Hypofractionated radiotherapy combined with lenalidomide improves systemic antitumor activity in mouse solid tumor models.

Background: Hypofractionated radiotherapy (hRT) can induce a T cell-mediated abscopal effect on non-irradiated tumor lesions, especially in combination with immune checkpoint blockade (ICB). However, clinically, this effect is still rare, and ICB-mediated adverse events are common. Lenalidomide (lena) is an anti-angiogenic and immunomodulatory drug used in the treatment of hematologic malignancies. We here investigated in solid tumor models whether lena can enhance the abscopal effect in double combination with hRT. Methods: In two syngeneic bilateral tumor models (B16-CD133 melanoma and MC38 colon carcinoma), the primary tumor was treated with hRT. Lena was given daily for 3 weeks. Besides tumor size and survival, the dependence of the antitumor effects on CD8+ cells, type-I IFN signaling, and T cell costimulation was determined with depleting or blocking antibodies. Tumor-specific CD8+ T cells were quantified, and their differentiation and effector status were characterized by multicolor flow cytometry using MHC-I tetramers and various antibodies. In addition, dendritic cell (DC)-mediated tumor antigen cross-presentation in vitro and directly ex vivo and the composition of tumor-associated vascular endothelial cells were investigated. Results: In both tumor models, the hRT/lena double combination induced a significant abscopal effect. Control of the non-irradiated secondary tumor and survival were considerably better than with the respective monotherapies. The abscopal effect was strongly dependent on CD8+ cells and associated with an increase in tumor-specific CD8+ T cells in the non-irradiated tumor and its draining lymph nodes. Additionally, we found more tumor-specific T cells with a stem-like (TCF1+ TIM3- PD1+) and a transitory (TCF1- TIM3+ CD101- PD1+) exhausted phenotype and more expressing effector molecules such as GzmB, IFNγ, and TNFα. Moreover, in the non-irradiated tumor, hRT/lena treatment also increased DCs cross-presenting a tumor model antigen. Blocking type-I IFN signaling, which is essential for cross-presentation, completely abrogated the abscopal effect. A gene expression analysis of bone marrow-derived DCs revealed that lena augmented the expression of IFN response genes and genes associated with differentiation, maturation (including CD70, CD83, and CD86), migration to lymph nodes, and T cell activation. Flow cytometry confirmed an increase in CD70+ CD83+ CD86+ DCs in both irradiated and abscopal tumors. Moreover, the hRT/lena-induced abscopal effect was diminished when these costimulatory molecules were blocked simultaneously using antibodies. In line with the enhanced infiltration by DCs and tumor-specific CD8+ T cells, including more stem-like cells, hRT/lena also increased tumor-associated high endothelial cells (TA-HECs) in the non-irradiated tumor. Conclusions: We demonstrate that lena can augment the hRT-induced abscopal effect in mouse solid tumor models in a CD8 T cell- and IFN-I-dependent manner, correlating with enhanced anti-tumor CD8 T cell immunity, DC cross-presentation, and TA-HEC numbers. Our findings may be helpful for the planning of clinical trials in (oligo)metastatic patients.

Programming peptide-oligonucleotide nano-assembly for engineering of neoantigen vaccine with potent immunogenicity.

Background: Neoantigen nanovaccine has been recognized as a promising treatment modality for personalized cancer immunotherapy. However, most current nanovaccines are carrier-dependent and the manufacturing process is complicated, resulting in potential safety concerns and suboptimal codelivery of neoantigens and adjuvants to antigen-presenting cells (APCs). Methods: Here we report a facile and general methodology for nanoassembly of peptide and oligonucleotide by programming neoantigen peptide with a short cationic module at N-terminus to prepare nanovaccine. The programmed peptide can co-assemble with CpG oligonucleotide (TLR9 agonist) into monodispersed nanostructures without the introduction of artificial carrier. Results: We demonstrate that the engineered nanovaccine promoted the codelivery of neoantigen peptides and adjuvants to lymph node-residing APCs and instigated potent neoantigen-specific T-cell responses, eliciting neoantigen-specific antitumor immune responses with negligible systemic toxicity. Furthermore, the antitumor T-cell immunity is profoundly potentiated when combined with anti-PD-1 therapy, leading to significant inhibition or even complete regression of established melanoma and MC-38 colon tumors. Conclusions: Collectively, this work demonstrates the feasibility and effectiveness of personalized cancer nanovaccine preparation with high immunogenicity and good biosafety by programming neoantigen peptide for nanoassembly with oligonucleotides without the aid of artificial carrier.

Anti-Anisakis antibodies in colon cancer patients and their relationship with γδ T-cells.

Many pathogens are related to carcinogenesis. Chronic inflammation, as a result of persistent infection, leads to DNA damage, higher expression of oncogenes, decreased apoptosis and immunosuppression, which are some of the reasons for cancer induction. Among parasites, Schistosoma, Opistorchis and Clonorchis are recognised as infectious agents which contribute to cancer. A relationship between Anisakis and cancer was hypothesised because cellular responses to Anisakis products could result in inflammation and DNA damage. Previous research has shown a decrease in CD8+ γδ T-cells and an increase in αß and γδ T-cell apoptosis in colon cancer (CC) samples. Ninety-two CC patients and 60 healthy subjects were recruited. γδ and αß T-cells were analysed, and their apoptosis was evaluated. Anti-Anisakis antibodies were tested in sera from CC patients and controls. Anti-Anisakis IgG, IgM, IgA and IgE antibodies were significantly higher in CC patients. A significant increase in anti-Anisakis IgA levels was observed in patients with angiolymphatic invasion. The number of all γδ T-cells, as well as CD3+ CD4+ αß T-cells, was significantly lower in CC patients. The apoptosis of all T-cells was significantly increased in patients with CC. We observed a significantly higher percentage of anti-Anisakis IgE positive patients having a deficit of CD3+ γδ T-cells. Our results suggest a relationship between Anisakis and CC.

Ruthenium-dihydroartemisinin complex: a promising new compound for colon cancer prevention via G1 cell cycle arrest, apoptotic induction, and adaptive immune regulation.

BACKGROUND: Artemisinin (ART) and its derivatives are important antimalaria agents and have received increased attention due to their broad biomedical effects, such as anticancer and anti-inflammation activities. Recently, ruthenium-derived complexes have attracted considerable attention as their anticancer potentials were observed in preclinical and clinical studies. METHODS: To explore an innovative approach in colorectal cancer (CRC) management, we synthesized ruthenium-dihydroartemisinin complex (D-Ru), a novel metal-based artemisinin derivative molecule, and investigated its anticancer, anti-inflammation, and adaptive immune regulatory properties. RESULTS: Compared with its parent compound, ART, D-Ru showed stronger antiproliferative effects on the human CRC cell lines HCT-116 and HT-29. The cancer cell inhibition of D-Ru comprised G1 cell cycle arrest via the downregulation of cyclin A and the induction of apoptosis. ART and D-Ru downregulated the expressions of pro-inflammatory cytokines IL-1ß, IL-6, and IL-8. Although ART and D-Ru did not suppress Treg cell differentiation, they significantly inhibited Th1 and Th17 cell differentiation. CONCLUSIONS: Our results demonstrated that D-Ru, a novel ruthenium complexation of ART, remarkably enhanced its parent compound's anticancer action, while the anti-inflammatory potential was not compromised. The molecular mechanisms of action of D-Ru include inhibition of cancer cell growth via cell cycle arrest, induction of apoptosis, and anti-inflammation via regulation of adaptive immunity.

m6A and m5C modification of GPX4 facilitates anticancer immunity via STING activation.

Cancer immunotherapy is arguably the most rapidly advancing realm of cancer treatment. Glutathione peroxidase 4 (GPX4) has emerged as the vital enzyme to prevent lipid peroxidation and maintain cellular redox homeostasis. However, the mechanism of GPX4 in the regulation of cancer immunotherapy of colon adenocarcinoma (COAD) are incompletely understood. In pan-cancer analysis, we found that GPX4 showed remarkably upregulated expression and exhibited significant association with overall survival in multiple cancer types, especially COAD. Furthermore, upregulated GPX4 expression was positively correlated with increased immune cells infiltration and enhanced expression of immunomodulators. Mechanistically, RBM15B- and IGFBP2-mediated N6-methyladenosine (m6A) modification and NSUN5-mediated 5-methylcytosine (m5C) modification of GPX4 facilitated anticancer immunity via activation of cyclic GMP-AMP synthase (cGAS)-stimulator of interferon (STING) signaling by maintaining redox homeostasis in COAD. The risk model and nomogram model constructed based on the GPX4-derived genes further confirmed the prognostic and treatment-guiding value of GPX4. In all, our study demonstrated that m6A and m5C modification of GPX4 may be a promising target for cancer immunotherapy via activating the cGAS-STING signaling pathway in COAD.

Comprehensive Analysis of CLCA1 Expression, Immune Infiltration and Immune Checkpoints in Colon Adenocarcinoma / Análisis Completo de la Expresión de CLCA1, Infiltración Inmune y Puntos de Control Inmunológico en Colonadenocarcinoma

SUMMARY: Colon adenocarcinoma (COAD) is a prevalent disease worldwide, known for its high mortality and morbidity rates. Despite this, the extent of investigation concerning the correlation between COAD's CLCA1 expression and immune cell infiltration remains insufficient. This study seeks to examine the expression and prognosis of CLCA1 in COAD, along with its relationship to the tumor immune microenvironment. These findings will offer valuable insights for clinical practitioners and contribute to the existing knowledge in the field. In order to evaluate the prognostic significance of CLCA1 in individuals diagnosed with colorectal cancers, we conducted a comprehensive analysis using univariate and multivariate Cox regression models along with receiver operating characteristic curve (ROC) analysis. This study was performed on the patient data of COAD obtained from The Cancer Genome Atlas (TCGA) database. Nomograms were developed to anticipate CLCA1 prognostic influence. Furthermore, the CLCA1 association with tumor immune infiltration, immune checkpoints, immune checkpoint blockade (ICB) response, interaction network, and functional analysis of CLCA1-related genes was analyzed. We found that Colon adenocarcinoma tissues significantly had decreased CLCA1 expression compared to healthy tissues. Furthermore, the study revealed that the group with high expression of CLCA1 demonstrated a significantly higher overall survival rate (OS) as compared to the group with low expression. Multivariate and Univariate Cox regression analysis revealed the potential of CLCA1 as a standalone risk factor for COAD. These results were confirmed using nomograms and ROC curves. In addition, protein-protein interaction (PPI) network analysis and functional gene enrichment showed that CLCA1 may be associated with functional activities such as pancreatic secretion, estrogen signaling and cAMP signaling, as well as with specific immune cell infiltration. Therefor, as a new independent predictor and potential biomarker of COAD, CLCA1 plays a crucial role in the advancement of colon cancer.

El adenocarcinoma de colon (COAD) es una enfermedad prevalente a nivel mundial, conocida por sus altas tasas de mortalidad y morbilidad. Sin embargo, el alcance de la investigación sobre la correlación entre la expresión de CLCA1 de COAD y la infiltración de células inmunes sigue siendo insuficiente. Este estudio busca examinar la expresión y el pronóstico de CLCA1 en COAD, junto con su relación con el microambiente inmunológico del tumor. Estos hallazgos ofrecerán conocimientos valiosos para los profesionales clínicos y contribuirán al conocimiento existente en el campo. Para evaluar la importancia de pronóstico de CLCA1 en personas diagnosticadas con cáncer colorrectal, realizamos un análisis exhaustivo utilizando modelos de regresión de Cox univariados y multivariados junto con un análisis de la curva característica operativa del receptor (ROC). Este estudio se realizó con los datos de pacientes de COAD obtenidos de la base de datos The Cancer Genome Atlas (TCGA). Se desarrollaron nomogramas para anticipar la influencia pronóstica de CLCA1. Además, se analizó la asociación de CLCA1 con la infiltración inmunitaria tumoral, los puntos de control inmunitarios, la respuesta de bloqueo de los puntos de control inmunitarios (ICB), la red de interacción y el análisis funcional de genes relacionados con CLCA1. Descubrimos que los tejidos de adenocarcinoma de colon tenían una expresión significativamente menor de CLCA1 en comparación con los tejidos sanos. Además, el estudio reveló que el grupo con alta expresión de CLCA1 demostró una tasa de supervivencia general (SG) significativamente mayor en comparación con el grupo con baja expresión. El análisis de regresión de Cox multivariado y univariado reveló el potencial de CLCA1 como factor de riesgo independiente de COAD. Estos resultados se confirmaron mediante nomogramas y curvas ROC. Además, el análisis de la red de interacción proteína- proteína (PPI) y el enriquecimiento de genes funcionales mostraron que CLCA1 puede estar asociado con actividades funcionales como la secreción pancreática, la señalización de estrógenos y la señalización de AMPc, así como con la infiltración de células inmunes específicas. Por lo tanto, como nuevo predictor independiente y biomarcador potencial de COAD, CLCA1 desempeña un papel crucial en el avance del cáncer de colon.

Prognostic Biomarker SLCO4A1 Is Correlated with Tumor Immune Infiltration in Colon Adenocarcinoma.

Background: Solute carrier organic anion transporter family member 4A1 (SLCO4A1), a member of solute carrier organic anion family, is a key gene regulating bile metabolism, organic anion transport, and ABC transport. However, the association of SLCO4A1 with prognosis and tumor immune infiltration in colon adenocarcinoma (COAD) remains indistinct. Methods: Firstly, we explored the expression level of SLCO4A1 in COAD via GEPIA, Oncomine, and UALCAN databases. Secondly, we used the Kaplan-Meier plotter and PrognoScan databases to investigate the effect of SLCO4A1 on prognosis in COAD patients. In addition, the correlation between SLCO4A1 and tumor immune infiltration was studied by using TIMER and TISIDB databases. Results: Our results showed that SLCO4A1 was overexpressed in COAD tissues. At the same time, our study showed that high expression of SLCO4A1 was associated with poor overall survival, disease-free survival, and disease-specific survival in COAD patients. The expression level of SLCO4A1 was negatively linked to the infiltrating levels of B cells, CD8+ T cells, and dendritic cells in COAD. Moreover, the expression of SLCO4A1 was significantly correlated with numerous immune markers in COAD. Conclusions: These results indicated that SLCO4A1 could be associated with the prognosis of COAD patients and the levels of tumor immune infiltration. Our study suggested that SLCO4A1 could be a valuable biomarker for evaluating prognosis and tumor immune infiltration in COAD patients.

γδ T cells are effectors of immunotherapy in cancers with HLA class I defects.

DNA mismatch repair-deficient (MMR-d) cancers present an abundance of neoantigens that is thought to explain their exceptional responsiveness to immune checkpoint blockade (ICB)1,2. Here, in contrast to other cancer types3-5, we observed that 20 out of 21 (95%) MMR-d cancers with genomic inactivation of ß2-microglobulin (encoded by B2M) retained responsiveness to ICB, suggesting the involvement of immune effector cells other than CD8+ T cells in this context. We next identified a strong association between B2M inactivation and increased infiltration by γδ T cells in MMR-d cancers. These γδ T cells mainly comprised the Vδ1 and Vδ3 subsets, and expressed high levels of PD-1, other activation markers, including cytotoxic molecules, and a broad repertoire of killer-cell immunoglobulin-like receptors. In vitro, PD-1+ γδ T cells that were isolated from MMR-d colon cancers exhibited enhanced reactivity to human leukocyte antigen (HLA)-class-I-negative MMR-d colon cancer cell lines and B2M-knockout patient-derived tumour organoids compared with antigen-presentation-proficient cells. By comparing paired tumour samples from patients with MMR-d colon cancer that were obtained before and after dual PD-1 and CTLA-4 blockade, we found that immune checkpoint blockade substantially increased the frequency of γδ T cells in B2M-deficient cancers. Taken together, these data indicate that γδ T cells contribute to the response to immune checkpoint blockade in patients with HLA-class-I-negative MMR-d colon cancers, and underline the potential of γδ T cells in cancer immunotherapy.

Pan-cancer analysis identifies the immunological and prognostic role of PAK4.

AIMS: P21-activated kinase 4 (PAK4) belongs to the wider family of Serine/Threonine p21-activated kinases (PAKs) and functions as a hub for signaling pathways in cancer progression. Numerous studies have indicated the significance of PAK4 for tumorigenesis, but no systematic pan-cancer analysis has been performed. MAIN METHODS: The current study aimed to investigate the prognostic and immunological functions of PAK4 through bioinformatic analysis of datasets from The Cancer Genome Atlas, UALCAN, GEPIA2, cBioPortal, TIMER2, and Human Protein Atlas. PAK4 expression was correlated with prognosis, DNA methylation, tumor mutational burden, microsatellite instability, and immune cell infiltration. KEY FINDINGS: PAK4 was highly expressed in various cancers but showed decreased expression in colon adenocarcinoma, kidney renal clear cell carcinoma, kidney renal papillary cell carcinoma, and thyroid carcinoma. PAK4 was found to have a positive or negative correlation with prognosis of different cancers. PAK4 expression was related to tumor mutational burden in 11 tumor types, and associated with microsatellite instability in 10 tumor types and was correlated with immune infiltration and immune checkpoint genes. SIGNIFICANCE: PAK4 could be considered as a prognostic and immunotherapeutic marker for some types of malignant tumor.

PSEN1 is associated with colon cancer development via potential influences on PD-L1 nuclear translocation and tumor-immune interactions.

Presenilin 1 (PSEN1), as a catalytical core of the γ-secretase complex, plays multiple actions through mediating transmembrane domain shedding of the substrates. Unlike extensive studies performed on investigating the functions of γ-secretase substrates or the effects of γ-secretase inhibitors, our findings uncover a potential action of PSEN1 on PD-L1 alternative truncation and nuclear translocation, broadening our understanding on how the γ-secretase contributes to colon cancer development as well as suggesting a potential strategy to improve the efficacy of PD-1/PD-L1 blockade. Immunohistochemical data showed loss of PD-L1 protein expression in all the primary colon adenocarcioma (COAD) cases in the HPA collection, while PSEN1 was scored to be highly expressed, indicating their converse expression patterns (p<0.001). Meanwhile a strongly positive gene correlation was explored by TIMER2 and GEPIA (p<0.001). Up-regulated PSEN1 expression in COAD might facilitate liberating a C-terminal PD-L1 truncation via proteolytic processing. Then following an established regulatory pathway of PD-L1 nuclear translocation, we found that PSEN1 showed significant correlations with multiple components in HDAC2-mediated deacetylation, clathrin-dependent endocytosis, vimentin-associated nucleocytoplasmic shuttling and importin family-mediated nuclear import. Moreover, connections of PSEN1 to the immune response genes transactivated by nuclear PD-L1 were tested. Additionally, contributions of PSEN1 to the tumor invasiveness (p<0.05) and the tumor infiltrating cell enrichments (p<0.001) were investigated by cBioportal and the ESTIMATE algorithm. Levels of PSEN1 were negatively correlated with infiltrating CD8+ T (p<0.05) and CD4+ T helper (Th) 1 cells (p<0.001), while positively correlated with regulatory T cells (Tregs) (p<0.001) and cancer associated fibroblasts (CAFs) (p<0.001). It also displayed significant associations with diverse immune metagenes characteristic of T cell exhaustion, Tregs and CAFs, indicating possible actions in immune escape. Despite still a preliminary stage of this study, we anticipate to deciphering a novel function of PSEN1, and supporting more researchers toward the elucidations of the mechanisms linking the γ-secretase to cancers, which has yet to be fully addressed.

Inhibition of stearoyl-CoA desaturase 1 (SCD1) enhances the antitumor T cell response through regulating ß-catenin signaling in cancer cells and ER stress in T cells and synergizes with anti-PD-1 antibody.

BACKGROUND: Understanding the mechanisms of non-T cell inflamed tumor microenvironment (TME) and their modulation are important to improve cancer immunotherapies such as immune checkpoint inhibitors. The involvement of various immunometabolisms has recently been indicated in the formation of immunosuppressive TME. In this study, we investigated the immunological roles of stearoyl-CoA desaturase 1 (SCD1), which is essential for fatty acid metabolism, in the cancer immune response. METHODS: We investigated the roles of SCD1 by inhibition with the chemical inhibitor or genetic manipulation in antitumor T cell responses and the therapeutic effect of anti-programmed cell death protein 1 (anti-PD-1) antibody using various mouse tumor models, and their cellular and molecular mechanisms. The roles of SCD1 in human cancers were also investigated by gene expression analyses of colon cancer tissues and by evaluating the related free fatty acids in sera obtained from patients with non-small cell lung cancer who were treated with anti-PD-1 antibody. RESULTS: Systemic administration of a SCD1 inhibitor in mouse tumor models enhanced production of CCL4 by cancer cells through reduction of Wnt/ß-catenin signaling and by CD8+ effector T cells through reduction of endoplasmic reticulum stress. It in turn promoted recruitment of dendritic cells (DCs) into the tumors and enhanced the subsequent induction and tumor accumulation of antitumor CD8+ T cells. SCD1 inhibitor was also found to directly stimulate DCs and CD8+ T cells. Administration of SCD1 inhibitor or SCD1 knockout in mice synergized with an anti-PD-1 antibody for its antitumor effects in mouse tumor models. High SCD1 expression was observed in one of the non-T cell-inflamed subtypes in human colon cancer, and serum SCD1 related fatty acids were correlated with response rates and prognosis of patients with non-small lung cancer following anti-PD-1 antibody treatment. CONCLUSIONS: SCD1 expressed in cancer cells and immune cells causes immunoresistant conditions, and its inhibition augments antitumor T cells and therapeutic effects of anti-PD-1 antibody. Therefore, SCD1 is an attractive target for the development of new diagnostic and therapeutic strategies to improve current cancer immunotherapies including immune checkpoint inhibitors.

MUC1-mediated Macrophage Activation Promotes Colitis-associated Colorectal Cancer via Activating the Interleukin-6/ Signal Transducer and Activator of Transcription 3 Axis.

BACKGROUND & AIMS: MUC1 is abnormally expressed in colorectal cancer, including colitis-associated colorectal cancer (CAC), but its role in tumorigenesis is unclear. This study investigated MUC1's effects in murine models of colitis and CAC and elucidated mechanisms of action. METHODS: Colitis and CAC were induced in mice by exposure to dextran sodium sulfate or azoxymethane plus dextran sodium sulphate. Clinical parameters, immune cell infiltration, and tumor development were monitored throughout disease progression. Experiments in knockout mice and bone marrow chimeras were combined with an exploration of immune cell abundance and function. RESULTS: Deficiency of Muc1 suppressed inflammation, inhibited tumor progression, increased abundance of CD8+ T lymphocytes, and reduced abundance of macrophages in colon tumors. Bone marrow chimeras showed promotion of CAC was primarily mediated by Muc1-expressing hematopoietic cells, and that MUC1 promoted a pro-tumoral immunosuppressive macrophage phenotype within tumors. Mechanistic studies revealed that Muc1 deficiency remarkably reduced interleukin-6 levels in the colonic tissues and tumors that was mainly produced by infiltrating macrophages at day 21, 42, and 85. In bone marrow-derived macrophages, MUC1 promoted responsiveness to chemoattractant and promoted activation into a phenotype with high Il6 and Ido1 expression, secreting factors which inhibited CD8+ T cell proliferation. MUC1 potently drives macrophages to produce interleukin-6, which in turn drives a pro-tumorigenic activation of signal transducer and activator of transcription 3 in colon epithelial tumor and stromal cells, ultimately increasing the occurrence and development of CAC. CONCLUSIONS: Our findings provide cellular and molecular mechanisms for the pro-tumorigenic functions of MUC1 in the inflamed colon. Therapeutic strategies to inhibit MUC1 signal transduction warrant consideration for the prevention or therapy of CAC.

CTHRC1 is a prognosis-related biomarker correlated with immune infiltrates in colon adenocarcinoma.

BACKGROUND: Colon adenocarcinoma (COAD) is one of the common cancers worldwide. Collagen triple helix repeat containing 1 (CTHRC1) has been reported to be involved in cell invasion, angiogenesis, and the promotion of epithelial-mesenchymal transformation by mediating multiple signaling pathways. However, the role of CTHRC1 in COAD has not yet been determined. METHODS: Differentially expressed genes were evaluated using gene expression data from the Oncomine and TIMER databases. Correlations between CTHRC1 gene expression and clinicopathological factors were analyzed using gene expression data from UALCAN databases. Then, we searched the GEPIA database to evaluate the association of CTHRC1 gene expression with clinical outcomes. The cBioPortal database was used to analyze CTHRC1 genetic alterations. Subsequently, the TIMER website was chosen to assess the correlation of CTHRC1 with the tumor immune cell infiltration level. The TCGA dataset was used for a gene set enrichment analysis (GSEA). RESULT: CTHRC1 was highly expressed in COAD patients, and significantly related to poor prognosis. In addition, elevated expression of CTHRC1 was related to the clinical stage and pathological type of COAD. The GSEA analysis showed that CTHRC1 was enriched in Gα signaling, GCPR ligand binding, neutrophil degranulation, interleukin signaling, and tumor-associated pathways. In addition, CTHRC1 was significantly associated with the expression of multiple immune markers related to specific immune cells. CONCLUSION: This study suggest that CTHRC1 expression is related to the prognosis and immune infiltration of COAD patients. Therefore, CTHRC1 may be a new candidate prognostic biomarker for determining immune infiltration levels and providing COAD prognoses.

Circadian Clock Genes Are Correlated with Prognosis and Immune Cell Infiltration in Colon Adenocarcinoma.

BACKGROUND: Colon adenocarcinoma (COAD) is a malignancy with a high incidence and is associated with poor quality of life. Dysfunction of circadian clock genes and disruption of normal rhythms are associated with the occurrence and progression of many cancer types. However, studies that systematically describe the prognostic value and immune-related functions of circadian clock genes in COAD are lacking. METHODS: Genomic data obtained from The Cancer Genome Atlas (TCGA) database was analyzed for expression level, mutation status, potential biological functions, and prognostic performance of core circadian clock genes in COAD. Their correlations with immune infiltration and TMB/MSI score were analyzed by Spearman's correlation analysis. Pearson's correlation analysis was performed to analyze their associations with drug sensitivity. Lasso Cox regression analysis was performed to construct a prognosis signature. Moreover, an mRNA-miRNA-lncRNA regulatory axis was also detected by ceRNA network. RESULTS: In COAD tissues, the mRNA levels of CLOCK, CRY1, and NR1D1 were increased, while the mRNA levels of ARNTL, CRY2, PER1, PER3, and RORA were decreased. We also summarized the relative genetic mutation variation landscape. GO and KEGG pathway analyses demonstrated that these circadian clock genes were primarily correlated with the regulation of circadian rhythms and glucocorticoid receptor signaling pathways. COAD patients with high CRY2, NR1D1, and PER2 expression had worse prognosis. A prognostic model constructed based on the 9 core circadian clock genes predicted the COAD patients' overall survival with medium to high accuracy. A significant association between prognostic circadian clock genes and immune cell infiltration was found. Moreover, the lncRNA KCNQ1OT1/hsa-miRNA-32-5p/PER2/CRY2 regulatory axis in COAD was also detected through a mRNA-miRNA-lncRNA network. CONCLUSION: Our results identified CRY2, NR1D1, and PER2 as potential prognostic biomarkers for COAD patients and correlated their expression with immune cell infiltration. The lncRNA KCNQ1OT1/hsa-miRNA-32-5p/PER2/CRY2 regulatory axis was detected in COAD and might play a vital role in the occurrence and progression of COAD.

Mapping Proteome Changes in Microsatellite Stable, Recurrent Colon Cancer Reveals a Significant Immune System Signature.

BACKGROUND/AIM: Better stratification of the risk of relapse will help select the right patients for adjuvant treatment and improve targeted therapies for patients with colon cancer. MATERIALS AND METHODS: To understand why a subset of tumors relapse, we compared the proteome of two groups of patients with colon cancer with similar stage, stratified based on the presence or absence of recurrence. RESULTS: Using tumor biopsies from the primary operation, we identified dissimilarity between recurrent and nonrecurrent mismatch satellite stable colon cancer and found that signaling related to immune activation and inflammation was associated with relapse. CONCLUSION: Immune modulation may have an effect on mismatch satellite stable colon cancer. At present, immune therapy is offered primarily to microsatellite instable colon cancer. Hopefully, immune therapy in mismatch satellite stable colon cancer beyond PD-1 and PD-L1 inhibitors can be implemented.

Three-dimensional colon cancer organoids model the response to CEA-CD3 T-cell engagers.

Rationale: The CEA-CD3 T cell bispecific antibody cibisatamab (CEA-TCB) is currently undergoing clinical trials. Here we study its performance against three-dimensional tumor organoids in cocultures with T cells as compared to a higher affinity CEACAM5-CD3 (CEACAM5-TCB) bispecific antibody using time-lapse confocal microscopy. Methods: Pre-labelled spheroids derived from colon cancer cell lines and primary organoids derived from four colorectal cancer surgical specimens, which expressed different graded levels of CEA, were exposed in cocultures to T lymphocytes. Cocultures were treated with CEA-CD3 T-cell engagers and were followed by live confocal microscopy. Caspase 3 activation detected in real-time was used as an indicator of tumor cell death. Co-cultures were also set up with autologous tumor-associated fibroblasts to test the co-stimulatory effect of a fibroblast activated protein (FAP)- targeted 4-1BBL bispecific antibody fusion protein currently undergoing clinical trials. Results: Tumor-cell killing of 3D colon carcinoma cultures was dependent on the levels of surface CEA expression, in such a way that the lower affinity agent (CEA-TCB) did not mediate killing by human preactivated T cells below a certain CEA expression threshold, while the high affinity construct (CEACAM5-TCB) remained active on the low CEA expressing organoids. Modelling heterogeneity in the levels of CEA expression by coculturing CEA high and low organoids showed measurable but weak bystander killing. Cocultures of tumor organoids, autologous fibroblasts and T cells allowed to observe a costimulatory effect of anti-FAP-4-1BBL both to release IFNγ and to attain more efficacious tumor cell killing. Conclusion: Three-dimensional tumor cocultures with T cells using live confocal microscopy provide suitable models to test the requirements for colon-cancer redirected killing as elicited by CEA-targeted T-cell engagers undergoing clinical trials and treatment allow combinations to be tested in a relevant preclinical system.

Comprehensive analysis of m6A regulator-based methylation modification patterns characterized by distinct immune profiles in colon adenocarcinomas.

Mounting evidences have indicated that RNA N6-methyladenosine (m6A) modification played important roles in tumor formation and growth. However, it is rarely reported that m6A modifications are involved in the immune regulation and tumor microenvironment (TME) formation. In this study, we aimed to investigate the correlation between m6A modifications and TME regulation of colon adenocarcinoma (COAD) by bioinformatic analysis. NMF algorithm was applied to carry out consensus molecular subtype analysis on 36 selected m6A regulators regarding methylation modification, to identify m6A modification patterns and characteristics of m6A related genes in colon adenocarcinoma (COAD). Further, the relative infiltration levels of different immune cell subsets were quantified by ssGSEA and CIBERSORT algorithms, and a m6Sig scoring scheme was constructed to predict the prognosis and evaluate the response to immunotherapy in the patients with COAD. Among 579 COAD samples, we identified three different m6A modification patterns which were related to different biological pathways and clinical outcomes. Then, a scoring scheme termed "m6Sig score" was developed based on m6A-related characteristic genes, and was utilized to score patients with COAD into groups. We found that COAD patients with lower m6Sig scores exhibited prolonged survival and potentiated immune infiltration, which were associated with higher tumor mutation load, lower PD-L1 expression, and higher mutation rates of SMG (such as TTN and KRAS). Moreover, analysis regarding evaluation of immune response revealed that the patients with lower m6Sig scores had higher Immunophenoscore. Collectively, our study provided in depth insight into the interactions between m6A modification and regulation of TME. In addition, the quantitative evaluation of m6A modification patterns in our results may have implications in further immunotherapy for individual COAD patients.

T-Cell-Specific CerS4 Depletion Prolonged Inflammation and Enhanced Tumor Burden in the AOM/DSS-Induced CAC Model.

To better understand the role of sphingolipids in the multifactorial process of inflammatory bowel disease (IBD), we elucidated the role of CerS4 in colitis and colitis-associated cancer (CAC). For this, we utilized the azoxymethane/dextran sodium sulphate (AOM/DSS)-induced colitis model in global CerS4 knockout (CerS4 KO), intestinal epithelial (CerS4 Vil/Cre), or T-cell restricted knockout (CerS4 LCK/Cre) mice. CerS4 KO mice were highly sensitive to the toxic effect of AOM/DSS, leading to a high mortality rate. CerS4 Vil/Cre mice had smaller tumors than WT mice. In contrast, CerS4 LCK/Cre mice frequently suffered from pancolitis and developed more colon tumors. In vitro, CerS4-depleted CD8+ T-cells isolated from the thymi of CerS4 LCK/Cre mice showed impaired proliferation and prolonged cytokine production after stimulation in comparison with T-cells from WT mice. Depletion of CerS4 in human Jurkat T-cells led to a constitutively activated T-cell receptor and NF-κB signaling pathway. In conclusion, the deficiency of CerS4 in T-cells led to an enduring active status of these cells and prevents the resolution of inflammation, leading to a higher tumor burden in the CAC mouse model. In contrast, CerS4 deficiency in epithelial cells resulted in smaller colon tumors and seemed to be beneficial. The higher tumor incidence in CerS4 LCK/Cre mice and the toxic effect of AOM/DSS in CerS4 KO mice exhibited the importance of CerS4 in other tissues and revealed the complexity of general targeting CerS4.

Multi-OMICs data analysis identifies molecular features correlating with tumor immunity in colon cancer.

BACKGROUND: There is a current need for new markers with higher sensitivity and specificity to predict immune status and optimize immunotherapy use in colon cancer. OBJECTIVE: We aimed to investigate the multi-OMICs features associated with colon cancer immunity and response to immunotherapy. METHODS: We evaluated the association of multi-OMICs data from three colon cancer datasets (TCGA, CPTAC2, and Samstein) with antitumor immune signatures (CD8+ T cell infiltration, immune cytolytic activity, and PD-L1 expression). Using the log-rank test and hierarchical clustering, we explored the association of various OMICs features with survival and immune status in colon cancer. RESULTS: Two gene mutations (TERT and ERBB4) correlated with antitumor cytolytic activity found also correlated with improved survival in immunotherapy-treated colon cancers. Moreover, the expression of numerous genes was associated with antitumor immunity, including GBP1, GBP4, GBP5, NKG7, APOL3, IDO1, CCL5, and CXCL9. We clustered colon cancer samples into four immuno-distinct clusters based on the expression levels of 82 genes. We have also identified two proteins (PREX1 and RAD50), ten miRNAs (hsa-miR-140, 146, 150, 155, 342, 59, 342, 511, 592 and 1977), and five oncogenic pathways (CYCLIN, BCAT, CAMP, RB, NRL, EIF4E, and VEGF signaling pathways) significantly correlated with antitumor immune signatures. CONCLUSION: These molecular features are potential markers of tumor immune status and response to immunotherapy.

Identification of an ACK1/TNK2-based prognostic signature for colon cancer to predict survival and inflammatory landscapes.

Activated Cdc42-associated kinase 1 (ACK1), a kind of tyrosine kinase, is considered to be an oncogene in many cancers, and it is likely to become a potential target for cancer treatment. We found that the expression of the ACK1 gene in colon cancer was higher than that in normal tissues adjacent to cancer, and high expression of the ACK1 gene was associated with poor prognosis of patients. We assessed the prognosis of colon cancer based on ACK1-related genes and constructed a model that can predict the prognosis of colon cancer patients in colon cancer data from The Cancer Genome Atlas (TCGA) database. We then explored the relationship between ACK1 and the immune microenvironment of colon cancer. The overexpression of ACK1 might hinder the function of antigen-presenting cells. The colon cancer prognosis prediction model we constructed has certain significance for clinicians to judge the prognosis of patients with colon cancer. The expression of the ACK1 gene might affect the infiltration level of a variety of immune cells and immunomodulators in the immune microenvironment.