NSUN2 is a glucose sensor suppressing cGAS/STING to maintain tumorigenesis and immunotherapy resistance

STING and metabolism-related diseases: Roles, mechanisms, and applications

The stimulator of interferon genes (STING) pathway plays a critical role in innate immunity, acting as a central mediator that links cytosolic DNA sensing to inflammatory signaling. STING not only responds to cellular metabolic states but also actively regulates key metabolic processes, including glycolysis, lipid metabolism, and redox balance. This bidirectional interaction underscores the existence of a dynamic feedback mechanism between STING signaling and metabolic pathways, which is essential for maintaining cellular homeostasis. This review provides a comprehensive analysis, beginning with an in-depth overview of the classical STING signaling pathway, followed by a detailed examination of its reciprocal regulation of various metabolic pathways. Additionally, it explores the role and mechanisms of STING signaling in metabolic disorders, including obesity, diabetes, and atherosclerosis. By integrating these insights into the mutual regulation between STING and its metabolism, novel therapeutic strategies targeting this pathway in metabolic diseases have been proposed.

Integrative multi-omics reveal NSUN2 facilitates glycolysis and histone lactylation-driven immune evasion in renal carcinoma

Clear cell renal carcinoma (ccRCC) is the most prevalent and aggressive subtype of kidney cancer. Targeting ccRCC metabolism is a promising therapeutic strategy, and some metabolic targets are currently undergoing clinical trials. Here, we collected multiple ccRCC clinical cohorts, including bulk RNA sequencing and single-cell sequencing datasets, to investigate mitochondrial metabolic genes' prognostic and therapeutic potential. Integrating 10 machine learning algorithms, we constructed 117 predictive models, with the optimal model selected and defined as Mitoscore for patient stratification and treatment. Furthermore, NSUN2, an RNA 5-methylcytosine (m5C) methyltransferase, was identified as the most important gene in the model and selected for further gene function experiments in vitro and in vivo. NSUN2 promoted cell proliferation, migration, and invasion; reprogrammed glycolysis metabolism and histone lactylation levels via maintaining NEO1 mRNA stability. In addition, NSUN2 increased PD-L1 expression in tumor cells via the MYC/POM121/CD274 axis in a lactylation-dependent manner. Knockdown of NSUN2 enhanced CD8 T cell killing effects in vitro, along with TNF-α + T cell infiltration in vivo. These results highlight that mitochondrial genes are optional therapeutic targets and prognostic markers; NSUN2 promotes mitochondrial glycolysis and histone lactylation in an m5C-dependent manner, thereby resulting in PD-L1-mediated immune escape, which elucidates novel NSUN2-mediated crosstalk between glycolysis and immune evasion.

The m5C methyltransferase NSUN2 promotes progression of acute myeloid leukemia by regulating serine metabolism

Acute myeloid leukemia (AML) is one of the most prevalent heterogeneous hematologic malignancies with a complicated etiology. RNA post-transcriptional modifications have been linked to the incidence and progression of AML, while the detailed mechanism remains to be elucidated. In this study, we find that NOP2/Sun domain family member 2 (NSUN2), a methyltransferase of 5-methylcytosine (m5C) RNA methylation, is upregulated in AML and predicts a poor prognosis for patients with AML. Knockdown of NSUN2 in AML cells inhibits proliferation and colony formation and promotes apoptosis. Depletion of NSUN2 in AML mice reduces the tumor burden and prolongs survival. Mechanistically, NSUN2 promotes the expression of phosphoglycerate dehydrogenase (PHGDH) and serine hydroxymethyltransferase 2 (SHMT2), two key enzymes in the serine/glycine biosynthesis pathway, by stabilizing the corresponding mRNAs through regulation of m5C modifications. Overall, our findings demonstrate a critical role of NSUN2 in AML development and highlight the therapeutic potential of targeting the NSUN2/m5C axis for the treatment of this cancer.

FOXA1-dependent NSUN2 facilitates the advancement of prostate cancer by preserving TRIM28 mRNA stability in a m5C-dependent manner

RNA epigenetics is gaining increased attention for its role in the initiation, metastasis, and drug resistance of tumors. These studies have primarily focused on m6A modification. However, despite being the second most abundant modification found in RNA, the role of m5C modification in prostate cancer remains largely unexplored. Here, we predict an RNA m5C methyltransferase, NSUN2, as a potential therapeutic target for prostate cancer using various bioinformatics approaches, and verify the potential of NSUN2 as a target through multiple preclinical models. Mechanistically, NSUN2 enhances the stability of TRIM28 mRNA by adding m5C modification, promoting the expression of TRIM28. Concurrently, FOXA1, a prostate cancer lineage-specific transcription factor, transcriptionally activates the expression of NSUN2. Our study confirms the clinical potential of targeting RNA epigenetics for the treatment of prostate cancer and elucidates, mechanistically, how RNA epigenetics participates in the complex biological activities within tumors via the FOXA1-NSUN2-TRIM28 axis.

Water-Dispersible MXene Governs Glycolysis for Cancer Synergistic Therapy

Targeted delivery of glucose oxidase (GOx) using MXene remains a great challenge due to its poor dispersion and susceptibility to oxidation, and the hypoxia and high glutathione (GSH) contents make the situation even more worrying. Herein, a bovine serum albumin-mediated non-chemical modification strategy is developed, endowing titanium carbide MXene with long-time water-dispersion and further integrating it as a glycolysis-controllable therapy system without any chemotherapeutic agents. The system also constructs an effective O2 cycling and GSH degradation pathway, which fundamentally adjusts the tumor microenvironment and greatly elevates both in vivo and in vitro therapy effects. Reactive oxygen species are also generated and disrupt the balance of oxidative stress. Moreover, the reduced efficiency of mitochondrial energy production significantly inhibits the level of glycolysis and hinders energy supply. The study presents an effective cancer treatment combining starvation/photothermal therapy, which has superior anti-cancer effects due to the dual effects of reducing glucose levels and diminishing cellular energy production capacity.

Glucose modulates IRF6 transcription factor dimerization to enable epidermal differentiation

Non-energetic roles for glucose are largely unclear, as is the interplay between transcription factors (TFs) and ubiquitous biomolecules. Metabolomic analyses uncovered elevation of intracellular glucose during differentiation of diverse cell types. Human and mouse tissue engineered with glucose sensors detected a glucose gradient that peaked in the outermost differentiated layers of the epidermis. Free glucose accumulation was essential for epidermal differentiation and required the SGLT1 glucose transporter. Glucose affinity chromatography uncovered glucose binding to diverse regulatory proteins, including the IRF6 TF. Direct glucose binding enabled IRF6 dimerization, DNA binding, genomic localization, and induction of IRF6 target genes, including essential pro-differentiation TFs GRHL1, GRHL3, HOPX, and PRDM1. These data identify a role for glucose as a gradient morphogen that modulates protein multimerization in cellular differentiation.

The carcinogenic metabolite acetaldehyde impairs cGAS activity to negatively regulate antiviral and antitumor immunity

The cGAS-MITA/STING pathway plays critical roles in both host defense against DNA virus and intrinsic antitumor immunity by sensing viral genomic DNA or dis-located mitochondrial/cellular DNA. Whether carcinogenic metabolites can target the cGAS-MITA axis to promote tumorigenesis is unknown. In this study, we identified acetaldehyde, a carcinogenic metabolite, as a suppressor of the cGAS-MITA pathway. Acetaldehyde inhibits the DNA virus herpes simplex virus 1 (HSV-1)- and transfected DNA-triggered but not cGAMP-induced activation of downstream components and induction of downstream effector genes. Mechanistically, acetaldehyde impairs the binding of cGAS to DNA as well as the phase separation of the cGAS-DNA complex in cells. In mouse models, acetaldehyde inhibits antiviral cytokine production, promotes viral replication and lethality upon HSV-1 infection. In a colorectal tumor xenograft model, acetaldehyde promotes tumor growth and inhibits CD8+ T cell infiltration by targeting cGAS in both the tumor cells and immune cells in mice. Bioinformatic analysis indicates that expression of acetaldehyde dehydrogenase 2 (ALDH2), which converts acetaldehyde to acetic acid, is negatively correlated with stimulatory immune signatures in clinical colorectal tumors, and higher ALDH2 expression exhibits better prognosis of colorectal cancer patients. Collectively, our results suggest that acetaldehyde impairs cGAS activity to inhibit the cGAS-MITA axis, which contributes to its effects on carcinogenesis.

RNA m5C modification: from physiology to pathology and its biological significance

RNA 5-methylcytosine (m5C) modification is a crucial epitranscriptomic mark that regulates RNA stability, processing, and translation. Emerging evidence highlights its essential role in various physiological processes, including cellular differentiation, stem cell maintenance, and immune responses. Dysregulation of m5C modification has been implicated in multiple pathological conditions, particularly in cancer, neurodegenerative disorders, and metabolic diseases. This review provides a comprehensive overview of the molecular mechanisms governing m5C deposition, its functional consequences in normal physiology, and its contributions to disease pathogenesis. Furthermore, we discuss the potential of m5C as a biomarker and therapeutic target, offering new insights into its biological significance and clinical relevance.

STING: a multifaced player in cellular homeostasis

The stimulator of interferon gene (STING) is an important innate immune mediator of the cytoplasmic DNA sensing pathway. As a mediator known for its role in the immune response to infections, STING is also surprisingly at the center of a variety of non-infectious human diseases, including cancer, autoimmune diseases and neurodegenerative diseases. Recent studies have shown that STING has many signaling activities, including type I interferon (IFN-I) and other IFN-independent activities, many of which are poorly understood. STING also has the unique property of being continuous transported from the ER to the Golgi then to the lysosome. Mutations of STING or trafficking cofactors are associated with human diseases affecting multiple immune and non-immune organs. Here, we review recent advances in STING trafficking and signaling mechanisms based in part on studies of STING-associated monogenic inborn error diseases.

Mitochondria-targeted manganese-based mesoporous silica nanoplatforms trigger cGAS-STING activation and sensitize anti PD-L1 therapy in triple-negative breast cancer

Activation of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway could effectively initiate antitumor immunity in triple-negative breast cancer. However, current nuclear DNA-mediated activation of STING pathway remains constrained by the tight protection of nuclear membrane and histones, highlighting the need for new strategies to enhance its efficacy. Mitochondrial DNA (mtDNA), in contrast, is more vulnerable to damage. Herein, our nanoplatforms exploited the high glutathione (GSH) environment characteristic of tumors to release abundant Mnb+, which induced mitochondrial dysfunction and the release of endogenous mtDNA. The released mtDNA, in conjunction with Mnb+ itself functioning as a strong cGAS agonist, effectively activated cGAS-STING pathway. Consequently, the cGAS-STING-dependent secretion of type I interferon successively enhanced the maturation of dendritic cells and cross-priming of CD8+ T cells. In a poorly immunogenic 4T1 tumor model, TPP-MMONs efficiently primed systemic antitumor immunity and significantly enhanced the therapeutic efficacy of αPD-L1 therapy, suppressing tumor growth in both localized and metastatic tumor models. These findings provided an innovative and straightforward strategy to enhance TNBC immunogenicity by targeting mitochondrial damage to induce mtDNA-mediated cGAS-STING activation, thereby sensitizing tumors to immune checkpoint inhibitor therapy. STATEMENT OF SIGNIFICANCE: The cGAS-STING pathway is a promising target for overcoming immunoresistance in TNBC. However, current nuclear DNA-based activation strategies are limited by the tight protection of nuclear membrane and histones. Herein, we reported novel manganese-rich, mitochondria-targeting nanoplatforms (TPP-MMONs), which can release abundant Mn²⁺ and significantly induce mitochondrial dysfunction, leading to the release of mtDNA. As a result, the nanoplatforms can effectively stimulate the cGAS-STING pathway, thereby enhancing immune responses and improving the therapeutic efficacy of αPD-L1 therapy, offering new insights into TNBC treatments.

A triple-cascade nanoreactor for potent anti-tumor chemodynamic and immunotherapy

Chemodynamic therapy (CDT) has shown promising effects in the treatment of malignant tumors, especially in inducing immunogenic cell death (ICD). However, the therapeutic efficacy of CDT is much weakened due to limitations in tumor oxidative stress response, and intracellular H2O2 and catalyst levels. In order to solve these challenges, we have designed an intracellular acid-activated cascade nanoreactor (Sal/Fe3O4@SiO2-NaCN) which induces ICD by accelerating the process of CDT-mediated ferroptosis. The nanoreactor operates in three synergistic steps. Firstly, the platform can catalyze the degradation of glucose to gluconic acid and H2O2 under ultrasound (US) exposure in an acidic environment. Secondly, Fe3O4 can then convert this H2O2 to ·OH. In addition, salinomycin (Sal) causes Fe accumulation in the cell and enhances the efficacy of the Fenton process. Extensive in vitro and in vivo experiments reveal the production of reactive oxygen species, accumulation of Fe in cells, and stimulation of ferroptosis and ICD. In a bilateral tumor model, magnetic resonance signals and excellent therapeutic effects were observed in vivo. This novel nanoreactor offers a promising strategy for CDT-based cancer treatment and immunotherapy.

Novel molecular mechanisms of immune evasion in hepatocellular carcinoma: NSUN2-mediated increase of SOAT2 RNA methylation

BACKGROUND

Hepatocellular carcinoma (HCC) is a deadly malignancy known for its ability to evade immune surveillance. NOP2/Sun RNA methyltransferase family member 2 (NSUN2), an RNA methyltransferase involved in carcinogenesis, has been associated with immune evasion and energy metabolism reprogramming. This study aimed to examine the molecular mechanisms underlying the involvement of NSUN2 in immune evasion and metabolic reprogramming of HCC.

METHODS

Single-cell transcriptomic sequencing was applied to examine cellular composition changes, particularly immune cell dynamics, in HCC and adjacent normal tissues. Bulk RNA-seq and proteomics identified key genes and proteins. Methylation sequencing and methylated RNA immunoprecipitation (MeRIP) were carried out to characterize the role of NSUN2 in 5-methylcytosine (m5C) modification of sterol O-acyltransferase 2 (SOAT2). Clinical samples from 30 HCC patients were analyzed using reverse transcription-quantitative polymerase chain reaction and Western blotting. Gene expression was manipulated using CRISPR/Cas9 and lentiviral vectors. In vitro co-culture models and metabolomics were used to study HCC cell-T cell interactions, energy metabolism, and immune evasion. Tumor growth in an orthotopic mouse model was monitored by bioluminescence imaging, with subsequent measurements of tumor weight, volume, and immunohistochemical staining.

RESULTS

Single-cell transcriptomic analysis identified a marked increase in malignant cells in HCC tissues. Cell communication analysis indicated that tumor cells might promote cancer progression by evading immune clearance. Multi-omics analyses identified NSUN2 as a key regulator in HCC development. MeRIP confirmed that NSUN2 facilitated the m5C modification of SOAT2. Analysis of human HCC tissue samples demonstrated pronounced upregulation of NSUN2 and SOAT2, along with elevated m5C levels in HCC tissues. In vitro experiments uncovered that NSUN2 augmented the reprogramming of energy metabolism and repressed the activity and cytotoxicity of CD8+ T cells, contributing to immune evasion. In vivo studies further substantiated the role of NSUN2 in fostering immune evasion and tumor formation of HCC by modulating the m5C modification of SOAT2.

CONCLUSIONS

The findings highlight the critical role of NSUN2 in driving HCC progression through the regulation of m5C modification on SOAT2. These findings present potential molecular markers for HCC diagnosis and therapeutic targets for its treatment.

Unveiling the crossroads of STING signaling pathway and metabolic reprogramming: the multifaceted role of the STING in the TME and new prospects in cancer therapies

The cGAS-STING signaling pathway serves as a critical link between DNA sensing and innate immunity, and has tremendous potential to improve anti-tumor immunity by generating type I interferons. However, STING agonists have shown decreasing biotherapeutic efficacy in clinical trials. Tumor metabolism, characterized by aberrant nutrient utilization and energy production, is a fundamental hallmark of tumorigenesis. And modulating metabolic pathways in tumor cells has been discovered as a therapeutic strategy for tumors. As research concerning STING progressed, emerging evidence highlights its role in metabolic reprogramming, independent its immune function, indicating metabolic targets as a strategy for STING activation in cancers. In this review, we delve into the interplay between STING and multiple metabolic pathways. We also synthesize current knowledge on the antitumor functions of STING, and the metabolic targets within the tumor microenvironment (TME) that could be exploited for STING activation. This review highlights the necessity for future research to dissect the complex metabolic interactions with STING in various cancer types, emphasizing the potential for personalized therapeutic strategies based on metabolic profiling.

5-Methylcytosine RNA modification and its roles in cancer and cancer chemotherapy resistance

Recent advancements in cancer therapies have improved clinical outcomes, yet therapeutic resistance remains a significant challenge because of its complex mechanisms. Among epigenetic factors, m5C RNA modification is emerging as a key player in cancer drug resistance, similar to the well-known m6A modification. m5C affects RNA metabolism processes, including splicing, export, translation, and stability, thereby influencing drug efficacy. This review highlights the critical roles of m5C in modulating resistance to chemotherapy, targeted therapy, radiotherapy, and immunotherapy. This review also discusses the functions of key regulators, including methyltransferases, demethylases, and m5C-binding proteins, as essential modulators of the m5C epigenetic landscape that contribute to its dynamic and complex regulatory network. Targeting these regulatory components offers a promising strategy to overcome resistance. We highlight the need for further research to elucidate the specific mechanisms by which m5C contributes to resistance and to develop precise m5C-targeted therapies, presenting m5C-focused strategies as potential novel anticancer treatments.

Moonlighting functions of glucose metabolic enzymes and metabolites in cancer

Glucose metabolic enzymes and their metabolites not only provide energy and building blocks for synthesizing macromolecules but also possess non-canonical or moonlighting functions in response to extracellular and intracellular signalling. These moonlighting functions modulate various cellular activities, including gene expression, cell cycle progression, DNA repair, autophagy, senescence and apoptosis, cell proliferation, remodelling of the tumour microenvironment and immune responses. These functions integrate glucose metabolism with other essential cellular activities, driving cancer progression. Targeting these moonlighting functions could open new therapeutic avenues and lead to cancer-specific treatments.

NSUN2 promotes colorectal cancer progression and increases lapatinib sensitivity by enhancing CUL4B/ErbB-STAT3 signalling in a non-m5C manner

NSUN2, a major methyltransferase that catalyzes m5C methylation in eukaryotes, is known to be implicated in the development of multiple cancers. However, its role in colorectal cancer (CRC) and the related molecular mechanisms have yet to be sufficiently determined. Here, we conducted an analysis of public database (722 CRC patients) and two distinct cohorts from our centre (1559 CRC patients), which revealed that NSUN2 is upregulated in CRC and correlates with unfavourable prognosis. Our analyses also showed that NSUN2 promotes the proliferation and metastasis capabilities of CRC cells. Intriguingly, NSUN2 was found to promote CRC via an m5C-independent mechanism, which has not been previously reported. Overexpression of both wild-type and m5C enzymatic-dead mutant NSUN2 upregulated and activated the ErbB-STAT3 signalling pathway. We also found that both wild-type and the m5C enzymatic-dead mutant NSUN2 closely interacted with CUL4B. Silencing of CUL4B effectively inhibited the m5C-independent function of NSUN2. Moreover, overexpression of NSUN2 enhanced the sensitivity of CRC cells to lapatinib. Taken together, our findings revealed a novel m5C-independent mechanism for NSUN2 in the malignancy and lapatinib sensitivity of CRC via activation of the CUL4B/ErbB-STAT3 pathway, which provides a potential therapeutic strategy for patients with CRC. HIGHLIGHTS: NSUN2 is upregulated in CRC and associated with poor prognosis of CRC patients. NSUN2 promotes CRC malignancy independently of its m5C-enzymatic activity, a mechanism that has not been previously reported. The non-m5C carcinogenic roles of NSUN2 may be mediated through interactions with CUL4B, thereby activating the ErbB-STAT3 signalling pathway. NSUN2-mediated upregulation of ErbB-STAT3 pathway enhances the sensitivity of CRC to lapatinib treatment.

Colorectal cancer cell-derived extracellular vesicles trigger macrophage production of IL6 through activating STING signaling to drive metastasis

Emerging evidence shows that extracellular vesicles (EVs)-mediated cargo shuttling between different kinds of cells constantly occurs in the tumor microenvironment, leading to the progression of a variety of cancers, but the biological role of DNA enriched in EVs has not been fully elucidated. Here, nuclear chromatin-originated DNA fragments were identified in human serum-derived EVs and exhibited a mild increase in the colorectal cancer patient group, unveiling their potential as a biomarker for cancer diagnosis. Molecular experiments showed that chromatin and mitochondrial DNA fragments adhered to the outer membrane of EVs were released from colorectal cancer cells and transported into macrophages where they stimulated STING signaling cascades, resulting in enhanced STAT1 phosphorylation and IL6 production. Further experiments revealed that STAT1 functioned as a potential IL6 transcription regulator through directly locating at its promoter regions to facilitate IL6 expression in macrophages. In the tumor microenvironment, the accumulated IL6 released by macrophages, in turn, provoked colorectal cancer cell epithelial to mesenchymal transition (EMT) through activating IL6R/STAT3 signaling. Our findings highlighted the importance of DNA carried by EVs in shaping the tumor environment and revealed their potential as a clinical diagnostic biomarker for colorectal cancer.

m5C methylation of mitochondrial RNA and non-coding RNA by NSUN3 is associated with variant gene expression and asexual blood-stage development in Plasmodium falciparum

BACKGROUND

Malaria is caused by Plasmodium spp. and is a prevalent parasitic disease worldwide. To evade detection by the immune system, by switching variant gene expression, the malaria parasite continually establishes new patterns displaying a single variant erythrocyte surface antigen. The distinct surface molecules encoded by clonally variant gene families include var, rif, stevor, Pfmc-2tm, and surfins. However, the mechanism behind the exclusive expression of a single member of the variant gene family is still not clear. This study aims to describe the molecular process of variant gene switching from the perspective of the epitranscriptome, specifically by characterizing the role of the Plasmodium falciparum RNA m5C methyltransferase NSUN3.

METHODS

A conditional gene knockdown approach was adopted by incorporating the glucosamine-inducible glmS ribozyme sequence into the 3' untranslated region (UTR) of the pfnsun3 gene. A transgenic parasite line PfNSUN3-Ty1-Ribo was generated using CRISPR-Cas9 methods. The knockdown effect in the transgenic parasite was measured by a growth curve assay and western blot analysis. The transcriptome changes influenced by PfNUSN3 knockdown were detected by RNA sequencing (RNA-seq), and the direct RNA transcripts regulated by PfNUSN3 were validated by RNA immunoprecipitation and high-throughput sequencing (RIP-seq).

RESULTS

Growth curve analysis revealed that conditional knockdown of PfNSUN3 interfered with parasite growth. The parasitemia of the PfNSUN3 knockdown line showed a significant decline at the third round of the life cycle compared with the control line. The knockdown of PfNSUN3 altered the global transcriptome. RNA-seq analysis showed that at the ring-stage depletion of PfNSUN3 silenced almost all var genes, as well as the guanine/cytosine (GC)-rich non-coding RNA (ncRNA) ruf6 family. RNA RIP-seq arrays revealed that PfNSUN3 directly interacted with several var genes.

CONCLUSIONS

Our findings demonstrate a vital role of PfNSUN3 in the process of the mutually exclusive expression of variant genes, and contribute to a better understanding of the complex mechanism of epigenetic regulation of gene expression in P. falciparum.

Pan-cancer analysis of the prognosis and immune infiltration of NSUN7 and its potential function in renal clear cell carcinoma

BACKGROUND

NSUN7, an enzyme responsible for the RNA m5c modification, has been recognized as a valuable indicator for predicting and diagnosing an array of cancer. Nevertheless, there is still a scarcity of thorough analyses exploring its diagnostic, predictive, and immune system-related importance in various types of cancer.

METHODS

We integrated multiple publicly available databases, including TCGA, TISIDB, TISCH2, and UALCAN, to comprehensively investigate the role of NSUN7 in pan-cancer across various omics data types. The research included examining survival rates, genetic mutations, immune cell presence in tumors, analyzing differences in gene expression, and studying individual cells, among other things.

RESULTS

NSUN7 expression showed an increase across 12 cancer types and a decrease in another 12 types. NSUN7 was discovered to be linked with enhanced survival rates in bladder urothelial carcinoma (BLCA), kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP), lung adenocarcinoma (LUAD), pheochromocytoma and paraganglioma (PCPG), skin cutaneous melanoma (SKCM), and uveal melanoma (UVM).On the other hand, NSUN7 seemed to have a detrimental impact on the prognosis of glioblastoma multiforme/brain lower grade glioma (GBMLGG), adrenocortical carcinoma (ACC),acute myeloid leukemia (LAML), stomach adenocarcinoma (STAD), and brain lower grade glioma (LGG). Furthermore, our experimental validation confirmed the inhibitory effect of NSUN7 on proliferation of renal clear cell carcinoma while elucidating its specific part in blocking cell cycle progression.

CONCLUSIONS

The findings underscore the potential utility of NSUN7 as a valuable prognostic indicator for patients and offer insights into the mechanisms underlying cancer initiation and progression.

High glucose levels promote glycolysis and cholesterol synthesis via ERRα and suppress the autophagy-lysosomal pathway in endometrial cancer

Endometrial cancer (EC) patients with Diabetes Mellitus (DM) always have a poor prognosis. Estrogen-related receptor α (ERRα) is known as the metabolic-related prognostic factor for EC. However, the mechanism linking glycolipid metabolism dysfunction mediated by ERRα to poor prognosis of EC with DM is still unclear. In vitro, high-glucose (HG) levels showed enhancement of ERRα expression, cell proliferation, and inhibition of the autophagic lysosomes and apoptosis by flow cytometry analysis, transmission electron microscopy, and CCK-8 assays. Mechanistically, lose-and-gain function assay, DNA sequencing, and CO-IP revealed HG increased ERRα expression to promote the transcription of HK2 and HMGCS1, which were the key rate-limiting enzyme of glycolysis-cholesterol synthesis and their metabolites suppressed the autophagy-lysosomal pathway in an ERRα-dependent manner. Furthermore, CO-IP and molecular dynamics simulation uncovered the protein residues (ARG 769HK2 vs. ARG 313HMGCS1) of HK2 and HMGCS1 could bind to p62 to form stable protein complexes involved in the autophagy-lysosomal pathway. In EC tissue from patients with comorbid DM, ERRα was significantly higher expressed compared to EC tissue from patients without evidence for DM (p < 0.05). The 3D EC organoid model with HG stimulation showed that the cell viability of XCT790 + carboplatin treatment was similar to that of metformin+carboplatin treatment, while the obviously bigger volume of organoids was more visible in the metformin+carboplatin group, indicating the therapy of XCT790 + carboplatin had the better inhibition of EC organoids with the same carboplatin dose. Besides insights into the interaction of HG and the autophagy-lysosomal pathway via ERRα, our present study points out the potential benefit of targeting ERRα in patients with EC with dysregulation of glucose and cholesterol metabolism.

Regulation and Function of the cGAS-STING Pathway: Mechanisms, Post-Translational Modifications, and Therapeutic Potential in Immunotherapy

Autoimmune diseases arise when the immune system attacks healthy tissues, losing tolerance for self-tissues. Normally, the immune system recognizes and defends against pathogens like bacteria and viruses. The cGAS-STING pathway, activated by pattern-recognition receptors (PRRs), plays a key role in autoimmune responses. The cGAS protein senses pathogenic DNA and synthesizes cGAMP, which induces conformational changes in STING, activating kinases IKK and TBK1 and leading to the expression of interferon genes or inflammatory mediators. This pathway is crucial in immunotherapy, activating innate immunity, enhancing antigen presentation, modulating the tumor microenvironment, and integrating into therapeutic strategies. Modulation strategies include small molecule inhibitors, oligonucleotide therapies, protein and antibody therapies, genetic and epigenetic regulation, cytokine and metabolite modulation, and nanoscale delivery systems. Post-translational modifications (PTMs) of the cGAS-STING pathway, such as phosphorylation, acetylation, ubiquitination, methylation, palmitoylation, and glycosylation, fine-tune immune responses by regulating protein activity, stability, localization, and interactions. These modifications are interconnected and collectively influence pathway functionality. We summarize the functions of cGAS-STING and its PTMs in immune and non-immune cells across various diseases, and explore potential clinical applications.

The multifaceted role of m5C RNA methylation in digestive system tumorigenesis

5-Methylcytosine (m5C) is a widespread RNA methylation modification, wherein a methyl group is enzymatically transferred to specific RNA sites by methyltransferases, such as the NSUN family and DNMT2. The m5C modification not only impacts RNA structure and stability but also governs post-transcriptional regulation by influencing RNA transport, translation, and protein interactions. Recently, the functional importance of m5C in complex diseases, including cancer, has gained substantial attention. Increasing evidence highlights the critical roles of m5C in digestive system malignancies, where it contributes to tumor progression by modulating oncogene expression and regulating processes such as tumor cell proliferation, migration, invasion, and resistance to chemotherapy. Furthermore, m5C's involvement in non-coding RNAs reveals additional dimensions in elucidating their roles in cancer. This review summarizes recent advances in m5C RNA methylation research within digestive system tumors, focusing on its functional mechanisms, clinical significance, and potential applications. Specifically, it aims to explore m5C's role in tumor diagnosis, prognosis, and treatment, while proposing future directions to address current challenges and broaden its clinical utility.

NONO regulates m5C modification and alternative splicing of PTEN mRNAs to drive gastric cancer progression

BACKGROUND

The effect of m5C modification on oncogene mRNAs has been well studied, while little is known about its influence on mRNAs of tumor suppressor genes (TSGs). Early studies showed PTEN, a key TSG, undergoes alternative splicing (AS) in cancers, however, the underlying regulatory mechanism remains elusive.

METHODS

We analyzed tissue microarrays and transcriptomic data derived from gastric cancer, with an emphasis on RNA splicing and m5C regulators. To unravel the role of NONO in GC, we employed RNA sequencing, RNA-Bis-Seq, RNA immunoprecipitation, RNA in situ hybridization, and Minigene reporter assay with NONO knockdown cells. The clinical relevance was validated using CDX models and human tissue microarrays.

RESULTS

Analysis of publicly available datasets and immunohistochemistry assay of tissue microarrays containing 40 GC tissues showed NONO was upregulated in GC and contributed to poor prognosis. In vitro and in vivo experiments indicated a positive regulatory role of NONO in terms of cell proliferation, migration, and invasion of GC. Mechanically, NONO interacted directly with PTEN pre-mRNA and recruited the RNA m5C methyltransferase NSUN2 via RNA-recognition motif (RRM) domains, altering the mRNA methylation pattern across PTEN pre-mRNA. The oncogenic role of NONO/NSUN2/PTEN axis in GC progression was further confirmed with pre-clinical experiments and clinical data.

CONCLUSION

Here, we revealed NONO-regulated AS of PTEN mRNA in an m5C-dependent manner, resulting in the downregulation of PTEN expression in gastric cancer (GC).This study unveils a novel regulatory mechanism of tumor suppressor gene inactivation mediated by m5C modification and related alternative splicing in cancer.

NSUN2/ALYREF axis-driven m5C methylation enhances PD-L1 expression and facilitates immune evasion in non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) represents a highly prevalent form of malignancy. 5-methylcytosine (m5C) methylation functions as a key post-transcriptional regulatory mechanism linked to cancer progression. The persistent expression of PD-L1 in tumor cells plays a pivotal role in facilitating immune evasion and promoting T-cell exhaustion. However, the involvement of m5C in NSCLC immune evasion remains inadequately understood. This study seeks to explore the function of the m5C methyltransferase NSUN2 in modulating PD-L1 expression and facilitating immune evasion in NSCLC. Our findings indicate elevated levels of NSUN2 and ALYREF in NSCLC, and both promote the growth of NSCLC cells and the progression of lung cancer. Moreover, the expression of PD-L1 in NSCLC tissues positively correlates with NSUN2 and ALYREF expression. We then discovered that PD-L1 acts as a downstream target of NSUN2-mediated m5C modification in NSCLC cells. Knocking down NSUN2 significantly reduces m5C modification of PD-L1 mRNA, thereby decreasing its stability via the m5C reader ALYREF-dependent manner. Furthermore, inhibiting NSUN2 enhanced CD8+ T-cell activation and infiltration mediated by PD-L1, thereby boosting antitumor immunity, as confirmed in both in vitro and in vivo experiments. Collectively, these results suggested that NSUN2/ALYREF/PD-L1 axis plays a critical role in promoting NSCLC progression and tumor cell immune suppression, highlighting its potential as a novel therapeutic strategy for NSCLC immunotherapy.

Detection, molecular function and mechanisms of m5C in cancer

Interest in RNA posttranscriptional modifications, particularly 5-methylcytosine (m5C), has surged in recent years. Studies have shown that m5C plays a key role in cellular processes and is closely linked to tumourigenesis. This growing focus emphasises the importance of understanding the diverse impacts of m5C modifications in both normal cellular functions and cancer development. Moreover, strides in methodologies for discerning m5C have facilitated intricate transcriptome cartography of RNA methylation at the solitary nucleotide echelon. This technical progress has fueled a surge in m5C-centric investigations, facilitating further exploration of this RNA modification. This review provides a comprehensive analysis of the oncogenic potential of m5C RNA modification, elucidating the precise molecular mechanisms driving its role in cancer development. It consolidates current knowledge regarding the biological consequences of m5C RNA modification in tumour cells. Understanding the role of methylation-related processes in tumourigenesis shows promise for advancing cancer diagnosis and therapeutic strategies. HIGHLIGHTS: m5C modifications are dynamically regulated by writers, readers, and erasers, influencing cancer progression, metastasis, and immune evasion. Distinct m5C regulatory networks exist across cancers, modulating oncogenic pathways and therapy responses. m5C signatures serve as biomarkers for cancer prognosis and treatment stratification, highlighting their role in precision oncology.

Multi-omic and machine learning analysis of mitochondrial RNA modification genes in lung adenocarcinoma for prognostic and therapeutic implications

Lung cancer remains the leading cause of cancer-related deaths, driven by complex pathogenesis and poor prognosis. Recognizing the pivotal role of mitochondrial RNA modifications (MRM) in cancer progression, this study aims to provide a comprehensive analysis of MRM-related genes and their clinical relevance in lung adenocarcinoma (LUAD). Integrating multi-omic datasets, we systematically explored the molecular features of MRM-related genes across various cancers and identified distinct expression patterns and prognostic associations. Single-cell analysis further reveals MRM-driven cell-cell interactions and pathway activation, particularly in cycling and epithelial cells. Using advanced machine learning techniques, we developed a novel prognostic signature-the Mitochondrial RNA Modification-related Signature (MRMS)-comprising nine genes: TXN, LDHA, HMGA1, SFTPB, KRT8, ALG3, S100A16, HSPD1, and ALDOA. The MRMS demonstrates superior predictive performance for LUAD survival compared to previously reported models. Our findings uniquely link MRMS to increased tumor mutational burden, genetic instability, and an immunosuppressive tumor microenvironment characterized by reduced immune cell infiltration and elevated tumor purity. Additionally, MRMS is associated with immunotherapy-related features, suggesting its potential in predicting treatment response. Experimental validation identified ALG3 as an oncogenic driver in LUAD, influencing tumor cell proliferation, migration, and invasion. In conclusion, this study establishes MRMS as a robust prognostic biomarker and highlights its dual role in shaping the tumor immune microenvironment and guiding therapeutic strategies. These findings provide novel insights into mitochondrial RNA modifications and their potential applications in personalized treatment for LUAD.

Anti-Tumor Strategies Targeting Nutritional Deprivation: Challenges and Opportunities

Higher and richer nutrient requirements are typical features that distinguish tumor cells from AU: cells, ensuring adequate substrates and energy sources for tumor cell proliferation and migration. Therefore, nutrient deprivation strategies based on targeted technologies can induce impaired cell viability in tumor cells, which are more sensitive than normal cells. In this review, nutrients that are required by tumor cells and related metabolic pathways are introduced, and anti-tumor strategies developed to target nutrient deprivation are described. In addition to tumor cells, the nutritional and metabolic characteristics of other cells in the tumor microenvironment (including macrophages, neutrophils, natural killer cells, T cells, and cancer-associated fibroblasts) and related new anti-tumor strategies are also summarized. In conclusion, recent advances in anti-tumor strategies targeting nutrient blockade are reviewed, and the challenges and prospects of these anti-tumor strategies are discussed, which are of theoretical significance for optimizing the clinical application of tumor nutrition deprivation strategies.

Enhanced cancer classification and critical feature visualization using Raman spectroscopy and convolutional neural networks

Cell misuse and cross-contamination pose a significant threat to the accuracy of cell research outcomes, often leading to the wasteful expenditure of time, manpower, and material resources. Consequently, the accurate identification of cell lines is paramount. However, traditional identification methods, which often involve staining and culturing procedures, are not only time-consuming but also laborious. This underscores the need for a novel approach that enables rapid and automated cell line identification, thereby enhancing research efficiency and accuracy. Raman spectroscopy, renowned for its label-free, rapid, and noninvasive nature, offers invaluable molecular insights into samples, making it a widely utilized technique in the biological field. In this study, the identification of one normal and five cancer cell lines was achieved using a sparrow search algorithm-convolutional neural networks (SSA-CNN), considering both the full spectra and fingerprint region perspectives. The SSA-CNN model demonstrated exceptional performance, not just in binary classification, but also in accurately distinguishing among six cell lines. It achieved the highest accuracy (around 95 %), and the lowest standard error (≤3%), for both the full spectra and fingerprint region. Based on the highly accurate SSA-CNN model, proposed the application of gradient-weighted class activation mapping (Grad-CAM) to visualize the Raman feature peaks. Upon comparing the visualized Raman features with reported biomarkers, found that not only were common biomolecules such as glucose, proteins, and liquids visualized, but specific feature peaks also aligned with reported biomarkers. The aforementioned results clearly demonstrated that the proposed strategy not only classifies cancer cell lines with remarkable accuracy but also served as a valuable tool for the discovery of novel biomarkers.

NSUN2 lactylation drives cancer cell resistance to ferroptosis through enhancing GCLC-dependent glutathione synthesis

Lactate-mediated lactylation on target proteins is recently identified as the novel posttranslational modification with profound biological functions. RNA 5-methylcytosine (m5C) modification possesses dynamic and reversible nature, suggesting that activity of its methyltransferase NSUN2 is actively regulated. However, how NSUN2 activity is response to acidic condition in tumor microenvironment and then regulates cancer cell survival remain to be clarified. Here, we demonstrate that NSUN2 activity is enhanced by lactate-mediated lactylation at lysine 508, which then targets glutamate-cysteine ligase catalytic subunit (GCLC) mRNA to facilitates GCLC m5C formation and mRNA stabilization. The activated GCLC induces higher level of intracellular GSH accompanied by decreased lipid peroxidation and resistant phenotype to ferroptosis induction by doxorubicin (Dox) in gastric cancer cells. Specifically, the effect of NSUN2 lactylation-GCLC-GSH pathway is nearly lost when NSUN2 K508R or GCLC C-A mutant (five cytosine sites) was introduced into the cancer cells. We further identify the catalytic subunit N-α-acetyltransferase 10 (NAA10) as the lactytransferase of NSUN2, and lactate treatment substantially enhances their association and consequent NSUN2 activation. Taken together, our findings convincingly elucidate the signaling axis of NAA10-NSUN2-GCLC that potently antagonizes the ferroptosis under acidic condition, and therefore, targeting NSUN2 lactylation might be an effective strategy in improving the prognosis of cancer patients.

DDX50 cooperates with STAU1 to effect stabilization of pro-differentiation RNAs

Glucose binding can alter protein oligomerization to enable differentiation. Here, we demonstrate that glucose binding is a general capacity of DExD/H-box RNA helicases, including DDX50, which was found to be essential for the differentiation of diverse cell types. Glucose binding to conserved DDX50 ATP binding sequences altered protein conformation and dissociated DDX50 dimers. DDX50 monomers bound STAU1 to redirect STAU1 from an RNA-decay-promoting complex with UPF1 to a DDX50-STAU1 ribonuclear complex. DDX50 and STAU1 bound and stabilized a common set of essential pro-differentiation RNAs, including JUN, OVOL1, CEBPB, PRDM1, and TINCR, whose structures they also modified. These findings uncover a DDX50-mediated mechanism of reprograming STAU1 from its canonical role in Staufen-mediated mRNA decay to an opposite role stabilizing pro-differentiation RNAs and establish an activity for glucose in controlling RNA structure and stability.

Nanomaterial-enabled metabolic reprogramming strategies for boosting antitumor immunity

Immunotherapy has become a crucial strategy in cancer treatment, but its effectiveness is often constrained. Most cancer immunotherapies focus on stimulating T-cell-mediated immunity by driving the cancer-immunity cycle, which includes tumor antigen release, antigen presentation, T cell activation, infiltration, and tumor cell killing. However, metabolism reprogramming in the tumor microenvironment (TME) supports the viability of cancer cells and inhibits the function of immune cells within this cycle, presenting clinical challenges. The distinct metabolic needs of tumor cells and immune cells require precise and selective metabolic interventions to maximize therapeutic outcomes while minimizing adverse effects. Recent advances in nanotherapeutics offer a promising approach to target tumor metabolism reprogramming and enhance the cancer-immunity cycle through tailored metabolic modulation. In this review, we explore cutting-edge nanomaterial strategies for modulating tumor metabolism to improve therapeutic outcomes. We review the design principles of nanoplatforms for immunometabolic modulation, key metabolic pathways and their regulation, recent advances in targeting these pathways for the cancer-immunity cycle enhancement, and future prospects for next-generation metabolic nanomodulators in cancer immunotherapy. We expect that emerging immunometabolic modulatory nanotechnology will establish a new frontier in cancer immunotherapy in the near future.

m5C methylation modification may be an accomplice in colorectal cancer escaping from anti-tumor effects of innate immunity-type I/III interferon

Colorectal cancer (CRC) is one of the most prevalent malignant tumors in the world, and its occurrence and development are closely related to the complex immune regulatory mechanisms. As the first barrier of the body's defense, innate immunity plays a key role in tumor immune surveillance and anti-tumor response, in which type I/III interferon (IFN) is an important mediator with significant antiviral and anti-tumor functions. 5-methylcytosine (m5C) modification of RNA is a key epigenetic regulation that promotes the expression of CRC oncogenes and immune-related genes. It can enhance the proliferation, migration, and invasion of tumor cells by affecting mRNA stability, translation efficiency, and nuclear export. In addition, m5C modification modulates the activity of innate immune signaling pathways and inhibits interferon production and function, further helping tumor cells evade immune surveillance. However, there are insufficient elucidations on the interaction between m5C modification and innate immunity in CRC. In this study, the mechanism of interferon I/III in colorectal cancer was systematically reviewed and explored. This work focused on how m5C modification promotes tumor immune escape by affecting the interferon signaling pathway, thereby providing new diagnostic markers and therapeutic targets for clinical use, and enhancing the immunotherapy efficacy.

Regulation of cGAS-STING signalling and its diversity of cellular outcomes

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signalling pathway, which recognizes both pathogen DNA and host-derived DNA, has emerged as a crucial component of the innate immune system, having important roles in antimicrobial defence, inflammatory disease, ageing, autoimmunity and cancer. Recent work suggests that the regulation of cGAS-STING signalling is complex and sophisticated. In this Review, we describe recent insights from structural studies that have helped to elucidate the molecular mechanisms of the cGAS-STING signalling cascade and we discuss how the cGAS-STING pathway is regulated by both activating and inhibitory factors. Furthermore, we summarize the newly emerging understanding of crosstalk between cGAS-STING signalling and other signalling pathways and provide examples to highlight the wide variety of cellular processes in which cGAS-STING signalling is involved, including autophagy, metabolism, ageing, inflammation and tumorigenesis.

Novel Modifications and Delivery Modes of Cyclic Dinucleotides for STING Activation in Cancer Treatment

The microenvironment tends to be immunosuppressive during tumor growth and proliferation. Immunotherapy has attracted much attention because of its ability to activate tumor-specific immune responses for tumor killing. The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is an innate immune pathway that activates antitumor immunity by producing type I interferons. Cyclic dinucleotides (CDNs), produced by cGAS sensing cytoplasmic abnormal DNA, are major intermediate activating molecules in the STING pathway. Nowadays, CDNs and their derivatives have widely worked as powerful STING agonists in tumor immunotherapy. However, their clinical translation is hindered by the negative electrical properties, sensitivity to hydrolytic enzymes, and systemic toxicity. Recently, various CDN delivery systems have made significant progress in addressing these issues, either through monotherapy or in combination with other treatment modalities. This review details recent advances in CDNs-based pharmaceutical development or delivery strategies for enriching CDNs at tumor sites and activating the STING pathway.

RNA modifications in cancer

RNA modifications are emerging as critical cancer regulators that influence tumorigenesis and progression. Key modifications, such as N6-methyladenosine (m6A) and 5-methylcytosine (m5C), are implicated in various cellular processes. These modifications are regulated by proteins that write, erase, and read RNA and modulate RNA stability, splicing, translation, and degradation. Recent studies have highlighted their roles in metabolic reprogramming, signaling pathways, and cell cycle control, which are essential for tumor proliferation and survival. Despite these scientific advances, the precise mechanisms by which RNA modifications affect cancer remain inadequately understood. This review comprehensively examines the role RNA modifications play in cancer proliferation, metastasis, and programmed cell death, including apoptosis, autophagy, and ferroptosis. It explores their effects on epithelial-mesenchymal transition (EMT) and the immune microenvironment, particularly in cancer metastasis. Furthermore, RNA modifications' potential in cancer therapies, including conventional treatments, immunotherapy, and targeted therapies, is discussed. By addressing these aspects, this review aims to bridge current research gaps and underscore the therapeutic potential of targeting RNA modifications to improve cancer treatment strategies and patient outcomes.

The role of cGAS-STING signaling pathway in colorectal cancer immunotherapy: Mechanism and progress

Colorectal cancer (CRC) is a common malignant tumor in the gastrointestinal tract, it is known as the "silent killer", which poses a serious threat to the lives of patients. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon gene (STING) signaling pathway responds to DNA by sensing, which plays an important role in anti-infection, autoimmune diseases and anti-tumor immunity. Recent studies have found that the activation of cGAS-STING pathway in CRC can induce the expression and secretion of type I interferon (IFN-I) and a variety of inflammatory factors, further activate anti-tumor CD8+ T cells, exert anti-tumor immune response, and inhibit the progression of CRC. Therefore, targeting the cGAS-STING pathway and developing drugs that can regulate the cGAS-STING pathway are of great significance for improving the therapeutic effect and prognosis of CRC patients. In this review, we introduce the cGAS-STING signaling pathway and the regulatory role of this signaling pathway in CRC immune microenvironment. In addition, we discussed the research progress of cGAS-STING pathway in CRC immunotherapy and the clinical research status of STING agonists developed against this pathway, emphasizing the clinical potential of CRC immunotherapy based on the cGAS-STING signaling pathway.

Metabolic reprogramming, sensing, and cancer therapy

The metabolic reprogramming of tumor cells is a crucial strategy for their survival and proliferation, involving tissue- and condition-dependent remodeling of certain metabolic pathways. While it has become increasingly clear that tumor cells integrate extracellular and intracellular signals to adapt and proliferate, nutrient and metabolite sensing also exert direct or indirect influences, although the underlying mechanisms remain incompletely understood. Furthermore, metabolic changes not only support the rapid growth and dissemination of tumor cells but also promote immune evasion by metabolically "educating" immune cells in the tumor microenvironment (TME). Recent studies have highlighted the profound impact of metabolic reprogramming on the TME and the potential of targeting metabolic pathways as a therapeutic strategy, with several enzyme inhibitors showing promising results in clinical trials. Thus, understanding how tumor cells alter their metabolic pathways and metabolically remodel the TME to support their survival and proliferation may offer new strategies for metabolic therapy and immunotherapy.

Downregulation of tRNA methyltransferase FTSJ1 by PM2.5 promotes glycolysis and malignancy of NSCLC via facilitating PGK1 expression and translation

Fine particulate matter (PM2.5) exposure has been associated with increased incidence and mortality of lung cancer. However, the molecular mechanisms underlying PM2.5 carcinogenicity remain incompletely understood. Here, we identified that PM2.5 suppressed the expression of tRNA methyltransferase FTSJ1 and Am modification level of tRNA in vitro and in vivo. FTSJ1 downregulation enhanced glycolytic metabolism of non-small cell lung cancer (NSCLC) cells, as indicated by increased levels of lactate, pyruvate, and extracellular acidification rate (ECAR). Whereas treatment with glycolytic inhibitor 2-DG reversed this effect. In contrast, upregulation of FTSJ1 significantly suppressed glycolysis of NSCLC cells. Mechanistically, the silencing of FTSJ1 increased NSCLC cell proliferation and glycolysis through enhancing the expression and translation of PGK1. In human NSCLC tumor samples, FTSJ1 expression was negatively correlated with PGK1 expression level and the SUVmax value of PET/CT scan. In summary, our work reveals a previously unrecognized function of PM2.5-downregulated FTSJ1 on PGK1-mediated glycolysis in NSCLC, suggesting that targeted upregulation of FTSJ1 may represent a potential therapeutic strategy for NSCLC.

Bibliometric analysis and visualization of the research on the relationship between RNA methylation and immune cell infiltration in tumors

Background

This research endeavors to delve into the research hotspots and trends concerning RNA methylation and tumor immune cells through the application of bibliometric analysis and visualization techniques.

Methods

A comprehensive search in WoSCC (2014-2023) for RNA methylation and tumor immune cell articles/reviews was conducted. Bibliometric analysis and visualization employed CiteSpace, Bibliometric, and VOSviewer tools.

Results

A total of 3295 articles were included in the analysis, with a continuously increasing number of publications linking RNA methylation to tumoral immune cells. Chinese authors and research institutions have demonstrated a sustained growth trend in both the number of publications and author influence. SUN YAT SEN UNIVERSITY, a Chinese institution, has published the highest number of articles in this field, while also demonstrating extensive international and inter-institutional collaborations. Meanwhile, HARVARD UNIVERSITY has also achieved impressive results. For instance, Frontiers in Immunology has published the largest number of articles in this category. Nature Communications has published articles that are most influential in this field, playing a pivotal role in disseminating research findings. The sustained vitality of this field is attributed to its solid research foundation, including the groundbreaking work published by Professor Chiappinelli KB in Cell and the widely cited paper by Professor Han DL in Nature. Analysis of research trend topics reveals that m5C, immunotherapy, and the immune microenvironment are current research focuses.

Conclusion

Future investigative efforts at the juncture of RNA methylation and tumor immune cells are anticipated to concentrate on domains including m5C, n7-methylguanosine, cuproptosis, prognosis assessment, immunotherapeutic strategies, and the tumor microenvironment.

Glucose binds and activates NSUN2 to promote translation and epidermal differentiation

Elevations in intracellular glucose concentrations are essential for epithelial cell differentiation by mechanisms that are not fully understood. Glucose has recently been found to directly bind several proteins to alter their functions to enhance differentiation. Among the newly identified glucose-binding proteins is NSUN2, an RNA-binding protein that we identified as indispensable for epidermal differentiation. Glucose was found to bind conserved sequences within NSUN2, enhancing its binding to S-adenosyl-L-methionine and boosting its enzymatic activity. Additionally, glucose enhanced NSUN2's proximity to proteins involved in mRNA translation, with NSUN2 modulating global messenger RNA (mRNA) translation, particularly that of key pro-differentiation mRNAs containing m5C modifications, such as GRHL3. Glucose thus engages diverse molecular mechanisms beyond its energetic roles to facilitate cellular differentiation processes.

Tumor microenvironment: Nurturing cancer cells for immunoevasion and druggable vulnerabilities for cancer immunotherapy

The tumor microenvironment (TME) is an intricate ecosystem where cancer cells thrive, encompassing a wide array of cellular and non-cellular components. The TME co-evolves with tumor progression in a spatially and temporally dynamic manner, which endows cancer cells with the adaptive capability of evading immune surveillance. To this end, diverse cancer-intrinsic mechanisms were exploited to dampen host immune system, such as upregulating immune checkpoints, impairing antigens presentation and competing for nutrients. In this review, we discuss how cancer immunoevasion is tightly regulated by hypoxia, one of the hallmark biochemical features of the TME. Moreover, we comprehensively summarize how immune evasiveness of cancer cells is facilitated by the extracellular matrix, as well as soluble components of TME, including inflammatory factors, lactate, nutrients and extracellular vesicles. Given their important roles in dictating cancer immunoevasion, various strategies to target TME components are proposed, which holds promising translational potential in developing novel therapeutics to sensitize anti-cancer immunotherapy such as immune checkpoint blockade.

cGAS-STING signaling pathway in lung cancer: Regulation on antitumor immunity and application in immunotherapy

The innate immune system has a primary role in defending against external threats, encompassing viruses, bacteria, and fungi, thereby playing a pivotal role in establishing robust protection. Recent investigations have shed light on its importance in the progression of tumors, with a particular emphasis on lung cancer. Among the various signaling pathways implicated in this intricate process, the cGAS-STING pathway emerges as a significant participant. Cyclic GMP-AMP synthase (cGAS) discerns free DNA and activates the stimulator of interferon genes (STING), subsequently culminating in the secretion of cytokines and exerting inhibitory effects on tumor development. Consequently, researchers are increasingly interested in creating anticancer drugs that specifically target the cGAS-STING pathway, offering promising avenues for novel therapeutic interventions. The objective of this review is to present a comprehensive overview of the ongoing research on the cGAS-STING signaling pathway within the realm of lung cancer. The primary emphasis is on understanding its involvement in lung cancer development and assessing its viability as a target for innovative therapeutic options.

Integrative Analysis Identifies NSUN2 as an Essential Coordinator for Glioma Malignancy and Glucose Metabolism

BACKGROUND

Glioma, particularly glioblastoma, is the most common and aggressive primary brain tumor, with poor prognosis due to its metabolic heterogeneity. NSUN2, an m5C RNA methyltransferase and direct glucose sensor, has been implicated in various malignancies, but its role in glioma remains unclear.

METHODS

Bioinformatic analysis was performed on multiple public databases and our glioma dataset from West China Hospital (WCH). In vitro experiments were conducted to assess the effects of NSUN2 knockdown on glioma cell proliferation, migration, and chemotherapeutic sensitivity. Transcriptomic analysis was employed to obtain mechanistic insights.

RESULTS

NSUN2 expression was significantly upregulated in gliomas and correlated with higher tumor grade and poor prognosis. NSUN2 knockdown reduced glioma cell proliferation, migration, and increased sensitivity to temozolomide. Transcriptomic analysis revealed that NSUN2 knockdown downregulated key genes involved in glioma progression. Mechanistically, NSUN2 positively regulates the activity of mTORC1 signaling, as indicated by phosphorylated S6 ribosomal protein and 4EBP1. Moreover, NSUN2 overexpression reciprocally increased tumor volume compared with controls, indicating NSUN2 promoting glioma cell proliferation in vivo.

CONCLUSIONS

Our findings highlight NSUN2 as a critical regulator of glioma malignancy. Targeting NSUN2 disrupts key pathways in glioma progression, suggesting it as a promising therapeutic target. Our work underscores the potential of NSUN2 inhibition to enhance treatment efficacy and improve patient outcomes in glioma.

The Quiet Giant: Identification, Effectors, Molecular Mechanism, Physiological and Pathological Function in mRNA 5-methylcytosine Modification

5-Methylcytosine (m5C) is a prevalent nucleotide alteration observed in transfer RNA (tRNA) and ribosomal RNA (rRNA), and it is also widely distributed in the transcriptome, serving as one of the internal modifications of messenger RNA (mRNA) in higher eukaryotes. Increasing evidence has substantiated the presence of m5C in mRNA. As research on m5C progresses, there is an initial comprehension of its molecular mechanisms and biological significance in mRNA. This work aims to provide a comprehensive summary of the most recent advancements in the identification and screening, distribution, molecular functions, and biological effects of m5C in mRNA. We outline the current status of research and provide prospects for potential future applications.

NSUN2 Promotes Head and Neck Squamous Cell Carcinoma Progression by Targeting EMT-Related Gene LAMC2 in an m5C-YBX1-Dependent Manner

BACKGROUND/OBJECTIVES

Head and neck squamous cell carcinoma (HNSCC) is a prevalent and aggressive cancer with high rates of metastasis and poor prognosis. Recent research highlights the role of 5-methylcytosine (m5C) in cancer progression. NSUN2, an m5C methyltransferase, has been implicated in various cancers, but its role in HNSCC remains elusive.

METHODS

NSUN2 expression and its impact on HNSCC were analyzed by using clinical samples and bioinformatic analysis. m5C-Bis-Seq was used to assess changes in mRNA m5C modification and identify downstream targets. Both in vitro and vivo studies were performed to evaluate the impact of NSUN2 manipulation on tumor growth and metastasis.

RESULTS

Results indicated that NSUN2 was significantly upregulated in HNSCC tissues compared to normal tissues and was associated with poor prognosis. NSUN2 knockdown led to decreased cell proliferation, migration, and invasion in vitro and reduced tumorigenicity and lymph node metastasis in vivo. m5C-Bis-Seq revealed altered m5C-modification patterns upon NSUN2 knockdown, with LAMC2 identified as a key downstream target.

CONCLUSIONS

NSUN2-mediated m5C-modification enhanced LAMC2 stability, promoting epithelial-mesenchymal transition (EMT) signaling pathways. These findings demonstrate that NSUN2 promotes the initiation and progression of HNSCC by stabilizing the LAMC2 transcript through m5C-dependent mechanisms, offering a promising epitranscriptomic-targeted therapeutic approach for HNSCC.

H3K18 Lactylation Potentiates Immune Escape of Non-Small Cell Lung Cancer

Recently discovered epigenetic modification lysine lactylation contributes to tumor development and progression in several types of cancer. In addition to the tumor-intrinsic effects, histone lactylation may mediate tumor microenvironment remodeling and immune evasion. In this study, we observed elevated pan-lysine lactylation and histone H3 lysine 18 lactylation (H3K18la) levels in non-small cell lung cancer (NSCLC) tissues, which was positively correlated with poor patient prognosis. Interruption of glycolysis by 2-deoxy-D-glucose and oxamate treatment and silencing of lactate dehydrogenase A and lactate dehydrogenase B reduced H3K18la levels and circumvented immune evasion of NSCLC cells by enhancing CD8+ T-cell cytotoxicity. Mechanistically, H3K18la directly activated the transcription of pore membrane protein 121 (POM121), which enhanced MYC nuclear transport and direct binding to the CD274 promoter to induce PD-L1 expression. In a mouse NSCLC xenograft model, combination therapy with a glycolysis inhibitor and an anti-PD-1 antibody induced intratumoral CD8+ T-cell function and exhibited strong antitumor efficacy. Overall, this work revealed that H3K18la potentiates the immune escape of NSCLC cells by activating the POM121/MYC/PD-L1 pathway, which offers insights into the role of posttranslational modifications in carcinogenesis and provides a rationale for developing an epigenetic-targeted strategy for treating NSCLC. Significance: H3K18 lactylation supports immunosuppression in non-small cell lung cancer by inducing POM121 to increase MYC activity and PD-L1 expression, which can be reversed by metabolic reprogramming and immunotherapy treatment.

The role of Tim-3 blockade in the tumor immune microenvironment beyond T cells

Numerous preclinical studies have demonstrated the inhibitory function of T cell immunoglobulin mucin domain-containing protein 3 (Tim-3) on T cells as an inhibitory receptor, leading to the clinical development of anti-Tim-3 blocking antibodies. However, recent studies have shown that Tim-3 is expressed not only on T cells but also on multiple cell types in the tumor microenvironment (TME), including dendritic cells (DCs), natural killer (NK) cells, macrophages, and tumor cells. Therefore, Tim-3 blockade in the immune microenvironment not only affect the function of T cells but also influence the functions of other cells. For example, Tim-3 blockade can enhance the ability of DCs to regulate innate and adaptive immunity. The role of Tim-3 blockade in NK cells function is controversial, as it can enhance the antitumor function of NK cells under certain conditions while having the opposite effect in other situations. Additionally, Tim-3 blockade can promote the reversal of macrophage polarization from the M2 phenotype to the M1 phenotype. Furthermore, Tim-3 blockade can inhibit tumor development by suppressing the proliferation and metastasis of tumor cells. In summary, increasing evidence has shown that Tim-3 in other cell types also plays a critical role in the efficacy of anti-Tim-3 therapy. Understanding the function of anti-Tim-3 therapy in non-T cells can help elucidate the diverse responses observed in clinical patients, leading to better development of relevant therapeutic strategies. This review aims to discuss the role of Tim-3 in the TME and emphasize the impact of Tim-3 blockade in the tumor immune microenvironment beyond T cells.

Recent insights into RNA m5C methylation modification in hepatocellular carcinoma

RNA 5-methylcytosine (m5C) methylation involves the addition of a methyl (-CH3) group to the cytosine (C) base within an RNA molecule, forming the m5C modification. m5C plays a role in numerous essential biological processes, including the regulation of RNA stability, nuclear export, and protein translation. Recent studies have highlighted the importance of m5C in the pathogenesis of various diseases, particularly tumors. Emerging evidence indicates that RNA m5C methylation is intricately implicated in the mechanisms underlying hepatocellular carcinoma (HCC). Dysregulation of m5C-associated regulatory factors is common in HCC and shows significant associations with prognosis, treatment response, and clinicopathological features. This review provides an in-depth analysis of the components and functions of m5C regulators, particularly emphasizing their research advancements in the context of HCC.

NSUN2-mediated RNA methylation: Molecular mechanisms and clinical relevance in cancer

Cancer remains a leading cause of morbidity and mortality worldwide, necessitating the ongoing investigation of molecular targets for improved diagnosis, prognosis, and therapy. Among these targets, RNA modifications, particularly N5-methylcytosine (m5C) in RNA, have emerged as critical regulators of gene expression and cellular functions. NOP2/Sun RNA methyltransferase family member 2 (NSUN2) is a key enzyme in m5C modification, significantly influencing various biological processes and tumorigenesis. NSUN2 methylates multiple RNA species, including transfer RNAs (tRNAs), messenger RNAs (mRNAs), and non-coding RNAs, impacting RNA stability, translation efficiency, and cellular stress responses. These modifications, in turn, affect cell proliferation, differentiation, and survival. In cancer, NSUN2 is frequently upregulated, associated with aggressive tumor phenotypes, poor prognosis, and therapy resistance. Its role in oncogenic signaling pathways further underscores its importance in cancer biology. This review offers a comprehensive overview of NSUN2's role in cancer, focusing on its involvement in RNA methylation and its implications for tumor initiation and progression. Additionally, we explore the potential of NSUN2 as a biomarker for cancer diagnosis and prognosis, and its promise as a therapeutic target.