Mouse Model Of Colorectal Cancer Research Articles

Percutaneous Delivery of Oncogel for Targeted Liver Tumor Ablation and Controlled Release of Therapeutics.

Advanced-stage liver cancers are associated with poor prognosis and have limited treatment options, often leading the patient to hospice care. Percutaneous intratumoral injection of anticancer agents has emerged as a potential alternative to systemic therapy to overcome tumor barriers, increase bioavailability, potentiate immunotherapy, and avoid systemic toxicity, which advanced-stage cancer patients cannot tolerate. Here, an injectable OncoGel (OG) comprising of a nanocomposite hydrogel loaded with an ionic liquid (IL) is developed for achieving a predictable and uniform tumor ablation and long-term slow release of anticancer agents into the ablation zone. Rigorous mechanical, physiochemical, drug release, cytotoxicity experiments, and ex vivo human tissue testing identify an injectable version of the OG with bactericidal properties against highly resistant bacteria. Intratumoral injection of OG loaded with Nivolumab (Nivo) and doxorubicin (Dox) into highly malignant tumor models in mice, rats, and rabbits demonstrates enhanced survival and tumor regression associated with robust tissue ablation and drug distribution throughout the tumor. Mass cytometry and proteomic studies in a mouse model of colorectal cancer that often metastasizes to the liver indicate an enhanced anticancer immune response following the intratumoral injection of OG. OG may augment immunotherapy and potentially improve outcomes in liver cancer patients.

Synergisitic anti-colorectal cancer effects of WNT974 combined with artesunate via cooperative regulation of p21, p27, and AKT

ObjectiveTo evaluate the synergistic effects and underlying mechanisms of WNT974 and artesunate (ART) combination therapy in the treatment of colorectal cancer (CRC). MethodsWe conducted an initial assessment of the synergistic impact of WNT974 and ART on cell viability using the MTT assay across eight CRC cell lines with diverse mutation statuses.Subsequently, a 3D in vitro model was utilized to confirm the synergistic effect of the combination. Flow cytometry was employed to analyze cell cycle distribution. The molecular mechanisms were further investigated by examining the expression levels of cell cycle-related proteins (p21, p27, and CDK2) and AKT activity through PCR and Western blot analyses. The in vivo efficacy of the combination therapy was evaluated using a xenograft mouse model of CRC. ResultsThe combination of WNT974 and ART significantly reduced cell viability in all eight CRC cell lines, demonstrating a synergistic effect. Additionally, the combination exhibited synergy in inhibiting 3D spheroid growth. Cell cycle analysis revealed that the combination therapy induced a marked G1/G0 arrest through CDK2 inhibition, surpassing the efficacy of individual treatments. Molecular analysis indicated that the combination therapy upregulated p21 and p27 expression and reduced AKT activity. In vivo, the combination therapy significantly inhibited tumor growth in the xenograft mouse model, notably outperforming 5FU, the standard first-line drug for CRC. ConclusionThe study highlights the synergistic anti-CRC effects of combining WNT974 and ART. This combination induces G1/G0 phase cell cycle arrest by cooperatively regulating p21, p27, and AKT, presenting a promising alternative to current CRC treatments. These findings elucidate the molecular basis of this interaction and provide a scientific foundation for advancing ART combined with WNT94 as a novel therapy for CRC, offering a potential new avenue.

Tumor microenvironment-responsive macrophage-mediated immunotherapeutic drug delivery

Immunotherapy, as a promising treatment strategy for cancer, has been widely employed in clinics, while its efficiency is limited by the immunosuppression of tumor microenvironment (TME). Tumor-associate macrophages (TAMs) are the most abundant immune cells infiltrating the TME and play a crucial role in immune regulation. Herein, a M0-type macrophage-mediated drug delivery system (PR-M) was designed for carrying Toll-like receptors (TLRs) agonist-loaded nanoparticles. When TLR agonist R848 was released by responding to the TME, the PR-Ms were polarized from M0-type to M1-type and TAMs were also stimulated from M2-type to M1-type, which eventually reversed the immunosuppressive states of TME. By synergizing with the released R848 agonists, the PR-M significantly activated CD4+ and CD8+ T cells in the TME and turned the ‘cold’ tumor into ‘hot’ tumor by regulating the secretion of cytokines including IFN-γ, TNF-α, IL-10, and IL-12, thus ultimately promoting the activation of antitumor immunity. In a colorectal cancer mouse model, the PR-M treatment effectively accumulated at the tumor site, with a 5.47-fold increase in M1-type and a 65.08 % decrease in M2-type, resulting in an 85.25 % inhibition of tumor growth and a 87.55 % reduction of tumor volume compared with the non-treatment group. Our work suggests that immune cell-mediated drug delivery systems can effectively increase drug accumulation at the tumor site and reduce toxic side effects, resulting in a strong immune system for tumor immunotherapy. Statement of significanceThe formation of TME and the activation of TAMs create an immunosuppressive network that allows tumor to escape the immune system and promotes its growth and spread. In this study, we designed an M0-type macrophage-mediated drug delivery system (PR-M). It leverages the synergistic effect of macrophages and agonists to improve the tumor immunosuppressive micro-environment by increasing M1-type macrophages and decreasing M2-type macrophages. As part of the treatment, the drug-loaded macrophages endowed the system with excellent tumor targeting. Furthermore, loading R848 into TME-responsive nanoparticles could protect macrophages and reduce the potential toxicity of agonists. Further investigations demonstrated that the designed PR-M could be a feasible strategy with high efficacy in tumor targeting, drug loading, autoimmunity activation, and lower side effects.

Investigating the anticancer properties of six benzothiazolopyrimidine derivatives on colon carcinoma cells, in vitro and in vivo.

Colorectal cancer (CRC) is the third most common cancer in the world. Despite considerable improvements in the treatment of this cancer, further research to discover novel and more effective agents is ongoing. In this study, possible cytotoxic and apoptotic properties of six benzothiazolopyrimidine derivatives were studied. To assess the IC50 values of these agents, MTT assay was performed on HCT 116, CT26, and NIH/3T3 cells. Moreover, cell death mechanism induced by studied compounds was evaluated by PI/annexin V staining. Then, based on molecular docking results and in vitro experiments, the compounds with the highest anticancer properties were further analyzed in vivo in a mouse model of CRC. MTT results indicated that BTP(1) and BTP(4) had the highest selective cytotoxicity on colorectal cancer cells. Furthermore, flow cytometry results demonstrated a considerable increase in the percentage of the early apoptotic cells in BTP(1)- and BTP(4)-treated groups. In vivo studies confirmed the antitumor properties of the two compounds by a significant regression in tumor size of BTP(1)- and BTP(4)-treated mice compared to control groups. Histopathological examination of tumor tissues showed an increased number of apoptotic cells in these two groups compared to the control animals. Additionally, hematoxylin and eosin staining of the spleen and liver of treated mice did not exhibit considerable tissue damage. Thus, BTP(1) and BTP(4) can be considered promising agents in the treatment of colorectal cancer, although further experiments are required to assess their mechanism of action before their application in clinical studies.

The effect of the probiotic bacteria <i>Akkermansia Muciniphila</i> in intestinal homeostasis and dss-induced inflammation in mice

Akkermansia muciniphila is a Gram-negative anaerobic bacterium, a component of the normal human intestinal microbiota. A decrease in the presence of this bacterium is associated with pathologies, including metabolic disorders, intestinal inflammation and colorectal cancer. A. muciniphila is a probiotic approved for patients with diabetes and obesity. In recent years, A. muciniphila was studied in the control of intestinal inflammation and colorectal cancer. The exact mechanisms of A. muciniphila action remain unclear, while the use of different administration protocols shows different effects in mouse models of colitis and colorectal cancer. We reported that A. muciniphila has distinct effects on intestinal mucin production depending on viable or pasteurized form of bacteria. Another factor affecting the outcome of the A. muciniphila administration is the number of bacteria. To address how the dose of bacteria may affect the severity of acute intestinal inflammation wild-type mice were subjected to daily oral injections with 10⁸ CFU or 109 CFU of viable A. muciniphila for two weeks; the control group was injected with PBS. After that, groups were subjected to the induction of acute colitis by adding 7% DSS to drinking water for five days. 8 days after the onset of colitis induction, a morphometric assessment of the colitis severity was performed. Mice given a high dose of A. muciniphila (109 CFU) were found to be protected from developing severe colitis. RT-PCR analysis of colon samples from mice receiving a high dose of bacteria showed an increase in the gene expression of antimicrobial peptides, IL-17A, IL-17F. Interestingly, the protective effect of A. muciniphila was observed only in a high dose group, but not in a low dose group. Our data suggest that A. muciniphila provides the protective effect in colitis and highlight the importance of selecting the dose of the bacterium for proper interpretation.

AFDN Deficiency Promotes Liver Tropism of Metastatic Colorectal Cancer.

Liver metastasis is a major cause of morbidity and mortality in patients with colorectal cancer. A better understanding of the biological mechanisms underlying liver tropism and metastasis in colorectal cancer could help to identify improved prevention and treatment strategies. In this study, we performed genome-wide CRISPR loss-of-function screening in a mouse colorectal cancer model and identified deficiency of AFDN, a protein involved in establishing and maintaining cell-cell contacts, as a driver of liver metastasis. Elevated AFDN expression was correlated with prolonged survival in patients with colorectal cancer. AFDN-deficient colorectal cancer cells preferentially metastasized to the liver but not in the lungs. AFDN loss in colorectal cancer cells at the primary site promoted cancer cell migration and invasion by disrupting tight intercellular junctions. Additionally, CXCR4 expression was increased in AFDN-deficient colorectal cancer cells via the JAK-STAT signaling pathway, which reduced the motility of AFDN-deficient colorectal cancer cells and facilitated their colonization of the liver. Collectively, these data shed light on the mechanism by which AFDN deficiency promotes liver tropism in metastatic colorectal cancer. Significance: A CRISPR screen reveals AFDN loss as a mediator of liver tropism in colorectal cancer metastasis by decreasing tight junctions in the primary tumor and increasing interactions between cancer cells and hepatocytes.

In vivo interaction screening reveals liver-derived constraints to metastasis

It is estimated that only 0.02% of disseminated tumour cells are able to seed overt metastases1. While this suggests the presence of environmental constraints to metastatic seeding, the landscape of host factors controlling this process remains largely unclear. Here, combining transposon technology2 and fluorescence niche labelling3, we developed an in vivo CRISPR activation screen to systematically investigate the interactions between hepatocytes and metastatic cells. We identify plexin B2 as a critical host-derived regulator of liver colonization in colorectal and pancreatic cancer and melanoma syngeneic mouse models. We dissect a mechanism through which plexin B2 interacts with class IV semaphorins on tumour cells, leading to KLF4 upregulation and thereby promoting the acquisition of epithelial traits. Our results highlight the essential role of signals from the liver parenchyma for the seeding of disseminated tumour cells before the establishment of a growth-promoting niche. Our findings further suggest that epithelialization is required for the adaptation of CRC metastases to their new tissue environment. Blocking the plexin-B2–semaphorin axis abolishes metastatic colonization of the liver and therefore represents a therapeutic strategy for the prevention of hepatic metastases. Finally, our screening approach, which evaluates host-derived extrinsic signals rather than tumour-intrinsic factors for their ability to promote metastatic seeding, is broadly applicable and lays a framework for the screening of environmental constraints to metastasis in other organs and cancer types.

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.

Therapeutic potential of Pien Tze Huang in colitis-associated colorectal cancer: mechanistic insights from a mouse model

BackgroundPien Tze Huang (PZH), a traditional Chinese medicine formulation, is recognized for its therapeutic effect on colitis and colorectal cancer. However, its protective role and underlying mechanism in colitis-associated colorectal cancer (CAC) remain to be elucidated.MethodsA CAC mouse model was established using AOM/DSS. Twenty mice were randomly divided into four groups (n = 5/group): Control, PZH, AOM/DSS, and AOM/DSS + PZH groups. Mice in the PZH and AOM/DSS + PZH group were orally administered PZH (250 mg/kg/d) from the first day of experiment, while the control and AOM/DSS group received an equivalent volume of distilled water. Parameters such as body weight, disease activity index (DAI), colon weight, colon length, colon histomorphology, intestinal tumor formation, serum concentrations of pro-inflammatory cytokines, proliferation and apoptosis in colon tissue were assessed. RNA sequencing was employed to identify the differentially expressed transcripts (DETs) in colonic tissues and related signaling pathways. Wnt/β-Catenin Pathway-Related genes in colon tissue were detected by QPCR and immunohistochemistry (IHC).ResultsPZH significantly attenuated AOM/DSS-induced weight loss, DAI elevation, colonic weight gain, colon shortening, histological damage, and intestinal tumor formation in mice. PZH also notably decreased serum concentration of IL-6, IL-1β, and TNF-α. Furthermore, PZH inhibited cell proliferation and promote apoptosis in tumor tissues. RNA-seq and KEGG analysis revealed key pathways influenced by PZH, including Wnt/β-catenin signaling pathway. IHC staining confirmed that PZH suppressed the expression of β-catenin, cyclin D1 and c-Myc in colonic tissues.ConclusionsPZH ameliorates AOM/DSS-induced CAC in mice by suppressing the activation of Wnt/β-catenin signaling pathway.

Prognostic value and potential regulatory relationship of miR-200c-5p in colorectal cancer.

This study aimed to investigate the relationship and potential mechanisms of miR-200c-5p in colorectal cancer (CRC) progression. Differentially expressed miRNAs were screened using the TCGA database. Subsequently, univariate analysis was performed to identify CRC survival-related miRNAs. Survival and receiver operator characteristic curves were generated. The target genes of miR-200c-5p and the relevant signaling pathways or biological processes were predicted by the miRNet database and enrichment analyses. The miR-200c-5p expression was detected usingquantitative reverse-transcription polymerase chain reaction,Cell Counting Kit-8, Transwell, and cell apoptosis experiments were performed to determine miR-200c-5p's impact on CRC cell viability, invasiveness, and apoptosis. Finally, we constructed a CRC mouse model with inhibited miR-200c-5p to evaluate its impact on tumors. miR-200c-5p was upregulated in CRC, implying a favorable prognosis. Gene set enrichment analysis revealed that miR-200c-5p may participate in signaling pathways such as the TGF-β signaling pathway, RIG-I-like receptor signaling pathway, renin-angiotensin system, and DNA replication. miR-200c-5p potentially targeted mRNAs, including KCNE4 and CYP1B1, exhibiting a negative correlation with their expression. Furthermore, these mRNAs may participate in biological processes like the regulation of intracellular transport, cAMP-dependent protein kinase regulatory activity, ubiquitin protein ligase binding, MHC class II protein complex binding, and regulation of apoptotic signaling pathway. Lastly, miR-200c-5p overexpression repressed the viability and invasiveness of CRC cells but promoted apoptosis. The tumor size, weight, and volume were significantly increased by inhibiting miR-200c-5p (p < 0.05). miR-200c-5p is upregulated in CRC, serving as a promising biomarker for predicting CRC prognosis.

Plasma-Derived Extracellular Vesicles and Non-Extracellular Vesicle Components from APCMin/+ Mice Promote Pro-Tumorigenic Activities and Activate Human Colonic Fibroblasts via the NF-κB Signaling Pathway.

Colorectal cancer (CRC) is the third most prevalent cancer worldwide. Current studies have demonstrated that tumor-derived extracellular vesicles (EVs) from different cancer cell types modulate the fibroblast microenvironment to contribute to cancer development and progression. Here, we isolated and characterized circulating large EVs (LEVs), small EVs (SEVs) and non-EV entities released in the plasma from wild-type (WT) mice and the APCMin/+ CRC mice model. Our results showed that human colon fibroblasts exposed from APC-EVs, but not from WT-EVs, exhibited the phenotypes of cancer-associated fibroblasts (CAFs) through EV-mediated NF-κB pathway activation. Cytokine array analysis on secreted proteins revealed elevated levels of inflammatory cytokine implicated in cancer growth and metastasis. Finally, non-activated cells co-cultured with supernatant from fibroblasts treated with APC-EVs showed increased mRNA expressions of CAFs markers, the ECM, inflammatory cytokines, as well as the expression of genes controlled by NF-κB. Altogether, our work suggests that EVs and non-EV components from APCMin/+ mice are endowed with pro-tumorigenic activities and promoted inflammation and a CAF-like state by triggering NF-κB signaling in fibroblasts to support CRC growth and progression. These findings provide insight into the interaction between plasma-derived EVs and human cells and can be used to design new CRC diagnosis and prognosis tools.

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.

Tuning Tumor Targeting and Ratiometric Photoacoustic Imaging by Fine-Tuning Torsion Angle for Colorectal Liver Metastasis Diagnosis.

Photoacoustic (PA) tomography is an emerging biomedical imaging technology for precision cancer medicine. Conventional small-molecule PA probes usually exhibit a single PA signal and poor tumor targeting that lack the imaging reliability. Here, we introduce a series of cyanine/hemicyanine interconversion dyes (denoted Cy-HCy) for PA/fluorescent dual-mode probe development that features optimized ratiometric PA imaging and tunable tumor-targeting ability for precise diagnosis and resection of colorectal cancer (CRC). Importantly, Cy-HCy can be presented in cyanine (inherent tumor targeting and long NIR PA wavelength) and hemicyanine (poor tumor targeting and short NIR PA wavelength) by fine-tuning torsion angle and the ingenious transformation between cyanine and hemicyanine through regulation optically tunable group endows the NIR ratiometric PA and tunable tumor-targeting properties. To demonstrate the applicability of Cy-HCy dyes, we designed the first small-molecule tumor-targeting and NIR ratiometric PA probe Cy-HCy-H2S for precise CRC liver metastasis diagnosis, activated by H2S (a CRC biomarker). Using this probe, we not only visualized the subcutaneous tumor and liver metastatic cancers in CRC mouse models but also realized PA and fluorescence image-guided tumor excision. We expect that Cy-HCy will be generalized for creating a wide variety of inherently tumor-targeting NIR ratiometric PA probes in oncological research and practice.

Shape Engineering of Exosomes for Endoplasmic Reticulum-Targeted Delivery and Amplified Anticancer Efficacy

Exosomes are nanoscale extracellular vesicles that have become pivotal in advancing targeted drug delivery strategies for cancer therapy. In this study, we conducted a comparative analysis of the intracellular targeting capabilities of differently shaped exosomes, including milk exosome nanorods (MR), ginger exosome nanorods (GR), and cancer cell exosome nanorods (HR), compared to their spherical counterparts. Our observations revealed that exosome nanorods demonstrated effective and sustained targeting of the endoplasmic reticulum (ER) within cancer cells, while exosome nanospheres were captured within lysosomes. Building on this principle, we chose milk-derived exosomes (mExo) for the in vivo research, engineering the surface of MR with folate to enhance their tumor-targeting efficacy. We demonstrated the effective accumulation of these folate-modified MR (FMR) around the ER in cancer cells, as validated in both orthotopic colorectal cancer (CRC) tissues and human CRC biopsy samples. Furthermore, when loaded with curcumin (Cur), the FMR@Cur exhibited remarkable efficacy in suppressing tumors in orthotopic CRC mouse models. This effect is attributed to the targeted delivery of FMR@Cur to the ER, leading to enhanced ER-stress induced apoptosis. Overall, our study underscores the pivotal role of shape engineering in exosome-mediated drug delivery, offering novel insights and paving the way for innovative strategies to enhance the precision of intracellular drug targeting in cancer therapy.

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.

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.

In vivo staging of colitis, adenoma and carcinoma in CRC progression by combination of H4R/DRD4-targeted fluorescent probes

Colorectal cancer (CRC) is the third most prevalent malignancy and the second leading cause of cancer-related mortality worldwide. Currently, CRC staging heavily relies on invasive surgical procedures for in vitro pathological analysis, which entails long detection cycles and increases the risk of metastasis. There is an urgent need for specific biomarkers to classify adenomas and cancers, while early in vivo staging detection could potentially reduce mortality and morbidity rates. This study focused on Type IV histamine receptor (H4R), which is highly expressed only in the inflammatory stage, and Dopamine receptor D4 (DRD4), which is highly expressed in colorectal adenoma and carcinoma stages. Fluorescent targeted molecular probes H4R-Cy5 and DRD4-M were constructed respectively. The in vitro cell level proves that H4R-Cy5 only has high specificity for RAW264.7 cells, and DRD4-M only has good affinity for HT29 cells. In inflammation-HT29 subcutaneous tumors, H4R-Cy5 and DRD4-M can target inflammation and tumor lesions respectively. In addition, this study is the first to combine the two probes to explore the feasibility of in vivo non-invasive staging on CRC mouse models. The results show that H4R-Cy5 can distinguish and identify the stages of inflammation in vivo, and the DRD4-M probe can accurately identify the stages of colorectal adenoma and carcinoma in vivo. The combination of these two probes can achieve precise non-invasive staging of colitis, adenoma and carcinoma, which is a major advance in the development of accurate diagnostic methods for colorectal precancerous lesions and has important implications for the selection of treatment strategies.