Colorectal Cancer Model Research Articles

Transforming Albumin into a Trojan Horse of Immunotherapy-Resistant Colorectal Cancer with a High Microsatellite Instability.

The therapeutic response of microsatellite instability-high (MSI-H) colorectal cancer (CRC) to immune checkpoint inhibitors (ICI) is indeed surprising; however, the emergence of acquired resistance poses an even greater threat to the survival of these patients. Herein, bioinformatics analysis of MSI-H CRC samples revealed that Wnt signaling pathway represents a promising target for acquired immune reactivation, while subsequent analysis and biochemical testing substantiated the inclination of Wnt-hyperactive CRC cells to engage in macropinocytosis with human serum albumin (HSA). These findings have inspired us to develop an engineered HSA that not only possesses the ability to specifically target cancer cells but also effectively suppresses the Wnt/β-catenin cascade within these malignant cells. In pursuit of this objective, a comprehensive screening of reported Wnt small-molecule inhibitors was conducted to evaluate their affinity with HSA, and it was discovered that Carnosic acid (CA) exhibited the highest affinity while simultaneously revealing multiple binding sites. Further investigation revealed that CA HSA the capability to engineer HSA into spherical and size-tunable nanostructures known as eHSA (Engineering HSA particle), which demonstrated optimized macropinocytosis-dependent cellular internalization. As anticipated, eHSA effectively suppressed the Wnt signaling pathway and reactivated the acquired immune response in vivo. Furthermore, eHSA successfully restored sensitivity to Anti-PD1's anticancer effects in both subcutaneous and orthotopic mouse homograft models of MSI-H CRC, as well as a humanized hu-PBMC patient-derived orthotopic xenograft (PDOX) mouse model of MSI-H CRC, all while maintaining a favorable safety profile. The collective implementation of this clinically viable immune reactivation strategy not only enables the delivery of Wnt inhibitors for CRC therapy, but also serves as an exemplary demonstration of precision-medicine-guided nanopharmaceutical development that effectively harnesses specific cellular indications in pathological states.

Huangqin tang alleviates colitis-associated colorectal cancer via amino acids homeostasisand PI3K/AKT/mtor pathway modulation

Ethnopharmacological relevanceHuangqin Tang (HQT), a traditional Chinese medicine formula, is commonly used in clinical practice for the treatment of inflammatory bowel diseases. It has been reported that HQT exerts antitumor effects on colitis-associated colorectal cancer (CAC). However, the mechanism by which HQT interferes with the inflammation-to-cancer transformation remains unclear. Aims of the studyThe purpose of this study was to dynamically evaluate the efficacy of HQT in alleviating or delaying CAC and to reveal the underlying mechanism. MethodsWe established a mouse model of CAC using azoxymethane combined with 1.5% dextran sodium sulphate. The efficacy of HQT was evaluated based on pathological sections and serum biochemical indices. Subsequently, amino acids (AAs) metabolism analyses were performed using ultra-performance liquid chromatography-tandem mass spectrometry, and the phosphatidylinositol 3 kinase/protein kinase B/mechanistic target of rapamycin (PI3K/AKT/mTOR) pathway was detected by western blotting. ResultsThe data demonstrated that HQT could alleviate the development of CAC in the animal model. HQT effectively reduced the inflammatory response, particularly interleukin-6 (IL-6), in the inflammation induction stage, as well as in the stages of proliferation initiation and tumorigenesis. During the proliferation initiation and tumorigenesis stages, immunohistochemistry staining showed that the expression of the proliferation marker Ki67 was reduced, while apoptosis was increased in the HQT group. Accordingly, HQT substantially decreased the levels of specific AAs in the colon with CAC, including glutamic acid, glutamine, arginine, and isoleucine. Furthermore, HQT significantly inhibited the activated PI3K/AKT/mTOR pathway, which may contribute to suppression of cell proliferation and enhancement of apoptosis. ConclusionHQT is effective in alleviating and delaying the colon “inflammation-to-cancer”. The mechanism of action may involve HQT maintained AAs metabolism homeostasis and regulated PI3K/AKT/mTOR pathway, so as to maintain the balance between proliferation and apoptosis, and then interfere in the occurrence and development of CAC.

A laponite-based immunologically active gel delivery system for long-acting tumor vaccine

Traditional bolus vaccines typically require multiple doses, which complicates the vaccination process and may cause missed shots, leading to sub-optimal immunity and reduced vaccine effectiveness. Herein, a gel-based long-acting vaccine system with self-adjuvant properties based on laponite was constructed to simplify vaccination procedures and improve vaccine effectiveness. Firstly, the gel system could recruit multiple types of immune cells to form immune niches. Secondly, it could achieve sustained delivery of antigens to lymph nodes by active transport and passive drainage. Then, the gel system triggered the formation of a large number of germinal centers, which elicited enhanced and durable humoral immune responses, as well as strong cellular immune responses. As a result, it eventually showed good prophylactic and therapeutic effects in a variety of tumor models including melanoma, colorectal cancer and peritoneal metastasis models. By further combining the immunoadjuvant CpG ODN and cytokine IL-12, the effect of the gel-vaccine could be further enhanced. In a murine peritoneal metastasis model of colorectal carcinoma, a single administration of the gel-vaccine resulted in complete tumor eradication in 8/9 mice. In summary, this study developed an immunologically active gel-vaccine system. And as a robust and versatile vaccine platform, by loading different antigens and adjuvants, this gel-vaccine system is expected to realize its better therapeutic potential.

Inhibition of DUSP18 impairs cholesterol biosynthesis and promotes anti-tumor immunity in colorectal cancer

Tumor cells reprogram their metabolism to produce specialized metabolites that both fuel their own growth and license tumor immune evasion. However, the relationships between these functions remain poorly understood. Here, we report CRISPR screens in a mouse model of colo-rectal cancer (CRC) that implicates the dual specificity phosphatase 18 (DUSP18) in the establishment of tumor-directed immune evasion. Dusp18 inhibition reduces CRC growth rates, which correlate with high levels of CD8+ T cell activation. Mechanistically, DUSP18 dephosphorylates and stabilizes the USF1 bHLH-ZIP transcription factor. In turn, USF1 induces the SREBF2 gene, which allows cells to accumulate the cholesterol biosynthesis intermediate lanosterol and release it into the tumor microenvironment (TME). There, lanosterol uptake by CD8+ T cells suppresses the mevalonate pathway and reduces KRAS protein prenylation and function, which in turn inhibits their activation and establishes a molecular basis for tumor cell immune escape. Finally, the combination of an anti-PD-1 antibody and Lumacaftor, an FDA-approved small molecule inhibitor of DUSP18, inhibits CRC growth in mice and synergistically enhances anti-tumor immunity. Collectively, our findings support the idea that a combination of immune checkpoint and metabolic blockade represents a rationally-designed, mechanistically-based and potential therapy for CRC.

TRIM59 deficiency promotes M1 macrophage activation and inhibits colorectal cancer through the STAT1 signaling pathway

Tumor-associated macrophages play a crucial role in the tumor microenvironment. Tripartite motif 59 (TRIM59), a member of the tripartite motif (TRIM) family, is known to be associated with immunological diseases and macrophage activation. The functional and molecular mechanisms by which TRIM59 affects the occurrence and development of colorectal cancer (CRC) through macrophages are still not well understood. To address this, we generated macrophage-specific TRIM59 conditional knockout mice and utilized these mice to establish colitis-associated cancer and MC38 transplanted CRC models for further investigation. We found that the deficiency of TRIM59 in macrophages inhibited colorectal tumorigenesis in mice. This tumor-suppressive effect was achieved by promoting the activation of M1 macrophages via STAT1 signaling pathway. Further mechanistic studies revealed that TRIM59 could regulate macrophage polarization by ubiquitinating and degrading STAT1. These findings provide evidence that TRIM59 deficiency promotes M1 macrophage activation and inhibits CRC through the STAT1 signaling pathway, suggesting that the TRIM59/STAT1 signaling pathway may be a promising target for CRC.

Tong-Xie-Yao-Fang induces mitophagy in colonic epithelial cells to inhibit colitis-associated colorectal cancer

Ethnopharmacological relevanceBased on the core pathogenesis of hepatosplenic disorder and qi transformation disorder in ulcerative colitis, Tong-Xie-Yao-Fang (TXYF) is a classical traditional Chinese medicine commonly used to treat ulcerative colitis. Our study revealed that it has the potential to prevent colitis-associated colorectal cancer, which embodies the academic concept in traditional Chinese medicine of treating the disease before it develops. Aim of the studyThis study was aimed at evaluating the therapeutic role of TXYF in treating colitis-associated colorectal cancer and exploring its possible underlying mechanisms. Materials and methodsA colitis-associated colorectal cancer model was established in mice using azoxymethane and dextran sulfate sodium salt to examine the therapeutic effect of TXYF. The mouse body weights were observed. Hematoxylin-eosin staining was used to evaluate mouse colon histopathology. Colon cancer cells and colon epithelial cells were used to explore the potential molecular mechanisms. The proliferation and apoptosis of cells were detected by CCK8 and cell colony assays, flow cytometry and western blotting. The epithelial–mesenchymal transition (EMT) and mitophagy markers were examined by immunohistochemistry, western blotting, quantitative real-time PCR and immunofluorescence staining. ResultsTXYF inhibited the tumorigenesis of mice with colitis-associated colorectal cancer and the growth of inflammatory colon cells. TXYF induced mitophagy in colon cancer cells through the PTEN-induced putative kinase 1 (PINK1)/Parkin pathway to reverse EMT, which was consistent with the results in mice with colitis-associated colorectal cancer. ConclusionsThe results of the present study demonstrated that TXYF effectively inhibited the progression of colitis-associated colorectal cancer through the PINK1/Parkin pathway, which provides new evidence for prevention strategies for this disease.

Effects of Ursolic Acid on Colorectal Cancer: A Review of Recent Evidence

Colorectal cancer is the third leading cause of cancer-related deaths, and the five-year survival rate of the metastatic disease is less than 15%. Treatment approaches include surgery, systemic chemotherapy and radiotherapy. The aggressive nature and low five-year survival rate of metastatic colorectal cancer indicate a need for new treatment options to help combat this disease. Ursolic acid is a pentacyclic triterpenoid naturally occurring in many plants, with high concentrations found in cranberries. This review summarizes evidence from the last ten years of the effects of ursolic acid on colorectal cancer. Overall, the available studies indicate that the treatment of colon cancer cells with ursolic acid results in a significant inhibition of proliferation and induction of apoptosis. In addition, the limited in vivo studies indicate a significant reduction in tumor volume and tumor angiogenesis in animal models of colorectal cancer administered ursolic acid. More in vivo animal studies are required to better understand the potential anticancer properties of ursolic acid and to form the basis for human clinical trials.

Targeting Nuclear Receptor Coactivator SRC-1 Prevents Colorectal Cancer Immune Escape by Reducing Transcription and Protein Stability of PD-L1.

Programmed death-ligand 1 (PD-L1) is overexpressed in multiple cancers and critical for their immune escape. It has previously shown that the nuclear coactivator SRC-1 promoted colorectal cancer (CRC) progression by enhancing CRC cell viability, yet its role in CRC immune escape is unclear. Here, we demonstrate that SRC-1 is positively correlated with PD-L1 in human CRC specimens. SRC-1 deficiency significantly inhibits PD-L1 expression in CRC cells and retards murine CRC growth in subcutaneous grafts by enhancing CRC immune escape via increasing tumor infiltration of CD8+ T cells. Genetic ablation of SRC-1 in mice also decreases PD-L1 expression in AOM/DSS-induced murine CRC. These results suggest that tumor-derived SRC-1 promotes CRC immune escape by enhancing PD-L1 expression. Mechanistically, SRC-1 activated JAK-STAT signaling by inhibiting SOCS1 expression and coactivated STAT3 and IRF1 to enhance PD-L1 transcription as well as stabilized PD-L1 protein by inhibiting proteasome-dependent degradation mediated by speckle type POZ protein (SPOP). Pharmacological inhibition of SRC-1 improved the antitumor effect of PD-L1 antibody in both subcutaneous graft and AOM/DSS-induced murine CRC models. Taken together, these findings highlight a crucial role of SRC-1 in regulating PD-L1 expression and targeting SRC-1 in combination with PD-L1 antibody immunotherapy may be an attractive strategy for CRC treatment.

A novel drug prejudice scaffold-imidazopyridine-conjugate can promote cell death in a colorectal cancer model by binding to β-catenin and suppressing the Wnt signaling pathway

IntroductionGlobally, colorectal cancer (CRC) is the third most common type of cancer, and its treatment frequently includes the utilization of drugs based on antibodies and small molecules. The development of CRC has been linked to various signaling pathways, with the Wnt/β-catenin pathway identified as a key target for intervention. ObjectivesWe have explored the impact of imidazopyridine-tethered chalcone-C (CHL-C) in CRC models. MethodsTo determine the influence of CHL-C on apoptosis and autophagy, Western blot analysis, annexin V assay, cell cycle analysis, acridine orange staining, and immunocytochemistry were performed. Next, the activation of the Wnt/β-catenin signaling pathway and the anti-cancer effects of CHL-C in vivo were examined in an orthotopic HCT-116 mouse model. ResultsWe describe the synthesis and biological assessment of the CHL series as inhibitors of the viability of HCT-116, SW480, HT-29, HCT-15, and SNU-C2A CRC cell lines. Further biological evaluations showed that CHL-C induced apoptosis and autophagy in down-regulated β-catenin, Wnt3a, FZD-1, Axin-1, and p-GSK-3β (Ser9), and up-regulated p-GSK3β (Tyr216) and β-TrCP. In-depth analysis using structure-based bioinformatics showed that CHL-C strongly binds to β-catenin, with a binding affinity comparable to that of ICG-001, a well-known β-catenin inhibitor. Additionally, our in vivo research showed that CHL-C markedly inhibited tumor growth and triggered the activation of both apoptosis and autophagy in tumor tissues. ConclusionCHL-C is capable of inducing apoptosis and autophagy by influencing the Wnt/β-catenin signaling pathway.

Construction of a new prognostic model for colorectal cancer based on bulk RNA-seq combined with The Cancer Genome Atlas data.

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths, and improving the prognosis of CRC patients is an urgent concern. The aim of this study was to explore new immunotherapy targets to improve survival in CRC patients. We analyzed CRC-related single-cell data GSE201348 from the Gene Expression Omnibus (GEO) database, and identified differentially expressed genes (DEGs). Subsequently, we performed differential analysis on the rectum adenocarcinoma (READ) and colon adenocarcinoma (COAD) transcriptome sequencing data [The Cancer Genome Atlas (TCGA)-CRC queue] and clinical data downloaded from TCGA database. Subgroup analysis was performed using CIBERSORTx and cluster analysis. Finally, biomarkers were identified by one-way cox regression as well as least absolute shrinkage and selection operator (LASSO) analysis. In this study, we analyzed CRC-related single-cell data GSE201348, and identified 5,210 DEGs. Subsequently, we performed differential analysis on the TCGA-CRC queue database, and obtained 4,408 DEGs. Then, we categorized the cancer samples in the sequencing data into three groups (k1, k2, and k3), with significant differences observed between the k1 and k2 groups via survival analysis. Further differential analysis on the samples in the k1 and k2 groups identified 1,899 DEGs. A total of 77 DEGs were selected among those DEGs obtained from three differential analyses. Through subsequent Cox univariate analysis and LASSO analysis, seven biomarkers (RETNLB, CLCA4, UGT2A3, SULT1B1, CCL24, BMP5, and ATOH1) were identified and selected to establish a risk score (RS). To sum up, this study demonstrates the potential of the seven-gene prognostic risk model as instrumental variables for predicting the prognosis of CRC.

Pexidartinib and Immune Checkpoint Inhibitors Combine to Activate Tumor Immunity in a Murine Colorectal Cancer Model by Depleting M2 Macrophages Differentiated by Cancer-Associated Fibroblasts.

Tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs) are known to play supportive roles in tumor development and progression, but their interactions in colorectal cancer (CRC) remain unclear. Here, we investigated the effects of colon-cancer-derived CAFs on TAM differentiation, migration, and tumor immunity, both in vitro and in vivo. When co-cultured with monocytes, CAFs attracted monocytes and induced their differentiation into M2 macrophages. Immunohistology of surgically resected human CRC specimens and orthotopically transplanted mouse tumors revealed a correlation between numbers of CAFs and numbers of M2 macrophages. In a mouse model of CRC orthotopic transplantation, treatment with an inhibitor of the colony-stimulating factor-1 receptor (PLX3397) depleted M2 macrophages and increased CD8-positive T cells infiltrating the tumor nest. While this treatment had a minor effect on tumor growth, combining PLX3397 with anti-PD-1 antibody significantly reduced tumor growth. RNA-seq following combination therapy showed activation of tumor immunity. In summary, CAFs are involved in the induction and mobilization of M2 macrophage differentiation in the CRC tumor immune microenvironment, and the combination of cancer immunotherapy and PLX3397 may represent a novel therapeutic option for CRC.

A self-reported symptom-based decision-making model helps to rule out outpatient cases at low risk for CRC before colonoscopy

ObjectivesEffective exclusion of low-risk symptomatic outpatient cases for colorectal cancer (CRC) remains diagnostic challenges. We aimed to develop a self-reported symptom-based decision-making model for application in outpatient scenarios. MethodsIn total, 8233 symptomatic cases at risk for CRC, as judged by outpatient physicians, were involved in this study at seven medical centers. A decision-making model was constructed using 60 self-reported symptom parameters collected from the questionnaire. Further internal and external validation cohorts were built to evaluate the discriminatory power of the CRC model. The discriminatory power of the CRC model was assessed by the C-index and calibration plot. After that, the clinical utility and user experience of the CRC model were evaluated. ResultsNine symptom parameters were identified as valuable predictors used for modeling. Internal and external validation cohorts verified the adequate discriminatory power of the CRC model. In the clinical application step, all 17 physicians found the model easy to grasp, 99.9 % of the patients were satisfied with the survey form. Application of this model detected all CRC cases. The total consistency ratio of outpatient cases undergoing colonoscopy was 81.4 %. None of the low-risk patients defined by the CRC model had been diagnosed with CRC. ConclusionThis multicenter study developed and validated a simple and user-friendly decision-making model covering self-reported information. The CRC model has been demonstrated to perform well in terms of rapid outpatient decision-making scenarios and clinical utility, particularly because it can better rule out low-risk outpatient cases.

NAT1 inhibits liver metastasis of colorectal cancer by regulating EMT and glycolysis.

Metastasis is the primary cause of cancer-related deaths, and colorectal cancer (CRC) liver metastasis is a major poor prognostic factor in CRC. NAT1 (N-acetyltransferase 1) plays a crucial role in the invasive and metastatic processes of colorectal cancer. The role and molecular mechanism of NAT1 on tumor cells were verified by establishing a cell model of overexpression and knockdown of NAT1, and further verified by establishing a liver metastasis model of colorectal cancer for animal experiments. In vivo and in vitro experiments have demonstrated that overexpression of NAT1 reduces the ability of metastasis and invasion of colorectal cancer cells. NAT1 overexpression inhibits the PI3K/AKT/mTOR signaling pathway, thereby suppressing the EMT (epithelial-mesenchymal transition) process and glycolytic ability of tumor cells. Additionally, decreased glycolytic ability results in reduced VEGF (Vascular endothelial growth factor) expression in colorectal cancer cells. The decreased VEGF expression leads to decreased angiogenesis and vascular permeability in liver metastases, ultimately reducing the occurrence of liver metastasis. Our findings highlight that overexpression of NAT1 significantly inhibits the PI3K/AKT/mTOR signaling pathway, thereby suppressing EMT, glycolytic ability, and VEGF expression in colorectal cancer cells, collectively preventing the development of liver metastasis.

Gut microbiota-mediated activation of GSDMD ignites colorectal tumorigenesis

Activation of Gasdermin D (GSDMD) results in its cleavage, oligomerization, and subsequent formation of plasma membrane pores, leading to a form of inflammatory cell death denoted as pyroptosis. The roles of GSDMD in inflammation and immune responses to infection are well documented. However, whether GSDMD also plays a role in sporadic cancer development, especially that in the gut epithelium, remains unknown. Here, we show that GSDMD is activated in colorectal tumors of both human and mouse origins. Ablation of GSDMD in a mouse model of sporadic colorectal cancer resulted in reduced tumor formation in the colon and rectum, suggesting a tumor-promoting role of the protein in the gut. Both antibiotic-mediated depletion of gut microbiota and pharmacological inhibition of NLRP3 inflammasome reduced the activation of GSDMD. Loss of GSDMD resulted in reduced infiltration of immature myeloid cells, and increased numbers of macrophages in colorectal tumors. Activation of GSDMD is also accompanied by the aggregation of the endosomal sorting complex required for transport (ESCRT) membrane repair proteins on the membrane of colorectal tumor cells, suggesting that active membrane repairment may prevent pyroptosis induced by the formation of GSDMD pore in tumor cells. Our results show that gut microbiota/NLRP3-mediated activation of GSDMD promotes the development of colorectal tumors, and supports the use of NLRP3 inhibitors to treat colon cancer.

APR-246 as a radiosensitization strategy for mutant p53 cancers treated with alpha-particles-based radiotherapy

Radiation therapy (RT) remains a common treatment for cancer patients worldwide, despite the development of targeted biological compounds and immunotherapeutic drugs. The challenge in RT lies in delivering a lethal dose to the cancerous site while sparing the surrounding healthy tissues. Low linear energy transfer (low-LET) and high linear energy transfer (high-LET) radiations have distinct effects on cells. High-LET radiation, such as alpha particles, induces clustered DNA double-strand breaks (DSBs), potentially inducing cell death more effectively. However, due to limited range, alpha-particle therapies have been restricted. In human cancer, mutations in TP53 (encoding for the p53 tumor suppressor) are the most common genetic alteration. It was previously reported that cells carrying wild-type (WT) p53 exhibit accelerated senescence and significant rates of apoptosis in response to RT, whereas cells harboring mutant p53 (mutp53) do not. This study investigated the combination of the alpha-emitting atoms RT based on internal Radium-224 (224Ra) sources and systemic APR-246 (a p53 reactivating compound) to treat tumors with mutant p53. Cellular models of colorectal cancer (CRC) or pancreatic ductal adenocarcinoma (PDAC) harboring mutant p53, were exposed to alpha particles, and tumor xenografts with mutant p53 were treated using 224Ra source and APR-246. Effects on cell survival and tumor growth, were assessed. The spread of alpha emitters in tumors was also evaluated as well as the spatial distribution of apoptosis within the treated tumors. We show that mutant p53 cancer cells exhibit radio-sensitivity to alpha particles in vitro and to alpha-particles-based RT in vivo. APR-246 treatment enhanced sensitivity to alpha radiation, leading to reduced tumor growth and increased rates of tumor eradication. Combining alpha-particles-based RT with p53 restoration via APR-246 triggered cell death, resulting in improved therapeutic outcomes. Further preclinical and clinical studies are needed to provide a promising approach for improving treatment outcomes in patients with mutant p53 tumors.

Preclinical efficacy of a HER2 synNotch/CEA-CAR combinatorial immunotherapy against colorectal cancer with HER2 amplification

HER2 amplification occurs in about 5% of colorectal cancer (CRC) cases and is associated only partially with clinical response to combined HER2/EGFR targeted treatment. An alternative approach based on adoptive cell therapy (ACT) using T-cells engineered with anti-HER2 chimeric antigen receptor (CAR) proved to be toxic due to "on-target off-tumor" activity. Here we describe a combinatorial strategy to safely target HER2 amplification and CEA expression in CRC using a synNotch-CAR based artificial regulatory network. The natural killer cell line NK-92 was engineered with an anti-HER2 synNotch receptor driving the expression of a CAR against CEA only when engaged. After being transduced and sorted for HER2-driven CAR expression, cells were cloned. The clone with optimal performances in terms of specificity and amplitude of CAR induction demonstrated significant activity in vitro and in vivo specifically against HER2amp/CEA+ CRC models, with no effects on cells with physiological HER2 levels. The HER2-synNotch/CEA-CAR-NK system provides an innovative, scalable and safe off-the shelf cell therapy approach with potential against HER2amp CRC resistant or partially responsive to HER2/EGFR blockade.

Bidirectional effects of the tryptophan metabolite indole-3-acetaldehyde on colorectal cancer.

Colorectal cancer (CRC) has a high incidence and mortality. Recent studies have shown that indole derivatives involved in gut microbiota metabolism can impact the tumorigenesis, progression, and metastasis of CRC. To investigate the effect of indole-3-acetaldehyde (IAAD) on CRC. The effect of IAAD was evaluated in a syngeneic mouse model of CRC and CRC cell lines (HCT116 and DLD-1). Cell proliferation was assessed by Ki-67 fluorescence staining and cytotoxicity tests. Cell apoptosis was analysed by flow cytometry after staining with Annexin V-fluorescein isothiocyanate and propidium iodide. Invasiveness was investigated using the transwell assay. Western blotting and real-time fluorescence quantitative polymerase chain reaction were performed to evaluate the expression of epithelial-mesenchymal transition related genes and aryl hydrocarbon receptor (AhR) downstream genes. The PharmMapper, SEA, and SWISS databases were used to screen for potential target proteins of IAAD, and the core proteins were identified through the String database. IAAD reduced tumorigenesis in a syngeneic mouse model. In CRC cell lines HCT116 and DLD1, IAAD exhibited cytotoxicity starting at 24 h of treatment, while it reduced Ki67 expression in the nucleus. The results of flow cytometry showed that IAAD induced apoptosis in HCT116 cells but had no effect on DLD1 cells, which may be related to the activation of AhR. IAAD can also increase the invasiveness and epithelial-mesenchymal transition of HCT116 and DLD1 cells. At low concentrations (< 12.5 μmol/L), IAAD only exhibited cytotoxic effects without promoting cell invasion. In addition, predictions based on online databases, protein-protein interaction analysis, and molecular docking showed that IAAD can bind to matrix metalloproteinase-9 (MMP9), angiotensin converting enzyme (ACE), poly(ADP-ribose) polymerase-1 (PARP1), matrix metalloproteinase-2 (MMP2), and myeloperoxidase (MPO). Indole-3-aldehyde can induce cell apoptosis and inhibit cell proliferation to prevent the occurrence of CRC; however, at high concentrations (≥ 25 μmol/L), it can also promote epithelial-mesenchymal transition and invasion in CRC cells. IAAD activates AhR and directly binds MMP9, ACE, PARP1, MMP2, and MPO, which partly reveals why it has a bidirectional effect.

IMT030122, A novel engineered EpCAM/CD3/4-1BB tri-specific antibody, enhances T-cell recruitment and demonstrates anti-tumor activity in mouse models of colorectal cancer

Colorectal cancer is a major global health burden, with limited efficacy of traditional treatment modalities in improving survival rates. However, recently advances in immunotherapy has improved treatment outcomes for patients with this cancer. To address the continuing need for improved treatment efficacy, this study introduced a novel tri-specific antibody, IMT030122, that targets EpCAM, 4-1BB, and CD3. We evaluated the pharmacological efficacy and mechanism of action of IMT030122 in vitro and in vivo. In in vitro studies, IMT030122 exhibited differential binding to antigens and cells expressing EpCAM, 4-1BB, and CD3. Moreover, IMT030122 relied on EpCAM-targeted activation of intracellular CD3 and 4-1BB signaling and mediated T cell cytotoxicity specific to HCT116 colorectal cancer cells. In vivo, IMT030122 demonstrated potent anti-tumor activity, significantly inhibiting the growth of colon cancer HCT116 and MC38-hEpCAM subcutaneous grafts. Further pharmacological analysis revealed that IMT030122 recruited lymphocytes from peripheral blood into colorectal cancer tissue and exerted durable anti-tumor activity, predominantly by promoting the activation, proliferation, and differentiation of CD8T cells. Notably, IMT030122 still exhibited anti-tumor efficacy even in the presence of significantly depleted lymphocytes in colorectal cancer tissue. The potent pharmacological activity and anti-tumor effects of IMT030122 suggest it may enhance treatment efficacy and substantially extend the survival of patients with colorectal cancer in the future.

Phase and Defect Engineering of MoSe2 Nanosheets for Enhanced NIR-II Photothermal Immunotherapy.

Inducing immunogenic cell death (ICD) during photothermal therapy (PTT) has the potential to effectively trigger photothermal immunotherapy (PTI). However, ICD induced by PTT alone is often limited by inefficient PTT, low immunogenicity of tumor cells, and a dysregulated redox microenvironment. Herein, we develop MoSe2 nanosheets with high-percentage metallic 1T phase and rich exposed active Mo centers through phase and defect engineering of MoSe2 as an effective nanoagent for PTI. The metallic 1T phase in MoSe2 nanosheets endows them with strong PTT performance, and the abundant exposed active Mo centers endow them with high activity for glutathione (GSH) depletion. The MoSe2-mediated high-performance PTT synergizing with efficient GSH depletion facilitates the release of tumor-associated antigens to induce robust ICD, thus significantly enhancing checkpoint blockade immunotherapy and activating systemic immune response in mouse models of colorectal cancer and triple-negative metastatic breast cancer.

Inhibition of O-GlcNAc transferase activates type I interferon-dependent antitumor immunity by bridging cGAS-STING pathway.

The O-GlcNAc transferase (OGT) is an essential enzyme that mediates protein O-GlcNAcylation, a unique form of posttranslational modification of many nuclear and cytosolic proteins. Recent studies observed increased OGT and O-GlcNAcylation levels in a broad range of human cancer tissues compared to adjacent normal tissues, indicating a universal effect of OGT in promoting tumorigenesis. Here, we show that OGT is essential for tumor growth in immunocompetent hosts by repressing the cyclic GMP-AMP synthase (cGAS)-dependent DNA sensing pathway. We found that deletion of OGT (Ogt -/- ) caused a marked reduction in tumor growth in both syngeneic tumor models and a genetic colorectal cancer (CRC) model induced by mutation of the Apc gene (Apc min ). Pharmacological inhibition or genetic deletion of OGT induced a robust genomic instability (GIN), leading to cGAS-dependent production of the type I interferon (IFN-I) and IFN-stimulated genes (ISGs). As a result, deletion of Cgas or Sting from Ogt -/- cancer cells restored tumor growth, and this correlated with impaired CD8+ T cell-mediated antitumor immunity. Mechanistically, we found that OGT-dependent cleavage of host cell factor C1 (HCF-1) is required for the avoidance of GIN and IFN-I production in tumors. In summary, our results identify OGT-mediated genomic stability and activate cGAS-STING pathway as an important tumor cell-intrinsic mechanism to repress antitumor immunity.