoma onset, progression, invasion, metastasis, treatment response, drug resistance, and prognosis. However, the underlying molecular mechanisms governing m6A modification of eRNAs in cancer remain elusive. Here, we review and synthesize current understanding of the regulatory roles of enhancers, eRNAs, and m6A modifications in cancer. Furthermore, we investigate the possible roles of eRNAs m6A modification in tumorigenesis based on existing literature, offering novel perspectives and directions for future research on epigenetic regulatory mechanisms in cancer cells.

Mechanistic study of Lonicerae Japonicae Flos (Caprifoliaceae) in non-small cell lung cancer prevention and treatment through integrative pharmacology, multi-machine learning, artificial intelligence, and in vitro experiments

ETHNOPHARMACOLOGICAL RELEVANCE

Lonicerae Japonicae Flos (Caprifoliaceae) (LJF), an herb with the homology of medicine and food, is traditionally utilized for its heat-clearing, detoxifying, and anticancer properties. Yet, the mechanism by which LJF may assist in the treatment of non-small cell lung cancer (NSCLC) remains unclear.

AIM OF THE STUDY

To elucidate the potential mechanisms of LJF in the treatment of NSCLC through phytochemical analysis, network pharmacology, machine learning, and in vitro experimental validation.

MATERIALS AND METHODS

LJF was analyzed for its components using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The active compounds and targets of LJF were identified from TCMSP, and NSCLC-related targets were retrieved from GeneCards, DisGeNET and OMIM. Network pharmacology and multi-machine learning algorithms predicted key features, and GSEA/GSVA assessed pathway enrichment. Immune infiltration analysis evaluated immune cell composition in the NSCLC microenvironment, and molecular docking was performed with AlphaFold. In vitro experiments assessed LJF's effects on A549 cells, and Western blot analyzed protein expression.

RESULTS

Network pharmacology and multi-machine learning indicated that PECAM1 and SPP1 are potential targets for LJF in the treatment of NSCLC. GSEA and immune infiltration analysis suggested PECAM1 and SPP1 influence NSCLC progression and immune evasion. In vitro experiments showed that LJF significantly inhibited A549 cells proliferation, migration, and invasion. Western blot results indicated upregulation of PECAM1 and SPP1 expression under LJF treatment.

CONCLUSION

LJF has an adjunctive therapeutic effect on NSCLC by regulating PECAM1 and SPP1 targets and their associated signaling pathways.

Reciprocal regulation between m6 A modifications and non-coding RNAs: emerging roles in cancer therapeutic resistance

In recent years, the interplay between N6-methyladenosine (m6A) modifications and non-coding RNAs (ncRNAs) has emerged as a pivotal research area, owing to their crucial involvement in the pathophysiological mechanisms underlying various diseases. A significant hurdle in cancer therapy is therapeutic resistance, which frequently contributes to adverse patient outcomes. Recent investigations have underscored the vital role that interactions between m6A modifications and ncRNAs play in mediating cancer therapeutic resistance via the MAPK, PI3K/Akt/mTOR, Wnt/β-catenin, HIPPO, and NF-κB pathways. This review elucidates how these interactions drive tumor therapeutic resistance by modulating these pathways. By dissecting the regulatory dynamics between m6A and ncRNAs in the context of cancer therapeutic resistance, this review aims to deepen the understanding of m6A-ncRNA interaction in cancer therapeutic resistance and identify potential therapeutic targets to improve cancer treatment efficacy.

Preamplification-Free Detection of RNA N6-Methyladenosine Modification at Single-Base Resolution Using the CRISPR Tandem Assay

N6-Methyladenosine (m6A) ranks among the most prevalent modifications in RNA, which serves as a biomarker for diseases, such as lung cancer. Herein, we developed a CRISPR/Cas13a-Csm6 tandem assay (termed CRISPRm6A assay) allowing for preamplification-free, sensitive, and rapid detection of RNA m6A modifications. The coupling of Cas13a-Csm6 tandem with MazF endoribonuclease enables the assay to identify m6A RNA with single-base resolution. Compared to the CRISPRm6A assay using Cas13a alone, the tandem CRISPRm6A assay yielded an improved sensitivity for RNA detection by ∼22 times, thus enabling preamplification-free detection of RNA m6A. Particularly, the proposed assay enabled quantification of m6A abundance down to 0.5% at the picomole level in lncRNA MALAT1 and demonstrated a 100% correlation in diagnosing nonsmall cell lung cancer. In summary, the CRISPRm6A assay supports two key applications in biological samples: (1) precise determination of m6A sites and (2) quantitative measurement of m6A fractions. Therefore, the CRISPR tandem method presents a promising tool for RNA epigenetics-based diagnostics.

METTL3-dependent epigenetic regulation of ULK2 autophagy in hypertrophic scarring

Increased autophagy in fibroblasts drives their differentiation into myofibroblasts, a key process in dermal fibrosis during hypertrophic scar (HS) progression. While N6-methyladenosine (m6A) modification is implicated in fibrosis and autophagy, its mechanistic role in HS remains unclear. In this study, we investigated the involvement of fibroblast autophagy in HS progression and the regulatory mechanisms underlying this process. Our findings demonstrated that HS development is associated with significant autophagy in both human patients and rabbit models, as evidenced by the activation of fibroblast-associated alpha-smooth muscle actin (α-SMA) and type I collagen. Pharmacological inhibition of autophagy using 3-methyladenine effectively suppressed fibroblast-to-myofibroblast differentiation. We further discovered that excessive m6A modifications enhanced autophagy in fibroblasts derived from HS tissues. Mechanistically, we elucidated that methyltransferase-like 3 (METTL3)-mediated m6A modification upregulated unc-51-like kinase 2 (ULK2), a key regulator of autophagy initiation, through techniques such as m6A RNA immunoprecipitation sequencing (MeRIP-seq), qRT-PCR, and Western blotting. Silencing METTL3 impaired autophagic flux, as confirmed by transmission electron microscopy and LC3-II/I ratio analysis, thereby inhibiting fibroblast-to-myofibroblast differentiation. Notably, subcutaneous injection of METTL3 small interfering RNA (siRNA) attenuated cellular autophagy in HS tissues and mitigated HS formation in rabbit ears. These results clarify the causal relationship between METTL3-mediated m6A modification, autophagy, and fibroblast-to-myofibroblast differentiation, providing a mechanistic basis for the therapeutic potential of targeting METTL3 in HS treatment.

Tumor cell-intrinsic circular RNA circFNDC3B attenuates CD8+ T cells infiltration in non-small cell lung cancer

Tumor-infiltrating CD8+ T cells are critical for anti-tumor immunity and positively associated with patient survival. However, the mechanisms governing CD8+ T cell infiltration remain incompletely elucidated, particularly those involving circular RNAs (circRNAs). In this study, we characterized circRNA expression profiles in four paired normal and tumor tissues of non-small-cell lung cancer (NSCLC) and identified that circFNDC3B, a circular transcript derived from exons 2 and 3 of the fibronectin type III domain containing 3B (FNDC3B) gene, as significantly upregulated in NSCLC tissues. Mechanistic investigations revealed that circFNDC3B directly binds to transcription factor II-I (TFII-I), forming an RNA-protein complex that competitively disrupts the interaction between TFII-I and STAT1. This sequestration abrogates the transcriptional activation of CXCL10 and CXCL11, two critical chemokines governing CD8+ T cell chemoattraction. Consequently, reduced CXCL10/11 expression significantly impairs CD8+ T cell infiltration into the tumor microenvironment. Consistently, the murine ortholog circFndc3b expression exhibits an inverse correlation with CD8+ T cell infiltration in tumors. Our study uncovers a crucial circRNA-mediated regulatory axis wherein circFNDC3B impedes anti-tumor immunity by suppressing chemokine-dependent CD8+ T cell recruitment, positioning circFNDC3B as a potential therapeutic target to enhance CD8+ T cell-mediated anti-tumor responses in NSCLC.

circRNA/TLR interaction: key players in immune regulation and autoimmune diseases

Circular RNAs are a class of non-coding RNAs with covalently closed loops. They have been revealed to regulate immune responses by affecting gene expression. Although initially considered splicing byproducts, new studies have indicated their role in transcriptional and post-transcriptional control, especially with TLRs. TLRs start inflammatory signaling and let the innate immune system recognize PAMPs. circRNAs interact context-dependently with TLR pathways to influence immune homeostasis and inflammation in either pathogenic or protective roles. In autoimmune diseases, dysregulated circRNA expression can aggravate immune responses and damage tissue. CircRNAs can interact with RNA-binding proteins, function as molecular sponges for miRNAs, and change inflammatory pathways like the NF-κB signaling cascade, influencing immune responses. They control adaptive immunity, function of antigen-presenting cells, and cytokine generation. The stability and presence of circRNAs in many body fluids make them therapeutic targets and biomarkers for inflammatory and autoimmune diseases. The several immune control roles of circRNA-TLR interactions are discussed in this review, as well as their consequences for immunologically mediated disease diagnosis and treatment.

CircRNAs in the tumor microenvironment: new frontiers in cancer progression and therapy

The tumor microenvironment (TME), a dynamic ecosystem which including immune cells, cancer-associated fibroblasts (CAFs), endothelial cells, pericytes and acellular components, is orchestrating cancer progression through crosstalk between malignant cells and stromal components and increasingly recognized as a therapeutic frontier. Within this intricate network, circular RNAs (circRNAs) have emerged as pivotal regulators due to their unique covalently closed structures, which confer exceptional stability and multifunctional capabilities. This regulation is mediated through multiple mechanisms, such as acting as microRNA (miRNA) sponges, interacting with proteins, and, in certain instances, encoding functional peptides. The interaction between circRNAs and the TME not only affects cancer growth and metastasis but also influences immune evasion and therapeutic resistance. Elucidating the mechanisms by which circRNAs orchestrate these interactions is essential for identifying novel diagnostic biomarkers and developing effective therapeutic strategies. Such insights are expected to bridge gaps in current cancer biology, offering promising avenues for precision oncology and ultimately improving clinical outcomes for cancer patients.

GIV/Girdin Modulation of Microglial Activation in Ischemic Stroke: Impact of FTO-Mediated m6A Modification

Ischemic stroke (IS) is one of the most common causes of death in the world. The lack of effective pharmacological treatments for IS was primarily due to a lack of understanding of its pathogenesis. Gα-Interacting vesicle-associated protein (GIV/Girdin) is a multi-modular signal transducer and guanine nucleotide exchange factor that controls important signaling downstream of multiple receptors. The purpose of this study was to investigate the role of GIV in IS. In the present study, we found that GIV is highly expressed in the central nervous system (CNS). GIV protein level was decreased, while GIV transcript level was increased in the middle cerebral artery occlusion reperfusion (MCAO/R) mice model. Additionally, GIV was insensitive lipopolysaccharide (LPS) exposure. Interestingly, we found that GIV overexpression dramatically restrained microglial activation, inflammatory response, and M1 polarization in BV-2 microglia induced by oxygen-glucose deprivation and reoxygenation (OGD/R). On the contrary, GIV knockdown had the opposite impact. Mechanistically, we found that GIV activated the Wnt/β-catenin signaling pathway by interacting with DVL2 (disheveled segment polarity protein 2). Notably, m6A demethylase fat mass and obesity-associated protein (FTO) decreased the N6-methyladenosine (m6A) modification-mediated increase of GIV expression and attenuated the inflammatory response in BV-2 stimulated by OGD/R. Taken together, our results demonstrate that GIV inhibited the inflammatory response via activating the Wnt/β-catenin signaling pathway which expression regulated in an FTO-mediated m6A modification in IS. These results broaden our understanding of the role of the FTO-GIV axis in IS development.

Induction of necroptosis in lung adenocarcinoma by miR‑10b‑5p through modulation of the PKP3/RIPK3/MLKL cascade

Globally, lung adenocarcinoma (LUAD) remains the leading cause of cancer‑related mortality, highlighting the urgent need for innovative therapeutic approaches. Necroptosis has been recognized as a crucial mechanism for inhibiting cancer progression. Research has revealed a significant association between microRNA (miRNA)‑mediated necroptosis and tumor progression. The present study aimed to elucidate the role and underlying mechanisms of miR‑10b‑5p in regulating necroptosis in the context of LUAD. In an investigation of LUAD, miRNA sequencing was conducted on both LUAD and adjacent non‑tumor tissues, followed by the integration of external database information to identify specific target miRNAs. The expression of miR‑10b‑5p was verified in LUAD tissues and corresponding adjacent non‑cancerous tissues using immunohistochemistry. In vitro experiments, utilizing LUAD cell lines engineered to modulate miR‑10b‑5p levels, assessed its effects on cellular activities and necroptosis. The inhibition of PKP3 by miR‑10b‑5p was determined using a dual luciferase reporter system. Furthermore, alterations in miR‑10b‑5p levels were found to affect PKP3 expression and inhibit the RIPK3/MLKL signaling pathway, as evidenced by western blot analysis in LUAD cell lines. The effect of PKP3 knockdown on cell activity and necroptosis in LUAD cell lines with low miR‑10b‑5p expression levels was assessed using cell function assays. Finally, a nude mouse xenograft model was used to investigate the effect of miR‑10b‑5p on LUAD growth in vivo and its specific mechanism of action. It has been revealed that miR‑10b‑5p levels are significantly elevated in LUAD specimens. Further investigations demonstrated that an increase in miR‑10b‑5p enhances the proliferation of LUAD cells and suppresses the progression of necroptosis, as evidenced by in vitro experiments. Through dual luciferase reporter assays, PKP3 was confirmed as a direct target negatively regulated by miR‑10b‑5p, leading to reduced expression levels. Western blot analysis indicated that miR‑10b‑5p inhibits the RIPK3/MLKL pathway activation through downregulation of PKP3, which leads to increased cell proliferation and decreased necroptosis. However, knockdown of PKP3 reversed the inhibitory effect of miR‑10b‑5p inhibitors on cellular activity and inhibited necrosis by suppressing the RIPK3/MLKL signalling pathway. In addition, animal model studies demonstrated that inhibition of miR‑10b‑5p activated the RIPK3/MLKL pathway by promoting PKP3 expression and significantly reduced LUAD growth by promoting necroptosis. In conclusion, our studies have revealed that the miR‑10b‑5p functions as a tumorigenic factor, enhancing various cellular activities in LUAD cells and suppressing necroptosis by specifically targeting PKP3, thereby inhibiting activation of the RIPK3/MLKL pathway. Importantly, interventions using inhibitors that specifically target miR‑10b‑5p have shown significant success in impeding the progression of LUAD by promoting necroptosis in both cellular and animal models. Thus, targeting miR‑10b‑5p holds considerable potential as a therapeutic strategy for LUAD.

miR-186-5p Down-Regulates PD-L1 Level in Acute Myeloid Leukemia Cells and Inhibits Tumorigenesis and Immune Escape

Acute myeloid leukemia (AML) is a malignant tumor of blood cells, which seriously interferes with the generation of normal cells. Although miR-186-5p is diminished in AML, its exact mechanism is not well understood. miR-186-5p and PD-L1 levels in AML cells (HL-60, KG-1, TF-1a, MOLT-3) and subcutaneous tumor tissue were discovered through qRT-PCR and Western blot. miR-186-5 p and PD-L1 combining sites were foreseen by the database and verified by dual luciferase and immunoprecipitation experiments. AML cells with miR-186-5p overexpression or knockdown and PD-L1 overexpression were cocultured with CD4+ and CD8+ T cells. The proliferation, migration, invasion and apoptosis of AML cells, CD8+ and CD4+ T cell growth and apoptosis, and activated markers (Perforin and Granzyme B) and secreted cytokines (IFN-γ, IL-4 and TNF-α) levels were detected by CCK8, Transwell, flow cytometry, CFSE, Western blot and ELISA, respectively. Subcutaneous xenograft magnitude and mass in nude mice were measured. Ki67 level was identified through immunohistochemistry. CD4+ and CD8+ T cell level and infiltration were detected by immunofluorescence and flow cytometry. miR-186-5p was downregulated, and PD-L1 was boosted in AML cells and subcutaneous tumor tissues (p < 0.05), while miR-186-5p targeted down-regulate PD-L1. miR-186-5p upregulation hindered AML cell multiplication, migration, invasion and facilitate cell death, and enhanced the proliferation activity, activation markers (Perforin and Granzyme B) and secreted cytokines (IFN-γ, IL-4, TNF-α) of CD8+ and CD4+ T cells, inhibited apoptosis, and inhibited immune escape (p < 0.05). Knockdown of miR-186-5p can promote AML progression, but PD-L1 upregulation weakens the antitumor impact of miR-186-5p overexpression (p < 0.05). Transplanted tumor mice experiments also found that miR-186-5p hindered PD-L1 and tumor growth (p < 0.05). In conclusion, miR-186-5p can target inhibit PD-L1, suppress AML cells multiplication, movement, invasion and immune escape, and then reduce AML, aiming to provide support and basis for the pathological mechanism and prevention and treatment strategy of AML.

N6-methyladenosine-modified circ_0000517 promotes non-small cell lung cancer metastasis via miR-1233-3p/CDH6 axis

Circular RNAs (circRNAs) exhibit dysregulation in non-small cell lung cancer (NSCLC) and regulate the malignant biological behavior of NSCLC. The N6-methyladenosine (m6A) modification of circRNAs plays a critical role in multiple malignant tumors, and their biological relevance in NSCLC is unclear. Herein, this study was conducted to investigate the novel functional mechanism of highly expressed circ_0000517 in NSCLC by developing in vitro experiments. We found that circ_0000517 was upregulated in NSCLC tissues and cells, and that increased circ_0000517 expression was associated with m6A modification. Biologically, silenced circ_0000517 hindered the proliferation, colony formation, migration and invasion of NSCLC cells in vitro, and also suppressed the EMT-related process. Mechanistically, highly expressed circ_0000517 activated CDH6 expression and EMT evolution through sponging miR-1233-3p. Notably, miR-1233-3p had the opposite effect and reversed the promotion effect of circ_0000517 on the malignant biological behavior of NSCLC cells. Our study revealed a promising novel endogenous regulatory network that m6A-modified circ_0000517 accelerated malignant evolution of NSCLC by targeting the miR-1233-3p/CDH6 axis.

Inhibition of NSUN3 suppresses immune escape in non-small cell lung cancer through stabilizing PD-L1 in a 5-methyladenosine dependent way

BACKGROUND

Alterations in 5-methyladenosine (m5C) RNA methyltransferase have been implicated in the pathogenesis of lung cancer. However, the role of NSUN3, a key m5C regulator, in modulating PD-L1 expression and immune evasion in Non-Small Cell Lung Cancer (NSCLC) remains poorly understood.

METHODS

NSUN3 expression levels in NSCLC tissues and cell lines were quantified using quantitative Reverse Transcription PCR (RT-qPCR). The impact of NSUN3 expression modulation on lung cancer cell viability and proliferation was assessed through CCK-8 assays and colony formation experiments. To evaluate immune cell interactions, CD8+ T-cells were co-cultured with NSCLC cells, and cytotoxic activity was measured by an LDH cytotoxicity detection kit. The in vivo tumorigenic role of NSUN3 was investigated using subcutaneous tumor xenograft models. Mechanistic insights into NSUN3-PD-L1 interactions were obtained through m5C-RIP, RIP, and dual-luciferase reporter assays.

RESULTS

Elevated NSUN3 mRNA levels were observed in NSCLC tissues compared to normal controls. Functional studies demonstrated that NSUN3 knockdown significantly inhibited cell viability and proliferation in both A549 and PC9 cell lines. Furthermore, NSUN3 depletion enhanced CD8+ T-cell-mediated cytotoxicity against NSCLC cells and suppressed tumor growth in vivo. Mechanistically, NSUN3 inhibition was found to stabilize PD-L1 mRNA, suggesting a regulatory role in immune checkpoint modulation.

CONCLUSIONS

The present findings establish NSUN3 as an oncogenic driver in NSCLC pathogenesis, functioning through PD-L1 mRNA stabilization. The identification of this NSUN3-PD-L1 regulatory axis provides new insights into the molecular mechanisms underlying immune escape in NSCLC and offers promising directions for developing targeted immunotherapies.

Regulatory mechanisms of m6A RNA methylation in esophageal cancer: a comprehensive review

Esophageal cancer is an aggressively malignant neoplasm characterized by a high mortality rate. Frequently diagnosed at an advanced stage, it presents challenges for optimal therapeutic intervention due to its non-specific symptoms, resulting in lost opportunities for effective treatment, such as surgery, radiotherapy, chemotherapy and target therapy. The N6-methyladenosine (m6A) modification represents the most critical post-transcriptional modification of eukaryotic messenger RNA (mRNA). The reversible m6A modification is mediated by three regulatory factors: m6A methyltransferases, demethylating enzymes, and m6A recognition proteins. These components identify and bind to specific RNA methylation sites, thereby modulating essential biological functions such as RNA processing, nuclear export, stability, translation and degradation, which significantly influence tumorigenesis, invasion, and metastasis. Given the importance of m6A modification, this paper offers a comprehensive examination of the regulatory mechanisms, biological functions, and future therapeutic implications of m6A RNA methylation in the context of esophageal cancer.

LINC01559 drives osimertinib resistance in NSCLC through a ceRNA network regulating miR-320a/IGF2BP3 axis

Background

Osimertinib resistance remains a major challenge in the treatment of lung adenocarcinoma. Long non-coding RNAs (lncRNAs) have emerged as key regulators of drug resistance, but their roles in osimertinib resistance are poorly understood. This study aimed to identify lncRNAs driving osimertinib resistance and elucidate their molecular mechanisms.

Methods

Multi-cohort analysis (GSE222820, GSE232890, GSE255958) identified osimertinib resistance-associated lncRNAs. Functional validation employed in vitro assays (proliferation, migration, invasion, drug sensitivity) and xenograft models. Mechanistic studies involved luciferase reporter assays, RNA immunoprecipitation (RIP), and Western blotting. Clinical correlations were analyzed using TCGA-LUAD data.

Results

Our findings demonstrated that LINC01559 was markedly upregulated in LUAD tissues and osimertinib-resistant cell lines, correlating with poor patient survival. Functional analyses revealed that LINC01559 critically regulates processes linked to drug resistance, enhancing tumor cell proliferation, migration, and invasive capabilities. Knockdown of LINC01559 sensitized resistant cells to osimertinib, significantly reducing colony-forming potential and suppressing migratory/invasive behaviors. In contrast, overexpression of LINC01559 exacerbated therapeutic resistance. Mechanistically, LINC01559 functions as a competing endogenous RNA (ceRNA) by sponging miR-320a, promote osimertinib -resistance and upregulate the expression of the miR-320a target IGF2BP3. Rescue experiments and xenograft models confirmed that Linc01559 drives resistance via the miR-320a/IGF2BP3 axis.

Conclusion

This study identifies LINC01559 as a novel ceRNA that drives osimertinib resistance in lung adenocarcinoma by sponging miR-320a to enhance IGF2BP3 expression. Targeting the LINC01559/miR-320a/IGF2BP3 axis may provide a therapeutic strategy to overcome osimertinib resistance.

Construction of a circRNA-miRNA-mRNA Regulatory Network for the Immune Regulation of Lung Adenocarcinoma

BACKGROUND

Recent research has highlighted the significance of circular RNAs (circRNAs) as pivotal regulators in the progression of tumors and the therapeutic response in non-small cell lung cancer (NSCLC). These circRNAs function through a sponge mechanism, interacting with microRNAs (miRNAs) to modulate mRNA expression levels. Nevertheless, the precise role of the circRNA-miRNA-mRNA regulatory network in immune regulation within lung adenocarcinoma (LUAD) remains inadequately understood.

METHODS AND MATERIALS

We utilized microarray datasets from the GEO NCBI database (GSE101586) to identify differentially expressed circRNAs (DEcircRNAs) in LUAD. CircBank was employed to predict the target miRNAs of DEcircRNAs, which were subsequently intersected with miRNAs from the GSE36681 database. The identified miRNAs were then predicted to target mRNAs using miRDB and miWalk, and intersections with immune-related genes from the IMMPORT database were analyzed. Protein-protein interaction (PPI) networks were constructed using Cytoscape software. The DAVID functional annotation tool was utilized to explore potential biological processes, molecular functions, and KEGG pathways associated with LUAD. Gene expression and Kaplan-Meier survival analyses were conducted to establish a key regulatory network and to assess immune cell infiltration and Pearson correlation for significant target genes. Finally, we selected the most significantly upregulated circRNA with differential expression for validation through in vitro experiments.

RESULTS

Our analysis identified a total of 7 upregulated and 42 downregulated circRNAs, along with 10 significant miRNAs and 20 target mRNAs. KEGG enrichment analysis indicated that these components are primarily enriched in the ErbB signaling pathway. Furthermore, Gene Ontology (GO) analysis revealed significant enrichment in responses to organic substances, cytokine-mediated signaling pathways, cellular responses to cytokines, responses to chemical stimuli, steroid hormone receptor activity, ErbB-3 class receptor binding, oxysterol binding, signal receptor activity, and molecular transducer activity. Notable core mRNAs identified included OAS1, VIPR1, and PIK3R1. Subsequently, we constructed a regulatory network comprising 6 DEcircRNAs, 3 DEmiRNAs, and 3 DEmRNAs. Through ssGSEA and CIBERSORT analyses, we observed significant differences in immune cell infiltration levels between the NSCLC cohort and the control group. Knocking down the expression of hsa_circ_0079557 significantly inhibited the viability, proliferation, migration, and invasion of LUAD cells.

CONCLUSION

We have established a circRNA-miRNA-mRNA regulatory network that offers novel insights into the molecular mechanisms governing immune regulation in LUAD. Future research should aim to translate these findings into clinical applications to enhance patient outcomes.

Cellular senescence in tumor immune escape: Mechanisms, implications, and therapeutic potential

Cellular senescence, a hallmark of aging, has emerged as a captivating area of research in tumor immunology with profound implications for cancer prevention and treatment. In the tumor microenvironment, senescent cells exhibit a dual role, simultaneously hindering tumor development through collaboration with immune cells and evading immune cell attacks by upregulating immunoinhibitory proteins. However, the intricate immune escape mechanism of cellular senescence in the tumor microenvironment remains a subject of intense investigation. Chronic inflammation is exacerbated by cellular senescence through the upregulation of pro-inflammatory factors such as interleukin-1β, thereby augmenting the risk of tumorigenesis. Additionally, the interplay between autophagy and cellular senescence adds another layer of complexity. Autophagy, known to slow down the aging process by reducing p53/p21 levels, may be downregulated by cellular senescence. To harness the therapeutic potential of cellular senescence, targeting its immunological aspects has gained significant attention. Strategies such as immune checkpoint inhibitors and T-cell senescence inhibition are being explored in the context of cellular senescence immunotherapy. In this comprehensive review, we provide a compelling overview of the regulation of cellular senescence and delve into the influencing factors, including chronic inflammation, autophagy, and circadian rhythms, associated with senescence in the tumor microenvironment. We specifically focus on unraveling the enigmatic dual role of cellular senescence in tumor immune escape. By deciphering the intricate nature of cellular senescence in the tumor microenvironment, this review aims to advance our understanding and pave the way for leveraging senescence as a promising target for tumor immunotherapy applications.

Regulation and application of m6A modification in tumor immunity

The m6A modification is an RNA modification that impacts various processes of RNA molecules, including transcription, splicing, stability, and translation. Recently, researchers have discovered that the presence of m6A modification can influence the interaction between tumor cells and immune cells and also play a role in regulating the expression of immune response-related genes. Additionally, m6A modification is intricately involved in the regulation of tumor immune evasion and drug resistance. Specifically, certain tumor cells can manipulate the gene expression through m6A modification to evade immune system attacks. Therefore, it might be possible to enhance tumor immune surveillance and improve the effectiveness of immune-based therapies by manipulating m6A modification. This review systematically discusses the role of m6A modification in tumor immunity, specifically highlighting its regulation of immune cells and immune-related genes in tumor cells. Furthermore, we explore the potential of m6A modification inhibitors as anti-cancer therapies and the significance of m6A regulatory factors in predicting the efficacy of tumor immune therapy.

CircNF1 modulates the progression and immune evasion of esophageal squamous cell carcinoma through dual regulation of PD-L1

BACKGROUND

Tumor immune escape is a pivotal gateway for esophageal squamous cell carcinoma (ESCC) development. Immune checkpoint-blocking therapies, represented by programmed cell death receptor-1/ligand 1 (PD-1/PD-L1) inhibitors, have achieved remarkable breakthroughs in ESCC treatment. However, not all patients with ESCC receive satisfactory clinical benefit. Therefore, identifying novel biomarkers for predicting the efficacy of immunotherapy in ESCC is of great importance.

METHODS

CircNF1 was screened from the circRNAs microarray, and its expression was measured by droplet digital polymerase chain reaction (ddPCR) and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assays in ESCC tissues and serum. Functional experiments were conducted to demonstrate the role of circNF1 in ESCC proliferation, metastasis, and tumor evasion. High-throughput RNA sequencing, chromatin immunoprecipitation (ChIP), co-immunoprecipitation (co-IP), and chromatin isolation by RNA purification-mass spectrometry (ChIRP-MS) were performed to clarify the underlying mechanisms of circNF1-mediated tumor progression.

RESULTS

The upregulation of circNF1 was closely associated with the response of anti-PD-L1 immunotherapy. Functionally, circNF1 promoted ESCC cell malignant phenotypes and regulated CD8+ T-cell-mediated antitumor immunity. Mechanistically, circNF1 drove the IL-6-induced oncogenic activation of the JAK-STAT3 pathway, which stimulated p-STAT3 binding of the promoter regions of PD-L1. Furthermore, circNF1 physically interacted with annexin A1 (ANXA1), blocking the ANXA1 deubiquitination induced by ubiquitin-specific protease 7 (USP7), resulting in increased interaction between USP7 and PD-L1 and augmented PD-L1 stability.

CONCLUSIONS

Our findings provide novel insights into the specific regulatory mechanism of PD-L1 in ESCC cells, which offer a new strategy for synergizing with anti-PD-L1 therapy.

XIAP promotes metastasis of bladder cancer cells by ubiquitylating YTHDC1

X-linked inhibitor of apoptosis protein (XIAP), a member of the IAP family, is overexpressed in a variety of tumors and plays an important role in tumor progression. Increasing evidence suggests that XIAP promotes metastasis of bladder cancer but the underlying mechanism is not very clear. The RNA N6-methyladenosine (m6A) reader YTHDC1 regulates RNA splicing, nuclear transport, and mRNA stability and is a potential tumor target; however, its ubiquitin E3 ligase has not been described. In this study, screening of proteins that specifically interact with XIAP identified YTHDC1 as its degradation substrate. Ectopic overexpression of XIAP promoted degradation of YTHDC1, and knockout of XIAP upregulated YTHDC1, which inhibited metastasis of bladder cancer. Furthermore, YTHDC1 reduced the expression of matrix metalloproteinase-2 (MMP-2) by destabilizing its mRNA. These experiments revealed that XIAP promotes ubiquitination of YTHDC1, positively regulating expression of the MMP-2 and promoting metastasis of bladder cancer. Collectively, these findings demonstrate that XIAP is a critical regulator of YTHDC1 and pinpoint the XIAP/YTHDC1/MMP-2 axis as a promising target for the treatment of bladder cancer.

CircRNAs: a novel potential strategy to treat breast cancer

Breast cancer is among the most prevalent malignant tumors worldwide, with triple-negative breast cancer (TNBC) being the most aggressive subtype and lacking effective treatment options. Circular RNAs (circRNAs) are noncoding RNAs that play crucial roles in the development of tumors, including breast cancer. This article examines the progress of research on circRNAs in breast cancer, focusing on four main areas: 1) breast cancer epidemiology, classification, and treatment; 2) the structure, discovery process, characteristics, formation, and functions of circRNAs; 3) the expression, mechanisms, clinical relevance, and recent advances in the study of circRNAs in breast cancer cells and the immune microenvironment, particularly in TNBC; and 4) the challenges and future prospects of the use of circRNAs in BC research.

Immunotherapy and the Tumor Microenvironment in Brain Metastases from Non-Small Cell Lung Cancer: Challenges and Future Directions

Brain metastases (BMs) are a relatively common and severe complication in advanced non-small cell lung cancer (NSCLC), significantly affecting patient prognosis. Metastatic tumor cells can alter the brain tumor microenvironment (TME) to promote an immunosuppressive state, characterized by reduced infiltration of tumor-infiltrating lymphocytes (TILs), diminished expression of programmed death-ligand 1 (PD-L1), and changes in other proinflammatory factors and immune cell populations. Microglia, the resident macrophages of the brain, play a pivotal role in modulating the central nervous system (CNS) microenvironment through interactions with metastatic cancer cells, astrocytes, and infiltrating T cells. The M2 phenotype of microglia contributes to immunosuppression in BM via the activation of signaling pathways such as STAT3 and PI3K-AKT-mTOR. Recent advances have enhanced our understanding of the immune landscape of BMs in NSCLC, particularly regarding immune evasion within the CNS. Current immunotherapeutic strategies, including immune checkpoint inhibitors, have shown promise for NSCLC patients with BM, demonstrating intracranial activity and manageable safety profiles. Future research is warranted to further explore the molecular and immune mechanisms underlying BM, aiming to develop more effective treatments.

Post-translational modifications of immune checkpoints: unlocking new potentials in cancer immunotherapy

Immunotherapy targeting immune checkpoints has gained traction across various cancer types in clinical settings due to its notable advantages. Despite this, the overall response rates among patients remain modest, alongside issues of drug resistance and adverse effects. Hence, there is a pressing need to enhance immune checkpoint blockade (ICB) therapies. Post-translational modifications (PTMs) are crucial for protein functionality. Recent research emphasizes their pivotal role in immune checkpoint regulation, directly impacting the expression and function of these key proteins. This review delves into the influence of significant PTMs-ubiquitination, phosphorylation, and glycosylation-on immune checkpoint signaling. By targeting these modifications, novel immunotherapeutic strategies have emerged, paving the way for advancements in optimizing immune checkpoint blockade therapies in the future.

The Role of M6A Modification in Autoimmunity: Emerging Mechanisms and Therapeutic Implications

N6-methyladenosine (m6A), a prevalent and essential RNA modification, serves a key function in driving autoimmune disease pathogenesis. By modulating immune cell development, activation, migration, and polarization, as well as inflammatory pathways, m6A is crucial in forming innate defenses and adaptive immunity. This article provides a comprehensive overview of m6A modification features and reveals how its dysregulation affects the intensity and persistence of immune responses, disrupts immune tolerance, exacerbates tissue damage, and promotes the development of autoimmunity. Specific examples include its contributions to systemic autoimmune disorders like lupus and rheumatoid arthritis, as well as conditions that targeting specific organs like multiple sclerosis and type 1 diabetes. Furthermore, this review explores the therapeutic promise of target m6A-related enzymes ("writers," "erasers," and "readers") and summarizes recent advances in intervention strategies. By focusing on the mechanistic and therapeutic implications of m6A modification, this review sheds light on its role as a promising tool for both diagnosis and treatment in autoimmune disorders, laying the foundation for advancements in customized medicine.

METTL3-mediated SMPDL3A promotes cell growth, metastasis and immune process of hepatocellular carcinoma by regulating LRPPRC

BACKGROUND

Methyltransferase-like protein 3 (METTL3) has been confirmed to act as a tumor promoter to regulate hepatocellular carcinoma (HCC) progression. Therefore, more roles and mechanisms of METTL3 in HCC progression deserve to be further revealed.

METHODS

The mRNA and protein levels of METTL3, sphingomyelin phodiesterase acid-like 3 A (SMPDL3A), and leucine rich pentatricopeptide repeat containing (LRPPRC) were determined by qRT-PCR and western blot. Cell proliferation, apoptosis, invasion and migration were detected by CCK8 assay, EdU assay, flow cytometry, transwell assay and wound healing assay. HCC cells were co-cultured with phytohemagglutinin-stimulated peripheral blood mononuclear cells, cytokine-induced killer cells, or CD8 + T-cells. IFN-γ, TNF-α levels, HCC cell survival rate and CD8 + T-cell apoptosis were determined to assess cell immune process. The interaction between METTL3, SMPDL3A and LRPPRC was assessed by MeRIP assay, RIP assay, dual-luciferase reporter assay or Co-IP assay. Animal experiments were performed to evaluate the effect of METTL3 knockdown on HCC tumorigenesis and lung metastasis.

RESULTS

METTL3 was upregulated in HCC tissues and cells, and its knockdown repressed HCC cell proliferation, invasion, migration, immune process and promoted apoptosis. METTL3 increased SMPDL3A mRNA stability by m6A methylation modification, and this modification could be recognized by IGF2BP1. SMPDL3A overexpression reversed the inhibitory effect of METTL3 knockdown on HCC cell growth, metastasis and immune process. SMPDL3A interacted with LRPPRC to positively regulate its expression, and LRPPRC overexpression also eliminated the regulation of SMPDL3A silencing on HCC progression. In addition, downregulation of METTL3 repressed HCC tumorigenesis and lung metastasis via mediating SMPDL3A/LRPPRC axis.

CONCLUSION

METTL3 accelerated HCC cell growth, metastasis and immune process by regulating SMPDL3A/LRPPRC axis, providing a potential target for HCC treatment.

Genome-wide profiling of N6-methyladenosine-modified pseudogene-derived long noncoding RNAs reveals the tumour-promoting and innate immune-restraining function of RPS15AP12 in ovarian cancer

BACKGROUND

Pseudogene-derived lncRNAs are widely dysregulated in cancer. Technological advancements have facilitated the functional characterization of increasing pseudogenes in cancer progression. However, the association between pseudogenes and RNA N6-methyladenosine (m6A) modification in cancer, as well as the underlying mechanisms, remains largely unexplored.

METHODS

We analyzed the expression of 12 146 pseudogenes and comprehensively examined the m6A modification of RNAs derived from them and their paralogs. Through integrative analysis of multi-omics data, we explored the associations between pseudogene dysregulation and m6A, identifying critical pseudogenes involved in HGSOC progression. Tumour promotion role of RPS15AP12 and its cognate parent gene was characterized by cell proliferation, transwell assays, and scratch assays in ovarian cells and xenograft nude mice. RNA decay assays were used to reveal the participation of m6A in decreasement of RPS15AP12 lncRNA stability. Luciferase reporter assays were performed to verify that RPS15AP12 enhances RPS15A expression by competitively binding to miR-96-3p. Western blot and phosphorylation assays were performed to investigate the impairment of RPS15AP12 towards the sensors of MAVS (RIG-I and MDA5), and downstream p-TBK1 and p-IRF3. Finally, ELISA assays were performed to explore the regulatory role of RPS15AP12 in IFN-β expression.

RESULTS

M6A is distributed across over a thousand pseudogenes, and hypomethylation leads to their upregulation in HGSOC. We identified a processed pseudogene, RPS15AP12, upregulated by FTO-mediated m6A demethylation. RPS15AP12 enhances the growth ability and metastatic capabilities of ovarian cancer (OC) cells via functioning as a competitive endogenous RNA (ceRNA) for its host gene, RPS15A, through the sequestration of miR-96-3p. Importantly, the deletion of RPS15AP12 diminishes the expression of RPS15A, leading to the upregulation of anti-tumour immune responses by activating RIG-I and MDA5 and downstream p-TBK1 and p-IRF3 as well as IFN-β levels.

CONCLUSION

Our findings expand the understanding of m6A-modulated pseudogenes in tumour growth and anti-tumour innate immunity in OC.

KEY POINTS

Genome-wide profiling reveals the redistribution of m6A modification on pseudogene-derived lncRNAs and m6A redistribution-relevant dysregulation of pseudogenes in HGSOC. RPS15AP12, as a representative processed pseudogene, is up-regulated by FTO-mediated demethylation and acts as a miRNA sponge to promote RPS15A expression via competitively binding to miR-96-3p. RPS15AP12/RPS15A axis inhibits MAVS sensors (RIG-I and MDA5) and downstream IFN-β levels in ovarian cancer.

m6A RNA methylation: a pivotal regulator of tumor immunity and a promising target for cancer immunotherapy

M6A modification is one of the most common regulatory mechanisms of gene expression in eukaryotic cells, influencing processes such as RNA splicing, degradation, stability, and protein translation. Studies have shown that m6A methylation is closely associated with tumorigenesis and progression, and it plays a key regulatory role in tumor immune responses. m6A modification participates in regulating the differentiation and maturation of immune cells, as well as related anti-tumor immune responses. In the tumor microenvironment, m6A modification can also affect immune cell recruitment, activation, and polarization, thereby promoting or inhibiting tumor cell proliferation and metastasis, and reshaping the tumor immune microenvironment. In recent years, immunotherapies for tumors, such as immune checkpoint inhibitors and adoptive cell immunotherapy, have been increasingly applied in clinical settings, achieving favorable outcomes. Targeting m6A modifications to modulate the immune system, such as using small-molecule inhibitors to target dysregulated m6A regulatory factors or inducing immune cell reprogramming, can enhance anti-tumor immune responses and strengthen immune cell recognition and cytotoxicity against tumor cells. m6A modification represents a new direction in tumor immunotherapy with promising clinical potential. This review discusses the regulatory role of m6A methylation on immune cells and tumor immune responses and explores new strategies for immunotherapy.

The m6A revolution: transforming tumor immunity and enhancing immunotherapy outcomes

N6-methyladenosine (m6A), the most prevalent RNA modification in eukaryotes, plays a critical role in the development and progression of various diseases, including cancer, through its regulation of RNA degradation, stabilization, splicing, and cap-independent translation. Emerging evidence underscores the significant role of m6A modifications in both pro-tumorigenic and anti-tumorigenic immune responses. In this review, we provide a comprehensive overview of m6A modifications and examine the relationship between m6A regulators and cancer immune responses. Additionally, we summarize recent advances in understanding how m6A modifications influence tumor immune responses by directly modulating immune cells (e.g., dendritic cells, tumor-associated macrophages, and T cells) and indirectly affecting cancer cells via mechanisms such as cytokine and chemokine regulation, modulation of cell surface molecules, and metabolic reprogramming. Furthermore, we explore the potential synergistic effects of targeting m6A regulators in combination with immune checkpoint inhibitor (ICI) therapies. Together, this review consolidates current knowledge on the role of m6A-mediated regulation in tumor immunity, offering insights into how a deeper understanding of these modifications may identify patients who are most likely to benefit from immunotherapies.

Mechanisms and strategies of immunosenescence effects on non-small cell lung cancer (NSCLC) treatment: A comprehensive analysis and future directions

Non-small cell lung cancer (NSCLC), the most prevalent form of lung cancer, remains a leading cause of cancer-related mortality worldwide, particularly among elderly individuals. The phenomenon of immunosenescence, characterized by the progressive decline in immune cell functionality with aging, plays a pivotal role in NSCLC progression and contributes to the diminished efficacy of therapeutic interventions in older patients. Immunosenescence manifests through impaired immune surveillance, reduced cytotoxic responses, and increased chronic inflammation, collectively fostering a pro-tumorigenic microenvironment. This review provides a comprehensive analysis of the molecular, cellular, and genetic mechanisms of immunosenescence and its impact on immune surveillance and the tumor microenvironment (TME) in NSCLC. We explore how aging affects various immune cells, including T cells, B cells, NK cells, and macrophages, and how these changes compromise the immune system's ability to detect and eliminate tumor cells. Furthermore, we address the challenges posed by immunosenescence to current therapeutic strategies, particularly immunotherapy, which faces significant hurdles in elderly patients due to immune dysfunction. The review highlights emerging technologies, such as single-cell sequencing and CRISPR-Cas9, which offer new insights into immunosenescence and its potential as a therapeutic target. Finally, we outline future research directions, including strategies for rejuvenating the aging immune system and optimizing immunotherapy for older NSCLC patients, with the goal of improving treatment efficacy and survival outcomes. These efforts hold promise for the development of more effective, personalized therapies for elderly patients with NSCLC.

Circular RNAs in cancer

Circular RNA (circRNA), a subtype of noncoding RNA, has emerged as a significant focus in RNA research due to its distinctive covalently closed loop structure. CircRNAs play pivotal roles in diverse physiological and pathological processes, functioning through mechanisms such as miRNAs or proteins sponging, regulation of splicing and gene expression, and serving as translation templates, particularly in the context of various cancers. The hallmarks of cancer comprise functional capabilities acquired during carcinogenesis and tumor progression, providing a conceptual framework that elucidates the nature of the malignant transformation. Although numerous studies have elucidated the role of circRNAs in the hallmarks of cancers, their functions in the development of chemoradiotherapy resistance remain unexplored and the clinical applications of circRNA-based translational therapeutics are still in their infancy. This review provides a comprehensive overview of circRNAs, covering their biogenesis, unique characteristics, functions, and turnover mechanisms. We also summarize the involvement of circRNAs in cancer hallmarks and their clinical relevance as biomarkers and therapeutic targets, especially in thyroid cancer (TC). Considering the potential of circRNAs as biomarkers and the fascination of circRNA-based therapeutics, the "Ying-Yang" dynamic regulations of circRNAs in TC warrant vastly dedicated investigations.

Progress in understanding the regulatory mechanisms of immune checkpoint proteins PD-1 and PD-L1 expression

Programmed Death Protein-1 (PD-1) is a cell surface receptor that serves as a checkpoint for T cells, playing a pivotal role in regulating T-cell apoptosis. The binding of PD-1 to its ligand, Programmed Death Ligand 1 (PD-L1), inhibits anti-tumor immunity by suppressing T-cell activation signals. Indeed, the PD-1/PD-L1 pathway governs the induction and maintenance of immune tolerance within the tumor microenvironment. Consequently, the regulation of PD-1/PD-L1 immune checkpoint expression is of paramount importance. This review summarizes the mechanisms governing PD1/PD-L1 expression at various stages, including transcription, post-transcription (mRNA processing), and post-translation (protein modifications), as well as immunotherapy targeting PD1/PD-L1, aiming to further explore novel strategies for tumor immunotherapy.

m6A methyltransferase METTL3 promotes non-small-cell lung carcinoma progression by inhibiting the RIG-I-MAVS innate immune pathway

Our experimental study showed that METTL3 was highly expressed in NSCLC cells and promoted the growth of tumor cells. METTL3 takes N6-methyladenosine (m6A) as the main means of mRNA modification to control the expression and function of RIG-I-MAVS signalling pathway. RIG-I-MAVS constitute the first line frontier in the innate immune defense of human cells. Activation of RIG-I-MAVS signaling can inhibit tumor cell growth and activate the immune microenvironment. Our experimental data reveal that lung cancer cells utilize METTL3-mediated methylation modifications to inhibit the activation of RIG-I-MAVS signaling pathway and immune responses. Our work provides new ideas for biotherapy and immunotherapy.

Cell-Derived Allograft Models as a Solution to the Obstacles of Preclinical Studies under Limited Resources: A Systematic Review on Experimental Lung Cancer Animal Models

BACKGROUND

The use of appropriate animal models for cancer studies is a major challenge, particularly for investigators who lack the resources to maintain and use xenograft animals or genetically engineered mouse models (GEMM). In addition, several countries intending to incorporate these models must conduct importation procedures, posing an additional challenge.

OBJECTIVE

This review aimed to explore the use of cell-derived allograft or syngeneic models under limited resources. The results can be used by investigators, specifically from low-middle-income countries, to contribute to lung cancer eradication.

METHODS

A literature search was carried out on various databases, including PubMed, Web of Science, and Scopus. In addition, the publication year of the selected articles was set between 2013 and 2023 with different search components (SC), namely lung cancer (SC1), animal models (SC2), and preclinical studies (SC3).

RESULTS

This systematic review focused on selecting animals, cells, and methods that could be applied to generating allograft-type lung cancer animal models from 101 included articles.

CONCLUSION

Based on the results, the use of cell-derived allograft models in cancer studies is feasible and relevant, and it provides valuable insights regarding the conditions with limited resources.

Optimal Structural Designs of Trispecific Antibodies to Enhance Therapeutic Efficacy in Solid Tumors and Hematological Malignancies

Engineered antibody therapies have significantly propelled the advancement of tumor immunotherapy. However, a considerable proportion of patients fail to respond to treatment or experience relapses following an initial positive response. Moreover, recurrence rates have increased due to antigen escape or downregulation. To address this challenge, novel strategies to engineer trispecific antibodies (tsAbs) have been developed in recent years. Here, we describe the molecular procedures of construction, expression, and purification of optimal tsAbs [specifically, Her2/VEGFR2/CD3 (SO) and CD19/CD22/CD3 (CC) tsAbs]. Also, we detail the experimental methods of functional validation of optimal tsAbs, including immunofluorescence analysis, cytokine release detection, and in vitro cytotoxicity assay and in vivo efficacy studies.

The miR-23a/27a/24 - 2 cluster drives immune evasion and resistance to PD-1/PD-L1 blockade in non-small cell lung cancer

Programmed cell death protein ligand-1 (PD-L1) and major histocompatibility complex I (MHC-I) are key molecules related to tumor immune evasion and resistance to programmed cell death protein 1 (PD-1)/PD-L1 blockade. Here, we demonstrated that the upregulation of all miRNAs in the miR-23a/27a/24 - 2 cluster was correlated with poor survival, immune evasion and PD-1/PD-L1 blockade resistance in patients with non-small cell lung cancer (NSCLC). The overexpression of all miRNAs in the miR-23a/27a/24 - 2 cluster upregulated PD-L1 expression by targeting Cbl proto-oncogene B (CBLB) and downregulated MHC-I expression by increasing the level of eukaryotic initiation factor 3B (eIF3B) via the targeting of microphthalmia-associated transcription factor (MITF). In addition, we demonstrated that the expression of the miR-23a/27a/24 - 2 cluster of miRNAs is maintained in NSCLC through increased Wnt/β-catenin signaling-regulated interaction of transcription factor 4 (TCF4) and the miR-23a/27a/24 - 2 cluster promoter. Notably, pharmacologic targeting of the eIF3B pathway dramatically increased sensitivity to PD-1/PD-L1 blockade in patients with high expression of the miR-23a/27a/24 - 2 cluster in NSCLC. This effect was achieved by increasing MHC-I expression while maintaining high expression of PD-L1 induced by the miR-23a/27a/24 - 2 cluster. In summary, we elucidate the mechanism by which the miR-23a/27a/24 - 2 cluster miRNAs maintain their own expression and the molecular mechanism by which the miR-23a/27a/24 - 2 cluster miRNAs promote tumor immune evasion and PD-1/PD-L1 blockade resistance. In addition, we provide a novel strategy for the treatment of NSCLC expressing high levels of the miR-23a/27a/24 - 2 cluster.

Histone lactylation-driven YTHDC1 promotes hepatocellular carcinoma progression via lipid metabolism remodeling

Lipid metabolism reprogramming is critical for the initiation and progression of hepatocellular carcinoma (HCC). However, how the dysregulation of lipid metabolism contributes to HCC development remains largely unknown. Here, we report that the m6A reader YTHDC1-mediated epigenetic regulation of the long noncoding RNA NEAT1 activates stearoyl-CoA desaturase (SCD)-associated lipid metabolic processes during HCC progression. Mechanistically, histone lactylation in HCC induces increased expression of YTHDC1, increasing the stability of m6A-modified NEAT1. The histone acetyltransferase p300 is then recruited by NEAT1 and activates SCD by increasing the level of histone acetylation at the SCD promoter, thus facilitating HCC progression via hepatocellular lipid metabolism remodeling. Taken together, these discoveries suggest a close link between the epigenetic machinery and lipid metabolic abnormalities, which promotes cancer progression.

RBM15-dependent m6A modification mediates progression of non-small cell lung cancer cells

BACKGROUND

Non-small cell lung cancer (NSCLC) is the predominant form of lung cancer, contributing significantly to global health and economic challenges. This study elucidated the role of RBM15 in NSCLC progression through its involvement in m6A modifications.

METHODS

RBM15 levels in NSCLC tissues and cells were assessed via RT-qPCR and Western blotting. The impact of RBM15 knockdown on NSCLC proliferation, invasion, and migration was evaluated using CCK-8, colony formation, and Transwell assays. Expression levels of KLF1, TRIM13, and ANXA8 were determined by RT-qPCR and Western blot. m6A methylation levels were analyzed, while RIP and MeRIP assays were employed to explore the interaction between YTHDF1/YTHDF2/m6A and KLF1/TRIM13, as well as KLF1 binding to the ANXA8 promoter. The ubiquitination of ANXA8 was examined through ubiquitination assays. Xenograft and metastasis models were utilized to assess RBM15's role in vivo.

RESULTS

RBM15 was found to be overexpressed in NSCLC. Silencing RBM15 led to decreased cell proliferation, invasion, and migration of NSCLC cells. RBM15 upregulated KLF1 and downregulated TRIM13 via YTHDF1/YTHDF2, resulting in the promotion of ANXA8 expression. KLF1 overexpression or TRIM13 downregulation partially reversed the suppressive effects of RBM15 knockdown on NSCLC cell proliferation. ANXA8, upregulated in NSCLC, mitigated the inhibitory effects of RBM15 silencing on malignant behaviors. In vivo, RBM15 downregulation hindered NSCLC cell proliferation and metastasis by modulating the KLF1-TRIM13/ANXA8 axis.

CONCLUSION

RBM15-mediated m6A methylation enhances KLF1 expression and suppresses TRIM13 via YTHDF1/YTHDF2, thereby promoting ANXA8 and facilitating NSCLC progression. These findings provide novel insights and potential therapeutic targets for NSCLC treatment.

N6-methyladenosine RNA methylation, a new hallmark of metabolic reprogramming in the immune microenvironment

N6-methyladenosine is one of the most common and reversible post-transcriptional modifications in eukaryotes, and it is involved in alternative splicing and RNA transcription, degradation, and translation. It is well known that cancer cells acquire energy through metabolic reprogramming to exhibit various biological behaviors. Moreover, numerous studies have demonstrated that m6A induces cancer metabolic reprogramming by regulating the expression of core metabolic genes or by activating metabolic signaling pathways. Meanwhile, m6A modifications and related regulators are key targets in the regulation of immune effects. We further summarize how m6A modifications contribute to tumor metabolism, and how these events affect the tumor immune microenvironment, with a specific focus on different cell types. Finally, we focus on the specific applications of this field to tumor immunotherapy. We review the potential role of m6A in metabolic reprogramming of tumor immune microenvironment and its regulatory mechanism, with the aim of providing new targets for tumor metabolic regulation and immunotherapy.

Decoding the prognostic landscape of LUAD: the interplay between N6-methyladenosine modification and immune microenvironment

Background

To determine the role of N6-methyladenosine (m6A) modification in the tumor immune microenvironment (TIME), as well as their association with lung adenocarcinoma (LUAD).

Methods

Consensus clustering was performed to identify the subgroups with distinct immune or m6A modification patterns using profiles from TCGA. A risk score model was constructed using least absolute shrinkage and selection operator regression and validated in two independent cohorts and LUAD tissue microarrays. For experimental validation, the regulation of METTL3/m6A axis in the expression of candidate genes by RIP-qPCR assay in A549 and H460 cell lines. Co-culture experiments with human T cells were performed to evaluate the impact of METTL3 on the enhancement of anti-tumor immunity through in vitro experiments.

Results

We identified 282 m6A regulator genes and 955 immune-related genes, selecting seven key genes (SFTPC, CYP24A1, KRT6A, PTTG1, S100P, FAM83A, and ANLN) to develop a risk score model using Lasso regression. High-risk patients, determined by this model, exhibited poorer prognosis, increased immune infiltration, higher tumor mutational burden, more neoantigens, and elevated PD-L1 expression. These findings were validated by two independent databases and LUAD tissue microarrays. METTL3 was found to impact the mRNA expression of these genes, with METTL3 deficiency abolishing these interactions. Inhibition of METTL3 enhanced anti-tumor immunity, T cell activation, exhaustion, and infiltration in vitro.

Conclusion

This risk score system shows promise for prognostic prediction and the development of personalized treatment strategies for LUAD patients.

Dual impacts of serine/glycine-free diet in enhancing antitumor immunity and promoting evasion via PD-L1 lactylation

The effect of the serine/glycine-free diet (-SG diet) on colorectal cancer (CRC) remains unclear; meanwhile, programmed death-1 (PD-1) inhibitors are less effective for most CRC patients. Here, we demonstrate that the -SG diet inhibits CRC growth and promotes the accumulation of cytotoxic T cells to enhance antitumor immunity. Additionally, we also identified the lactylation of programmed death-ligand 1 (PD-L1) in tumor cells as a mechanism of immune evasion during cytotoxic T cell-mediated antitumor responses, and blocking the PD-1/PD-L1 signaling pathway is able to rejuvenate the function of CD8+ T cells recruited by the -SG diet, indicating the potential of combining the -SG diet with immunotherapy. We conducted a single-arm, phase I study (ChiCTR2300067929). The primary outcome suggests that the -SG diet is feasible and safe for regulating systemic immunity. Secondary outcomes include patient tolerability and potential antitumor effects. Collectively, our findings highlight the promising therapeutic potential of the -SG diet for treating solid tumors.

WTAP-Mediated m6A Modification of circSMOC1 Accelerates the Tumorigenesis of Non-Small Cell Lung Cancer by Regulating miR-612/CCL28 Axis

Accumulating evidence reveals that deregulated N6-methyladenosine (m6A) RNA methylation and circular RNAs (circRNAs) are required for the tumorigenesis of non-small cell lung cancer (NSCLC). We aimed to uncover the underlying mechanisms by which WTAP-mediated m6A modification of circRNA contributes to NSCLC. The differentially-expressed circRNAs were identified by a circRNA profiling microarray. The association of circSMOC1 with clinicopathological features and prognosis in patients with NSCLC was estimated by fluorescence in situ hybridization. WTAP-mediated m6A modification of circRNA was validated by RNA immunoprecipitation (RIP) and methylated RIP (MeRIP) assays. The role of circSMOC1 in NSCLC cells was validated by in vitro functional experiments and in vivo tumorigenesis models. CircSMOC1-specific binding with miR-612 was verified by RIP, luciferase gene report and RT-qPCR assays. The effect of circSMOC1 and/or miR-612 on CCL28 expression was detected by RT-qPCR and Western blotting analysis. We found that the expression levels of circSMOC1 were elevated in NSCLC tissues and associated with TNM stage and poor survival in patients with NSCLC. Knockdown of circSMOC1 impaired the tumorigenesis of NSCLC in vitro and in vivo, whereas restored expression of circSMOC1 displayed the opposite effect. Furthermore, WTAP was upregulated in NSCLC and mediated m6A modification of circSMOC1 and circSMOC1 abolished WTAP knockdown-caused tumour-suppressive effects. Then, circSMOC1 acted as a sponge of miR-612 to upregulate CCL28 and miR-612 inhibitors abrogated circSMOC1 knockdown-caused anti-proliferation effects and CCL28 downregulation in NSCLC cells. Knockdown of CCL28 inhibited cell proliferation and invasion and counteracted miR-612 inhibitor-caused tumour-promoting effects. Our findings unveil that WTAP-mediated m6A modification of circSMOC1 facilitates the tumorigenesis of NSCLC by regulating the miR-612/CCL28 axis.

The effect of m6A methyltransferase METTL3 mediated TMEM30A regulation on tumor energy metabolism and cisplatin anti-tumor activity in oral squamous cell carcinoma

AIMS

Cisplatin (CDDP) is still one of the most commonly used first-line treatments for advanced and recurrent oral squamous cell carcinoma (OSCC) patients in clinical practice. However, the decrease in tumor sensitivity to CDDP weakens its therapeutic effect. There is still limited research on the effect of METTL3-mediated methylation of m6A on CDDP sensitivity in OSCC. TMEM30A widely exists in biomembranes and regulates the lipid asymmetry of the membrane, but there is no report on its function in OSCC. This study aims to explore the specific mechanism by which METTL3 regulates m6A methylation of TMEM30A and affects the occurrence and development of OSCC, and further investigate the effects of METTL3 and TMEM30A on the anti-tumor activity of CDDP.

KEY FINDINGS

In OSCC, METTL3 plays a pro-cancer role and weakens the anti-tumor efficacy of CDDP; METTL3 positively regulates the expression of TMEM30A by m6A methylation modification and binding to TMEM30A; The abnormally high expression of TMEM30A in OSCC not only weakens CDDP sensitivity, but also enhances the malignant evolution of cancer cells, regulates the metabolic balance of ATP and lactate in cells, and is a potential oncogenic gene.

SIGNIFICANCE

TMEM30A promotes malignant progression of tumors through METTL3 mediated m6A methylation modification, participates in maintaining the balance of tumor ATP and lactate metabolism, and reduces the anti-tumor activity of CDDP. TMEM30A is a potential gene target for CDDP anti-tumor activity in OSCC.

OTUB1 regulation of ferroptosis and the protective role of ferrostatin-1 in lupus nephritis

Lupus nephritis (LN) is a prevalent and severe manifestation of systemic lupus erythematosus (SLE), leading to significant morbidity and mortality. OTUB1, a deubiquitinating enzyme, has emerged as a potential therapeutic target due to its role in cellular protection and regulation of ferroptosis, a form of cell death linked to LN. Our study revealed significantly reduced OTUB1 expression in the glomeruli of LN patients and podocytes, correlated with disease severity. CRISPR/Cas9-mediated OTUB1 knockout in podocytes resulted in pronounced injury, indicated by decreased levels of nephrin and podocin. Ferrostatin-1 treatment effectively mitigated this injury, restoring SLC7A11 expression and significantly reducing MDA levels, Fe2+ levels, BODIPY C11 expression, and normalized cysteine and glutathione expression. In the MRL/lpr mouse model, Ferrostatin-1 significantly improved renal function decreased proteinuria, and ameliorated renal histopathological changes, including reduced glomerular endothelial swelling, mesangial cell proliferation, and leukocyte infiltration. These results underscore the protective role of Ferrostatin-1 in modulating the pathogenesis of LN. OTUB1 plays a crucial protective role against podocyte injury in LN by regulating ferroptosis. Ferrostatin-1 effectively mitigates podocyte damage induced by OTUB1 deficiency, suggesting that targeting ferroptosis could be a promising therapeutic strategy for LN.

Leonurine improves atherosclerosis by activating foam cell autophagy and metabolic remodeling via METTL3-mediated AKT1S1 mRNA stability modulation

BACKGROUND

Atherosclerosis (AS) is the most prevalent cardiovascular disease and remains the major contributor to death and mortality globally. Leonurine (LEO) is a unique alkaloid compound with protective effects on the cardiovascular system. However, the exact mechanisms underlying its cardiovascular-protecting action are still not fully elucidated. The methyltransferase 3 (METTL3), the catalytic core of the N6-methyladenosine modification (m6A) methyltransferase complex, has been shown to inhibit autophagy and exacerbate the process of AS via regulation of m6A modification of mRNA.

PURPOSE

We aimed to determine whether the inhibited effect of LEO on AS is related to METTL3-mediated AKT1S1 stability.

METHODS

The apolipoprotein E (ApoE) knockout mice was subjected to a high-fat diet (HFD), and THP-1 derived macrophages was exposed to oxidized low-density lipoprotein (ox-LDL), to establish the animal and cellular models of AS, respectively.

RESULTS

We found that LEO effectively improved AS and reduced the plaque area and inflammation via diminishing macrophage lipid accumulation and remodeling the lipid metabolism profile. LEO activated ox-LDL-induced macrophage autophagy, enhancing lipid metabolism decrease, according to the lipidomic and molecular biology analyses. Additionally, LEO caused a marked increase in autophagy marker levels in mouse models with advanced AS. Furthermore, we found that LEO reactivated autophagy and reversed lipid accumulation by suppressing METTL3 expression. The m6A-seq from ox-LDL-induced macrophages showed that a total of five autophagy-related mRNA transcripts (AKT1S1, AKT1, RB1CC1, CFLAR, and MTMR4) were altered, and AKT1S1 was significantly upregulated by LEO. Mechanistically, LEO-mediated regulation of METTL3 decreased AKT1S1 expression by attenuating its mRNA stability. Silencing AKT1S1 inhibited LEO-METTL3 axis-mediated autophagy and enhanced lipid accumulation in ox-LDL-induced macrophages.

CONCLUSION

The study first revealed that LEO exerts anti-atherosclerotic effect by activating METTL3-mediated macrophage autophagy in vivo and in vitro. The mechanism of LEO was further found to be the enhancement of METTL3-mediated AKT1S1 stability to activate autophagy thereby reducing lipid accumulation. This study provides a new perspective of natural medicines on the treatment of AS via an epigenetic manner.

Fusobacterium nucleatum promotes PD-L1 expression in cancer cells to evade CD8+ T cell killing in breast cancer

BACKGROUND

A significant percentage of cancer-related fatalities are caused by breast cancer (BC). Fusobacterium nucleatum (Fn) is a common Gram-negative anaerobic bacterium found in various inflammatory diseases, and there are also reports suggesting its involvement in cancer progression. This study discussed molecular mechanisms of Fn-induced immune escape in BC cells.

METHODS

mRNA and protein PD-L1 expression in BC cells were detected using qRT-PCR and western blot (WB). WB assayed NF-κB-related marker expressions (p-p65, p-65, p-p50, p-50) in cells. PD-L1 expression levels on the cell surface, apoptosis and proliferation of CD8+ T and BC cells were measured via flow cytometry. ELISA tested TNFα, IFNγ, and granzyme B to assess the activation level of CD8+ T cells. The secretion level of LDH in the co-culture system was tested using an LDH detection kit to evaluate the cell death rate.

RESULTS

BC cells stimulated by Fn can blunt tumor-killing of CD8+ T cells and their vitality. Fn treatment upregulates PD-L1 in BC cells. Rescue experiments using NF-κB inhibitors suggested that Fn treatment mediated NF-κB signaling and fostered PD-L1 expression in cancer cells. Fn repressed the killing effect of CD8+ T cells on BC cells by triggering the NF-κB/PD-L1 signaling pathway.

CONCLUSION

Fn helps BC cells evade the killing effect of CD8+ T cells through the NF-κB/PD-L1 pathway.

The interaction between m6A modification and noncoding RNA in tumor microenvironment on cancer progression

Cancer development is thought to be closely related to aberrant epigenetic regulation, aberrant expression of specific non-coding RNAs (ncRNAs), and tumor microenvironment (TME). The m6A methylation is one of the most abundant RNA modifications found in eukaryotes, and it can determine the fate of RNA at the post-transcriptional level through a variety of mechanisms, which affects important biological processes in the organism. The m6A methylation modification is involved in RNA processing, regulation of RNA nuclear export or localisation, RNA degradation and RNA translation. This process affects the function of mRNAs and ncRNAs, thereby influencing the biological processes of cancer cells. TME accelerates and promotes cancer generation and progression during tumor development. The m6A methylation interacting with ncRNAs is closely linked to TME formation. Mutual regulation and interactions between m6A methylation and ncRNAs in TME create complex networks and mediate the progression of various cancers. In this review, we will focus on the interactions between m6A modifications and ncRNAs in TME, summarising the molecular mechanisms by which m6A interacts with ncRNAs to affect TME and their roles in the development of different cancers. This work will help to deepen our understanding of tumourigenesis and further explore new targets for cancer therapy.

Tumor-related IGF2BP1-derived molecular subtypes to predict prognosis and immune microenvironment in head and neck squamous cell carcinoma

Background

Recent studies have underscored the biological significance of RNA modifications in tumorigenicity and progression. However, the potential roles of RNA modifications in immune regulation and the formation of the tumor microenvironment (TME) in head and neck squamous carcinoma (HNSC) remain unclear.

Methods

We collected 199 untreated HNSC samples and clinicopathological data from Fujian Provincial Cancer Hospital. MeRIP-seq and RNA-seq were performed to generate methylation and gene expression profiles, respectively. Consensus molecular subtyping was employed to identify prognosis-related genes and RNA modification patterns in HNSC. Experiments confirmed the potential oncogenic behavior influenced by key genes. Molecular subtypes were identified through consensus clustering and validated using external cohort validation sets.

Results

Among the RNA modification-related genes, IGF2BP1 emerged as the most prognostic. HNSC patients were categorized into high and low IGF2BP1 expression groups. High-expressing patients exhibited poorer survival and reduced chemosensitivity, coupled with increased tumor mutational burden, low PD-L1 expression, and limited immune cell infiltration, indicative of aggressive disease. Analysis revealed two distinct RNA modification patterns associated with IGF2BP1 expression: biosynthetically intense type (BIT) and oncogenically active type (OAT), each characterized by distinct clinical features, outcomes, and biological pathways. In an independent immunotherapy cohort, BIT patients displayed enhanced immune responses and sustained clinical benefits.

Conclusions

This study highlights the crucial link between RNA modification and TME diversity. Evaluating RNA modification in tumors improves our understanding of TME features and supports the development of effective immunotherapy strategies.

Multi-omics analysis unveils the predictive value of IGF2BP3/SPHK1 signaling in cancer stem cells for prognosis and immunotherapeutic response in muscle-invasive bladder cancer

BACKGROUND

Muscle invasive bladder cancer (MIBC) is a life-threatening malignant tumor characterized by high metastasis rates, poor prognosis, and limited treatment options. Immune checkpoint inhibitors (ICIs) targeting PD-1 and PD-L1 represent an emerging treatment for MIBC immunotherapy. However, the characteristics of patients likely to benefit from immunotherapy remain unclear.

METHODS

We performed single-cell mass cytometry (CyTOF) analysis of 179,483 single cells to characterize potential immunotherapy-related cancer stem cells (CSCs)-like populations in the tumor microenvironment of 38 MIBC tissues. The upregulated expression of IGF2BP3 in CD274 + ALDH + CSC-like cells, which was associated with poor clinical prognosis, was analyzed by bulk RNA-sequencing data from an in-house cohort. The functional role of IGF2BP3 was determined through cell proliferation, colony formation, cell apoptosis and sphere formation assays. The regulation of SPHK1 expression by IGF2BP3 was  investigated using methylated RNA immunoprecipitation sequencing (MeRIP-seq) and bulk RNA-sequencing (bulk RNA-seq). We further utilized single-nucleus RNA sequencing (snRNA-seq) data from 67,988 cells of 25 MIBC tissues and single-cell RNA sequencing (scRNA-seq) data from MIBC patient-derived organoids to characterize the molecular features of bladder cancer cells co-expressing IGF2BP3 and SPHK1. Spatial transcriptomics (ST) and co-detection by indexing (CODEX) analysis were used to describe the spatial distribution and interactions of IGF2BP3 + SPHK1 + bladder cancer cells and immune cells.

RESULTS

A subset of CD274 + ALDH + CSC-like cells was identified, associating with immunosuppression and low survival rates in MIBC patients. IGF2BP3, an m6A reader gene, was found to be upregulated in the CD274 + ALDH + CSC-like cell population and linked to poor clinical prognosis in MIBC. Knockout of IGF2BP3 dramatically promoted cell apoptosis and reduced cell proliferation in T24 cells. By integrating MeRIP-seq and bulk RNA-seq analyses, we identified SPHK1 served as a substrate for IGF2BP3 in an m6A-dependent manner. Further snRNA-seq, scRNA-seq, ST, and CODEX analysis revealed a closer topographical distance between IGF2BP3 + SPHK1 + bladder cancer cells and exhausted CD8 + T cells, providing one explanation for the superior response to immunotherapy in IGF2BP3 + SPHK1 + bladder cancer cells-enriched patients. Finally, an ICI-associated signature was developed based on the enriched genes of IGF2BP3 + SPHK1 + bladder cancer cells, and its potential ability to predict the response to immunotherapy was validated in two independent immunotherapy cohort.

CONCLUSIONS

Our study highlighted the critical involvement of the IGF2BP3/SPHK1 signaling in maintaining the stemness of CSCs and promoting MIBC progression. Additionally, these findings suggested that the IGF2BP3/SPHK1 signaling might serve as a biomarker for prognosis and immunotherapy response in MIBC.

Identification of m6A modification patterns and RBM15 mediated macrophage phagocytosis in pancreatic cancer: An integrative analysis

Pancreatic cancer (PC) responds weakly to conventional immunotherapy. RNA N6-methyladenosine (m6A) modification has an essential role in the immune response, while its potential role in PC tumor microenvironment (TME) immune cell infiltration remains unknown. In this study, we thoroughly assessed the m6A modification patterns of 472 PC samples using 19 m6A regulators, and we systematically correlated these modification patterns with TME immune cell infiltration characteristics. We also created the m6Ascore and evaluated the m6A modification patterns of individual tumors, identified three different m6A modification patterns, and explored the role of the important m6A "writer" RBM15 in the regulation of macrophage function in PC. Two independent PC cohorts confirmed that patients with higher m6Ascore showed significant survival benefit. We verified that knockdown of RBM15 has the ability to inhibit PC growth and to promote macrophage infiltration and enhance phagocytosis of PC cells by macrophages. In conclusion, m6A modifications play a non-negligible role in the formation of TME diversity and complexity in PC. We reveal that inhibition of RBM15 suppresses PC development and modulates macrophage phagocytosis, and provide a more effective immunotherapeutic strategy for PC.