e20145 Background: Response to immune checkpoint inhibitor (ICI)–based therapy in extensive-stage small cell lung cancer (ES-SCLC) is highly heterogeneous, and robust predictive biomarkers remain scarce. Growing evidence suggests that gut microbiota-derived metabolites regulate systemic antitumor immunity by modulating CD8+ T cell function. Inulin, a dietary prebiotic, can reshape gut microbial composition, but its role in ES-SCLC immunotherapy has not been fully elucidated. This study investigated whether Inulin enhances immunotherapy efficacy in ES-SCLC through modulation of the gut microbiota-metabolite-CD8+ T cell axis. Methods: A retrospective cohort study was conducted on patients with ES-SCLC who received first-line treatment with PD-1 inhibitor. The patients were grouped based on the baseline peripheral blood CD8+ T cell level. The high group consisted of 9 patients and the low group of 15 patients. The progression-free survival (PFS) of the two groups was analyzed. Baseline fecal samples underwent metagenomic sequencing and untargeted metabolomics to characterize gut microbial and metabolic features associated with therapeutic outcomes. A SCLC mouse model was used to evaluate the antitumor effects of Inulin, anti-PD-1 therapy, and their combination. Tumor growth, immune infiltration, and cytokine production were assessed by flow cytometry and ELISA. In vitro assays examined the direct effects of Inulin on tumor cells and CD8+ T cell function. Results: Patients with higher baseline CD8+ T cell levels exhibited significantly prolonged PFS following immunotherapy. Distinct gut microbial profiles were observed between patients with favorable and poor responses. Metabolomic analysis revealed higher fecal Inulin levels in patients with elevated CD8+ T cell levels, and Inulin demonstrated predictive value for immunotherapy benefit. In vivo, Inulin significantly enhanced the antitumor efficacy of anti-PD-1 therapy, accompanied by increased tumor-infiltrating CD8+ T cells and elevated IFN-γ, TNF-α, and granzyme B production. In vitro experiments showed that Inulin had no direct cytotoxic effects on tumor cells but augmented CD8+ T cell effector function. Conclusions: Immunotherapy efficacy in ES-SCLC is closely linked to gut microbiota composition and metabolic features. Inulin enhances CD8+ T cell-mediated antitumor immunity through modulation of the gut microenvironment and synergizes with anti-PD-1 therapy, supporting its potential as both an adjunctive therapeutic strategy and a candidate biomarker for immunotherapy responsiveness.

e20017 Background: Lung squamous cell carcinoma (LUSC) is the second most common subtype of lung cancer. Due to its low driver gene mutation rate, immunotherapy has become the first-line treatment for most patients. However, comprehensive tools to predict immunotherapy efficacy remain inadequately established. The role of gut microbiota and their metabolites in predicting response to immune checkpoint inhibitor (ICI) therapy for LUSC is largely unclear. This study aimed to explore the predictive value of gut microbiota and their metabolites for ICI efficacy in LUSC patients, as well as their regulatory effects on the immune system. Methods: Twenty-seven LUSC patients were enrolled and stratified into two groups by progression-free survival (PFS): responders (PFS ≥ 6 months, n = 16) and non-responders (PFS < 6 months, n = 11). A total of 54 fecal samples were collected at three time points: baseline (before immunotherapy), response (partial response [PR]), and progression (progressive disease [PD]). Integrated metagenomic and untargeted metabolomic analyses were performed within and between the two groups. Machine learning models were used to identify potential biomarkers linked to treatment outcomes. Results: Baseline gut microbiome composition was comparable between the two cohorts. During immunotherapy, non-responders showed progressive gut microbiota dysregulation, along with increased microbial diversity. Genera including Cryptobacterium, Faecalibacterium, Alistipes, and Lactimicrobium were identified as potential key determinants of treatment response before immunotherapy initiation. Moreover, relative abundances of probiotic genera (Romboutsia, Lactobacillus, Akkermansia, Lactiplantibacillus, Ligilactobacillus) and "pathogenic" genera (Finegoldia, Mycoplasma, Desulfobulbus, Peptoniphilus, Mycobacterium, Streptococcus) emerged as promising indicators for real-time monitoring of ICI efficacy. Metabolomic profiling revealed that lipid metabolic pathways play a pivotal role in immunotherapy, with multiple lipid metabolites showing significant level alterations. Furthermore, machine learning models identified static biomarkers (PG(i-19:0/PGE2), SM(d18:2(4E,14Z)/6-keto-PGF1α)) and dynamic biomarkers (DL-2-hydroxystearic acid, isoleucyl-valine, 22-hydroxydocosanoic acid, (9Z)-octadecenoic acid), which are highly promising for early prediction and dynamic monitoring of ICI efficacy. Conclusions: Our findings demonstrate that gut microbiota and their metabolites may modulate the efficacy of immunotherapy in LUSC patients. The identified static and dynamic biomarkers possess substantial potential for the early prediction and real-time monitoring of treatment responses.

The ubiquitin-proteasome system is a master regulator of anti-tumor immunity in lung cancer, which primarily functions through controlling the stability of immune checkpoint proteins. The present review offers a synthesis concerning how a dynamic balance between E3 ubiquitin ligases (E3s) and deubiquitinases (DUBs) dictates the fate of key checkpoint proteins, including programmed cell death protein 1/programmed death-ligand 1, lymphocyte-activating gene 3 and B7 homolog 4. Although specific E3s are known to promote checkpoint degradation to enhance T-cell function in certain contexts, and DUBs frequently stabilize these proteins to foster immune evasion, these effects are context-dependent; for example, certain E3s are paradoxically able to promote immune evasion, whereas the inhibition of select DUBs synergizes with immune checkpoint blockade. This regulatory interplay extends to core oncogenic pathways, including the phosphoinositide 3-kinase/AKT and mitogen-activated protein kinase signaling pathways, which indirectly modulate checkpoint expression. Therapeutically, targeting these enzymes with various agents, such as the ubiquitin-specific peptidase 7 inhibitor P5091 or the repurposed drug canagliflozin, has the effect of synergizing with immune checkpoint blockade through reshaping the tumor microenvironment. However, clinical translation is challenged by tumor heterogeneity, pathway redundancy and the complexity of the ubiquitin network. Future progress in this area hinges on precision drug design, predictive biomarker development and rational combination therapies that are informed by a deeper mechanistic understanding of ubiquitin-driven immune regulation.

Small cell lung cancer (SCLC) is a highly aggressive malignancy, and chemotherapy frequently causes nausea and vomiting, which can impair treatment tolerance. Because thalidomide (THD) has shown potential clinical benefit in alleviating nausea and anorexia, we investigated whether its effects might be associated with changes in gut microbial composition and metabolite profiles. Fecal samples were collected from patients with SCLC and categorized into THD-treated and control groups. Metagenomic sequencing and nontargeted metabolomic profiling were performed to characterize microbial composition and metabolic signatures. THD treatment was also associated with higher microbial alpha diversity and increased abundance of genera such as Eubacterium and Prevotella. Metabolomic analysis identified several differential metabolites, including hydrogenated MDI, becocalcidiol, β-octylglucoside, and azelaic acid. Collectively, these findings suggest that the gut microbiota-metabolite axis may be associated with the potential effects of THD on CINV and anorexia in patients with SCLC. The identified microbial taxa and metabolites may serve as candidate biomarkers or potential therapeutic targets, although further validation in larger studies is necessary.

e20513 Background: Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-related mortality worldwide. Despite advances in targeted therapy and immunotherapy, overall prognosis remains poor, underscoring the need to better understand the molecular drivers of tumor progression. Ribosomal proteins, including ribosomal protein L37 (RPL37), have been implicated in extra-ribosomal oncogenic functions in several cancers, but their role in NSCLC is unclear. This study aimed to investigate the function and mechanism of RPL37 in NSCLC pathogenesis. Methods: Bioinformatics analysis of TCGA data assessed RPL37 expression in NSCLC. RPL37 was modulated in A549, H1299, and PC9 cell lines via siRNA/plasmid transfection and lentiviral knockdown. Functional assays included colony formation, wound healing, and Transwell migration/invasion. EMT markers (E-cadherin, ZO-1, N-cadherin, Vimentin, Snail) and Wnt/β-catenin pathway components (cyclin D1, β-catenin, MMP9, c-myc) were analyzed by Western blot. Subcutaneous xenograft models in nude mice evaluated tumor growth in vivo. Transcriptome sequencing identified potential downstream pathways. Results: We found that RPL37 is upregulated in NSCLC tissues compared to adjacent normal tissues. Using loss-of-function and gain-of-function approaches in A549, PC9, and H1299 cell lines, we demonstrated that RPL37 promotes NSCLC cell proliferation, migration, and invasion in vitro, and facilitates epithelial-mesenchymal transition (EMT). In vivo, RPL37 knockdown significantly inhibited tumor growth in a subcutaneous xenograft model. Mechanistically, transcriptome sequencing and western blotting revealed that RPL37 regulates key components of the Wnt/β-catenin pathway, including cyclin D1, β-catenin, MMP9, and c-myc. Conclusions: Collectively, our findings indicate that RPL37 functions as an oncoprotein in NSCLC by enhancing malignant phenotypes through activation of the Wnt/β-catenin signaling pathway. RPL37 may thus represent a potential therapeutic target for NSCLC intervention.

8548 Background: Distant metastasis is the major cause of poor prognosis in non–small cell lung cancer (NSCLC). Emerging evidence suggests that gut microbiota and their metabolites influence tumor progression, but their role in NSCLC metastasis remains unclear. This study aimed to characterize gut microbiota and metabolic features associated with NSCLC metastasis and to elucidate the role and mechanism of the key metabolite testosterone. Methods: Fecal samples from 60 NSCLC patients (48 with distant metastasis, 12 without) were analyzed using metagenomic sequencing and untargeted metabolomics. Multi-omics integration with machine learning identified metastasis-associated metabolites. The effects of testosterone on NSCLC cell migration, invasion, and epithelial–mesenchymal transition (EMT) were evaluated in vitro (PC9, A549, H1299) and in vivo using a mouse metastasis model. Molecular mechanisms were investigated by Western blot, transcriptomics, Mendelian randomization analysis, and functional studies of FGF21. Finasteride was used as a pharmacologic antagonist. Results: Patients with metastatic NSCLC showed distinct gut microbiota profiles, with increased alpha diversity and altered community structure compared with non-metastatic patients. Opportunistic pathogens including Oscillospiraceae, Ruminococcus, and Actinobacteria were enriched in metastatic patients, while Fusobacteria was enriched in non-metastatic patients. Metabolomic analysis revealed significant enrichment of steroid-related metabolites in metastatic NSCLC, with markedly elevated testosterone levels. Testosterone demonstrated good predictive value for metastasis (AUC = 0.761). Testosterone significantly enhanced NSCLC cell migration and invasion and induced EMT, characterized by decreased E-cadherin and ZO-1 and increased N-cadherin and Snail expression. In vivo, testosterone promoted liver metastasis and EMT marker expression. Mechanistically, testosterone activated AKT/mTOR signaling, showed a causal association with AKT phosphorylation, and upregulated FGF21. Functional assays confirmed that FGF21 promoted EMT and metastasis via AKT/mTOR activation. Finasteride reversed testosterone-induced EMT, signaling activation, and metastasis by inhibiting the FGF21/AKT/mTOR axis. Conclusions: Metastatic NSCLC is associated with a distinct gut microbiota and metabolic profile. Gut microbiota–derived testosterone is a key metabolite that promotes NSCLC distant metastasis by activating the FGF21/AKT/mTOR pathway and inducing EMT. Finasteride effectively antagonizes this process, suggesting potential therapeutic value. The testosterone/FGF21/AKT/mTOR axis may serve as a biomarker and therapeutic target for metastatic NSCLC.

e20605 Background: Hepatic immune-related adverse events (HRAEs) are clinically significant toxicities of immune checkpoint inhibitors in lung cancer with substantial inter-individual heterogeneity. Reliable baseline biomarkers for susceptibility are lacking. The contribution of pre-treatment host immune status and gut microbial and metabolic background to HRAE risk remains insufficiently defined. Methods: We conducted a single-center retrospective observational cohort of n = 70 lung cancer patients receiving PD-1 or PD-L1 inhibitors between January 2022 and June 2025, with biospecimens collected at baseline and at HRAE onset. Patients were followed from treatment initiation until HRAE onset, treatment discontinuation, or end of follow-up, with clinically significant HRAEs defined as Common Terminology Criteria for Adverse Events version 5.0 grade 2 or higher liver injury. Peripheral immune cell subsets, liver function indices, and fecal samples were assessed at baseline. In patients who developed HRAEs, paired immune and fecal samples were analyzed at HRAE onset for immune phenotyping, shotgun metagenomic sequencing, and untargeted metabolomic profiling. Associations with HRAEs were evaluated using logistic regression. Results: Baseline demographic and treatment characteristics were comparable between groups. Prior to treatment, reduced B-cell components and increased helper and naive CD4-positive T-cell proportions, together with intermediate activated T-cell proportions, defined a high-risk baseline immune phenotype for HRAEs. Baseline metagenomic profiling revealed distinct gut microbial community structures between risk states, including differential abundance of Phocaeicola coprocola and Ruminococcus, supporting a pre-existing microbial background for HRAE susceptibility. Untargeted metabolomics demonstrated enrichment of nucleoside-related, fatty acid metabolism–related, and microbiota-derived metabolites in HRAE-susceptible patients, with higher baseline adenosine, palmitoylcarnitine, and phenylacetylglutamine, indicating a coordinated immune–microbial–metabolic background linked to toxicity risk. At HRAE onset, immune changes were dominated by functional activation, with increased activated CD4-positive and CD8-positive T cells and natural killer cell activation, without evidence of systemic immune restructuring. Astilbin exhibited a stage-dependent pattern, with higher baseline levels followed by a decrease at HRAE onset. Conclusions: HRAE susceptibility in lung cancer reflects a pre-existing immune–microbial–metabolic background rather than immune checkpoint inhibitor exposure. Reduced B-cell components and increased helper and naive CD4-positive T-cell features define an immune-susceptible state linked to toxicity risk and may inform pre-treatment risk stratification.

e20756 Background: First-line third-generation EGFR tyrosine kinase inhibitors (EGFR-TKIs) are standard therapy for EGFR-mutant non–small cell lung cancer (NSCLC); however, clinical outcomes vary among patients with advanced disease. Increasing evidence suggests that the gut microbiome and its metabolites may influence treatment efficacy. This study investigated baseline gut microbiome and metabolomic features associated with durable response to first-line third-generation EGFR-TKIs in stage IV EGFR-mutant NSCLC. Methods: Baseline fecal samples were collected from 29 patients with stage IV EGFR-mutant NSCLC treated with first-line third-generation EGFR-TKIs. Patients were classified as durable responders (R, n = 19; median progression-free survival [PFS], 24 months) or non-responders (NR, n = 10; median PFS, 6 months). Shotgun metagenomic sequencing and untargeted metabolomics were performed, followed by differential abundance, diversity, and integrative microbiome–metabolome analyses. Results: Baseline gut microbiome and metabolomic profiles differed significantly between groups. Species-level α-diversity analysis demonstrated gut microbiome dysbiosis in the NR group, with higher microbial richness and diversity than in the R group (P < 0.05). Alistipes sp. HGB5, Eubacterium sp. AF22_9, and Tyzzerella nexilis were significantly enriched in the R group (all P < 0.05). Metabolomic profiling showed higher levels of chenodeoxycholic acid, testosterone glucuronide, and palmitic acid in responders (all P < 0.05). Integrative analysis identified Tyzzerella nexilis as a key species correlated with lipid and bile acid metabolism. Conclusions: Baseline gut microbiome and metabolomic profiles differed significantly between groups. Species-level α-diversity analysis demonstrated gut microbiome dysbiosis in the NR group, with higher microbial richness and diversity than in the R group (P < 0.05). Alistipes sp. HGB5, Eubacterium sp. AF22_9, and Tyzzerella nexilis were significantly enriched in the R group (all P < 0.05). Metabolomic profiling showed higher levels of chenodeoxycholic acid, testosterone glucuronide, and palmitic acid in responders (all P < 0.05). Integrative analysis identified Tyzzerella nexilis as a key species correlated with lipid and bile acid metabolism.

e20552 Background: For patients with non-small cell lung cancer (NSCLC) who are treated with third-generation EGFR-TKIs, drug-induced liver injury (DILI) is a common adverse reaction that affects the therapeutic outcome. The gut microbiota and metabolites may participate in the occurrence of DILI through the gut-liver axis. Methods: From the clinical samples, 41 patients with lung adenocarcinoma who received first-line treatment with third-generation EGFR-TKI from April 2021 to April 2023 were enrolled in this study. According to the presence or absence of DILI, they were divided into DILI group (group D, n = 18) and N group (n = 23). Fecal metagenomic sequencing and untargeted metabolomics analysis were used to compare the differences in gut microbiota composition and metabolites between the fecal samples of patients with DILI at the time of DILI (Doccur group) and at baseline (Dbase group). The CCK-8 assay, LDH kit, colony formation experiment and flow cytometry were used to investigate whether BA could enhance the inhibitory effect of osimertinib on hepatocytes. Establish an mouse model of oxaliplatin-induced liver injury, and investigate the regulatory effects of BA on liver tissue pathology, serum liver enzymes (ALT/AST/LDH), and inflammatory factors.The TLR4/MyD88/NF- κB signaling pathway was analyzed through transcriptome sequencing, Western blot and ELISA. Results: The diversity of the intestinal flora in DILI patients was significantly reduced, while the abundance of Bacteroides / Faecalibacterium species increased, and the abundance of Clostridium decreased; the level of metabolite Brevifolincarboxylic acid（BA） was significantly downregulated.BA pre-treatment can reverse the hepatocyte toxicity induced by osimertinib (inhibiting apoptosis, reducing LDH release, and improving proliferation ability). BA intragastric administration alleviates liver tissue inflammatory damage in mice, significantly reducing serum levels of ALT/AST/LDH as well as inflammatory factors (IL-6/IL-1β/TNF-α). BA may exert liver-protective effects by inhibiting the activation of the TLR4/MyD88/NF- κB signaling pathway. Conclusions: By regulating the TLR4/MyD88/NF- κB signaling pathway, BA alleviates liver damage induced by third-generation EGFR-TKIs, providing a new target for the prevention and treatment of DILI based on the intestinal-liver axis.

AIMS:Citrullination, a post-translational modification catalyzed by peptidylarginine deiminases (PADs), is closely linked to cancer progression. Despite PADs' clinical importance, effective inhibitors are urgently needed. We aimed to identify a novel PAD inhibitor, salvianolic acid A (SAA), and to characterize the mechanism by which SAA inhibits PAD activity and exerts anti-tumor effects. MATERIALS AND METHODS:Citrullination of histone H3 (CitH3), drug affinity responsive target stability (DARTS) assays, in vitro enzymatic activity, and molecular docking were used to investigate SAA's direct interaction with PAD family members. PAD oligomerization was evaluated by disuccinimidyl suberate (DSS) cross-linking, native PAGE, and proximity ligation assay (PLA). PAD-histone H3 interaction was assessed by co-immunoprecipitation and PLA. Cellular effects were evaluated in colorectal cancer cell lines and mouse intestinal organoids using CCK-8, Transwell, EdU, and karyotype analyses. KEY FINDINGS:SAA was identified as a reversible pan-PAD inhibitor that binds directly to PAD1, PAD2, PAD3, and PAD4. Unlike traditional covalent inhibitors, SAA promotes PAD oligomerization and enhances PAD-histone H3 interaction while inhibiting histone H3 citrullination. SAA significantly inhibited cancer cell proliferation, migration, and organoid growth, and induced numerical chromosomal abnormalities in a PAD2/4-dependent manner. SIGNIFICANCE:These findings establish PADs as functional targets of SAA and reveal a novel mechanism for PAD inhibition, positioning SAA as a promising chemical probe for treating citrullination-related diseases.

Background:Alectinib is a second-generation tyrosine kinase inhibitor (TKI) that selectively targets anaplastic lymphoma kinase (ALK) rearrangements and is recommended as first-line therapy for patients with advanced ALK-positive non-small cell lung cancer (NSCLC). Pivotal clinical trials have demonstrated its superior efficacy and favorable safety profile compared with earlier ALK inhibitors and chemotherapy. However, long-term real-world outcomes remain insufficiently characterized, particularly in patients harboring concurrent ALK alterations and additional rare genetic variants, whose clinical relevance is often unclear. Case Description:We report a case of a 41-year-old female diagnosed with stage IV lung adenocarcinoma (LUAD) following routine imaging. Comprehensive diagnostic evaluation, including positron emission tomography/computed tomography (PET-CT), cervical lymph node biopsy, and targeted next-generation sequencing, revealed an EML4-ALK fusion (variant 1) together with a concurrent RET p.R820H mutation. The patient initiated first-line treatment with alectinib at a daily dose of 1,200 mg. A partial response was achieved within two months of therapy, and disease control was sustained throughout long-term follow-up. Remarkably, after more than 62 months of continuous alectinib treatment, the patient remained progression-free, with no evidence of disease relapse, distant metastasis, or treatment-related adverse events. The identified RET p.R820H alteration is currently classified as a variant of uncertain significance, and its functional or clinical impact has not been established. Conclusions:This case demonstrates an exceptionally durable response to first-line alectinib in an ALK-positive LUAD patient with a concurrent rare RET variant. It underscores the long-term efficacy and tolerability of alectinib and highlights the importance of comprehensive genomic profiling in guiding personalized targeted therapy for genetically complex NSCLC.

AimsRiboflavin (VB2) is primarily utilized as an adjuvant in cancer therapy. This study aims to investigate the preventive and therapeutic effects of VB2 alone on hepatocellular carcinoma (HCC).Main methodsThe preventive and therapeutic efficacy of VB2 against HCC was evaluated using a Hras12V transgenic mouse model of HCC. Initial mechanistic insights were obtained through transcriptome sequencing combined with bioinformatic analyses, and key findings were validated via molecular biology techniques.Key findingsVB2 administration significantly suppressed hepatic tumorigenesis, as evidenced by reductions in liver tumor burden and improved histology. Bioinformatic analysis revealed that VB2-mediated tumor suppression may involve the regulation of multiple metabolic pathways, including fatty acid and amino acid metabolism. Subsequent molecular validation indicated that VB2 enhanced hepatic retinol metabolism by upregulating key metabolic enzymes. It concurrently inhibited hepatocellular proliferation through p21-mediated G1/S phase arrest and suppressed DNA replication by downregulating the Mcm helicase complex. Additionally, VB2 exhibited inhibitory activity against the progression of established tumors, although this effect was not as significant as its suppression of hepatic tumorigenesis. Safety assessments in wild-type C57BL/6 mice revealed no significant treatment-related toxicity.SignificanceTo our knowledge, this study is the first to demonstrate in vivo that VB2 alone can significantly suppress hepatic tumorigenesis by enhancing retinol metabolism and inhibiting cell proliferation pathways, highlighting its potential as a chemopreventive agent for HCC.

8112 Background: While immune checkpoint inhibitors (ICIs) have reshaped the therapeutic landscape for extensive-stage small-cell lung cancer (ES-SCLC), they are frequently associated with immune-related adverse events (irAEs) that may lead to treatment disruption. Early prediction of irAEs remains challenging due to their atypical clinical manifestations. This study aimed to identify risk factors and predictive biomarkers for irAEs in ES-SCLC patients undergoing ICIs therapy. Methods: 88 patients with ES-SCLC who received ICIs treatment between May 2021 and September 2023 were enrolled. Fecal samples were collected at baseline and before each treatment cycle until therapy discontinuation. The metagenomic and untargeted metabolomic analyses were performed on the fecal samples. Peripheral blood samples were collected from patients for flow cytometry analysis. Tumor response was assessed in accordance with RECIST 1.1 criteria, and irAEs were graded based on the Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Results: Among 88 patients, 41 developed irAEs (median onset: 118 days), with the most common manifestations being pneumonia (41.5%) and hepatitis (22.0%). Patients who developed irAEs exhibited distinct peripheral immune profiles. Compared to their own baseline levels, these patients exhibited decreased peripheral B-cell counts alongside elevated percentages of activated CD4 + and CD8 + T cells, including early-activated CD8 + T cells (CD3 + CD8 + CD69 + T cells), late-activated helper T cells (CD3 + CD4 + CD38 + T cells), and Th2 cells. Furthermore, at baseline, the irAE group demonstrated a significantly higher percentage of PD-1 in CD8 + T cells compared to the non-irAE group. Metabolomic analyses revealed distinct baseline metabolic profiles between the two groups, Micrococcus was significantly enriched at baseline in the irAE group, whereas Phocaeicola coprocola and Oscillibacter were more abundant in patients without irAEs, and calcitriol was identified as a potential predictive biomarker for irAEs. Following irAE onset, significant enrichment of Selenomonadaceae , Ruminococcus , Actinobacteria , and Erysipelatoclostridium was observed, along with significant shifts in metabolites and related metabolic pathways. Conclusions: In ES-SCLC patients treated with ICIs, the development of irAEs is associated with distinct alterations in peripheral immune cell subsets, as well as gut microbial and metabolic profiles at baseline. Monitoring these features, particularly PD-1 expression on CD8+ T cells and calcitriol levels, may help predict the risk of irAEs. Dynamic changes in the gut microbiome and metabolome after ICIs initiation further aid in the early recognition of irAEs.

Cancer poses a significant threat to human health. The immune response plays a pivotal role in tumor cell elimination, with increasing attention given to the spatiotemporal dynamics of immune cells across temporal, spatial, and functional dimensions. The gut microbiota, which constitutes the majority of the human microbiome, contributes to tumor initiation and progression. The tumor microenvironment (TME) serves as the primary site for immune cell-mediated anti-tumor responses, with the gut microbiota and its metabolites driving immune cell activation and spatiotemporal remodeling. This review explores the mechanisms by which the gut microbiota and its metabolites influence anti-tumor immunity, alongside the impact of immune cell dynamics on tumors. Furthermore, it proposes novel research strategies, including the “gut microbiota-immune cell dynamic monitoring model” and the “organoid-microbe co-culture platform.” This work lays a theoretical foundation for advancing our understanding of the underlying mechanisms and developing innovative therapeutic approaches.

BackgroundImmune-related adverse events (irAEs) represent an urgent clinical challenge. Although accumulating evidence suggests that irAEs are associated with the gut microbiota and its metabolites, our understanding of the dynamic alterations in the gut microbiota and related metabolic profiles throughout the onset and progression of irAEs remains limited.MethodsA total of 48 fecal samples were collected from 32 lung cancer patients treated with immune checkpoint inhibitors, including 16 patients who developed irAEs and 16 who did not. Fecal samples were collected at baseline and, in patients with irAEs, at the time of irAEs onset. Metagenomic sequencing and untargeted metabolomics analyses were performed to identify baseline differences in gut microbiota and metabolites, characterize longitudinal dynamic changes in gut microbiota and metabolite profiles in patients with irAEs, and construct a machine learning based random forest model to predict the occurrence of irAEs.ResultsThere were baseline differences in microbial communities and metabolites between the two groups. In the non-irAEs group, Phocaeicola coprocola was enriched and Micrococales decreased. At baseline, viomycin was positively correlated with irAEs, while metabolites such as calcitriol and L-isoleucine were negatively correlated with irAEs. The roles of valine, leucine and isoleucine metabolism and vitamin B6 metabolism pathways were downregulated in the irAEs group. Compared to baseline, there were significant changes in gut microbiota and metabolites during the onset of irAEs, and the abundance of Veillonella increased during irAEs onset. Dynamic monitoring of metabolic changes in irAEs revealed decreased levels of trypsin butylester, BQ 123, DL-o-tyrosine, and nicotinamide-beta-riboside during irAEs attacks. Lysine degradation, arachidonic acid metabolism, folate biosynthesis, nicotinate and nicotinamide metabolism, and C5-branched dibasic acid metabolism were downregulated during the progression of irAEs. A model for predicting the occurrence of irAEs based on differential microbiota and metabolites was constructed, and after robust validation, the model showed good performance and excellent discriminative power.ConclusionsThe occurrence and development of irAEs are associated with the composition of the gut microbiota and metabolites, as well as their dynamic changes over time. These findings highlight the potential of gut microbiota and metabolites as biomarkers for predicting the occurrence and progression of irAEs.

Cancer remains a leading cause of morbidity and mortality worldwide. While classical psychedelics have been used clinically to treat cancer-associated psychiatric disorders, their impact on tumor progression is unclear. Here, we show that by targeting the serotonin receptor 5-HT2AR, lysergic acid diethylamide (LSD) enhances CD8+ T cell-mediated antitumor immunity and suppresses colorectal cancer (CRC) growth. To harness this activity while avoiding psychedelic effects, we developed IHCH-8110, a non-brain-penetrant 5-HT2AR agonist that selectively targets peripheral 5-HT2AR. We show that IHCH-8110 inhibits CRC progression by activating 5-HT2AR on enteric glial cells, thereby inducing CXCL10 and interleukin (IL)-18 expression to promote CD8+ T cell recruitment and effector polarization within the tumor microenvironment. By converting immune-cold CRC into a more immunologically responsive state, IHCH-8110 enhances the efficacy of PD-1 blockade. Together, our findings identify enteric 5-HT2AR signaling as a regulator of antitumor immunity and support peripheral 5-HT2AR agonists as a therapeutic strategy for CRC immunotherapy.

Hypopharyngeal carcinoma is a malignant tumour with a concealed location and difficult to detect in the early stages. Accurate prognosis assessment of hypopharyngeal cancer can help doctors develop reasonable treatment plans. Given that MRI is a primary modality for early-stage hypopharyngeal carcinoma detection, developing an AI-powered prognostic assessment system for hypopharyngeal cancer MRI examinations demonstrates substantial clinical value. However, hypopharyngeal cancer MRI adopts vertical-axis acquisition with larger slice gaps, resulting in lower pixel density along the vertical axis compared to coronal and sagittal axes. This poses a challenge for traditional 2D or 3D intelligent neural networks to adequately extract features from hypopharyngeal cancer MRI images. To this end, we propose Twist3DNet, a multiscale bidirectional 2D-3D information fusion prognostic classification network for hypopharyngeal cancer. We design a bidirectional fusion module, BT Block, to bidirectionally fuse the context from 2D Branch and 3D Branch. We propose a module, 3D M Module, with multiple receptive fields to capture global and local information in MRI images. We validate our method on the hypopharyngeal cancer dataset, BraTS2018 dataset and 3DLSC-COVID dataset. The experimental results demonstrate that our method achieves exceptional performance on these datasets, achieving mF1 scores of 75.78%, 89.09%, and 89.87%, respectively. Furthermore, a comparative analysis reveals that our method can effectively transform 2D networks into 2D-3D hybrid networks, surpassing the performance of corresponding 3D networks. We have made our code available. The code is available at: https://github.com/yk1842/Twist3DNet.

Oxaliplatin resistance continues to undermine therapeutic outcomes in colon cancer (CC). Recent investigations point to unc-51 like kinase 1 (ULK1)-mediated disruption of apoptotic pathways as a potential driver of chemoresistance, though the exact mechanisms remain incompletely characterized. Using established CC cell lines, we developed oxaliplatin-resistant models through stepwise dose escalation. ULK1 expression was modulated through targeted siRNA knockdown and stable overexpression. Protein interactions were examined via co-immunoprecipitation coupled with mass spectrometry, supplemented by kinase activity assays. Functional impact was assessed through proliferation kinetics, apoptosis profiling, and tumor xenograft studies. Clinical correlations were derived from TCGA analysis and immunohistochemical evaluation of patient tumor specimens. ULK1 overexpression consistently correlated with oxaliplatin resistance and adverse clinical parameters. At the molecular level, ULK1 catalyzed Bcl-2 associated X protein (Bax) phosphorylation at Ser184, creating a recognition motif for Parkin-mediated ubiquitination and proteasomal targeting. Disruption of this axis through ULK1 inhibition restored Bax protein levels, enhanced apoptotic response, and reversed oxaliplatin resistance in both cellular and animal models. These findings identify ULK1-dependent phosphorylation as a novel regulatory mechanism governing Bax stability in CC. The study provides preclinical rationale for targeting the ULK1-Bax interface to overcome oxaliplatin resistance, while highlighting the need for further investigation into optimal therapeutic strategies.

e14586 Background: In recent years, the relationship between gut microbiota and metabolites and immunotherapy for non-small cell lung cancer （NSCLC） has gradually become a research hotspot. Rhamnose is a monosaccharide that can be secreted by the gut microbiome and has certain potential in regulating immune responses. The mechanism by which Rhamnose regulates the efficacy of immunotherapy for NSCLC is not yet clear. The aim of this study is to explore the mechanism by which gut microbiome metabolite rhamnose regulates the efficacy of immunotherapy for non-small cell lung cancer, providing new ideas for improving the efficacy of immunotherapy for non-small cell lung cancer. Methods: According to the progression free survival (PFS) of NSCLC patients after immunotherapy, they were divided into a response group (PFS > 6 months, R group) and a non-response group (PFS ≤ 6 months, NR group). Baseline fecal samples were collected from patients for non-targeted metabolomics sequencing to screen for rhamnose. Using a mouse lung cancer model, mice were divided into a control group, a rhamnose group, an anti-PD-1 treatment group, and a combination therapy group (rhamnose +anti-PD-1). Observe the changes in tumor volume in different groups of mice. Flow cytometry and immunohistochemical were used to detect changes in tumor infiltrating CD8 + T cells in different groups of mice. ELISA was used to detect the expression levels of IFN - γ and Granzyme B in the plasma of different groups of mice. Results: Non-targeted metabolomics sequencing found that compared with the NR group, the R group had significantly increased levels of rhamnose. In vivo studies on mice showed that compared to the anti-PD-1 monotherapy group, the combination treatment group showed a significant slowdown in tumor volume growth. The results of flow cytometry and immunohistochemical showed that compared with the anti-PD-1 monotherapy group, the infiltration of CD8 + T cells in tumor tissues increased in the combination treatment group. According to the ELISA results, the proportion of IFN - γ and Granzyme B in peripheral blood of the combined treatment group also increased, indicating the regulatory effect of rhamnose on systemic immune response. Conclusions: The efficacy of NSCLC immunotherapy may be related to gut microbiome metabolite rhamnose. Rhamnose enhances the function of CD8 + T cells by increasing tumor infiltration and raising the levels of cytokine IFN–γ and Granzyme B.