Fusobacterium nucleatum is a Gram-negative oncobacterium that is associated with colorectal cancer. The molecular mechanisms utilized by F. nucleatum to promote colorectal tumor development have largely focused on adhesin-mediated binding to the tumor tissue and on the pro-inflammatory capacity of F. nucleatum. However, the exact manner in which F. nucleatum promotes inflammation in the tumor microenvironment and subsequent tumor promotion remains underexplored. Here, we show that both living F. nucleatum and sterile F. nucleatum-conditioned medium promote CXCL8 release from the intestinal adenocarcinoma HT-29 cell line. We determined that the observed pro-inflammatory effect was ALPK1-dependent in both HEK293 and HT-29 cells and that the released F. nucleatum molecule had characteristics that match those of the pro-inflammatory ALPK1 ligand ADP-heptose or related heptose phosphates. In addition, we determined that not only F. nucleatum promoted an ALPK1-dependent pro-inflammatory environment but also other Fusobacterium species such as F. varium, F. necrophorum and F. gonidiaformans generated similar effects, indicating that ADP-heptose or related heptose phosphate secretion is a conserved feature of the Fusobacterium genus. By performing transcriptional analysis of ADP-heptose stimulated HT-29 cells, we found several inflammatory and cancer-related pathways to be differentially regulated, including DNA mismatch repair genes and the immune inhibitory receptor PD-L1. Finally, we show that stimulation of HT-29 cells with F. nucleatum resulted in an ALPK1-dependent upregulation of PD-L1. These results aid in our understanding of the mechanisms by which F. nucleatum can affect tumor development and therapy and pave the way for future therapeutic approaches.

Targeted therapies leveraging the innate immune system are emerging as promising cancer treatments. The mitochondrial antiviral signaling protein (MAVS) plays a crucial role in initiating innate immune responses, but its clinical use is limited by the risk of uncontrolled activation and systemic toxicity. To address this, we developed a novel therapeutic agent, the truncated interferon activation switch (TRIAS), combining MAVS truncates with a tumor antigen-targeting single-chain variable fragment (scFv). This design ensures antigen-dependent, controlled activation. Lentiviral delivery of TRIAS induced significant antitumor responses, including complete tumor regression in some cases. Flow cytometry (FCM) analysis further confirmed that tumor cells were the predominant population expressing the transgene. TRIAS-expressing tumor cells exhibited enhanced antitumor activity, likely due to increased cytokine release and upregulated major histocompatibility complex (MHC) expression, enabling tumor cells to function as antigen-presenting cells. This activated other immune cells, driving adaptive immune responses. Additionally, TRIAS promoted a proinflammatory shift in the tumor microenvironment (TME). In conclusion, TRIAS was validated as an innovative immunotherapeutic agent with MAVS-like immune-activating properties and tightly controlled mechanisms, offering a safer and more effective approach for clinical cancer immunotherapy.

Cell death-based therapies combined with immunotherapy have great potential in cancer therapy. To further explore and apply the combined therapies, the immunogenicity of different cell death modes in colorectal cancer (CRC) was evaluated by a cause-and-effect framework encompassing 12 cell death modes. Results show robust correlations among cuproptosis, immunogenic cell death (ICD) and immunity in CRC, as observed in our in-house and other independent cohorts, which are substantiated by in vitro and in vivo experiments. Subsequent investigations demonstrate that cuproptosis induces endoplasmic reticulum stress, leading to the release of damage-associated molecular patterns from CRC cells and triggering the maturation of antigen-presenting cells. Moreover, for in vivo therapeutic approaches, an in situ cuproptosis-inducing system was devised, which can further strengthen the effects of immune cells. Through the combined analysis including single-cell RNA sequencing, cuproptosis is shown to mobilize cytotoxic T lymphocytes and M1 macrophages within the tumor microenvironment (TME). Additionally, co-treatment with Imiquimod, the TLR7 agonist, augments the anti-tumor immune responses induced by cuproptosis. Overall, we provide compelling evidence that cuproptosis induces ICD thus fostering an inflammatory TME, and the cuproptosis-based delivery system further promotes this inflammatory environment, demonstrating considerable potential for enhancing tumor therapy efficacy.

Colorectal cancer (CRC) is a leading health issue and treatments to eradicate it, such as conventional chemotherapy, are non‑selective and come with a number of complications. The present review focuses on the relatively new area of precision oncolytic viral therapy (OVT), with genetic targeting and immune modifications that offer a new future for CRC treatment. In the present review, an overview of the selection factors that are considered optimal for an oncolytic virus, mechanisms of oncolysis and immunomodulation applied to the OVT, as well as new strategies to improve the efficacy of this method are described. Additionally, cause‑and‑effect relationships are examined for OVT efficacy, mediated by the tumor microenvironment, and directions for genetic manipulation of viral specificity are explored. The possibility of synergy between OVT and immune checkpoint inhibitors and other treatment approaches are demonstrated. Incorporating the details of the present review, biomarker‑guided combination therapies in precision OVT for individualized CRC care, significant issues and future trends in this required area of medicine are highlighted. Increasingly, OVT is leaving the experimental stage and may become routine practice; it provides a new perspective on overcoming CRC and highlights the importance of further research and clinical work.

Colorectal cancer (CRC) is a leading cause of cancer-related mortality globally, with metastasis playing a key role in its unfavorable prognosis. Emerging research has emphasized the pivotal role of mitochondria in tumor immune regulation. Nevertheless, the clinical relevance and functional role of SLC25A24, a mitochondrial solute carrier, in CRC remain largely unexplored. Through bioinformatics analyses and validation in clinical cohorts, this study identifies SLC25A24 as an independent prognostic marker in CRC, significantly linked to immune infiltration in CRC tissues. Our findings demonstrated that SLC25A24 expression is markedly reduced in CRC cell lines and tissues. Kaplan-Meier survival analysis revealed that lower SLC25A24 expression is associated with worse overall survival and progression-free survival in CRC patients. Interestingly, SLC25A24 expression was higher in microsatellite instability (MSI) CRC, which shows greater responsiveness to immune checkpoint inhibitors (ICIs). Functional experiments indicated that SLC25A24 overexpression suppresses CRC cell proliferation, migration, and invasion. Mechanistic studies revealed that SLC25A24 positively regulates the cGMP/PKG1 signaling pathway in CRC, influencing mitochondrial potential, apoptosis, and proliferation-related markers. This research highlights the SLC25A24-PKG1 axis as a potential therapeutic target to bolster anti-tumor immunity and curb CRC progression.

The understanding of how gut microbiota metabolites modulate immune escape mechanisms in colorectal cancer (CRC) remains limited. In the present study, the impact of gut microbiota metabolites on the efficacy of programmed cell death protein 1 (PD-1) and programmed cell death ligand-1 (PD-L1) immunotherapy in CRC was explored, with a particular focus on the short-chain fatty acid, sodium propionate (SP), as they key metabolite. The results of the present study, determined by CCK-8 and flow cytometry, demonstrated that 10 mM SP significantly suppressed CRC cell proliferation and induced apoptosis. By contrast, 40 mM SP, but not 10 mM, markedly increased the PD-L1 mRNA and protein expression levels. Insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) expression, analyzed via bioinformatics using The Cancer Genoma Atlas datasets, was significantly higher in CRC tissues compared with healthy tissues. Additionally, survival analysis uncovered that elevated IGF2BP3 levels in tumor tissues were strongly associated with poor clinical outcomes. Moreover, 40 mM SP significantly induced the expression of IGF2BP3 mRNA and protein in CRC cells. The actinomycin D assay was conducted to assess mRNA stability, whereas methylated RNA immunoprecipitation coupled with quantitative polymerase chain reaction (qPCR) and RNA immunoprecipitation-qPCR were utilized to confirm the interaction between IGF2BP3 and PD-L1 mRNA. These results indicated that IGF2BP3 served as an N6-methyladenosine (m6A) reader for PD-L1, stabilizing its mRNA in an m6A-dependent manner, thereby upregulating the PD-L1 mRNA and protein expression levels. Therefore, high-dose SP may promote tumor immune escape via the IGF2BP3/PD-L1 axis in CRC. As such, high-dose SP may synergize with PD-1/PD-L1 blockade therapies to improve clinical outcomes in patients with CRC, particularly by upregulating PD-L1 expression.

Oxaliplatin resistance poses a significant challenge in colorectal cancer (CRC) treatment. Recent studies have implicated CPSF6 in cancer progression and drug resistance, although its role in chemotherapy resistance and regulatory mechanisms is unclear. This study investigates CPSF6's involvement in oxaliplatin resistance in CRC and its regulation via m6A methylation by METTL3. We assessed CPSF6 expression in oxaliplatin-resistant (OxR) CRC cell lines (HT29-OxR and HCT116-OxR) compared to sensitive counterparts using qRT-PCR and Western blotting. CPSF6 was significantly upregulated in OxR cells, and its knockdown reduced cell viability, colony formation, and glycolytic activity while increasing apoptosis. m6A modification of CPSF6 mRNA was elevated in OxR cells, correlating with increased METTL3 expression. METTL3 knockdown decreased CPSF6 levels and m6A enrichment, enhancing mRNA degradation, while its overexpression stabilized CPSF6 mRNA, promoting resistance. Xenograft experiments showed that CPSF6 knockdown suppressed tumor growth and glycolysis. Thus, CPSF6 is identified as a mediator of oxaliplatin resistance in CRC, regulated by the METTL3/m6A axis, suggesting potential therapeutic targets to overcome resistance.

As traditional medicinal fungi, Ganoderma lucidum and Sanghuangporus vaninii are widely used in the treatment of tumor related diseases and cancer adjuvant therapy with potent anticancer effects. However, the anticancer effect and mechanism of action of their compound extract remain unclear.

To investigate the anticancer effect of Ganoderma lucidum and Sanghuangporus vaninii compound extract and explore the underlying mechanism.

First, MTT assay was performed to investigate the effect of 8 different extracts on tumor cell viability. Moreover, the synergistic effect of Ganoderma lucidum spore and Sanghuangporus vaninii was evaluated by Chou-Talalay method. Subsequently, the fractional extractions were conducted to further isolate anti-tumor active components. Next, network pharmacology combined with transcriptomics was used to explore the potential mechanisms underlying the anticancer effect of compound extract. Finally, the mechanism of action was verified using in vitro and in vivo models.

Among all 8 extracts, Ganoderma lucidum spore and Sanghuangporus vaninii compound ethanol extract (GSEE) showed the most significant cell viability inhibitory effect on cancer cells, especially colorectal cancer (CRC) cells, which was even better than combination of Sanghuangporus vaninii ethanol extract (SVEE) and Ganoderma lucidum spore ethanol extract (GLEE). The ethyl acetate fraction of GSEE (GSEAE) was screened as the anti-tumor active fraction of GSEE and could suppress CRC proliferation in vitro and in vivo. The CYP24A1-mediated Vitamin D receptor (VDR) pathway and TERT-mediated Wnt signaling pathway were identified as the main mechanisms of GSEAE against CRC. Multiple CRC models confirmed that GSEAE suppressed CRC metastasis, arrested cell cycle and induced mitochondrial apoptosis of CRC cells via VDR pathway and Wnt signaling pathway.

Collectively, our data suggest that compound extract GSEAE exerts anti-CRC effects via CYP24A1-mediated VDR pathway and TERT-mediated Wnt signaling pathway.

Numerous studies have demonstrated that extracellular vesicles (EVs) carry a variety of noncoding RNAs (ncRNAs), which can be taken up by neighboring cells or transported to distant sites via bodily fluids, thereby facilitating intercellular communication and regulating multiple cellular functions. Within the tumor microenvironment, EV-ncRNA, on the one hand, regulate the expression of PD-L1, thereby influencing tumor immune evasion, promoting tumor cell proliferation, and enhancing tumor growth, invasion, and metastasis in vivo. On the other hand, these specific EV-ncRNAs can also modulate the functions of immune cells (such as CD8 + T cells, macrophages, and NK cells) through various molecular mechanisms, inducing an immunosuppressive microenvironment and promoting resistance to anti-PD-1 therapy. Therefore, delving into the molecular mechanisms underlying EV-ncRNA regulation of immune checkpoints presents compelling therapeutic prospects for strategies that selectively target EV-ncRNAs. In this review, we elaborate on the cutting-edge research progress related to EV-ncRNAs in the context of cancer and dissect their pivotal roles in the PD-1/PD-L1 immune checkpoint pathway. We also highlight the promising clinical applications of EV-ncRNAs in anti-PD-1/PD-L1 immunotherapy, bridging basic research with practical clinical applications.

Immune checkpoint inhibitors (ICIs) have revolutionized colon cancer treatment, but their efficacy is largely restricted by the limited presence of CD8+ cytotoxic T lymphocytes (CTLs). However, the specific genetic alterations that impact the CD8+ CTL infiltration in colon cancer remain poorly understood. Here, we analyzed clinical and multi-omics data from the Memorial Sloan-Kettering Cancer Center (MSKCC) ICIs-treated and The Cancer Genome Atlas (TCGA) colon adenocarcinoma (COAD) cohorts to screen the key mutations that may influence the efficacy of immunotherapy. We found that patients with NCOA3 mutations exhibit better response to immunotherapy and higher CD8+ CTL infiltration. In vitro and in vivo experiments revealed that mutant NCOA3 increases the efficacy of anti-PD-L1 and CD8+ CTL recruitment by upregulating C-X-C motif chemokine ligand 9 (CXCL9), which is dependent on its impaired intrinsic histone acetyltransferase activity. Mechanistically, wild-type NCOA3 as histone acetyltransferase upregulates Heat shock protein 90 alpha (HSP90α) by enhancing histone H3 lysine 27 acetylation (H3K27ac) at its promoter region. Increased HSP90α stabilizes Enhancer of zeste homolog 2 (EZH2), which then increase the histone H3 lysine 27 trimethylation (H3K27me3) at the CXCL9 promoter region, thereby suppressing the expression of CXCL9. Targeted inhibition of NCOA3 by small molecular inhibitor SI-2 improves the efficacy of PD-L1 blockade therapy. NCOA3 could serve as a novel biomarker and potential target to improve the efficacy of immunotherapy.

Natural killer (NK) cells are a subset of innate lymphoid cells that possess cytotoxic properties, playing a pivotal role in immune surveillance against tumor cells. However, it remains unclear whether there are any alterations in the quantity and functional status of NK cells in colorectal cancer (CRC).

In this study, we collected peripheral blood samples from both CRC patients and age- and sex-matched healthy controls (HCs). The distribution characteristics, phenotypic changes, functional status, apoptosis susceptibility, and proliferative capacity of circulating NK cells were detected and analyzed by flow cytometry. An in vitro study was performed to investigate the blocking effect of KLRG1 antibody on peripheral blood NK cells in CRC patients.

The frequency and absolute number of circulating NK cells were significantly decreased in CRC patients compared to those in HCs. Meanwhile, the function of NK cells from CRC patients was compromised, as shown by the reduced production of IFN-γ, TNF-α, and CD107a, with this impairment becoming increasingly significant as neural invasion progressed and tumor invasion advanced. We further found that the expression of activating receptors NKp30 and NKp46 were reduced, while the expression of inhibitory receptor KLRG1 was remarkably increased. The increased proportion of KLRG1 on NK cells was associated with CRC progression, and KLRG1+ NK cells showed impaired production of IFN-γ, TNF-α, and CD107a and were more susceptible to apoptosis. Importantly, blockade of the KLRG1 pathway could restore the cytokine production and degranulation ability of NK cells from CRC patients.

The present study demonstrates that NK cells in CRC patients exhibit functional exhaustion, and KLRG1 blockade restores the effector function of NK cells, indicating that targeting KLRG1 represents a promising strategy for immunotherapy in patients with CRC.

Colon adenocarcinoma (COAD) is a globally prevalent and deadly malignancy of the digestive system. Recently, migrasomes have gained significant attention as important regulators of tumor cell migration and metastasis. The current research developed a highly accurate prognostic model using migrasome-related long non-coding RNAs (lncRNAs) in COAD, providing new insights for prognostic assessment and immunotherapy of COAD patients.

RNA sequencing data from COAD patients were acquired from The Cancer Genome Atlas Program (TCGA) database to construct a prognostic lncRNA model based on known migrasome-related genes (MRGs). The model's predictive accuracy was then assessed using concordance index (C-index) analysis, nomograms, principal component analysis, and receiver operating characteristic curves. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted to identify significant differences in biological functions and signaling pathways associated with differentially expressed genes in the high-risk subgroup. A comprehensive evaluation of the model incorporated clinical-pathological features, tumor microenvironment, and chemotherapy sensitivity. The expression levels of prognostic genes in COAD patients were validated via quantitative reverse transcription polymerase chain reaction (RT-qPCR). Furthermore, the role of LCMT1-AS1 in colorectal cancer was examined through CCK-8 assays, colony formation assays, and Transwell experiments.

Migrasome-related lncRNAs were identified as robust prognostic predictors for COAD. Multivariate analysis revealed that the risk score derived from these lncRNAs is an independent prognostic factor for COAD. Patients in the low-risk group exhibited significantly longer overall survival (OS) compared to those in the high-risk group. Accordingly, the nomogram prediction model we developed, which integrates clinical features and risk scores, demonstrated excellent prognostic performance. In vitro experiments further showed that LCMT1-AS1 promotes the proliferation and migration of COAD cells.

Despite advances in cancer immunotherapies across various cancers, survival outcomes in colorectal cancer (CRC) with these agents remain largely unsatisfactory despite the high tumour burden. Colorectal stem cells (CSCs), especially LGR5+ CSCs, are the significant drivers in CRC initiation, progression and resistance to conventional therapies. Although native immune surveillance is sufficient to combat early tumour formation, CRC evades early immune detection with its well-documented adenoma-to-carcinoma sequence. The exact mechanism underlying this phenomenon still needs to be better understood. SRY-related HMG box gene 17 (SOX17), a transcription factor that specifies embryonic gut formation, is increasingly recognised as a significant factor in CRC tumourigenesis. However, its role as a tumour suppressor or oncogene is still debated. Evidence from a recent study highlighted the critical role of SOX17 in reshaping the tumour immune ecosystem through the simultaneous inhibition of CD8+ T cells and selective suppression of LGR5 expression in CSCs through transcriptional repression, thereby facilitating disease progression. Given its role in immune evasion, SOX17 could be a promising marker in personalised therapy. Additionally, SOX17 could play a role in the diagnostic arena, potentially identifying dysplasia in the gastrointestinal tract. Future clinical, basic and genetic studies focusing on SOX17 are needed to ascertain its mechanistic role in tumour immunomodulation in CRC and diagnosing preneoplastic lesions in the gastrointestinal tract.

Colorectal cancer liver metastasis (CRLM) remains the leading cause of mortality among colorectal cancer (CRC) patients, with more than half eventually developing hepatic metastases. Achieving long-term survival in CRLM necessitates early detection, robust stratification, and precision treatment tailored to individual classifications. These processes encompass critical aspects such as tumor staging, predictive modeling of therapeutic responses, and risk stratification for survival outcomes. The rapid evolution of artificial intelligence (AI) has ushered in unprecedented opportunities to address these challenges, offering transformative potential for clinical oncology. This review summarizes the current methodologies for CRLM grading and classification, alongside a detailed discussion of the machine learning models commonly used in oncology and AI-driven applications. It also highlights recent advances in using AI to refine CRLM subtyping and precision medicine approaches, underscoring the indispensable role of interdisciplinary collaboration between clinical oncology and the computational sciences in driving innovation and improving patient outcomes in metastatic colorectal cancer.

We identified a subset of patients with colorectal cancer (CRC) enriched with "collagen-TAMs," designated the CM class, using large integrated colon cancer transcriptome and single-cell transcriptome datasets. This classification system could be used as an extension of the traditional CMS classification system for CRC to guide more accurate classification and treatment.We also screened CAF-derived THBS2 as a potential biomarker for CM and found that it plays an important role in CRC disease models in vitro and in vivo, promoting tumor development and metastasis as well as TAM recruitment. Targeting THBS2 combined with PD-1 therapy effectively improved the therapeutic effect of immunotherapy in vivo. The CM classification provides a new perspective for CRC treatment, and THBS2, which is highly expressed in CM cases, can be used as a new potential combined target for immunotherapy.

Dendritic cells (DCs), as specialized antigen-presenting cells, are the commanders of the human immune cell system, directing and controlling various functions of the immune system. However, the competitive plunder of glutamine by tumor cells and the cancer cell stemness significantly impair the functional activation of DCs. Herein, we developed a Mn-coordination driven glutamine and cancer stemness dual-tailored nano-herb (HA/E-M@Purpurin NPs) for high-efficiency activation of DCs. The nano-herb is composed of ellagic acid (EA), divalent manganese ion (Mn2+), and purpurin. EA exerts an inhibitory effect on cell stemness, Mn2+ activate DCs by activating the cGAS-STING pathway, and purpurin inhibits the breakdown of glutamine, leading to a compensatory increase in glutamine content and further activating DCs. After surface modification with hyaluronic acid (HA), the nano-herb can target tumor cells and release drugs to exert corresponding effects. Taken together, our findings underscore the substantial promise of nano-herbs in overcoming cancer stemness-driven immune escape, offering a transformative approach to enhance the success of immunotherapy regimens.

Colorectal cancer (CRC) is one of the most common malignant tumors in the digestive system worldwide, with its mortality ranking second among all cancers. Studies have indicated that disruptions in circadian rhythm (CR) are associated with the occurrence of various cancers; however, the relationship between CR and CRC requires further evidence, and research on the application of CR in CRC is still limited.

In this study, we employed both bulk and single-cell RNA sequencing to explore the dysregulation of CR in patients with CRC. By constructing a CR subtype classifier, we conducted an in-depth analysis of the prognostic significance, the status of the tumor microenvironment, and response to immune checkpoint blockade (ICB) therapy between different CR clusters. Furthermore, we developed a CR scoring system (CRS) using machine learning to predict overall survival and identified several genes as potential targets affecting CRC prognosis.

Our findings revealed significant alterations in CR genes and status between CRC and normal tissues using bulk and single-cell transcriptome sequencing. Patients with CRC could be categorized into two distinct CR clusters (CR cluster 1 and 2). The prognosis of CR cluster 2, with higher epithelial-mesenchymal transition (EMT) and angiogenesis scores, was significantly worser than that of CR cluster 1. These clusters exhibited distinct levels of tumor-infiltrating lymphocytes. CR cluster 2 with a notably higher proportion of patients with microsatellite-instability-high (MSI-H), potentially benefit from ICB therapy. The proportion of patients belonging to consensus molecular subtype 4 (CMS4) in CR cluster 2 was also notably higher than in CR cluster 1. Additionally, the CRS combined with tumor stage demonstrated superior overall survival prediction efficacy compared to traditional tumor stage. We revealed a potential link between model genes (LSAMP, MS4A2, NAV3, RAB3B, SIX4) and the disruption of CR and patient prognosis.

This study not only provide new insights into the assessment of CR status in CRC patients but also develop a prognosis model based on CR-related genes, offering a new tool for personalized risk assessment in CRC.

The vast majority of colorectal cancers (CRCs) are proficient mismatch repair (pMMR) and microsatellite stable, and their immune microenvironment appears as a "cold tumor," which is not sensitive to single immunotherapy based on immune checkpoint inhibitors (ICIs). The utilization of ICIs in pMMR advanced CRC is still in the exploratory phase. Cutaneous metastasis from colorectal carcinoma is extremely rare, presenting with diverse clinical manifestations, and there is a lack of standard treatment options for such cases. Patients with skin metastasis from CRC usually progress rapidly and are associated with a dismal prognosis. Herein, we report the case of a 66-year-old woman with extensive cutaneous metastasis of pMMR advanced rectal carcinoma. The patient presented to the abdominal oncology clinic with a complaint of erythema on the right lower limb, perineum, and abdominal skin. The patient underwent radical surgery for rectal carcinoma 3 years before the presentation. The histologic examination revealed low-grade squamous cell subepithelial adenocarcinoma. The patient was treated with sintilizumab in combination with fruquintinib, which exhibited remarkable efficacy and improved the patient's quality of life significantly. Previous cases of cutaneous metastasis of colorectal carcinoma were retrieved to characterize the clinicopathological features. For the rare subset of patients with skin metastasis from CRC, immunotherapy combined with anti-angiogenic targeted therapy may be considered.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a poor prognosis. While immunotherapy has shown limited efficacy in most PDAC cases due to an immunosuppressive tumour microenvironment, tumours with microsatellite instability-high (MSI-H) or deficient mismatch repair (dMMR) status exhibit increased responsiveness to immune checkpoint inhibitors.

We report the case of a 45-year-old woman with Lynch syndrome who was diagnosed with MSI-H/dMMR PDAC during routine surveillance. Given the borderline resectable nature of her tumour and previous chemotherapy-related neurotoxicity, she was treated with neoadjuvant pembrolizumab instead of conventional chemotherapy. Following four cycles of pembrolizumab, imaging revealed a marked metabolic response, allowing for successful R0 pancreatoduodenectomy. Postoperative histology confirmed a significant reduction in tumour size, and immunohistochemical analysis demonstrated increased CD8 + T cell infiltration, supporting an enhanced anti-tumour immune response. The patient continues adjuvant pembrolizumab therapy without complications.

This case highlights the potential role of neoadjuvant pembrolizumab in MSI-H/dMMR PDAC, demonstrating successful tumour downstaging and facilitating surgical resection. Our findings support further investigation into the integration of immunotherapy as a neoadjuvant strategy for select PDAC patients.

A T cell-inflamed tumor microenvironment is predictive of better prognosis and clinical response to immunotherapy. Proteinase-activated receptor 2 (PAR2), a member of G-protein coupled receptors is involved in inflammatory process and the progression of various cancers. However, the role of PAR2 in modulating the tumor microenvironment remains unclear. Here, we found that PAR2 high-expression was associated with a favorable prognosis in patients with colorectal cancer. Intriguingly, PAR2 expression in human colorectal cancer was mainly confined to tumor cells and was significantly associated with CD8+ T cell infiltration. Tumor-intrinsic PAR2 deficiency blunted antitumor immune responses to promote tumor growth and attenuated the therapeutic efficacy of anti-PD1 in a mouse model of colon cancer. Tumors with downregulated PAR2 showed decreased CD8+ T cell infiltration and impaired effector function. Mechanistically, PAR2 activation in tumor cells induced CXCL9 and CXCL10 production via PI3K/AKT/mTOR signaling, thereby enhancing CD8+ T cell recruitment in the tumor microenvironment. In addition, PAR2 was essential for dendritic cell activation and differentiation towards conventional type 1 subset. PAR2 deficiency in dendritic cells markedly impaired their ability to prime CD8+ T cells and control tumor growth in vivo. Thus, our findings identify new roles for PAR2 in promoting antitumor immunity and provide a promising target to improve immunotherapy efficacy in colorectal cancer.

V-set and immunoglobulin domain containing 4 (VSIG4) is a B7-family-related protein almost exclusively expressed on macrophages. The difference in its expression mediates the dynamic transformation of the polarization state of macrophages, but the underlying mechanism is still unclear. We sought to reveal the correlation between VSIG4 and the polarization of tumour-associated macrophages (TAMs) and the immune escape of tumour cells in colorectal cancer (CRC).

THP-1 monocyte-derived macrophages expressing different levels of VSIG4 were used for in vitro investigations. In addition, the co-culture system was used to verify the effect of tumour cells on the expression of VSIG4 in macrophages, and the effect of VSIG4 expression level on tumour cells in turn. Subcutaneous xenograft models evaluated the tumour growth inhibition efficacy of VSIG4 blockade as monotherapy and combined with immune checkpoint inhibitors (ICIs).

CRC cells secreted lactate to promote VSIG4 expression in macrophages. On the contrary, VSIG4 promoted macrophage M2 polarization and induced malignant progression of tumour cells by promoting M2 macrophage secretion of heparin-bound epidermal growth factor. In vivo experiments confirmed that knockdown VSIG4 inhibited tumour growth and improved the efficacy of ICIs therapy. Mechanistically, lactate secreted by CRC cells promoted its expression by influencing the epigenetic modification of VSIG4 in macrophages. In addition, VSIG4 enhanced the fatty acid oxidation (FAO) of macrophages and upregulated PPAR-γ expression by activating the JAK2/STAT3 pathway, which ultimately induced M2 polarization of macrophages. Downregulation of VSIG4 or blocking of FAO reversed the M2 polarization process of macrophages.

Our findings provide a molecular basis for VSIG4 to influence TAMs polarization by regulating the reprogramming of FAO, suggesting that targeting VSIG4 in macrophages could enhance the ICIs efficacy and represent a new combination therapy strategy for immunotherapy of CRC.

Colorectal cancer cells secrete lactate to upregulate VSIG4 in macrophages via the H3K18la-METTL14-m6A axis. VSIG4 promotes fatty acid oxidation of macrophages and drives its M2-type polarization. These VSIG4-expressing M2 macrophages promote tumour progression and an immunosuppressive microenvironment. Inhibition of VSIG4 expression can synergistically enhance the therapeutic effect of anti-PD-1 antibody.

Metabolic interventions are critical for enhancing immunotherapy efficacy, but reliable metabolic targets remain absent for colorectal cancer (CRC). This study aims to investigate the interplay between metabolic and immunological factors in CRC, identify metabolic immunoregulatory molecules, and propose targets for prognostic and therapeutic applications.

Immune infiltration and metabolic pathways in CRC were analyzed using CIBERSORT and gene set variation analyses. Cox regression identified survival-related metabolic genes, forming a metabolic-related gene prognostic index (MRGPI), which was validated through survival analysis, timeROC, GSEA, CIBERSORT, and TIDE. Hub genes in the MRGPI were assessed using enrichment and co-expression network analyses. The expression of carnitine palmitoyltransferase 2 (CPT2) was validated through multiplex immunofluorescence of tissue microarrays. While its role was examined by western blot, CCK-8 assay, flow cytometry, qRT-PCR, Elisa, chemotaxis assays, etc. RESULTS: Fatty acid oxidation (FAO) pathways were significantly altered in CRC and correlated with immune cell infiltration and patient survival. The MRGPI, constructed from five survival-related metabolic genes, demonstrated strong prognostic and immunotherapeutic predictive value. Moreover, CPT2, a key hub gene in the MRGPI, whose lower expression in plasma cells predicts unfavorable patients' survival and could be an independent prognostic indicator, while its knockout in tumor cells significantly increases the infiltrating levels of CD8+ T cells via promoting the release of CCL25.

The FAO-dominated MRGPI is a promising biomarker for predicting patient outcomes and immunotherapy response. CPT2 holds potential as a prognostic marker and therapeutic target for CRC metabolic immunotherapy.

BRAF mutation affects the biological characteristics and microenvironment of the tumor during the development of colorectal cancer. Tumor-associated lymph nodes are the key sites of immune response. This study aimed to systematically evaluate the impact of BRAF gene mutations on the remodeling of the CRC immune microenvironment, with a particular focus on their effects on the maturation and function of TLS·In this study, clinical samples of CRC patients were collected, and immune cell subsets were analyzed by single-cell RNA sequencing, and pseudo-temporal locus analysis and spatial transcriptome analysis were performed to explore intercellular communication and functional enrichment analysis. The distribution and maturity of TLS were evaluated by immunohistochemistry and multiple fluorescence staining techniques, and statistical analysis was performed.The results showed that BRAF mutation significantly affected the number and maturity of lymphatic structures infiltrated by tumors, and was negatively correlated with patient prognosis. BRAF mutations lead to alterations in T cell subsets, particularly the dual role of CD4+ CXCL13 cells in TLS maturation. B-cell subpopulation analysis revealed functional deficits in CRC patients with BRAF mutations, which further drove the remodeling of the tumor immune microenvironment.

Immuno-oncology (IO) is one of the fastest growing therapeutic areas within oncology. IO agents work indirectly via the host's adaptive and innate immune system to recognize and eradicate tumor cells. Despite checkpoint inhibitors being only introduced to the market since 2011, they have become the second most approved product category. Current Food and Drug Administration (FDA)-approved classes of IO agents include: immune checkpoint inhibitors (ICIs), chimeric antigen receptor T-cell therapy (CAR-T), bi-specific T-cell engager (BiTE) antibody therapy, T-cell receptor (TCR) engineered T cell therapy, tumor-infiltrating lymphocyte (TIL) therapy, cytokine therapy, cancer vaccine therapy, and oncolytic virus therapy. Cancer immunotherapy has made progress in multiple cancer types including melanoma, non-small cell lung cancer (NSCLC), renal cell carcinoma (RCC), and urothelial carcinoma; however, several cancers remain refractory to immunotherapy. Future directions of IO include exploration in the neoadjuvant/perioperative setting, combination strategies, and optimizing patient selection through improved biomarkers.

The very prevalent nature, genetic variability, and intricate tumor microenvironment (TUME) of colorectal cancer (COREC) are its defining features. In order to better understand the molecular and cellular make-up of COREC, this work used single-cell RNA sequencing (SRNAS) to isolate and characterize important cell types as well as their interactions within the TUME. Our analysis of 51,204 cells yielded six distinct types: epithelial, fibroblast, endothelial, T&NK, B, and myeloid. C3 B cells were shown to be the most active in immunological regulation, according to chemokine signaling study, which was one of seven clusters of B cells that were thoroughly subtyped. The examination of copy number variation (CONUV) revealed a great deal of genetic variability, especially in epithelial cells. We traced the activity of three key transcription factor clusters (M1, M2, and M3) across all B cell subtypes using transcription factor analysis. We created a predictive model that correctly sorts patients according to survival results by using marker genes from C3 B cells. In addition, the relationship between genetic changes and the immune system was better understood by tumor mutational burden (TUMUB) and immune infiltration studies. Our research sheds light on the genetic complexity and cellular variety of COREC, which in turn opens up new possibilities for targeted treatments and individualized approaches to patient care.

Immune checkpoint blockade, particularly targeting programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1), shows promise in treating hepatocellular carcinoma (HCC). However, acquired resistance, especially in patients with 'hot tumours', limits sustained benefits. Lysine-specific demethylase 1 (LSD1) plays a role in converting 'cold tumours' to 'hot tumours', but its involvement in PD-1 inhibitor resistance in HCC is unclear.

LSD1 and PD-L1 expression, along with CD8+ T cell infiltration, were assessed using immunohistochemistry in HCC tissues, correlating these markers with patient prognosis. The impact of LSD1 deletion on tumour cell proliferation and CD8+ T cell interactions was examined in vitro. Mouse models were used to study the combined effects of LSD1 inhibition and anti-PD-1 therapy on tumour growth and the tumour microenvironment (TME). The clinical relevance of LSD1, CD74 and effector CD8+ T cells was validated in advanced HCC patients treated with PD-1 blockade.

LSD1 overexpression in HCC patients correlated with reduced PD-L1 expression, less CD8+ T cell infiltration and poorer prognosis. LSD1 deletion increased PD-L1 expression, boosted effector CD8+ T cells in vitro and inhibited tumour growth in vivo. While anti-PD-1 monotherapy initially suppressed tumour growth, it led to relapse upon antibody withdrawal. In contrast, combining LSD1 inhibition with anti-PD-1 therapy effectively halted tumour growth and prevented relapse, likely through TME remodelling, enhanced CD8+ T cell activity and improved CD74-mediated antigen presentation. Clinically, low LSD1 expression was associated with better response to anti-PD-1 therapy.

LSD1 deletion reshapes the TME, enhances CD8+ T cell function and prevents acquired resistance to anti-PD-1 therapy in HCC. The combination of LSD1 inhibitors and PD-1 blockade offers a promising strategy for overcoming resistance in advanced HCC.

Uncovering the synthetic lethality resulting from LSD1 deletion and PD1 inhibitor co-administration, evaluating their combined effects on tumour growth and TME remodelling. Elucidating the mechanism underlying the combined therapy of LSD1 deletion with PD1 inhibition for HCC. Exploring the implications of LSD1, CD74 and effector CD8+ T cell expression levels in advanced HCC patients undergoing anti-PD1 treatment.

Colorectal cancer (CRC) is the second most common malignant tumor in the world. With its increasing incidence and younger age trend, its impact on human health has been paid more and more attention. Currently, we have a variety of chemotherapy drugs that can be used to treat colorectal cancer. However, the drug resistance of colorectal cancer has become a significant factor affecting its cure rate. Some studies have reported that exosomes are related to the occurrence of drug resistance. However, the exact mechanism is not precise. Therefore, we focused on the role of cancer associated-fibroblast-derived (CAFs-derived) exosomes in colorectal progression. It was found that cancer cells transmit information through exosome interaction and induce chemotherapy resistance by promoting epithelial-mesenchymal transition (EMT), up-regulating the Wnt/β-catenin signaling pathway, transforming growth factor-β1 (TGF-β1) pathway, promoting angiogenesis and other possible molecular mechanisms. In addition, in terms of clinical significance and therapeutic strategies, we explore the clinical relevance of CAFs-derived exosomes in colorectal cancer patients and their potential as potential biomarkers for predicting chemotherapy response. We also provide a new possible direction for overcoming chemotherapy resistance in colorectal cancer by targeting CAFs-derived exosomes.

Nutrient metabolisms are vitally interrelated to cancer progression and immunotherapy. However, the mechanisms by which nutrient metabolisms interact to remodel immune surveillance within the tumor microenvironment remain largely unexplored. Here it is demonstrated that methionine restriction inhibits the expression of proprotein convertase subtilisin/kexin type 9 (PCSK9), a key regulator of cholesterol homeostasis and a potential target for cancer immunotherapy, in colorectal cancer (CRC) but not in the liver. Mechanistically, methionine is catabolized to S-adenosylmethionine (SAM), promoting mRNA transcription of PCSK9 through increased DNA methyltransferase 1 (DNMT1)-mediated DNA methylation and suppression of sirtuin 6 (SIRT6) expression. Furthermore, both PCSK9 inhibition and dietary methionine restriction (DMR) potentiate PD-1 blockade therapy and foster the infiltration of CD8+ T cells in Colon 26 tumor-bearing mice-a proficient mismatch repair (pMMR)/microsatellite stable (MSS) CRC model that exhibits limited response to anti-PD-1 therapy. Moreover, combining 5-fluorouracil (5-FU) chemotherapy with PCSK9 inhibition and PD-1 blockade further augments therapeutic efficacy for MSS CRC. The findings establish a mechanistic link between amino acid metabolism and cholesterol metabolism within the tumor microenvironment where tumor cells sense methionine to regulate PCSK9 expression, highlighting promising combination therapeutic strategies that may greatly benefit MSS CRC patients.

Existing organoid models fall short of fully capturing the complexity of cancer because they lack sufficient multicellular diversity, tissue-level organization, biological durability and experimental flexibility. Thus, many multifactorial cancer processes, especially those involving the tumor microenvironment, are difficult to study ex vivo. To overcome these limitations, we herein implemented tissue-engineering and microfabrication technologies to develop topobiologically complex, patient-specific cancer avatars. Focusing on colorectal cancer, we generated miniature tissues consisting of long-lived gut-shaped human colon epithelia ('mini-colons') that stably integrate cancer cells and their native tumor microenvironment in a format optimized for real-time, high-resolution evaluation of cellular dynamics. We demonstrate the potential of this system through several applications: a comprehensive evaluation of drug effectivity, toxicity and resistance in anticancer therapies; the discovery of a mechanism triggered by cancer-associated fibroblasts that drives cancer invasion; and the identification of immunomodulatory interactions among different components of the tumor microenvironment. Similar approaches should be feasible for diverse tumor types.

Immune checkpoint blockade (ICB) therapy has shown promise in treating advanced colorectal cancer, particularly in patients with microsatellite instability-high (MSI-H) tumors. However, only a subset of these patients responds favorably, highlighting the need for strategies to improve immunotherapy efficacy.

To identify potential regulators of immunotherapy response, we conducted a comprehensive analysis of colorectal cancer datasets from The Cancer Genome Atlas (TCGA). We performed multi-omics analyses and functional assays in both human and murine colorectal cancer cell lines. Additionally, we evaluated tumor growth and immune cell infiltration using syngeneic mouse models.

Our analysis revealed that RNA binding motif protein 15 (RBM15) is highly expressed in colorectal cancer and correlates with poor patient prognosis. Functional studies demonstrated that RBM15 loss led to increased expression of fumarate hydratase (FH). This led to decreased levels of fumarate, a metabolite known to suppress anti-tumor immune responses. In vivo, RBM15 depletion significantly delayed tumor progression and enhanced CD8⁺ T cell infiltration and activation in the tumor microenvironment.

These findings identify RBM15 as a negative regulator of anti-tumor immunity in colorectal cancer. Targeting RBM15 may represent a novel strategy to boost immune responsiveness and improve outcomes for patients undergoing immunotherapy.

Despite advances in cancer immunotherapy, colorectal cancer patients exhibit limited therapeutic responses. Therefore, the exploration of strategies combining immunotherapy with adjuvant approaches to enhance adaptive immune responses is in demand. Here, we perform a customized in vivo CRISPR-Cas9 screen to target genes encoding membrane and secreted proteins in CRC mouse models with different immune characteristics. We observe that loss of membrane-bound transcription factor site-1 protease (MBTPS1) in tumor cells enhances antitumor immunity and potentiates anti-PD-1 therapy. Mechanistic studies reveal that tumor cell-intrinsic MBTPS1 competes with USP13 for binding to STAT1, thereby disrupting the USP13-dependent deubiquitination-mediated STAT1 stabilization. The upregulated STAT1-transcribed chemokines including CXCL9, CXCL10, and CXCL11, promote CXCR3+CD8+ T cell infiltration. Notably, the regulatory role of MBTPS1 in antitumor immunity operates independently of its classic function in cleaving membrane-bound transcription factors. Collectively, our results provide a theoretical basis for MBTPS1 as a potential immunotherapy target.

Tumor metabolism often interferes with the immune microenvironment. Although natural killer (NK) cells play pivotal roles in antitumor immunity, the connection between NK cells and tumor metabolism remains unclear. Our systematic analysis of multiomics data and survival data from colorectal cancer (CRC) patients uncovered a novel association between mitochondrial acetyl-CoA acetyltransferase 1 (ACAT1) and NK cell infiltration that influences disease progression. ACAT1, a metabolic enzyme involved in reversible conversion of acetoacetyl-CoA to two molecules of acetyl-CoA, exhibits nuclear protein acetylation activity through its translocation. Under immune stimulation, mitochondrial ACAT1 can be phosphorylated at serine 60 (S60) and enters the nucleus; however, this process is hindered in nutrient-poor tumor microenvironments. Nuclear ACAT1 directly acetylates lysine 146 of p50 (NFKB1), attenuating its DNA binding and transcriptional repression activity and thereby increasing the expression of immune-related factors, which in turn promotes NK cell recruitment and activation to suppress colorectal cancer growth. Furthermore, significant associations are found among low nuclear ACAT1 levels, decreased S60 phosphorylation, and reduced NK cell infiltration, as well as poor prognosis in CRC. Our findings reveal an unexpected function of ACAT1 as a nuclear acetyltransferase and elucidate its role in NK cell-dependent antitumor immunity through p50 acetylation.