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

Objective TXN is a thioredoxin (TXN) that participates in many redox reactions and plays a crucial role in various signaling pathways. However, the role of TXN in many cancers is still unclear. The objective of this study is to investigate and visualize the diagnostic, prognostic, and immunological implications of TXN expression across various cancer types. Methods The clinical data were downloaded from the cancer genome mapping project(TCGA) database to analyze the expression level of TXN in pan cancer, and the expression level was preliminarily verified by human protein mapping (HPA)(https://www.proteinatlas.org/)database. The ESTIMATE algorithm and CIBERSORT algorithm were applied to calculate the correlation between TXN expression and immune cell infiltration. The correlation between TXN and microsatellite instability (MSI) and tumor mutation burden (TMB) was analyzed using Spearman method. Gene Set Enrichment Analysis (GSEA) is used for gene biology functional analysis and sensitivity analysis of genes to pan cancer therapeutic drugs. Results TXN is highly expressed in most malignant tumors. The high expression of TXN is associated with overall survival (OS), disease-specific survival (DSS), disease-free interval (DFI), and progression free interval (PFI) in various cancers. Moreover, TXN expression is associated with TMB, MSI, tumor microenvironment, chemotherapy sensitivity and so on. Conclusion TXN may become a potential prognostic biomarker in pan cancer, providing strong theoretical basis for future tumor diagnosis and prognosis judgment. The retinoic acid-inducible gene-I (RIG-I)-like receptor signaling pathway, Toll-like receptor (TLR) signaling pathway, and nucleotide binding oligomerization domain (NOD)-like receptor signaling pathway may be crucial pathways through which TXN influences tumor immunity.
Humans ; Prognosis ; Neoplasms/diagnosis* ; Thioredoxins/metabolism* ; Microsatellite Instability ; Gene Expression Regulation, Neoplastic ; Biomarkers, Tumor/genetics* ; Mutation ; Tumor Microenvironment

Rectal cancer is one of the most common malignant tumors in China, with more than half of patients diagnosed at the locally advanced stage. Currently, the standard treatment for locally advanced rectal cancer (LARC) primarily involves neoadjuvant chemoradiotherapy followed by radical surgery. The advent of immune checkpoint inhibitors has revolutionized the neoadjuvant treatment landscape for mismatch repair-deficient/microsatellite instability-high (dMMR/MSI-H) rectal cancer. However, most rectal cancer patients exhibit mismatch repair-proficient/microsatellite stable (pMMR/MSS) status and show poor responsiveness to immunotherapy. In recent years, multiple studies have demonstrated that neoadjuvant short-course radiotherapy followed by chemotherapy and immunotherapy can improve the pathological complete response rate in pMMR/MSS LARC patients. Nevertheless, controversies persist regarding patient selection, efficacy evaluation, adverse event management, postoperative adjuvant therapy, and follow-up strategies. Considering the Colorectal Surgery Group of the Surgery Branch of the Chinese Medical Association, in collaboration with the Colorectal and Anal Surgery Committee of the Chinese Research Hospital Association, the Chinese Colorectal Cancer Clinical Research Collaborative Group, and related experts, has developed this consensus document by referencing domestic and international research advancements. The aim is to provide standardized guidance for the clinical application of this treatment approach.
Humans ; Rectal Neoplasms/genetics* ; Neoadjuvant Therapy ; Immunotherapy ; DNA Mismatch Repair ; Microsatellite Instability ; Consensus ; Combined Modality Therapy

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*

OBJECTIVES: To explore the potential of pyrroline-5-carboxylate reductase 1 (PYCR1) as a pan-cancer biomarker and investigate its expression, function, and clinical significance in bladder cancer (BLCA). METHODS: Bioinformatics analysis was conducted to evaluate the associations of PYCR1 with prognosis, immune microenvironment remodeling, tumor mutation burden (TMB), and microsatellite instability (MSI) in cancer patients. Using the TCGA-BLCA dataset, univariate and multivariate regression analyses were performed to assess the potential of PYCR1 as an independent prognostic risk factor for BLCA, and a clinical decision model was constructed. The IMvigor210 cohort was utilized to evaluate the potential of PYCR1 for independently predicting the efficacy of immunotherapy. The pRRophetic was employed to screen candidate chemotherapeutic agents for treating BLCA with high PYCR1 expression. The CMap-XSum algorithm and molecular docking techniques were used to explore and validate small molecule inhibitors of PYCR1. RESULTS: A high expression of PYCR1 was significantly associated with poor prognosis, immune cell infiltration, TMB and MSI in various tumors (r>0.3). PYCR1 was overexpressed in BLCA, and high PYCR1 expression was closely related to poor prognosis in BLCA patients (HR: 1.14, 95% CI: 1.02-1.68, P=0.006). The IC₅₀ of the anti-cancer drugs cetuximab, 5-fluorouracil, and doxorubicin increased significantly in BLCA cell lines with high PYCR1 expressions (P<0.0001). CONCLUSIONS High PYCR1 expression is an independent risk factor for poor prognosis in BLCA patients and can serve as a significant indicator for clinical decision-making as well as a marker for predicting sensitivity to chemotherapeutic agents and the efficacy of immunotherapy.
Humans ; Urinary Bladder Neoplasms/genetics* ; Immunotherapy ; Prognosis ; Pyrroline Carboxylate Reductases/metabolism* ; Biomarkers, Tumor/genetics* ; delta-1-Pyrroline-5-Carboxylate Reductase ; Microsatellite Instability ; Tumor Microenvironment ; Mutation ; Computational Biology ; Molecular Docking Simulation

OBJECTIVES: To investigate the expression levels of marginal zone B and B1-cell-specific protein (MZB1) in pan-cancer and its association with patient prognosis and tumor microenvironment (TME). METHODS: MZB1 expression data, clinicopathological parameters, and survival data from 33 cancer types were extracted from the UCSC database for analyzing the correlations of MZB1 with clinical stage, patient prognosis, immunomodulatory genes, immune checkpoint genes, tumor stemness, immune cell infiltration, tumor mutational burden (TMB), and microsatellite instability (MSI). MZB1 gene mutations in pan-cancer were assessed using cBioPortal online database, and the value of MZB1 for cancer diagnosis was evaluated using ROC curve analysis. MZB1 expression levels in myeloid leukemia and renal carcinoma cells were detected using RT-qPCR and Western blotting, and the effect of MZB1 knockdown on cell proliferation was examined using EdU assay. RESULTS: MZB1 was significantly overexpressed in 20 cancer types, including kidney renal clear cell carcinoma (KIRC), breast invasive carcinoma, and acute myeloid leukemia. Its expression was associated with TNM stage, clinical stage, overall survival, and progression-free survival in multiple cancers. In most tumors, MZB1 expression was correlated significantly with immunomodulatory genes, immune checkpoint genes, tumor stemness, immune cell infiltration, TMB, and microsatellite instability. Gene amplification was the predominant mutation type of MZB1 in pan-cancer, and MZB1 showed high diagnostic value for skin cutaneous melanoma, KIRC, and head and neck squamous cell carcinoma. MZB1 was highly expressed in different myeloid leukemia cell lines and renal carcinoma cell lines, and MZB1 knockdown significantly suppressed the proliferation of HL60 and 769-P cells. CONCLUSIONS MZB1 is highly expressed in a variety of tumors, and its aberrant expression affects the occurrence and prognosis of many tumors, suggesting its potential as a novel tumor biomarker and immunomodulatory target.
Humans ; Prognosis ; Tumor Microenvironment ; Neoplasms/pathology* ; Cell Line, Tumor ; Mutation ; Kidney Neoplasms ; Microsatellite Instability ; Cell Proliferation ; Carcinoma, Renal Cell

Humans ; Small Cell Lung Carcinoma/drug therapy* ; Lung Neoplasms/drug therapy* ; Colonic Neoplasms/drug therapy* ; Microsatellite Instability ; DNA Mismatch Repair ; Colorectal Neoplasms

Objective: To explore the concordance and causes of different mismatch repair (MMR) and microsatellite instability (MSI) detection results in endometrial carcinoma (EC) molecular typing. Methods: A total of 214 EC patients diagnosed from January 2021 to April 2023 were selected at the Department of Pathology, Peking University Third Hospital. The immunohistochemistry (IHC) results of MMR protein were reviewed. Tumor specific somatic mutations, MMR germline mutations, microsatellite scores and tumor mutation burden (TMB) were detected by next-generation sequencing (NGS) with multi-gene panel. Methylation-specific PCR was used to detect the methylation status of MLH1 gene promoter in cases with deficient MLH1 protein expression. In cases with discrepant results between MMR-IHC and MSI-NGS, the MSI status was detected again by PCR (MSI-PCR), and the molecular typing was determined by combining the results of TMB and MLH1 gene promoter methylation. Results: (1) In this study, there were 22 cases of POLE gene mutation subtype, 55 cases of mismatch repair deficient (MMR-d) subtype, 29 cases of p53 abnormal subtype, and 108 cases of no specific molecular profile (NSMP). The median age at diagnosis of MMR-d subtype (54 years old) and the proportion of aggressive histological types (40.0%, 22/55) were higher than those of NSMP subtype [50 years old and 12.0% (13/108) respectively; all P<0.05]. (2) Among 214 patients, MMR-IHC test showed that 153 patients were mismatch repair proficient (MMR-p), 49 patients were MMR-d, and 12 patients were difficult to evaluate directly. MSI-NGS showed that 164 patients were microsatellite stable (MSS; equal to MMR-p), 48 patients were high microsatellite instability (MSI-H; equal to MMR-d), and 2 patients had no MSI-NGS results because the effective sequencing depth did not meet the quality control. The overall concordance between MMR-IHC and MSI-NGS was 94.3% (200/212). All the 12 discrepant cases were MMR-d or subclonal loss of MMR protein by IHC, but MSS by NGS. Among them, 10 cases were loss or subclonal loss of MLH1 and (or) PMS2 protein. Three discrepant cases were classified as POLE gene mutation subtype. In the remaining 9 cases, 5 cases and 3 cases were confirmed as MSI-H and low microsatellite instability (MSI-L) respectively by MSI-PCR, 6 cases were detected as MLH1 gene promoter methylation and 7 cases demonstrated high TMB (>10 mutations/Mb). These 9 cases were classified as MMR-d EC. (3) Lynch syndrome was diagnosed in 27.3% (15/55) of all 55 MMR-d EC cases, and the TMB of EC with MSH2 and (or) MSH6 protein loss or associated with Lynch syndrome [(71.0±26.2) and (71.5±20.1) mutations/Mb respectively] were significantly higher than those of EC with MLH1 and (or) PMS2 loss or sporadic MMR-d EC [(38.2±19.1) and (41.9±24.3) mutations/Mb respectively, all P<0.01]. The top 10 most frequently mutated genes in MMR-d EC were PTEN (85.5%, 47/55), ARID1A (80.0%, 44/55), PIK3CA (69.1%, 38/55), KMT2B (60.0%, 33/55), CTCF (45.5%, 25/55), RNF43 (40.0%, 22/55), KRAS (36.4%, 20/55), CREBBP (34.5%, 19/55), LRP1B (32.7%, 18/55) and BRCA2 (32.7%, 18/55). Concurrent PTEN, ARID1A and PIK3CA gene mutations were found in 50.9% (28/55) of MMR-d EC patients. Conclusions: The concordance of MMR-IHC and MSI-NGS in EC is relatively high.The discordance in a few MMR-d EC are mostly found in cases with MLH1 and (or) PMS2 protein loss or MMR protein subclonal staining caused by MLH1 gene promoter hypermethylation. In order to provide accurate molecular typing for EC patients, MLH1 gene methylation, MSI-PCR, MMR gene germline mutation and TMB should be combined to comprehensively evaluate MMR and MSI status.
Female ; Humans ; Middle Aged ; Class I Phosphatidylinositol 3-Kinases/metabolism* ; Colorectal Neoplasms, Hereditary Nonpolyposis/diagnosis* ; DNA Mismatch Repair/genetics* ; Endometrial Neoplasms/pathology* ; Microsatellite Instability ; Mismatch Repair Endonuclease PMS2/genetics* ; Molecular Typing

OBJECTIVE: To investigate the correlation of stress-inducible phosphoprotein 1 (STIP1) expression level with prognosis of different cancers and its potential role in immunotherapy. METHODS: TCGA, TARGET and GTEx databases were used for bioinformatic analysis of STIP1 expression level and its prognostic value in different cancers. We also detected STIP1 expression immunohistochemically in 10 pairs of colorectal cancer and adjacent tissues. We further analyzed the correlation of STIP1 expression level with tumor mutational burden, microsatellite instability, immune cell infiltration, immune regulators and outcomes of different cancers. STIP1- related proteins were identified using protein- protein interaction (PPI) network analysis, and functional enrichment analysis was performed to analyze the regulatory pathways involving STIP1. RESULTS: Bioinformatics analysis showed that STIP1 was highly expressed in most tumors compared with the normal tissues (P < 0.05), which was confirmed by immunohistochemistry of the 10 pairs of colorectal cancer tissues. STIP1 expression level was correlated with clinical stages of multiple cancers (P < 0.05), and in some cancer types, an upregulated STIP1 expression was correlated with a poor prognosis of the patients in terms of overall survival, disease-specific survival, disease-free survival and progression-free survival (P < 0.05). STIP1 expression was significantly correlated with tumor mutational burden, microsatellite instability, immune cell infiltration and immunomodulatory factors in most tumors (P < 0.05). PPI network analysis indicated that STIP1-related proteins included HSPA4, HSPA8, and HSP90AA1. KEGG enrichment analysis suggested that the high expression of STIP1 in liver cancer was related mainly with valerate metabolism, tryptophan metabolism, and butyrate metabolism pathways; HALLMARK enrichment analysis suggested high STIP1 expression in liver cancer was involved in bile acid and fatty acid metabolism. CONCLUSION STIP1 is up-regulated in multiple cancer types and its expression level is correlated with clinical tumor stage, tumor mutational burden, microsatellite instability, immune cell infiltration and immunomodulatory factors.
Humans ; Microsatellite Instability ; Liver Neoplasms ; Immunotherapy ; Prognosis ; Computational Biology ; Heat-Shock Proteins ; Colorectal Neoplasms

Immunotherapy has been one of the hot topics in the field of colorectal cancer research in recent years. Patients with microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) are the main beneficiaries of immunotherapy. The response rate of patients with dMMR/MSI-H colorectal cancer receiving neoadjuvant immunotherapy is nearly 100%, of which the pathological complete response rate approximately accounts for 60%-67%. The prospect of neoadjuvant immunotherapy in dMMR or MSI-H colorectal cancer patients, especially in the rectal cancer patients, lies in achieving sustainable clinical complete response so as to achieve organ preservation and avoid adverse effects on reproductive, sexual, bowel and bladder function after surgery and radiotherapy. Studies have shown that part of the colorectal cancer patients of microsatellite stability (MSS) or mismatch repair proficient (pMMR) can respond to neoadjuvant immunotherapy in combination with other treatment methods such as radiotherapy and chemotherapy. In pMMR or MSS colorectal cancer, optimizing neoadjuvant immunotherapy regimens and finding effective efficacy prediction biomarkers are important research directions. In neoadjuvant immunotherapy, overcoming primary and secondary resistance and identifying the pseudoprogression and hyperprogression of neoadjuvant immunotherapy are clinical challenges that require attention. This paper comprehensively reviews the research progress, controversies,challenges and future research directions of neoadjuvant immunotherapy (mainly immune checkpoint inhibitors) in colorectal cancer.
Humans ; Neoadjuvant Therapy/methods* ; Colorectal Neoplasms/drug therapy* ; Colonic Neoplasms/pathology* ; Immunotherapy/methods* ; DNA Mismatch Repair ; Microsatellite Instability