Colorectal cancer (CRC), a major global health concern, necessitates innovative treatments. Chimeric antigen receptor (CAR) T cells have shown promises, yet they grapple with challenges. The spotlight pivots to the rising heroes: CAR natural killer (NK) cells, offering advantages such as higher safety profiles, cost-effectiveness, and efficacy against solid tumors. Nevertheless, the specific mechanisms underlying CAR NK cell trafficking and their interplay within the complex tumor microenvironment require further in-depth exploration. Herein, we provide insights into the design and engineering of CAR NK cells, antigen targets in CRC, and success in overcoming resistance mechanisms with an emphasis on the potential for clinical trials.
Colorectal Neoplasms/immunology* ; Humans ; Killer Cells, Natural/metabolism* ; Receptors, Chimeric Antigen/genetics* ; Immunotherapy, Adoptive/methods* ; Tumor Microenvironment/immunology* ; Animals

Microsatellite instability (MSI) serves as a molecular marker for DNA mismatch repair deficiency (dMMR), present in approximately 15% of colorectal cancer patients. The MSI status provides predictive information guiding treatment decisions; for instance, patients with microsatellite instability-high colorectal cancer demonstrate better responses to immune checkpoint inhibitor therapy. Currently, MSI testing requires methods such as immunohistochemistry or next-generation sequencing. Although multiple clinical guidelines recommend routine MSI testing, its widespread adoption within China remains limited due to various constraints. Deep learning algorithms offer a novel AI-driven pattern recognition classification strategy, presenting a feasible approach to overcome limitations in MSI testing and enhance immunotherapy efficacy evaluation. Consequently, the Colorectal Surgery Group of the Surgery Branch of the Chinese Medical Association, in collaboration with Beihang University and drawing on current research utilizing artificial intelligence systems to assess colorectal cancer immunotherapy efficacy, has formulated the "Expert consensus on clinical application of immunotherapy intelligent prediction for colorectal cancer based on artificial intelligence platform（2025 version）". This consensus aims to facilitate the prediction of MSI status and other relevant indicators in colorectal cancer patients, while also supporting clinical decision-making regarding the selection and application of immunotherapy regimens.
Humans ; Colorectal Neoplasms/immunology* ; Artificial Intelligence ; Immunotherapy ; Microsatellite Instability ; Consensus ; Deep Learning ; Algorithms

Recent data suggest that vascular endothelial growth factor receptor inhibitor (VEGFRi) can enhance the anti-tumor activity of the anti-programmed cell death-1 (anti-PD-1) antibody in colorectal cancer (CRC) with microsatellite stability (MSS). However, the comparison between this combination and standard third-line VEGFRi treatment is not performed, and reliable biomarkers are still lacking. We retrospectively enrolled MSS CRC patients receiving anti-PD-1 antibody plus VEGFRi (combination group, n=54) or VEGFRi alone (VEGFRi group, n=32), and their efficacy and safety were evaluated. We additionally examined the immune characteristics of the MSS CRC tumor microenvironment (TME) through single-cell and spatial transcriptomic data, and an MSS CRC immune cell-related signature (MCICRS) that can be used to predict the clinical outcomes of MSS CRC patients receiving immunotherapy was developed and validated in our in-house cohort. Compared with VEGFRi alone, the combination of anti-PD-1 antibody and VEGFRi exhibited a prolonged survival benefit (median progression-free survival: 4.4 vs. 2.0 months, P=0.0024; median overall survival: 10.2 vs. 5.2 months, P=0.0038) and a similar adverse event incidence. Through single-cell and spatial transcriptomic analysis, we determined ten MSS CRC-enriched immune cell types and their spatial distribution, including naive CD4⁺ T, regulatory CD4⁺ T, CD4⁺ Th17, exhausted CD8⁺ T, cytotoxic CD8⁺ T, proliferated CD8⁺ T, natural killer (NK) cells, plasma, and classical and intermediate monocytes. Based on a systemic meta-analysis and ten machine learning algorithms, we obtained MCICRS, an independent risk factor for the prognosis of MSS CRC patients. Further analyses demonstrated that the low-MCICRS group presented a higher immune cell infiltration and immune-related pathway activation, and hence a significant relation with the superior efficacy of pan-cancer immunotherapy. More importantly, the predictive value of MCICRS in MSS CRC patients receiving immunotherapy was also validated with an in-house cohort. Anti-PD-1 antibody combined with VEGFRi presented an improved clinical benefit in MSS CRC with manageable toxicity. MCICRS could serve as a robust and promising tool to predict clinical outcomes for individual MSS CRC patients receiving immunotherapy.
Humans ; Colorectal Neoplasms/drug therapy* ; Male ; Female ; Immunotherapy ; Middle Aged ; Aged ; Tumor Microenvironment/immunology* ; Retrospective Studies ; Microsatellite Instability ; Transcriptome ; Single-Cell Analysis ; Programmed Cell Death 1 Receptor/immunology* ; Gene Expression Profiling ; Immune Checkpoint Inhibitors/therapeutic use* ; Adult ; Receptors, Vascular Endothelial Growth Factor/antagonists & inhibitors*

Objective To investigate the efficacy and safety of Xihuang capsules as an adjuvant treatment for metastatic colorectal cancer and their impact on immune function. Methods A retrospective analysis was conducted on clinical data from 112 patients diagnosed with metastatic colorectal cancer. The patients were categorized into two groups: a control group (n=56) that did not take Xihuang capsules and an observation group (n=56) that did. The efficacy, improvement of quality of life, toxic and side effects and immune function of the two groups were analyzed and compared. Results After treatment, the disease control rate (DCR) and the rate of improvement in quality of life were significantly higher in the observation group compared to the control group. Additionally, levels of carcinoembryonic antigen (CEA) and the incidence of adverse reactions, including bone marrow suppression and liver and kidney function damage, were significantly lower in the observation group. Furthermore, the percentages of CD4⁺ and CD8⁺ T cells, the CD8⁺/CD4⁺ T cells ratio, as well as serum levels of high mobility group box-1 (HMGB1) and interleukin 2 (IL-2) in observation group were significantly elevated compared to pre-treatment levels. Subgroup analysis revealed that patients with a Karnofsky Performance Status (KPS) score ≤80, a high CD8⁺/CD4⁺ T cells ratio, and elevated HMGB1 levels experienced a significantly higher objective response rate (ORR) in the observation group. Conversely, patients with stage IVB disease, who had KPS score ≤80, a low CD8⁺/CD4⁺ T cells ratio and high CEA and IL-2 levels demonstrated a more pronounced DCR in the observation group. Conclusion Xihuang capsules exhibit promising clinical efficacy as an adjuvant treatment for advanced colorectal cancer. They not only enhance patients' quality of life and reduce the toxic and adverse effects of chemotherapy, but also improve immune function. These benefits are particularly significant in patients with a high tumor burden, indicating that Xihuang capsules are worthy of clinical application.
Humans ; Colorectal Neoplasms/immunology* ; Male ; Female ; Middle Aged ; Drugs, Chinese Herbal/adverse effects* ; Capsules ; Aged ; Carcinoembryonic Antigen/blood* ; Retrospective Studies ; Quality of Life ; Adult ; Neoplasm Metastasis ; Interleukin-2/blood* ; HMGB1 Protein/blood* ; Chemotherapy, Adjuvant

Objective To investigate the effect of insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) on the proliferation, migration and tumor immune microenvironment of colorectal cancer cells and its possible molecular mechanism. Methods The Cancer Genome Atlas (TCGA) database was used to analyze the expression levels of IGF2BP2 and MYC in colorectal cancer and adjacent tissues. The expression of IGF2BP2 in HCT-116 and SW480 human colorectal cancer cells was silenced by RNA interference (RNAi), and the silencing effect was detected by quantitative real-time PCR. After knocking down IGF2BP2, colony formation assay, CCK-8 assay and 5-ethynyl-2'-deoxyuridine (EdU) assay were employed to detect cell colony formation and proliferation ability. Transwell^TM assay was used to detect cell migration ability. Quantitative real-time PCR was used to detect the mRNA expression of IGF2BP2, MYC, tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β) and interleukin-10 (IL-10). The protein expression of IGF2BP2 and MYC was detected by western blot. The binding ability of IGF2BP2 and MYC in HCT-116 cells was detected by quantitative real-time PCR after RNA immunoprecipitation. Results The results of TCGA database showed that the expression of IGF2BP2 and MYC in colorectal cancer tissues was significantly higher than that in adjacent tissues, and the survival time of colorectal cancer patients with high expression of IGF2BP2 was shorter. After silencing IGF2BP2, the viability, proliferation and migration of HCT-116 and SW480 cells were decreased. The mRNA expression of MYC, TGF-β and IL-10 in IGF2BP2 knockdown group was significantly decreased, while the expression of TNF-α mRNA was increased. The expression of MYC protein and the stability of MYC mRNA were significantly decreased. RIP-qPCR results showed that IGF2BP2 could bind to MYC mRNA. Conclusion Knockdown of IGF2BP2 inhibits colorectal cancer cell proliferation, migration and promotes tumor immunity by down-regulating MYC expression.
Humans ; Cell Line, Tumor ; Cell Movement/genetics* ; Cell Proliferation/genetics* ; Colorectal Neoplasms/metabolism* ; Gene Expression Regulation, Neoplastic ; Interleukin-10/metabolism* ; RNA, Messenger ; RNA-Binding Proteins/metabolism* ; Transforming Growth Factor beta/genetics* ; Tumor Microenvironment/immunology* ; Tumor Necrosis Factor-alpha/metabolism* ; Proto-Oncogene Proteins c-myc/metabolism*

Colorectal cancer (CRC) is a common malignant tumor in the digestive tract, and 30%-85% of CRCs express epidermal growth factor receptors (EGFRs). Recently, treatments using cetuximab, also named C225, an anti-EGFR monoclonal antibody, for CRC have been demonstrated to cause an S492R mutation in EGFR. However, little is known about the biological function of S492R EGFR. Therefore, we attempted to elucidate its biological function in CRC cells and explore new treatment strategies for this mutant form. Our study indicated that EGFR and S492R EGFR accelerate the growth of CRC cells in vitro and in vivo and monoclonal antibody CH12, which specifically recognizes an EGFR tumor-specific epitope, can bind efficiently to S492R EGFR. Furthermore, mAb CH12 showed significantly stronger growth suppression activities and induced a more potent antibody-dependent cellular cytotoxicity effect on CRC cells bearing S492R EGFR than mAb C225. mAb CH12 obviously suppressed the growth of CRC xenografts with S492R EGFR mutations in vivo. Thus, mAb CH12 may be a promising therapeutic agent in treating patients with CRC bearing an S492R EGFR mutation.
Animals ; Antibodies, Monoclonal ; pharmacology ; Antineoplastic Agents, Immunological ; pharmacology ; Caco-2 Cells ; Cell Proliferation ; drug effects ; Colorectal Neoplasms ; therapy ; ErbB Receptors ; genetics ; immunology ; Female ; HT29 Cells ; Humans ; Mice ; Mice, Inbred BALB C ; Mutation ; Xenograft Model Antitumor Assays

The mechanism underlying CD4CD25Foxp3regulatory T cells (Tregs) promoting the development of colorectal cancer (CRC) was elucidated in the present study. Forty-eight cases of colorectal carcinomas, 22 cases of colon polyps and 21 cases of normal colorectal tissues were collected. The correlation among Foxp3, IL-10 and Stat3, and the clinical relevance of these three indexes were analyzed. The results showed that the levels of Foxp3 expressed in infiltrating CD4CD25Foxp3Tregs, and IL-10 and Stat3 in CRC tissues were all significantly higher than those in polypus tissues and normal colon tissues (P< 0.01). Pearson correlation analysis indicated that the expression level of Foxp3 was positively correlated with Stat3 at mRNA level (r=0.526, P=0.036), and was positively correlated with IL-10 at protein level (r=0.314, P=0.030). The Foxp3 expressed in CD4CD25Foxp3Tregs was correlated with the histological grade, lymph node metastasis and TNM stage of CRC (P<0.05 for all). The IL-10 expression was correlated with the histological grade and TNM stage (both P<0.05). The Stat3 expression was correlated with the lymph node metastasis and TNM stage (both P<0.05). It was concluded that CD4CD25Foxp3Tregs can inhibit tumor immunity in combination with some other related inhibitory cytokines and that Foxp3 expression in CD4CD25Foxp3Tregs correlates with CRC progression.
Adult ; Aged ; CD4-Positive T-Lymphocytes ; immunology ; Colorectal Neoplasms ; genetics ; immunology ; pathology ; Female ; Forkhead Transcription Factors ; biosynthesis ; genetics ; immunology ; Gene Expression Regulation, Neoplastic ; immunology ; Humans ; Immunity ; genetics ; Interleukin-10 ; biosynthesis ; immunology ; Interleukin-2 Receptor alpha Subunit ; immunology ; Lymphatic Metastasis ; Male ; Middle Aged ; STAT3 Transcription Factor ; biosynthesis ; immunology ; T-Lymphocytes, Regulatory ; immunology

Cancer immunoediting consists of three sequential phases: elimination, equilibrium, and escape. For colorectal adenoma-carcinoma sequence, the adenoma dysplastic progression may represent an equilibrium phase and the cancer stage as escape phase. Immune system eliminates transformed enterocytes by destroying them at first, sculpts them at the same time and selects the variants subsequently that are no longer recognized and insensitive to immune effectors, and finally induces immunosuppressive state within the tumor microenvironment that facilitates immune escape and tumor outgrowth. Immunosuppression and inflammation are the two crucial features of Pi (Spleen)-deficiency. Classic quotations, immune evidence and clinical observations suggest that Spleen (but not other organs) deficiency is the key pathogenesis of colorectal cancer (CRC) microenvironment. Weakness of old age, immunosuppressive cytokines from chronic inflammation, tumor-derived immunosuppressive factors and surrendered immune cells-regulatory T cells, myeloid-derived suppressor cells and tumor associated macrophages (TAMs) constitutes CRC microenvironment of Pi-deficiency. Furthermore, excess in superficiality, such as phlegm stagnation, blood stasis and toxin accumulation are induced by chronic inflammation on the basis of asthenia in origin, an immunosuppressive state. Great masters of Chinese medicine emphasize that strengthen Pi is the chief therapeutic principle for CRC which receives good therapeutic effects. So, Pi-deficiency based syndrome is the pivotal pathogenesis of tumor microenvironment. The immunosuppressive microenvironment facilitates immune escape which play an important role in the transition from adenoma to adenocarcinoma. There are some signs that strengthen Pi based treatment has potential capacity to ameliorate tumor environment. It might be a novel starting point to explore the mechanism of strengthen Pi based therapy in the prevention and treatment of CRC through regulation of tumor environment and immunoediting.
Colorectal Neoplasms ; immunology ; Humans ; Immune Evasion ; Immunosuppression ; Spleen ; immunology ; Syndrome ; Tumor Microenvironment ; immunology

Granulocyte colony-stimulating factor (G-CSF) is an essential regulator of neutrophil trafficking and is highly expressed in multiple tumors. Myeloid derived suppressor cells (MDSCs) promote neoplastic progression through multiple mechanisms by immune suppression. Despite the findings of G-CSF function in colon cancer progression, the precise mechanism of G-CSF on MDSCs regulation and its blockade effects on tumor growth remains a worthy area of investigation. In this study we observed an overexpression of G-CSF in a mouse colitis-associated cancer (CAC) model, which was consistent with the accumulation of MDSCs in mouse colon tissues. Further in vitro studies demonstrated that G-CSF could promote MDSCs survival and activation through signal transducer and activator of transcription 3 (STAT3) signaling pathway. Moreover, compared with isotype control, anti-G-CSF mAb treatment demonstrated reduced MDSC accumulation, which led to a marked decrease in neoplasm size and number in mice. Our results indicated that G-CSF is a critical regulating molecule in the migration, proliferation and function maintenance of MDSCs, which could be a potential therapeutic target for colitis-associated cancer.
Animals ; Carcinogenesis ; Colitis ; complications ; Colorectal Neoplasms ; complications ; drug therapy ; immunology ; metabolism ; Female ; Gene Expression Regulation, Neoplastic ; Granulocyte Colony-Stimulating Factor ; genetics ; metabolism ; Immunotherapy ; Mice ; Molecular Targeted Therapy ; Myeloid Cells ; immunology ; metabolism ; pathology

Antigens, Neoplasm ; metabolism ; Antigens, Surface ; metabolism ; Colorectal Neoplasms ; immunology ; pathology ; Humans ; Prognosis ; Trophoblasts ; immunology