N-glycosylation Regulates Intrinsic IFN-γ Resistance in Colorectal Cancer: Implications for Immunotherapy

Glycoproteomics of Gastrointestinal Cancers and Its Use in Clinical Diagnostics

Cancer is a leading cause of death worldwide, resulting in substantial economic costs. Because cancer is a complex, heterogeneous group of diseases affecting a variety of cells, its detection may sometimes be difficult. Herein we review a large group of the gastrointestinal cancers (oral, esophageal, stomach, pancreatic, liver, and bowel cancers) and the possibility of using glycans conjugated to protein backbones for less-invasive diagnoses than the commonly used endoscopic approaches. The reality of bacterial N-glycosylation and the effect of epithelial mucosa on gut microbiota are discussed. Current advantages, barriers, and advantages in the prospective use of selected glycomic approaches in clinical practice are also detailed.

Downregulation of MGAT3 Promotes Benzo[a]pyrene-Mediated Lung Carcinogenesis by Regulating Cell Invasion and Migration Activity

Environmental chemical carcinogens are major factors in the induction of lung cancer, with benzo[a]pyrene (B[a]P) being one of the most widespread and highly carcinogenic among them. Although studies have reported that B[a]P exerts its carcinogenic effects by causing mutations, inducing cytotoxicity, and inhibiting DNA synthesis, the early molecular regulatory events and mechanisms involved in B[a]P-induced tumor initiation remain unclear. This study found that the MGAT3 gene was significantly downregulated in B[a]P-induced mouse lung tumorigenesis, suggesting its important tumor-suppressive function. Further investigation revealed that suppression of MGAT3 expression promoted the invasion and migration abilities of lung cancer cells, while overexpression of MGAT3 in these cells inhibited these effects. Western blot analysis also showed that MGAT3 regulated the expression of epithelial-mesenchymal transition markers, thereby affecting the motility of lung cancer cells. Xenograft assay also confirmed the inhibitory effect of MGAT3 overexpression on tumor proliferation. Analysis of lung cancer tissue expression further validated that MGAT3 is significantly downregulated in lung cancer tissues, and this decrease in expression is associated with a poor prognosis in lung cancer patients. Our research indicates that the suppression of MGAT3 expression and its downstream regulatory molecules plays a crucial role in lung cancer development induced by environmental chemical carcinogens.

Deciphering the Metabolic Impact and Clinical Relevance of N-Glycosylation in Colorectal Cancer through Comprehensive Glycoproteomic Profiling

Colorectal cancer (CRC) progression is driven by complex metabolic alterations, including aberrant N-glycosylation patterns that critically influence tumor development. However, the metabolic and functional roles of N-glycosylation in CRC remain poorly understood. Herein, comprehensive proteomic and N-linked intact glycoproteomics analyses are performed on 45 CRC tumors, and normal adjacent tissues (NATs) are matched, identifying 7125 intact N-glycopeptides from 704 glycoproteins. Through analysis of glycoform expression profiles and structural characteristics, a glycosylation site-protein function association network is constructed to uncover metabolic dysregulation driven by N-glycosylation in CRC. Moreover, an arithmetic model is developed that integrates N-glycan expression patterns, which effectively distinguishes tumors from NATs, reflecting metabolic reprogramming in cancer. These findings identify Chloride Channel Accessory 1 (CLCA1) and Olfactomedin 4 (OLFM4) as potential metabolic biomarkers for CRC diagnosis. Immunohistochemistry and Cox regression analyses validated the prognostic power of these markers. Notably, the critical role of specific N-glycosylation at N196 of Adipocyte plasma membrane-associated protein (APMAP) is highlighted, a key player in tumor metabolism and CRC progression, providing a potential target for therapeutic intervention. These findings offer valuable insights into the metabolic roles of N-glycosylation in CRC, advancing biomarker discovery, enhancing metabolic-based diagnostic precision, and improving personalized treatment strategies targeting cancer metabolism.

Abnormal proportions and functions of myeloid-derived suppressor cells in peripheral blood of patients with diffuse large B-cell lymphoma

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) are a subset of immature myeloid cells with immunosuppressive properties. Evidence suggests that abnormal immune system can lead to immune dysfunction and increase the risk of developing diffuse large B-cell lymphoma (DLBCL). This study investigated the abnormality of MDSCs in the peripheral blood of patients with DLBCL.

METHODS

Expression, apoptosis, and proliferation of MDSCs was measured in the peripheral blood DLBCL patients and healthy donors (HDs) via flow cytometer. The co-culture groups included the MDSCs and DLBCL cells line and MDSCs and T cells. Using flow cytometry detected MDSCs and T cells proliferation, apoptosis, T cells activation and function in the co-culture groups. RNA transcriptome sequencing analysis was conducted on DLBCL-MDSCs and HDs-MDSCs. Combined with the clinicopathological data of DLBCL patients, the correlation between MDSCs and DLBCL progression was analyzed.

RESULTS

The expression of MDSCs in patients newly diagnosed with DLBCL was elevated. DLBCL tumor cells could stimulate MDSCs growth. DLBCL-MDSCs showed stronger immunosuppressive ability to T cells proliferation, activation and secretion of cytokines and associated with several clinical indicators such as Ann Arbor stage, serum LDH level, and lymphoma IPI score.

CONCLUSION

This study investigated the abnormality of MDSCs and underscored the critical role of MDSCs in suppressing T cell function in DLBCL patients. It provides certain laboratory evidence for MDSCs as biomarkers of disease progression and treatment response in DLBCL.

Ginsenoside Rh2 in combination with IFNγ potentiated the anti-cancer effect by enhancing interferon signaling response in colorectal cancer cells

Interferon gamma (IFNγ) can amplify immune cell-mediated anti-tumor immunity, as well as directly kill cancer cells. Ginsenoside Rh2 (Rh2), a bioactive compound in traditional Chinese medicine, exhibits anti-cancer effects such as inhibiting proliferation and metastasis. Our earlier research found that Rh2 combined with IFNγ enhanced CXCL10 secretion in cancer cells. Here, we explored whether Rh2 and IFNγ exerted more potent anti-cancer activity in vitro and in vivo, along with its mechanisms and clinical value. Our data showed that Rh2 in combination with IFNγ resulted in a remarkably increased cytotoxicity in colorectal cancer cells including HT29, LoVo and T84 cell lines. Consistently, intratumoral injection with Rh2 plus IFNγ further restricted the HT29 tumor growth in vivo, and importantly, it was demonstrated to be safe for mice. Meanwhile, the combo treatment activated the stimulator of interferon genes (STING) pathway in cancer cells, promoting the transcription of downstream type I interferon. RNA sequencing revealed a dramatically transcriptional alteration in cancer cells with combo treatment and indicated that Rh2 further augmented the activation of interferon signaling pathway, compared with the IFNγ alone. Inhibition of janus kinase (JAK) by ruxolitinib could significantly rescue the cell death-triggered by the combo treatment. Then, a gene set named Rh2+IFNγ signature genes (RISG) was defined, which contained top 20 significantly upregulated genes from the combo treatment. Patients who exhibited a favorable response to the immunotherapy had a higher expression of RISG in tumor compared with those who did not respond. And the high expression of RISG was correlated with better clinical outcome in patients with colorectal cancer (CRC) and skin cutaneous melanoma (SKCM). Herein, the combination of Rh2 with IFNγ served as a promising strategy for cancer treatment, and its-derived RISG gene set also exhibited potential value in predicting clinical outcome. Schematic diagram of the anti-cancer effect of Rh2 combined with IFNγ. The schematic diagram illustrated that ginsenoside Rh2 in combination with IFNγ robustly activated the interferon signals in cancer cells, ultimately leading a significant cell death of cancer cells. ISGs, interferon-stimulated genes. Created with BioRender.com.

Aberrant protein glycosylation in the colon adenoma-cancer sequence: Colorectal cancer mechanisms and clinical implications

Colorectal cancer (CRC) is a leading contributor to global cancer-related morbidity and mortality. Glycosylation is a common post-translational protein modification. Aberrant protein glycosylation is a hallmark of cancer, affecting biological processes and driving malignant CRC phenotypes. Specifically, abnormal N-glycosylation manifests as structural alterations in high mannose, sialylated, and fucosylated structures, collectively promoting cancer stemness and invasiveness. Concurrently, O-GlcNAcylation facilitates tumorigenesis through metabolic reprogramming and oncogene activation. Dysregulated mucin-type O-glycans (e.g., Core-1/Core-3 imbalance) and elevated SLex/SLea antigen expression are significantly correlated with tumor adhesion, metastatic dissemination, and adverse clinical outcomes. Furthermore, protein glycosylation contributes to chemoresistance through anti-apoptotic mechanisms, aberrant signaling activation, and pro-angiogenic pathways. This review systematically examines the dynamic evolution of protein glycosylation during CRC progression from normal mucosa to adenoma to adenocarcinoma. It also evaluates the CRC diagnostic and therapeutic implications of glycoproteins and glycans. This review can provide a molecular understanding for advancing CRC diagnostics and treatment.

The role of glycan-lectin interactions in the tumor microenvironment: immunosuppression regulators of colorectal cancer

Colorectal cancer (CRC) is a common malignant tumour and a serious global health issue. Glycosylation, a type of posttranslational modification, has been extensively studied in relation to cancer growth and metastasis. Aberrant glycosylation alters how the immune system in the microenvironment perceives the tumour and drives immune suppression through glycan-binding receptors. Interestingly, specific glycan signatures can be regarded as a new pattern of immune checkpoints. Lectins are a group of proteins that exhibit high affinity for glycosylation structures. Lectins and their ligands are found on endothelial cells (ECs), immune cells and tumour cells and play important roles in the tumour microenvironment (TME). In CRC, glycan-lectin interactions can accelerate immune evasion promoting the differentiation of tumour-associated M2 macrophages, altering T cell, dendritic cell (DC), natural killer (NK) cell, and regulatory T (Treg) cell activity to modify the functions of antigen-presenting cells functions. Here, we review our current knowledge on how glycan-lectin interactions affect immune-suppressive circuits in the TME and discuss their roles in the development of more effective immunotherapies for CRC.

T-cell branched glycosylation as a mediator of colitis-associated colorectal cancer progression: a potential new risk biomarker in inflammatory bowel disease

BACKGROUND AND AIMS

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract, established as a risk factor for colorectal cancer (CRC) development. Long-standing inflammation appears to play a central role in colitis-associated colorectal cancer (CAC). However, the molecular mechanism underlying CAC progression is still elusive. Previous evidence showed that levels of branched glycosylation regulate T-cell-mediated immune response associated with IBD severity. Here, we revealed that colonic T cells from IBD patients are dynamically regulated by branched N-glycosylation and associated with the risk of CAC development.

METHODS

We performed in silico analysis for glycome and immune profile of a publicly available human dataset of CAC patients. Additionally, in a well-characterized cohort of CAC patients, we evaluated the N-glycosylation profile of infiltrated colonic immune cells at different stages of carcinogenesis (colitis, dysplasia and cancer). In vivo studies were conducted in Mgat5 KO mice, using AOM/DSS model to induce CAC. Tumor development and colonic T cells glycoprofile were characterized during CAC development.

RESULTS

The combined analysis of human IBD and CAC clinical samples, together with glycoengineered mouse model susceptible to CAC, revealed a gradual and dynamic increase of branched N-glycans in T cells from colitis to dysplasia and cancer. This glycosylation switch was shown to impose inhibitory properties in T cells, precluding an effective antitumor immune response. Mechanistically, we demonstrated that the deletion of branched N-glycans in Mgat5 knockout mice led to CAC suppression due to increased infiltration of CD8+and γδ T cells, contributing to an effective antitumor immune response. From the clinical standpoint, we demonstrated that branched N-glycosylation levels detected in inflamed lesions from IBD patients predicted CAC progression with a sensitivity of 83.3% and specificity of 67.9% when assessed together with age at diagnosis.

CONCLUSIONS

Overall, we here disclosed a new mechanism underlying CAC development, identifying a potential clinical biomarker plausible to improve the efficacy of cancer surveillance programs through the early identification of high-risk IBD patients, for preventive clinical and therapeutic strategies.

N-glycosylation of GSTO1 promotes cervical cancer migration and invasion through JAK/STAT3 pathway activation

Protein glycosylation is strongly associated with tumor progression. Glutathione S-transferase omega 1 (GSTO1) is a member of the glutathione S-transferase family. The significance of GSTO1 N-glycosylation in the progression of cervical cancer (CC) has remained elusive. In this study, we investigated the functional significance of GSTO1 N-glycosylation in CC progression. We employed immunohistochemistry to detect the relative expression of evaluating the link between GSTO1 in CC and benign tissues and the overall survival (OS) and progression-free survival (PFS) in CC patients.In vitro and in vivo experiments to detect CC cell proliferation or metastatic ability after GSTO1 downregulation. NetNGly1.0 Server database predicts potential N-glycosylation modification sites of GSTO1 (Asn55, Asn135, Asn190). Investigating GSTO1 N-glycosylation's function in cellular migration, invasion and epithelial-mesenchymal transition (EMT), we mutated the N-glycosylation sites of GSTO1 through lentivirus-based insertional mutagenesis. Detection of signalling pathways associated with N-glycosylation-modified GSTO1 by enrichment analysis and Western blot. Compared to normal cervical tissue, CC tissue showed significantly higher GSTO1 expression. Further, high GSTO1 levels were a poor predictor of OS and PFS. Both cell and animal experiments suggested that down-regulation of GSTO1 inhibited cell proliferation and metastasis. Glycosylation modification of targeted mutant GSTO1 at positions 55, 135 and 190 significantly inhibits migration and invasion of CC cells. GSTO1 N-glycosylation fixed point mutation inhibits EMT process in CC cells. Mechanistically, N-glycosylated GSTO1 promoted the expression of JAK/STAT3 pathway related markers. GSTO1 N-glycosylation is associated with CC progression and may promote EMT via JAK/STAT3 signaling.

CoNglyPred: Accurate Prediction of N-Linked Glycosylation Sites Using ESM-2 and Structural Features With Graph Network and Co-Attention

N-Linked glycosylation is crucial for various biological processes such as protein folding, immune response, and cellular transport. Traditional experimental methods for determining N-linked glycosylation sites entail substantial time and labor investment, which has led to the development of computational approaches as a more efficient alternative. However, due to the limited availability of 3D structural data, existing prediction methods often struggle to fully utilize structural information and fall short in integrating sequence and structural information effectively. Motivated by the progress of protein pretrained language models (pLMs) and the breakthrough in protein structure prediction, we introduced a high-accuracy model called CoNglyPred. Having compared various pLMs, we opt for the large-scale pLM ESM-2 to extract sequence embeddings, thus mitigating certain limitations associated with manual feature extraction. Meanwhile, our approach employs a graph transformer network to process the 3D protein structures predicted by AlphaFold2. The final graph output and ESM-2 embedding are intricately integrated through a co-attention mechanism. Among a series of comprehensive experiments on the independent test dataset, CoNglyPred outperforms state-of-the-art models and demonstrates exceptional performance in case study. In addition, we are the first to report the uncertainty of N-linked glycosylation predictors using expected calibration error and expected uncertainty calibration error.

Immunosensitivity cuts across mismatch repair status in colorectal cancer

In this issue of Cancer Cell, Acha-Sagredo et al. reveal an interferon-high immunophenotype in colorectal cancer that predicts responsiveness to immune checkpoint inhibitors across both mismatch repair-deficient and mismatch repair-proficient subtypes. They identify CD74 as a biomarker and establish the importance of epithelial interferon levels in regulating immune responses.

N-glycosylation of ACTRIIB enhances protein stability leading to rapid cell proliferation and strong resistance to docetaxel in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant tumor predominantly influenced by Epstein-Barr virus infection and genetic factors. The transforming growth factor-beta (TGF-β) superfamily is implicated in various cellular processes, including tumorigenesis. This study aimed to detect the role of one TGF-β superfamily member activin receptor type IIB (ACTRIIB) in NPC. This study analyzed NPC datasets, including GSE12452, GSE102349, and GSE53819. ACTRIIB expression and N-glycosylation levels were assessed by western blot, real-time PCR, immunofluorescence, and immunohistochemistry in NPC cells and tissues. As indicated by the datasets, ACTRIIB was significantly upregulated in NPC tissues, and the up-regulation was associated with poor prognosis. This study confirmed the N-glycosylation of ACTRIIB primarily at the forty-second amino acid, an asparagine. The N-glycosylation of ACTRIIB promoted the localization of ACTRIIB to the cell membrane and prevented the degradation of the protein by lysosomes, through which ACTRIIB activated the downstream Smard1/2 to promote tumor cell proliferation and invasion. Inhibition of N-glycosylation or knockdown of ACTRIIB resulted in reduced cell proliferation and invasion and increased the cell sensitivity to docetaxel. In conclusion, N-glycosylation of ACTRIIB was a critical post-translational modification that enhanced protein stability and induced membrane localization, which facilitates the functions of ACTRIIB in cell proliferation and invasion in NPC. Inhibition of ACTRIIB N-glycosylation could potentially serve as a therapeutic strategy to improve the efficacy of chemotherapy in NPC.

N-glycosylation Modification of CTSD Affects Liver Metastases in Colorectal Cancer

Liver metastasis is the primary factor contributing to unfavorable prognosis in colorectal cancer (CRC). Although N-glycosylation is implicated in metastasis, there is a notable paucity of comprehensive studies addressing the N-glycosylation proteomics associated with liver metastasis in CRC. In this study, N-glycosylated proteins and N-glycosylation sites of differential expression between primary lesions and paired liver metastatic lesions are identified. Cathepsin D (CTSD) is further screened as a potentially pivotal N-glycosylated protein in CRC liver metastasis. Glycosyltransferases complex DDOST and STT3B can regulate N-glycosylation modification at residue 263 of CTSD (a protease), thereby affecting CTSD protease to lyse ACADM. ACADM can regulate ferroptosis-related proteins (ACSL4, SLC7A11, and GPX4) to further influence the invasion and metastasis of CRC cells. This newly discovered mechanism provides potential therapeutic targets for CRC treatment and insights for controlling CRC progression and metastasis.

Glycosylation gene expression profiles enable prognosis prediction for colorectal cancer

This study developed a prognostic model for patients with colon adenocarcinoma (COAD) based on glycosylation-associated genes. By analyzing TCGA-COAD data, 110 key genes were identified, and a prognostic model incorporating five glycosylation-related genes was constructed. The model exhibits good predictive performance and is significantly associated with clinical features such as age, N stage, M stage, and lymph node count. The prognostic genes are involved in various biological processes and pathways, influence T cell differentiation, and may contribute to CRC development. High-risk patients show a higher degree of immune cell infiltration. This model aids in the early diagnosis, prognosis assessment, and treatment planning for CRC, and offers a direction for further research.

Post-translational modifications in drug resistance

Resistance to antitumor drugs, antimicrobial drugs, and antiviral drugs severely limits treatment effectiveness and cure rate of diseases. Protein post-translational modifications (PTMs) represented by glycosylation, ubiquitination, SUMOylation, acetylation, phosphorylation, palmitoylation, and lactylation are closely related to drug resistance. PTMs are typically achieved by adding sugar chains (glycosylation), small proteins (ubiquitination), lipids (palmitoylation), or functional groups (lactylation) to amino acid residues. These covalent additions are usually the results of signaling cascades and could be reversible, with the triggering mechanisms depending on the type of modifications. PTMs are involved in antitumor drug resistance, not only as inducers of drug resistance but also as targets for reversing drug resistance. Bacteria exhibit multiple PTMs-mediated antimicrobial drug resistance. PTMs allow viral proteins and host cell proteins to form complex interaction networks, inducing complex antiviral drug resistance. This review summarizes the important roles of PTMs in drug resistance, providing new ideas for exploring drug resistance mechanisms, developing new drug targets, and guiding treatment plans.

Altered glycosylation in cancer: molecular functions and therapeutic potential

Glycosylation, a key mode of protein modification in living organisms, is critical in regulating various biological functions by influencing protein folding, transportation, and localization. Changes in glycosylation patterns are a significant feature of cancer, are associated with a range of pathological activities in cancer-related processes, and serve as critical biomarkers providing new targets for cancer diagnosis and treatment. Glycoproteins like human epidermal growth factor receptor 2 (HER2) for breast cancer, alpha-fetoprotein (AFP) for liver cancer, carcinoembryonic antigen (CEA) for colon cancer, and prostate-specific antigen (PSA) for prostate cancer are all tumor biomarkers approved for clinical use. Here, we introduce the diversity of glycosylation structures and newly discovered glycosylation substrate-glycosylated RNA (glycoRNA). This article focuses primarily on tumor metastasis, immune evasion, metabolic reprogramming, aberrant ferroptosis responses, and cellular senescence to illustrate the role of glycosylation in cancer. Additionally, we summarize the clinical applications of protein glycosylation in cancer diagnostics, treatment, and multidrug resistance. We envision a promising future for the clinical applications of protein glycosylation.

Characterization of three non-canonical N-glycosylation motifs indicates Nglyco-A reduces DNA N6-methyladenine and Nglyco-D alters G/F actin ratio in Phytophthora sojae

Asparagine (Asn, N)-linked glycosylation is an abundant post-translational modification in which Asn, typically in Nglyco-X-S/T; X ≠ P motifs, are modified with N-glycans. It has essential regulatory roles in multicellular organisms. In this study, we systematically investigate the function of three N-glycosylation motifs (Nglyco-A, Nglyco-D and Nglyco-S) previously identified in Phytophthora sojae, through site-directed mutagenesis and functional assays. In P. sojae expressing glycosylation-dead variants pre-PsDMAP1N70A (Nglyco-A motif) or PsADFN64A (Nglyco-D motif), zoospore release or cyst germination is impaired. In particular, the pre-PsDMAP1N70A mutant reduces DNA methylation levels, and the PsADFN64A mutant disrupts the actin forms, which could explain the decrease in pathogenicity after N-glycosylation is destroyed. Similarly, P. sojae expressing PsNRXN132A (Nglyco-S motif) shows increased sensitivity to H2O2 and heat. Through autophagy or 26S proteasome pathway inhibition assays, we found that unglycosylated pre-PsDMAP1N70A and PsADFN64A are degraded via the 26S proteasome pathway, while the autophagy pathway is responsible for PsNRXN132A clearance. These findings demonstrate that glycosylation of these motifs regulates the stability and function of glycoproteins necessary for P. sojae growth, reproduction and pathogenicity, which expands the scope of known N-glycosylation regulatory functions in oomycetes.

Integrative analysis of the immunological significances of guanylate binding protein family genes in microsatellite stability colorectal cancer

Background

Microsatellite stability (MSS) colorectal cancer (CRC) has poor sensitivity to immunotherapy and its underlying mechanisms are still unclear. Guanylate binding proteins (GBPs) are a family of GTPase involving innate immune responses by providing defense against invading microbes and pathogens. However, the immunological significances of GBPs in MSS CRC remain unknown.

Methods

We utilized bioinformatic tools to comprehensively analysis the expression pattern, clinical relevance, prognostic value, biological function, and immunoregulation effect of distinct GBP members in MSS CRC.

Results

The expression of all seven GBPs in MSS samples are remarkably decreased compared to microsatellite instability-high (MSI-H) samples. Among them, GBP1/2/4/5 are obviously correlated with distant metastasis status. High expression of GBP1/4/5/6 was remarkably related to favorable overall survival (OS) and progression-free survival (PFS) in CRC patients with MSS tumor. Subsequent enrichment analysis revealed that Interferon-gamma (IFN-γ) and NOD-like receptor signaling are the most relevant functions. Besides, the expression patterns of GBPs are remarkably associated with several tumor infiltrated immune cells (e.g. regulatory T cells, CD4+ T cells, and macrophages) and diverse immunoregulatory molecules (e.g. immune checkpoint biomarkers (ICBs) and major histocompatibility complex (MHC) molecules). Moreover, high GBP1/2/4/5 expression predicted better immunotherapy responsiveness in immunotherapy cohorts.

Conclusion

These findings might provide novel insights for the identification of therapeutic targets and potential prognostic biomarkers of GBP family in CRC with MSS samples.

USP18 Is Associated with PD-L1 Antitumor Immunity and Improved Prognosis in Colorectal Cancer

BACKGROUND

Compared with conventional chemotherapy and targeted therapy, immunotherapy has improved the treatment outlook for a variety of solid tumors, including lung cancer, colorectal cancer (CRC), and melanoma. However, it is effective only in certain patients, necessitating the search for alternative strategies to targeted immunotherapy. The deubiquitinating enzyme USP18 is known to play an important role in various aspects of the immune response, but its role in tumor immunity in CRC remains unclear.

METHODS

In this study, multiple online datasets were used to systematically analyze the expression, prognosis, and immunomodulatory role of USP18 in CRC. The effect of USP18 on CRC was assessed via shRNA-mediated knockdown of USP18 expression in combination with CCK-8 and colony formation assays. Finally, molecular docking analysis of USP18/ISG15 and programmed death-ligand 1 (PD-L1) was performed via HDOCK, and an ELISA was used to verify the potential of USP18 to regulate PD-L1.

RESULTS

Our study revealed that USP18 expression was significantly elevated in CRC patients and closely related to clinicopathological characteristics. The experimental data indicated that silencing USP18 significantly promoted the proliferation and population-dependent growth of CRC cells. In addition, high USP18 expression was positively correlated with the CRC survival rate and closely associated with tumor-infiltrating CD8+ T cells and natural killer (NK) cells. Interestingly, USP18 was correlated with the expression of various chemokines and immune checkpoint genes. The results of molecular docking simulations suggest that USP18 may act as a novel regulator of PD-L1 and that its deficiency may potentiate the antitumor immune response to PD-L1 blockade immunotherapy in CRC.

CONCLUSIONS

In summary, USP18 shows great promise for research and clinical application as a potential target for CRC immunotherapy.

Glycosylation: mechanisms, biological functions and clinical implications

Protein post-translational modification (PTM) is a covalent process that occurs in proteins during or after translation through the addition or removal of one or more functional groups, and has a profound effect on protein function. Glycosylation is one of the most common PTMs, in which polysaccharides are transferred to specific amino acid residues in proteins by glycosyltransferases. A growing body of evidence suggests that glycosylation is essential for the unfolding of various functional activities in organisms, such as playing a key role in the regulation of protein function, cell adhesion and immune escape. Aberrant glycosylation is also closely associated with the development of various diseases. Abnormal glycosylation patterns are closely linked to the emergence of various health conditions, including cancer, inflammation, autoimmune disorders, and several other diseases. However, the underlying composition and structure of the glycosylated residues have not been determined. It is imperative to fully understand the internal structure and differential expression of glycosylation, and to incorporate advanced detection technologies to keep the knowledge advancing. Investigations on the clinical applications of glycosylation focused on sensitive and promising biomarkers, development of more effective small molecule targeted drugs and emerging vaccines. These studies provide a new area for novel therapeutic strategies based on glycosylation.

Protein O-fucosyltransferase 1 promotes PD-L1 stability to drive immune evasion and directs liver cancer to immunotherapy

BACKGROUND AND AIMS

The immunosuppressive tumor microenvironment (TME) plays an essential role in cancer progression and immunotherapy response. Despite the considerable advancements in cancer immunotherapy, the limited response to immune checkpoint blockade (ICB) therapies in patients with hepatocellular carcinoma (HCC) remains a major challenge for its clinical implications. Here, we investigated the molecular basis of the protein O-fucosyltransferase 1 (POFUT1) that drives HCC immune evasion and explored a potential therapeutic strategy for enhancing ICB efficacy.

METHODS

De novo MYC/Trp53-/- liver tumor and the xenograft tumor models were used to evaluate the function of POFUT1 in immune evasion. Biochemical assays were performed to elucidate the underlying mechanism of POFUT1-mediated immune evasion.

RESULTS

We identified POFUT1 as a crucial promoter of immune evasion in liver cancer. Notably, POFUT1 promoted HCC progression and inhibited T-cell infiltration in the xenograft tumor and de novo MYC/Trp53-/- mouse liver tumor models. Mechanistically, we demonstrated that POFUT1 stabilized programmed death ligand 1 (PD-L1) protein by preventing tripartite motif containing 21-mediated PD-L1 ubiquitination and degradation independently of its protein-O-fucosyltransferase activity. In addition, we further demonstrated that PD-L1 was required for the tumor-promoting and immune evasion effects of POFUT1 in HCC. Importantly, inhibition of POFUT1 could synergize with anti-programmed death receptor 1 therapy by remodeling TME in the xenograft tumor mouse model. Clinically, POFUT1 high expression displayed a lower response rate and worse clinical outcome to ICB therapies.

CONCLUSIONS

Our findings demonstrate that POFUT1 functions as a novel regulator of tumor immune evasion and inhibition of POFUT1 may be a potential therapeutic strategy to enhance the efficacy of immune therapy in HCC.

The prognostic implications and tumor-promoting functions of CHSY3 in gastric cancer

Chondroitin sulfate synthase 3 (CHSY3) is an important enzyme that regulates glycosylation, but its role in tumors has not been determined. Here, we showed that high CHSY3 expression promotes proliferation in gastric cancer (GC) cells and is associated with poor prognosis in GC patients. We analyzed the immunohistochemistry data of 150 gastric cancer patients to determine the clinicopathological and survival significance of CHSY3. Immunofluorescence was used to detect the colocalization of CHSY3 with infiltrating immune cells. Additionally, CHSY3 was predominantly found in tumor tissues and showed higher abundance compared to matched adjacent tissues. High CHSY3 expression was associated with more advanced tumor stage, higher recurrence risk and worse survival. Immunohistochemistry and bioinformatic analysis revealed that CHSY3 expression was significantly positively correlated with tumor-associated macrophage (TAM) infiltration. Moreover, after knocking down CHSY3, the proliferation of cells was decreased, and the migration ability was reduced, as shown by scratch, monoclonal and transwell assays. In conclusion, this study revealed that CHSY3 has a tumor-promoting effect on GC, suggesting a novel therapeutic strategy against this disease.

Advances in molecular targeted drugs in combination with CAR-T cell therapy for hematologic malignancies

Molecular targeted drugs and chimeric antigen receptor (CAR) T cell therapy represent specific biological treatments that have significantly improved the efficacy of treating hematologic malignancies. However, they face challenges such as drug resistance and recurrence after treatment. Combining molecular targeted drugs and CAR-T cells could regulate immunity, improve tumor microenvironment (TME), promote cell apoptosis, and enhance sensitivity to tumor cell killing. This approach might provide a dual coordinated attack on cancer cells, effectively eliminating minimal residual disease and overcoming therapy resistance. Moreover, molecular targeted drugs can directly or indirectly enhance the anti-tumor effect of CAR-T cells by inducing tumor target antigen expression, reversing CAR-T cell exhaustion, and reducing CAR-T cell associated toxic side effects. Therefore, combining molecular targeted drugs with CAR-T cells is a promising and novel tactic for treating hematologic malignancies. In this review article, we focus on analyzing the mechanism of therapy resistance and its reversal of CAR-T cell therapy resistance, as well as the synergistic mechanism, safety, and future challenges in CAR-T cell therapy in combination with molecular targeted drugs. We aim to explore the benefits of this combination therapy for patients with hematologic malignancies and provide a rationale for subsequent clinical studies.

Molecular and immunological characteristics of postoperative relapse in lymph node-positive esophageal squamous cell cancer

BACKGROUND

The molecular and immunological characteristics of primary tumors and positive lymph nodes in esophageal squamous cell carcinoma (ESCC) are unknown and the relationship with recurrence is unclear, which this study attempted to explore.

METHODS

A total of 30 ESCC patients with lymph node positive (IIB-IVA) were enrolled. Among them, primary tumor and lymph node specimens were collected from each patient, and subjected to 551-tumor-targeted DNA sequencing and 289-immuno-oncology RNA panel sequencing to identify the different molecular basis and immunological features, respectively.

RESULTS

The primary tumors exhibited a higher mutation burden than lymph nodes (p < 0.001). One-year recurrent ESCC exhibited a higher Mucin16 (MUC16) mutation rate (p = 0.038), as well as univariate and multivariate analysis revealed that MUC16 mutation is independent genetic factor associated with reduced relapse-free survival (univariate, HR: 5.39, 95% CI: 1.67-17.4, p = 0.005; multivariate, HR: 7.36, 95% CI: 1.79-30.23, p = 0.006). Transcriptomic results showed non-relapse group had higher cytolytic activity (CYT) score (p = 0.025), and was enriched in the IFN-α pathway (p = 0.036), while those in the relapsed group were enriched in the TNF-α/NF-κB (p = 0.001) and PI3K/Akt pathway (p = 0.014).

CONCLUSION

The difference in molecular characteristics between primary lesions and lymph nodes may be the cause of the inconsistent clinical outcomes. Mutations of MUC16 and poor immune infiltration are associated with rapid relapse of nodes-positive ESCC.

Interferons in Colorectal Cancer Pathogenesis and Therapy

As key modulators of the immune response, interferons play critical roles following infection and during the pathogenesis of cancer. The idea that these cytokines might be developed as new therapies emerged soon after their discovery. While enthusiasm for this approach to cancer therapy has waxed and waned over the ensuing decades, recent advances in cancer immunotherapy and our improved understanding of the tumor immune environment have led to a resurgence of interest in this unique class of biologic drug. Here, we review how interferons influence the growth of colorectal cancers (CRCs) and highlight new insights into how interferons and drugs that modulate interferon expression might be most effectively deployed in the clinic.

Glycosylation Targeting: A Paradigm Shift in Cancer Immunotherapy

Immunotherapy has shown great potential in cancer treatment. However, even with the intervention of techniques such as immune checkpoint inhibitor therapy, tumors can still achieve immune escape, leading to a low response rate. Abnormal glycosylation is a widely recognized hallmark of cancer. The development of a complex "glyco-code" on the surface of tumor cells can potentially influence the immune system's ability to monitor tumors and can impact the anti-tumor immune response. Therefore, abnormal glycosylation has emerged as a promising target for immunotherapy. Many recent studies have shown that targeted glycosylation can reshape the tumor microenvironment (TME) and promote the immune response, thereby improving the response to immunotherapy. This review summarizes how glycosylation affects anti-tumor immune function in the TME and synthesizes the latest research progress on targeted glycosylation in immunotherapy. It is hoped that by elucidating the basic laws and biological connotations of glycosylation, this review will enable researcher to thoroughly analyze the mechanism of its influence on the immune metabolic regulation network, which will provide a theoretical tool for promoting the clinical application of glycosylation codes.

Deregulation of interferon-gamma receptor 1 expression and its implications for lung adenocarcinoma progression

Interferon-gamma (IFN-γ) plays a dual role in cancer; it is both a pro- and an antitumorigenic cytokine, depending on the type of cancer. The deregulation of the IFN-γ canonic pathway is associated with several disorders, including vulnerability to viral infections, inflammation, and cancer progression. In particular, the interplay between lung adenocarcinoma (LUAD) and viral infections appears to exist in association with the deregulation of IFN-γ signaling. In this mini-review, we investigated the status of the IFN-γ signaling pathway and the expression level of its components in LUAD. Interestingly, a reduction in IFNGR1 expression seems to be associated with LUAD progression, affecting defenses against viruses such as severe acute respiratory syndrome coronavirus 2. In addition, alterations in the expression of IFNGR1 may inhibit the antiproliferative action of IFN-γ signaling in LUAD.

Utilizing multimodal mass spectrometry imaging for profiling immune cell composition and N-glycosylation across colorectal carcinoma disease progression

Colorectal cancer (CRC) stands as a leading cause of death worldwide, often arising from specific genetic mutations, progressing from pre-cancerous adenomas to adenocarcinomas. Early detection through regular screening can result in a 90% 5-year survival rate for patients. However, unfortunately, only a fraction of CRC cases are identified at pre-invasive stages, allowing progression to occur silently over 10-15 years. The intricate interplay between the immune system and tumor cells within the tumor microenvironment plays a pivotal role in the progression of CRC. Immune cell clusters can either inhibit or facilitate tumor initiation, growth, and metastasis. To gain a better understanding of this relationship, we conducted N-glycomic profiling using matrix-assisted laser desorption-ionization mass spectrometry imaging (MALDI-MSI). We detected nearly 100 N-glycan species across all samples, revealing a shift in N-glycome profiles from normal to cancerous tissues, marked by a decrease in high mannose N-glycans. Further analysis of precancerous to invasive carcinomas showed an increase in pauci-mannose biantennary, and tetraantennary N-glycans with disease progression. Moreover, a distinct stratification in the N-glycome profile was observed between non-mucinous and mucinous CRC tissues, driven by pauci-mannose, high mannose, and bisecting N-glycans. Notably, we identified immune clusters of CD20+ B cells and CD3/CD44+ T cells distinctive and predictive with signature profiles of bisecting and branched N-glycans. These spatial N-glycan profiles offer potential biomarkers and therapeutic targets throughout the progression of CRC.

Protein post-translational modifications: A key factor in colorectal cancer resistance mechanisms

Colorectal cancer (CRC) is one of the leading causes of cancer-related death. Despite advances in treatment, drug resistance remains a critical impediment. Post-translational modifications (PTMs) regulate protein stability, localization, and activity, impacting vital cellular processes. Recent research has highlighted the essential role of PTMs in the development of CRC resistance. This review summarizes recent advancements in understanding PTMs' roles in CRC resistance, focusing on the latest discoveries. We discuss the functional impact of PTMs on signaling pathways and molecules involved in CRC resistance, progress in drug development, and potential therapeutic targets. We also summarize the primary enrichment methods for PTMs. Finally, we discuss current challenges and future directions, including the need for more comprehensive PTM analysis methods and PTM-targeted therapies. This review identifies potential therapeutic interventions for addressing medication resistance in CRC, proposes prospective therapeutic options, and gives an overview of the function of PTMs in CRC resistance.

The DC-T cell axis is an effective target for the treatment of non-small cell lung cancer

The dendritic cell (DC)-T cell axis is a bridge that connects innate and adaptive immunities. The initial immune response against tumors is mainly induced by mature antigen-presenting DCs. Enhancing the crosstalk between DCs and T cells may be an effective approach to improve the immune response to non-small cell lung cancer (NSCLC). In this article, a review was made of the interaction between DCs and T cells in the treatment of NSCLC and how this interaction affects the treatment outcome.

The role of IFN-γ-signalling in response to immune checkpoint blockade therapy

Treatment with immune checkpoint inhibitors, widely known as immune checkpoint blockade therapy (ICBT), is now the fourth pillar in cancer treatment, offering the chance of durable remission for patients with advanced disease. However, ICBT fails to induce objective responses in most cancer patients with still others progressing after an initial response. It is necessary, therefore, to elucidate the primary and acquired resistance mechanisms to ICBT to improve its efficacy. Here, we highlight the paradoxical role of the cytokine interferon-γ (IFN-γ) in ICBT response: on the one hand induction of IFN-γ signalling in the tumour microenvironment correlates with good ICBT response as it drives the cellular immune responses required for tumour destruction; nonetheless, IFN-γ signalling is implicated in ICBT acquired resistance. We address the negative feedback and immunoregulatory effects of IFN-γ signalling that promote immune evasion and resistance to ICBT and discuss how these can be targeted pharmacologically to restore sensitivity or circumvent resistance.

Warning Signs From the Crypt: Aberrant Protein Glycosylation Marks Opportunities for Early Colorectal Cancer Detection

Colorectal cancer (CRC) remains a leading cause of cancer-related deaths despite being the most preventable and treatable forms of cancer when caught early through screening. There is an unmet need for novel screening approaches with improved accuracy, less invasiveness, and reduced costs. In recent years, evidence has accumulated around particular biological events that happen during the adenoma-to-carcinoma transition, especially focusing on precancerous immune responses in the colonic crypt. Protein glycosylation plays a central role in driving those responses, and recently, numerous reports have been published on how aberrant protein glycosylation both in colonic tissue and on circulating glycoproteins reflects these precancerous developments. The complex field of glycosylation, which exceeds complexity of proteins by several orders of magnitude, can now be studied primarily because of the availability of new high-throughput technologies such as mass spectrometry and artificial intelligence-powered data processing. This has now opened new avenues for studying novel biomarkers for CRC screening. This review summarizes the early events taking place from the normal colon mucosa toward adenoma and adenocarcinoma formation and associated critical protein glycosylation phenomena, both on the tissue level and in the circulation. These insights will help establish an understanding in the interpretation of novel CRC detection modalities that involve high-throughput glycomics.

Dysregulation in IFN-γ signaling and response: the barricade to tumor immunotherapy

Interferon-gamma (IFN-γ) has been identified as a crucial factor in determining the responsiveness to immunotherapy. Produced primarily by natural killer (NK) and T cells, IFN-γ promotes activation, maturation, proliferation, cytokine expression, and effector function in immune cells, while simultaneously inducing antigen presentation, growth arrest, and apoptosis in tumor cells. However, tumor cells can hijack the IFN-γ signaling pathway to mount IFN-γ resistance: rather than increasing antigenicity and succumbing to death, tumor cells acquire stemness characteristics and express immunosuppressive molecules to defend against antitumor immunity. In this review, we summarize the potential mechanisms of IFN-γ resistance occurring at two critical stages: disrupted signal transduction along the IFNG/IFNGR/JAK/STAT pathway, or preferential expression of specific interferon-stimulated genes (ISGs). Elucidating the molecular mechanisms through which tumor cells develop IFN-γ resistance help identify promising therapeutic targets to improve immunotherapy, with broad application value in conjugation with targeted, antibody or cellular therapies.

Fundamental concepts of protein therapeutics and spacing in oncology: an updated comprehensive review

Current treatment regimens in cancer cases cause significant side effects and cannot effectively eradicate the advanced disease. Hence, much effort has been expended over the past years to understand how cancer grows and responds to therapies. Meanwhile, proteins as a type of biopolymers have been under commercial development for over three decades and have been proven to improve the healthcare system as effective medicines for treating many types of progressive disease, such as cancer. Following approving the first recombinant protein therapeutics by FDA (Humulin), there have been a revolution for drawing attention toward protein-based therapeutics (PTs). Since then, the ability to tailor proteins with ideal pharmacokinetics has provided the pharmaceutical industry with an important noble path to discuss the clinical potential of proteins in oncology research. Unlike traditional chemotherapy molecules, PTs actively target cancerous cells by binding to their surface receptors and the other biomarkers particularly associated with tumorous or healthy tissue. This review analyzes the potential and limitations of protein therapeutics (PTs) in the treatment of cancer as well as highlighting the evolving strategies by addressing all possible factors, including pharmacology profile and targeted therapy approaches. This review provides a comprehensive overview of the current state of PTs in oncology, including their pharmacology profile, targeted therapy approaches, and prospects. The reviewed data show that several current and future challenges remain to make PTs a promising and effective anticancer drug, such as safety, immunogenicity, protein stability/degradation, and protein-adjuvant interactions.