MGP promotes CD8+ T cell exhaustion by activating the NF-κB pathway leading to liver metastasis of colorectal cancer

Progress of IL-10 and liver metastasis

Liver metastasis can occur in a wide range of cancers and have a significant impact on patient survival and prognosis. Once liver metastasis occurs, patients often lose the opportunity for surgery, and although a small percentage of patients can undergo hepatic resection to prolong survival, the benefit is not great. There were also many factors affecting liver metastasis, including reprogramming of the primary tumor metabolism, disturbances in the immune microenvironment and immune cells, alterations in the gut microbiota, and epigenetic changes. Interleukin-10 (IL-10) has a dual role as a cytokine that has been found in recent years to be pro-inflammatory as well as pro-liver metastasis. IL-10 exerts pro-metastatic effects mainly by regulating the polarization of tumor macrophages in the tumor microenvironment, especially by promoting the polarization of M2 macrophages. However, the role of IL-10 in tumorigenesis and progression remains controversial and the molecular mechanism involved in promoting liver metastasis is currently unclear. In view of the increasing role of IL-10 in promoting liver metastasis, this review summarizes the role of IL-10 in liver metastasis of colorectal cancer, breast cancer and other tumors in recent years, and provides ideas for subsequent clinical practice and basic research.

RUNX1/SLAMF3 Axis Drives Immunosuppression to Contribute to Colorectal Cancer Liver Metastasis by Blocking Phagocytosis and Depleting C1QC+ Tumor-Associated Macrophages

Colorectal cancer liver metastasis (CRLM) is a leading cause of death in colorectal cancer (CRC) patients and is characterized by an immunosuppressive tumor microenvironment (TME). This study employs mouse in vivo selection to isolate highly metastatic CRLM derivatives for profiling their transcriptomic, proteomic, and metabolomic alterations associated with CRLM. Notably, the expression of SLAMF3 is significantly upregulated in CRLM derivatives and its knockdown effectively suppresses CRLM in mice. RUNX1 transcriptionally upregulates SLAMF3 expression and combined targeting of the RUNX1/SLAMF3 axis synergistically suppresses liver metastasis in mice. In parallel, SLAMF3 suppresses macrophage-mediated phagocytosis of CRC cells through the SHP-1/2/mTORC1 pathway. Conversely, SLAMF3 knockdown promotes M1 polarization in liver metastases and activates the CCL signaling pathway between macrophages and CD8+ T cells. It also reduces the exhausted CD8+ T cells in liver metastases and the expression of inhibitory receptors PD-1 and TIM-3, thus alleviating the immunosuppressive TME. Clinically, activation of the RUNX1/SLAMF3 axis is closely associated with CRLM progression and correlates with a reduced proportion of clinically beneficial C1QC⁺ tumor-associated macrophages (TAMs). Collectively, these findings identify the RUNX1/SLAMF3 axis as a key driver of immunosuppressive TME remodeling and CRLM progression, highlighting its potential as a promising therapeutic target for CRLM.

Targeting BATF2-RGS2 axis reduces T-cell exhaustion and restores anti-tumor immunity

OBJECTIVE

This study aims to investigate the role of RGS2 in immune regulation in lung cancer (LC) and explore the regulatory relationship between RGS2 and BATF2 in modulating T cell exhaustion and tumor immune evasion.

METHODS

Single-cell transcriptome-based analysis was performed to identify CD8+ T-cell profiles and regulatory factors in six LC patients receiving neoadjuvant PD-1 blockade therapy. Mouse 3LL cells or murine tumor organoid models were transplanted into wild-type, RGS2 knock-out (RGS2-/-), or BATF2 knock-out (BATF2-/-) mice to analyze the effects of RGS2 and BATF2 on tumor growth, metastasis, and immune cell infiltration. CD8+ from these mice were isolated and co-cultured with cancer cells to analyze T cell cytotoxicity in vitro. The transcriptional regulation of RGS2 by BATF2 was analyzed using luciferase reporter assays.

RESULTS

RGS2 was highly expressed in CD8+ T-exhausted (Tex) cells and was associated with pro-inflammatory pathways. High RGS2 expression predicted poor clinical outcomes and limited response to PD-1/PD-L1 blockade therapy. In RGS2-/- mice, tumor metastasis and angiogenesis were suppressed, CD8+ effector T cells were enhanced, and T cell exhaustion markers were reduced. BATF2 was identified as a key transcriptional regulator of RGS2, promoting T cell exhaustion through inhibition of CXCL13 secretion. Knockdown of BATF2 or RGS2 impaired lung cancer cell proliferation and enhanced sensitivity to NK cell-mediated cytotoxicity in vitro. In BATF2-/- mice, the populations of immune active CD8+ T cells were increased, while exhausted T cells were reduced, leading to improved anti-tumor immune responses.

CONCLUSIONS

RGS2, regulated by BATF2, plays a critical role in driving T cell exhaustion and tumor immune evasion in LC. Targeting the BATF2-RGS2 axis may enhance the effectiveness of immunotherapy by reversing T cell exhaustion and improving anti-tumor immunity.

Mechanisms of CD8+ T cell exhaustion and its clinical significance in prognosis of anti-tumor therapies: A review

In recent years, immunotherapy has gradually become one of the main strategies for cancer treatment, with immune checkpoint inhibitors (ICIs) offering new possibilities for tumor therapy. However, some cancer patients exhibit low responses and resistance to ICIs treatment. T cell exhaustion, a process associated with tumor progression, refers to a subset of T cells that progressively lose effector functions and exhibit increased expression of inhibitory receptors. These exhausted T cells are considered key players in the therapeutic efficacy of immune checkpoint inhibitors. Therefore, understanding the impact of T cell exhaustion on tumor immunotherapy and the underlying mechanisms is critical for improving clinical treatment outcomes. Several elegant studies have provided insights into the prognostic value of exhausted T cells in cancers. In this review, we highlight the process of exhausted T cells and its predictive value in various cancers, as well as the relevant mechanisms behind it, providing new insights into the immunotherapy of cancer.

MGP regulates the adipogenic differentiation of mesenchymal stem cells in osteoporosis via the Ca2+/CaMKII/RIP140/FABP3 axis

The dysregulation of bone marrow mesenchymal stem cells (BM-MSCs) is crucial in the pathogenesis of osteoporosis, and adipogenic differentiation of BM-MSCs is considered an essential factor in this process. However, the mechanisms underlying the regulation of MSC adipogenic differentiation require further investigation. MGP (Matrix Gla Protein) was reported to impair the osteogenic differentiation. However, the mechanisms through which MGP regulates osteoporosis and bone-fat imbalance in MSCs are still unclear. In this study, we confirmed that the expression of MGP upregulated in osteoporosis and has a negative correlation with BMD (bone mineral density). Gain- and loss-of-function experiments were performed to ensure the role of MGP in MSC adipogenic differentiation. Mechanistically, MGP increased intracellular free Ca2+ levels and enhanced CaMKII phosphorylation, which in turn activated RIP140 protein degradation. This led to an increase in the transcription of FABP3, ultimately promoting adipogenic differentiation in MSCs. Furthermore, we demonstrated that using recombinant adeno-associated virus 9 (rAAV9) to silence MGP has the effect of alleviating bone loss and reversing the excessive bone marrow adipose tissue in mice with osteoporosis. In summary, our research has unveiled the regulatory role of MGP/Ca2+/CaMKII/RIP140/FABP3 axis in adipogenic differentiation in MSC and it might be a promising approach for osteoporosis treatment.

The tumor microenvironment and dendritic cells: Developers of pioneering strategies in colorectal cancer immunotherapy?

Colorectal cancer (CRC) is the world's third most frequent cancer, and both its incidence and fatality rates are rising. Despite various therapeutic approaches, neither its mortality rate nor its recurrence frequency has decreased significantly. Additionally, conventional treatment approaches, such as chemotherapy and radiotherapy, have several side effects and risks for patients with CRC. Accordingly, the need for alternative and effective treatments for CRC patients is critical. Immunotherapy that utilizes dendritic cells (DCs) harnesses the patient's immune system to combat cancer cells effectively. DCs are the most potent antigen-presenting cells (APCs), which play a vital role in generating anti-cancer T cell responses. A significant barrier to the immune system's ability to eliminate CRC is the establishment of a potent immunosuppressive tumor milieu by malignant cells. Since DCs are frequently defective in this milieu, the tumor setting significantly reduces the effectiveness of DC-based therapy. Determining central mechanisms contributing to tumor growth by unraveling and comprehending the interaction between CRC tumor milieu and DCs may lead to new therapeutic approaches. This study aims to review DC biology and discuss its role in T-cell-mediated anti-tumor immunity, as well as to highlight the immunosuppressive effects of the CRC tumor milieu on the function of DCs. We will also highlight the tumor microenvironment (TME)-related factors that interfere with DC function as a possible therapeutic target to enhance DC-based cell therapy efficacy.

A novel mouse model of upper tract urothelial carcinoma highlights the impact of dietary intervention on gut microbiota and carcinogenesis prevention despite carcinogen exposure

Animal models of N-butyl-N-(4-hydroxy butyl) nitrosamine (BBN)-induced urothelial carcinoma (UC), particularly bladder cancer (BC), have long been established. However, the rare incidence of BBN-induced upper urinary tract UC (UTUC), which originates from the same urothelium as BC, remains elusive. The scarcity of animal models of UTUC has made it challenging to study the biology of UTUC. To address this problem, we tried to establish a novel mouse model of UTUC by treating multiple mice strains and sexes with BBN. The molecular consistency between the UTUC mouse model and human UTUC was confirmed using multi-omics analyses, including whole-exome, whole-transcriptome, and spatial transcriptome sequencing. 16S ribosomal RNA metagenome sequencing, metabolome analysis, and dietary interventions were employed to assess changes in the gut microbiome, metabolome, and carcinogenesis of UTUC. Of all treated mice, only female BALB/c mice developed UTUC over BC. Multi-omics analyses confirmed that the UTUC model reflected the molecular characteristics and heterogeneity of human UTUC with poor prognosis. Furthermore, the model exhibited increased Tnf-related inflammatory gene expression in the upper urinary tract and a low relative abundance of Parabacteroides distasonis in the gut. Dietary intervention, mainly without alanine, led to P. distasonis upregulation and successfully prevented UTUC, as well as suppressed Tnf-related inflammatory gene expression in the upper urinary tract despite the exposure to BBN. This is the first report to demonstrate a higher incidence of UTUC than BC in a non-engineered mouse model using BBN. Overall, this model could serve as a useful tool for comprehensively investigating UTUC in future studies.

Migrasome-Related Genes as Potential Prognosis and Immunotherapy Response Predictors for Colorectal Cancer

Background: Studies highlight the role of migrasomes as mediators of intercellular communication and signaling, critical in influencing tumorigenesis and progression. Yet migrasome-related genes and their potential role in colorectal cancer prognosis remain unexplored. Methods: Differentially expressed gene set A (DEG set A) was identified in the TCGA-CRC dataset, and Weighted Gene Co-expression Network Analysis (WGCNA) was performed to identify the most important modules associated with migrasome-related gene (MRG) scores. Single-cell RNA-seq dataset GSE231559 DEG set B was determined. Candidate migrasome-related genes were filtered by intersecting DGE set A, key module genes, and DEG set B. Prognostic genes were subsequently screened through regression analysis, and a risk model was developed. Patients with CRC in the TCGA cohort were stratified into high- and low-risk groups based on the optimal cutoff of the risk score. Immunotherapy response-related analyses were then performed. Finally, cell-to-cell communication analysis was carried out for key cells identified based on prognostic gene expression analysis in annotated cells. Results: The six candidate migrasome-related genes were identified through the overlap of 5158 DEG set A, 1960 key module genes, and 146 DEG set B. Further screening led to the selection of T1MP1, CXCL8, and MGP as potential prognostic biomarkers. Immune-related analysis indicated that the high-risk group exhibited a better response to immunotherapy. Notably, the prognostic genes showed elevated expression levels in monocytes and tissue stem cells, thereby designating them as key cell types. Conclusions: We conducted bioinformatic analysis of migrasome-related genes and identified significant involvement of T1MP1, CXCL8, and MGP in influencing CRC prognosis and immunotherapy response. Our research provides novel insights into the role of migrasomes in CRC biology.

The role of calcium signaling in organotropic metastasis of cancer

Tumor metastasis is an important event in cancer progression, representing an enduring and irrevocable hallmark of cancers. The causes of tumor metastasis are complex and diverse. Arising evidence shows that the dysregulation of calcium signaling plays a crucial role in its initiation and progress. Calcium is an essential secondary messenger that regulates signaling pathways associated with tumor metastasis. The transient accumulation of calcium potentially promotes the advancement of tumor metastasis, while calcium-dependent proteins and calcium-related channels also significantly contribute to such malignant process. Thus, compounds specially targeting calcium channels, transporters or pumps may be therapeutic approaches prohibiting tumor metastasis. This review focuses on exploring the roles of calcium ions, calcium-dependent proteins and calcium-related channels in organotropic metastasis of cancer and its clinical applications in the treatment of metastatic cancers.

Single-cell and spatial transcriptomics reveal pre-metastatic subsets and therapeutic targets in penile carcinoma

Tumor heterogeneity, driven by branching evolution and genomic mutations, complicates cancer treatment. Understanding malignant cell evolution across various tumors aids in identifying pre-metastatic subpopulations for optimized therapies. Using bulk RNA sequencing (6 primary penile carcinomas, 6 metastatic lymph nodes, GSE196978), single-cell RNA sequencing (4 advanced penile carcinomas), spatial transcriptomics (Squamous cell carcinoma [SCC]: GSE144239-GSM4565823 and SCC: GSE144239-GSM4565826), and cell assays with Silmitasertib, we mapped heterogeneity and pinpointed therapeutic targets. In penile carcinoma, we discovered an MMP3+SPP1+ pre-metastatic subset and casein kinase 2 alpha 1 (CK2α) overexpression. The nuclear factor κB (NF-κB) pathway may drive metastasis. Pan-cancer analysis showed that MMP3 and SPP1 link to epithelial mesenchymal transition (EMT) and drug resistance, while CK2α activates oncogenes. Silmitasertib, a CK2α inhibitor, exhibited anti-tumor effects in penile carcinoma cells. Validated across 98 single-cell and 6 spatial datasets, our study advances the understanding of tumorigenesis and metastasis, highlighting Silmitasertib as a potential therapeutic agent.

Advancements in cellular immunotherapy: overcoming resistance in lung and colorectal cancer

Immunotherapy has revolutionized cancer treatment, offering hope for patients with otherwise treatment-resistant tumors. Among the most promising approaches are cellular therapies, particularly chimeric antigen receptor T-cell (CAR-T) therapy, which has shown remarkable success in hematologic malignancies. However, the application of these therapies to solid tumors, such as lung and colorectal cancers, has faced significant challenges. Tumor resistance mechanisms-ranging from immune evasion, antigen loss, and immune checkpoint upregulation, to tumor microenvironment immunosuppression-remain major obstacles. This mini-review highlights the latest advancements in tumor immunotherapy, with a focus on cellular therapies, and addresses the resistance mechanisms that hinder their effectiveness in lung and colorectal cancers. We examine the evolution of CAR-T cell therapy, as well as the potential of engineered natural killer (NK) cells and macrophages in solid tumor treatment. The review also explores cutting-edge strategies aimed at overcoming resistance, including combination therapies, gene editing technologies, and nanotechnology for targeted drug delivery. By discussing the molecular, cellular, and microenvironmental factors contributing to resistance, we aim to provide a comprehensive overview of how these challenges can be overcome, paving the way for more effective, personalized immunotherapies in lung and colorectal cancer treatment.

Tumor Necrosis Factor-α-Dependent Inflammation Upregulates High Mobility Group Box 1 To Induce Tumor Promotion and Anti-Programmed Cell Death Protein-1 Immunotherapy Resistance in Lung Adenocarcinoma

Tumor-associated chronic lung inflammation depends on tumor necrosis factor (TNF)-α to activate several cytokines as part of an inflammatory loop, which plays a critical role in tumor progression in lung adenocarcinoma. High mobility group box 1 (HMGB1) is a cytokine that mediates inflammation. Whether TNF-α-induced inflammation regulates HMGB1 to contribute to tumor progression and promotion in lung adenocarcinoma remains unclear. Thus, human samples and a urethane-induced inflammation-driven lung adenocarcinoma (IDLA) mouse model were used to explore the involvement of HMGB1 in tumorigenesis and tumor progression and efficacy of anti-programmed cell death protein (PD)-1 immunotherapy. High levels of HMGB1 were observed in human lung adenocarcinoma associated with poor overall survival in patients. HMGB1 upregulation was positively correlated with TNF-α-related inflammation and TIM-3+ infiltration. TNF-α upregulated intracellular and extracellular HMGB1 expression to contribute to tumor promotion in A549 cells in vitro. Using a urethane-induced IDLA mouse model, we found HMGB1 upregulation was associated with increased TIM-3+ T-cell infiltration. Blocking TNF-α-dependent inflammation downregulated HMGB1 expression and inhibited tumorigenesis in the IDLA model. Anti-PD-1 treatment alone did not inhibit tumor growth in the TNF-α-dependent IDLA, whereas anti-PD-1 combined with TNF-α blockade overcame anti-PD-1 immunotherapy resistance. Furthermore, anti-PD-1 combined with anti-HMGB1 also inhibited tumor growth in IDLA, suggesting that increased HMGB1 release by TNF-α contributes to the resistance of anti-PD-1 immunotherapy in IDLA. Thus, tumor-associated TNF-α-dependent inflammation upregulated intracellular and extracellular HMGB1 expression in an inflammatory loop, contributing to tumor promotion and anti-PD-1 immunotherapy resistance in lung adenocarcinoma.

Single-cell RNA sequencing and spatial transcriptomics of esophageal squamous cell carcinoma with lymph node metastases

Esophageal squamous cell carcinoma (ESCC) patients often face a grim prognosis due to lymph node metastasis. However, a comprehensive understanding of the cellular and molecular characteristics of metastatic lymph nodes in ESCC remains elusive. In this study involving 12 metastatic ESCC patients, we employed single-cell sequencing, spatial transcriptomics (ST), and multiplex immunohistochemistry (mIHC) to explore the spatial and molecular attributes of primary tumor samples, adjacent tissues, metastatic and non-metastatic lymph nodes. The analysis of 161,333 cells revealed specific subclusters of epithelial cells that were significantly enriched in metastatic lymph nodes, suggesting pro-metastatic characteristics. Furthermore, stromal cells in the tumor microenvironment, including MMP3+IL24+ fibroblasts, APLN+ endothelial cells, and CXCL12+ pericytes, were implicated in ESCC metastasis through angiogenesis, collagen production, and inflammatory responses. Exhausted CD8+ T cells in a cycling status were notably prevalent in metastatic lymph nodes, indicating their potential role in facilitating metastasis. We identified distinct cell-cell communication networks and specific ligand-receptor pathways. Our findings were validated through a spatial transcriptome map and mIHC. This study enhances our comprehension of the cellular and molecular aspects of metastatic lymph nodes in ESCC patients, offering potential insights into novel therapeutic strategies for these individuals.

Tumor-Infiltrating Immune Cells in Colorectal Cancer

Colorectal cancer encompasses a heterogeneous group of malignancies that differ in pathophysiological mechanisms, immune response and infiltration, therapeutic response, and clinical prognosis. Numerous studies have highlighted the clinical relevance of tumor-infiltrating immune cells among different types of colorectal tumors yet vary in cell type definitions and cell identification strategies. The distinction of immune signatures is particularly challenging when several immune subtypes are involved but crucial to identify novel intercellular mechanisms within the tumor microenvironment. In this review, we compile human and non-human studies on tumor-infiltrating immune cells and provide an overview of immune subtypes, their pathophysiological functions, and their prognostic role in colorectal cancer. We discuss how differentiating immune signatures can guide the development of immunotherapeutic targets and personalized treatment regimens. We analyzed comprehensive human protein biomarker profiles across the entire immune spectrum to improve interpretability and application of tumor studies and to ultimately enhance immunotherapy and advance precision medicine for colorectal cancer patients.

Effect and mechanism of novel HDAC inhibitor ZDLT-1 in colorectal cancer by regulating apoptosis and inflammation

BACKGROUND

Histone deacetylase (HDAC) is a potential target for Colorectal Cancer (CRC) molecular target therapy, dehydroharmine derivative ZDLT-1 was designed to inhibit CRC cell proliferation by inhibiting HDAC target. This study aimed to explore the effect of ZDLT-1 could induce apoptosis in CRC in vitro and in vivo, and determine the mechanism of ZDLT-1.

METHODS

First, MTT assay, colony formation, wound healing, Transwell assay, Hoechst33342 staining and Annexin V-FITC/PI double staining assay were used to investigate the in vitro effect of ZDLT-1. Second, the toxicity and the anti-tumor effect of ZDLT-1 by subcutaneous tumorigenesis assay were used to determine the in vivo effect of ZDLT-1. In terms of mechanism, we evaluated the effect of ZDLT-1 on HDAC downstream proteins such as HIF-1α, NF-κB, Cleaved-Caspase-3/9, GSDMD and acetylated histone by immunofluorescence and Western blot assessments.

RESULTS

This study confirmed that ZDLT-1 had anti-tumor activity by inhibiting cell proliferation in vitro and solid tumor growth in vivo. Furthermore, ZDLT-1 can inhibit CRC cell invasion, migration and apoptosis in vitro. Moreover, ZDLT-1 can promote the expression of apoptosis proteins in HIF-1α/Caspase-3/Caspase-9 pathway and inhibit the expression of tumor-related immune proteins mainly in NF-κB/GSDMD/GSDME pathway.

CONCLUSION

ZDLT-1 as HDAC inhibitor could suppresses CRC cell growth in vivo and in vitro by triggering HIF-1α/Caspase-3/Caspase-9 pathway in promoting apoptosis, and triggering NF-κB/GSDMD/GSDME pathway in inhibiting tumor inflammation. Our results propose dehydroharmine derivative ZDLT-1 as a promising therapeutic small molecular agent for CRC.

Immune dynamics shaping pre-metastatic and metastatic niches in liver metastases: from molecular mechanisms to therapeutic strategies

Liver metastases are commonly detected in the advanced stages of various malignant tumors, representing a significant clinical challenge. Throughout the process of liver metastases formation, immune cells play a pivotal role, particularly in the pre-metastatic and metastatic niches within the liver. Immune cells establish extensive and intricate interactions with tumor cells and other components in the liver, collectively promoting and sustaining the growth of liver metastases. Despite the limited efficacy of existing therapeutic modalities against some advanced liver metastases, novel immune-based treatment approaches are continuously being explored and validated. Building on the systematic elucidation of the immunosuppressive characteristics of liver metastases, we explored the potential of novel immunotherapies applicable to patients with liver metastases from multiple dimensions.

Fusobacterium nucleatum promotes PD-L1 expression in cancer cells to evade CD8+ T cell killing in breast cancer

BACKGROUND

A significant percentage of cancer-related fatalities are caused by breast cancer (BC). Fusobacterium nucleatum (Fn) is a common Gram-negative anaerobic bacterium found in various inflammatory diseases, and there are also reports suggesting its involvement in cancer progression. This study discussed molecular mechanisms of Fn-induced immune escape in BC cells.

METHODS

mRNA and protein PD-L1 expression in BC cells were detected using qRT-PCR and western blot (WB). WB assayed NF-κB-related marker expressions (p-p65, p-65, p-p50, p-50) in cells. PD-L1 expression levels on the cell surface, apoptosis and proliferation of CD8+ T and BC cells were measured via flow cytometry. ELISA tested TNFα, IFNγ, and granzyme B to assess the activation level of CD8+ T cells. The secretion level of LDH in the co-culture system was tested using an LDH detection kit to evaluate the cell death rate.

RESULTS

BC cells stimulated by Fn can blunt tumor-killing of CD8+ T cells and their vitality. Fn treatment upregulates PD-L1 in BC cells. Rescue experiments using NF-κB inhibitors suggested that Fn treatment mediated NF-κB signaling and fostered PD-L1 expression in cancer cells. Fn repressed the killing effect of CD8+ T cells on BC cells by triggering the NF-κB/PD-L1 signaling pathway.

CONCLUSION

Fn helps BC cells evade the killing effect of CD8+ T cells through the NF-κB/PD-L1 pathway.

PTPN11 is a potential biomarker for type 2 diabetes mellitus complicated with colorectal cancer

Epidemiological surveys have shown that the incidence of type 2 diabetes mellitus (T2DM) and malignancies is rapidly increasing worldwide and has become a major disease that threatens human life. In this study, we quantitatively analyzed the proteome of tumor tissues and adjacent normal tissues from six patients withT2DM combined with colorectal cancer (CRC) and eight non-diabetic CRC, focusing on the effect of T2DM on tumor tissues. We analyzed the functional enrichment of differentially expressed proteins (DEPs) using clusterProfiler in R and the expression level of protein tyrosine phosphatase non-receptor type 11 (PTPN11) and other key proteins in the TIMER and GEPIA2 databases. The HPA database was used to validate PTPN11 protein expression. The correlation between PTPN11 expression and clinicopathological features was analyzed by UALCAN database. The impact of PTPN11 on clinical prognosis was evaluated utilizing Kaplan-Meier Plotter. The correlation between PTPN11 expression and tumor-infiltrated immune cells was investigated via TIMER and TISIDB databases. Gene set enrichment analysis (GSEA) was performed to examined the pathway of PTPN11 enrichment in CRC using data from The Cancer Genome Atlas (TCGA) database. Furthermore, small interfering (si) RNA was used to knock down PTPN11 in CRC cell line SW480. Western blot analysis was used to detect PTPN11 expression in tissue samples or cells and the effect of PTPN11 knockdown on key proteins related to PI3K/AKT and cell cycle pathway in SW480 cells. Cell proliferation and wound healing assays were used to detect the effects of cell proliferation and migration after knockdown of PTPN11 or treatment with high glucose. We found that metabolic pathways such as oxidative phosphorylation, glycolysis/gluconeogenesis, and insulin secretion were significantly enriched in tumor tissues from diabetic patients compared to non-diabetic patients. In addition, PTPN11, a marker gene associated with T2DM and CRC, were mined in diabetic tumor tissues. PTPN11 showed high expression in diabetic tumor tissues compared to normal tissues. High PTPN11 expression predicted poor prognosis in CRC. PTPN11 expression was strongly associated with immune infiltrating cells in CRC. GSEA analysis revealed that PTPN11 was enriched in cancer-related pathways. Western blotting analysis indicated that PTPN11 knockdown reduced the protein levels of p-PI3K, p-AKT, CDK1 and CYCLIN D, without altering PI3K and AKT protein levels. Cell proliferation and wound healing data showed that PTPN11 and high glucose could increase the proliferation and migration ability. These findings showed that PTPN11 may be a potential key biomarker for CRC in patients with diabetes, which will provide new potential targets for future intervention of T2DM complicated with CRC.

Multi-stage mechanisms of tumor metastasis and therapeutic strategies

The cascade of metastasis in tumor cells, exhibiting organ-specific tendencies, may occur at numerous phases of the disease and progress under intense evolutionary pressures. Organ-specific metastasis relies on the formation of pre-metastatic niche (PMN), with diverse cell types and complex cell interactions contributing to this concept, adding a new dimension to the traditional metastasis cascade. Prior to metastatic dissemination, as orchestrators of PMN formation, primary tumor-derived extracellular vesicles prepare a fertile microenvironment for the settlement and colonization of circulating tumor cells at distant secondary sites, significantly impacting cancer progression and outcomes. Obviously, solely intervening in cancer metastatic sites passively after macrometastasis is often insufficient. Early prediction of metastasis and holistic, macro-level control represent the future directions in cancer therapy. This review emphasizes the dynamic and intricate systematic alterations that occur as cancer progresses, illustrates the immunological landscape of organ-specific PMN creation, and deepens understanding of treatment modalities pertinent to metastasis, thereby identifying some prognostic and predictive biomarkers favorable to early predict the occurrence of metastasis and design appropriate treatment combinations.

Immunomodulatory molecules in colorectal cancer liver metastasis

Colorectal cancer (CRC) ranks as the third most common cancer and the second leading cause of cancer-related deaths. According to clinical diagnosis and treatment, liver metastasis occurs in approximately 50 % of CRC patients, indicating a poor prognosis. The unique immune tolerance of the liver fosters an immunosuppressive tumor microenvironment (TME). In the context of tumors, numerous membrane and secreted proteins have been linked to tumor immune evasion as immunomodulatory molecules, but much remains unknown about how these proteins contribute to immune evasion in colorectal cancer liver metastasis (CRLM). This article reviews recently discovered membrane and secreted proteins with roles as both immunostimulatory and immunosuppressive molecules within the TME that influence immune evasion in CRC primary and metastatic lesions, particularly their mechanisms in promoting CRLM. This article also addresses screening strategies for identifying proteins involved in immune evasion in CRLM and provides insights into potential protein targets for treating CRLM.

Fatty acid metabolism-related enzymes in colorectal cancer metastasis: from biological function to molecular mechanism

Colorectal cancer (CRC) is a highly aggressive and life-threatening malignancy that metastasizes in ~50% of patients, posing significant challenges to patient survival and treatment. Fatty acid (FA) metabolism regulates proliferation, immune escape, metastasis, angiogenesis, and drug resistance in CRC. FA metabolism consists of three pathways: de novo synthesis, uptake, and FA oxidation (FAO). FA metabolism-related enzymes promote CRC metastasis by regulating reactive oxygen species (ROS), matrix metalloproteinases (MMPs), angiogenesis and epithelial-mesenchymal transformation (EMT). Mechanistically, the PI3K/AKT/mTOR pathway, wnt/β-catenin pathway, and non-coding RNA signaling pathway are regulated by crosstalk of enzymes related to FA metabolism. Given the important role of FA metabolism in CRC metastasis, targeting FA metabolism-related enzymes and their signaling pathways is a potential strategy to treat CRC metastasis.

Mechanism insights and therapeutic intervention of tumor metastasis: latest developments and perspectives

Metastasis remains a pivotal characteristic of cancer and is the primary contributor to cancer-associated mortality. Despite its significance, the mechanisms governing metastasis are not fully elucidated. Contemporary findings in the domain of cancer biology have shed light on the molecular aspects of this intricate process. Tumor cells undergoing invasion engage with other cellular entities and proteins en route to their destination. Insights into these engagements have enhanced our comprehension of the principles directing the movement and adaptability of metastatic cells. The tumor microenvironment plays a pivotal role in facilitating the invasion and proliferation of cancer cells by enabling tumor cells to navigate through stromal barriers. Such attributes are influenced by genetic and epigenetic changes occurring in the tumor cells and their surrounding milieu. A profound understanding of the metastatic process's biological mechanisms is indispensable for devising efficacious therapeutic strategies. This review delves into recent developments concerning metastasis-associated genes, important signaling pathways, tumor microenvironment, metabolic processes, peripheral immunity, and mechanical forces and cancer metastasis. In addition, we combine recent advances with a particular emphasis on the prospect of developing effective interventions including the most popular cancer immunotherapies and nanotechnology to combat metastasis. We have also identified the limitations of current research on tumor metastasis, encompassing drug resistance, restricted animal models, inadequate biomarkers and early detection methods, as well as heterogeneity among others. It is anticipated that this comprehensive review will significantly contribute to the advancement of cancer metastasis research.

Single-cell sequencing combined with spatial transcriptomics reveals that the IRF7 gene in M1 macrophages inhibits the occurrence of pancreatic cancer by regulating lipid metabolism-related mechanisms

AIM

The main focus of this study is to explore the molecular mechanism of IRF7 regulation on RPS18 transcription in M1-type macrophages in pancreatic adenocarcinoma (PAAD) tissue, as well as the transfer of RPS18 by IRF7 via exosomes to PAAD cells and the regulation of ILF3 expression.

METHODS

By utilising single-cell RNA sequencing (scRNA-seq) data and spatial transcriptomics (ST) data from the Gene Expression Omnibus database, we identified distinct cell types with significant expression differences in PAAD tissue. Among these cell types, we identified those closely associated with lipid metabolism. The differentially expressed genes within these cell types were analysed, and target genes relevant to prognosis were identified. Flow cytometry was employed to assess the expression levels of target genes in M1 and M2 macrophages. Cell lines with target gene knockout were constructed using CRISPR/Cas9 editing technology, and cell lines with target gene knockdown and overexpression were established using lentiviral vectors. Additionally, a co-culture model of exosomes derived from M1 macrophages with PAAD cells was developed. The impact of M1 macrophage-derived exosomes on the lipid metabolism of PAAD cells in the model was evaluated through metabolomics analysis. The effects of M1 macrophage-derived exosomes on the viability, proliferation, division, migration and apoptosis of PAAD cells were assessed using MTT assay, flow cytometry, EdU assay, wound healing assay, Transwell assay and TUNEL staining. Furthermore, a mouse PAAD orthotopic implantation model was established, and bioluminescence imaging was utilised to assess the influence of M1 macrophage-derived exosomes on the intratumoural formation capacity of PAAD cells, as well as measuring tumour weight and volume. The expression of proliferation-associated proteins in tumour tissues was examined using immunohistochemistry.

RESULTS

Through combined analysis of scRNA-seq and ST technologies, we discovered a close association between M1 macrophages in PAAD samples and lipid metabolism signals, as well as a negative correlation between M1 macrophages and cancer cells. The construction of a prognostic risk score model identified RPS18 and IRF7 as two prognostically relevant genes in M1 macrophages, exhibiting negative and positive correlations, respectively. Mechanistically, it was found that IRF7 in M1 macrophages can inhibit the transcription of RPS18, reducing the transfer of RPS18 to PAAD cells via exosomes, consequently affecting the expression of ILF3 in PAAD cells. IRF7/RPS18 in M1 macrophages can also suppress lipid metabolism, cell viability, proliferation, migration, invasion and intratumoural formation capacity of PAAD cells, while promoting cell apoptosis.

CONCLUSION

Overexpression of IRF7 in M1 macrophages may inhibit RPS18 transcription, reduce the transfer of RPS18 from M1 macrophage-derived exosomes to PAAD cells, thereby suppressing ILF3 expression in PAAD cells, inhibiting the lipid metabolism pathway, and curtailing the viability, proliferation, migration, invasion of PAAD cells, as well as enhancing cell apoptosis, ultimately inhibiting tumour formation in PAAD cells in vivo. Targeting IRF7/RPS18 in M1 macrophages could represent a promising immunotherapeutic approach for PAAD in the future.

The combined detection of carcinoembryonic antigen, carcinogenic antigen 125, and carcinogenic antigen 19-9 in colorectal cancer patients

BACKGROUND

Hepatic metastases are common and difficult to treat after colorectal cancer (CRC) surgery. The predictive value of carcinoembryonic antigen (CEA), cancer antigen (CA) 125 and CA19-9 combined tests for liver metastasis is unclear.

AIM

To evaluate predictive value of combined tests for CEA, CA125, and CA19-9 levels in patients with liver metastases of CRC.

METHODS

The retrospective study included patients with CRC alone (50 cases) and patients with CRC combined with liver metastases (50 cases) who were hospitalized between January 2021 and January 2023. Serum CEA, CA125 and CA19-9 levels were compared between the two groups, and binary logistic regression was used to analyze the predictive value of the combination of these tumor markers in liver metastasis. In addition, we performed receiver operating characteristic (ROC) curve analysis to assess its diagnostic accuracy.

RESULTS

The results showed that the serum CEA, CA125 and CA19-9 levels in the CRC with liver metastasis group were significantly higher than those in the CRC alone group. Specifically, the average serum CEA level in the CRC with liver metastasis group was 162.03 ± 810.01 ng/mL, while that in the CRC alone group was 5.71 ± 9.76 ng/mL; the average serum CA125 levels were 43.47 ± 83.52 U/mL respectively. and 13.5 ± 19.68 U/mL; the average serum CA19-9 levels were 184.46 ± 473.13 U/mL and 26.55 ± 43.96 U/mL respectively. In addition, binary logistic regression analysis showed that CA125 was significant in predicting CRC liver metastasis (P < 0.05). ROC curve analysis results showed that the areas under the ROC curves of CEA, CA125 and CA19-9 were 0.607, 0.692 and 0.586.

CONCLUSION

These results suggest that combined detection of these tumor markers may help early detection and intervention of CRC liver metastasis, thereby improving patient prognosis.

Versatile function of NF-ĸB in inflammation and cancer

Nuclear factor-kappaB (NF-ĸB) plays a crucial role in both innate and adaptive immune systems, significantly influencing various physiological processes such as cell proliferation, migration, differentiation, survival, and stemness. The function of NF-ĸB in cancer progression and response to chemotherapy has gained increasing attention. This review highlights the role of NF-ĸB in inflammation control, biological mechanisms, and therapeutic implications in cancer treatment. NF-ĸB is instrumental in altering the release of inflammatory factors such as TNF-α, IL-6, and IL-1β, which are key in the regulation of carcinogenesis. Specifically, in conditions including colitis, NF-ĸB upregulation can intensify inflammation, potentially leading to the development of colorectal cancer. Its pivotal role extends to regulating the tumor microenvironment, impacting components such as macrophages, fibroblasts, T cells, and natural killer cells. This regulation influences tumorigenesis and can dampen anti-tumor immune responses. Additionally, NF-ĸB modulates cell death mechanisms, notably by inhibiting apoptosis and ferroptosis. It also has a dual role in stimulating or suppressing autophagy in various cancers. Beyond these functions, NF-ĸB plays a role in controlling cancer stem cells, fostering angiogenesis, increasing metastatic potential through EMT induction, and reducing tumor cell sensitivity to chemotherapy and radiotherapy. Given its oncogenic capabilities, research has focused on natural products and small molecule compounds that can suppress NF-ĸB, offering promising avenues for cancer therapy.

miR-122-3p targets UBE2I to regulate the immunosuppression of liver cancer and the intervention of Liujunzi formula

ETHNOPHARMACOLOGICAL RELEVANCE

Liujunzi formula has been used to treat liver cancer in China for many years, but its underlying mechanism remains unclear. We previously found that decreased expression of miR-122-3p was associated with liver cancer. In this study, we aimed to explore the target of miR-122-3p and the effect of the Liujunzi formula on miR-122-3p and its downstream events in liver cancer.

MATERIAL AND METHODS

Bioinformatics pinpointed potential targets of miR-122-3p. The actual target was confirmed by miRNA mimic/inhibitor transfections and a dual-luciferase reporter assay. RNA-seq looked at downstream genes impacted by this target. Flow cytometry checked for changes in T cell apoptosis levels after exposing them to liver cancer cells. Gene expression was measured by RT-qPCR, western blotting, and immunofluorescence staining.

RESULTS

Cell experiments found the Liujunzi extract (LJZ) upregulated miR-122-3p and in a dose-dependent manner. Bioinformatics analysis found UBE2I was a potential target of miR-122-3p, which was validated through experiments using miRNA mimics/inhibitors and a dual-luciferase reporter assay. RNA-seq data implicated the NF-κB pathway as being downstream of the miR-122-3p/UBE2I axis, further confirmed by forcing overexpression of UBE2I. Bioinformatic evidence suggested a link between UBE2I and T cell infiltration in liver cancer. Given that the NF-κB pathway drives PD-L1 expression, which can inhibit T cell infiltration, we investigated whether PD-L1 is a downstream effector of miR-122-3p/UBE2I. This was corroborated through mining public databases, UBE2I overexpression studies, and tumor-T cell co-culture assays. In addition, we also confirmed that LJZ downregulates UBE2I and NF-κB/PD-L1 pathways through miR-122-3p. LJZ also suppressed SUMOylation in liver cancer cells and protected PD-1+ T cells from apoptosis induced by co-culture with tumor cells. Strikingly, a miR-122-3p inhibitor abrogated LJZ's effects on UBE2I and PD-L1, and UBE2I overexpression rescued the LJZ-mediated effects on NF-κB and PD-L1.

CONCLUSIONS

miR-122-3p targets UBE2I, thereby suppressing the NF-κB signaling cascade and downregulating PD-L1 expression, which potentiates anti-tumor immune responses. LJZ bolsters anti-tumor immunity by modulating the miR-122-3p/UBE2I/NF-κB/PD-L1 axis in liver cancer cells.

Parecoxib and 5-Fluorouracil Synergistically Inhibit EMT and Subsequent Metastasis in Colorectal Cancer by Targeting PI3K/Akt/NF-κB Signaling

Colorectal cancer is one of the most common causes of cancer mortality worldwide, and innovative drugs for the treatment of colorectal cancer are continually being developed. 5-Fluorouracil (5-FU) is a common clinical chemotherapeutic drug. Acquired resistance to 5-FU is a clinical challenge in colorectal cancer treatment. Parecoxib is a selective COX-2-specific inhibitor that was demonstrated to inhibit metastasis in colorectal cancers in our previous study. This study aimed to investigate the synergistic antimetastatic activities of parecoxib to 5-FU in human colorectal cancer cells and determine the underlying mechanisms. Parecoxib and 5-FU synergistically suppressed metastasis in colorectal cancer cells. Treatment with the parecoxib/5-FU combination induced an increase in E-cadherin and decrease in β-catenin expression. The parecoxib/5-FU combination inhibited MMP-9 activity, and the NF-κB pathway was suppressed as well. Mechanistic analysis denoted that the parecoxib/5-FU combination hindered the essential molecules of the PI3K/Akt route to obstruct metastatic colorectal cancer. Furthermore, the parecoxib/5-FU combination could inhibit reactive oxygen species. Our work showed the antimetastatic capacity of the parecoxib/5-FU combination for treating colorectal cancers via the targeting of the PI3K/Akt/NF-κB pathway.

Interactions between LAMP3+ dendritic cells and T-cell subpopulations promote immune evasion in papillary thyroid carcinoma

BACKGROUND

The incidence of papillary thyroid cancer (PTC) continues to rise all over the world, 10-15% of the patients have a poor prognosis. Although immunotherapy has been applied in clinical practice, its therapeutic efficacy remains far from satisfactory, necessitating further investigation of the mechanism of PTC immune remodeling and exploration of novel treatment targets.

METHODS

This study conducted a single-cell RNA sequencing (scRNA-seq) analysis using 18 surgical tissue specimens procured from 14 patients diagnosed with adjacent tissues, non-progressive PTC or progressive PTC. Key findings were authenticated through spatial transcriptomics RNA sequencing, immunohistochemistry, multiplex immunohistochemistry, and an independent bulk RNA-seq data set containing 502 samples.

RESULTS

A total of 151,238 individual cells derived from 18 adjacent tissues, non-progressive PTC and progressive PTC specimens underwent scRNA-seq analysis. We found that progressive PTC exhibits the following characteristics: a significant decrease in overall immune cells, enhanced immune evasion of tumor cells, and disrupted antigen presentation function. Moreover, we identified a subpopulation of lysosomal associated membrane protein 3 (LAMP3+) dendritic cells (DCs) exhibiting heightened infiltration in progressive PTC and associated with advanced T stage and poor prognosis of PTC. LAMP3+ DCs promote CD8+ T cells exhaustion (mediated by NECTIN2-TIGIT) and increase infiltration abundance of regulatory T cells (mediated by chemokine (C-C motif) ligand 17 (CCL17)-chemokine (C-C motif) receptor 4 (CCR4)) establishing an immune-suppressive microenvironment. Ultimately, we unveiled that progressive PTC tumor cells facilitate the retention of LAMP3+ DCs within the tumor microenvironment through NECTIN3-NECTIN2 interactions, thereby rendering tumor cells more susceptible to immune evasion.

CONCLUSION

Our findings expound valuable insights into the role of the interaction between LAMP3+ DCs and T-cell subpopulations and offer new and effective ideas and strategies for immunotherapy in patients with progressive PTC.

Unveiling YWHAH: A potential therapeutic target for overcoming CD8+ T cell exhaustion in colorectal cancer

Colorectal cancer (CRC) is a significant global health challenge, with increasing rates of incidence and mortality. Despite advancements in immunotherapy, resistance, particularly due to T cell exhaustion, remains a major hurdle. This study explores the role of YWHAH, mediated by N4-acetylcytidine (ac4C) modification, in CRC progression and its impact on CD8+ T cell exhaustion. Analysis of five paired CRC patient tissue samples using acetylated RNA immunoprecipitation and sequencing (acRIP-seq)identified ac4C-modified mRNAs. Functional assays, including cell culture, transfection, qRT-PCR, and immune assays, investigated the influence of YWHAH expression on CRC advancement. Bioinformatics analysis of TCGA data assessed the correlation between YWHAH and immune responses, as well as checkpoint inhibitors. Flow cytometry and Immunohistochemistry validated these findings, complemented by a co-culture experiment involving CD8+ T cells and CRC cell lines (LOVO and HCT116). acRIP-seq revealed YWHAH as a potential driver of CRC progression, exhibiting ac4C modification-mediated stability and upregulation. High YWHAH levels correlated with adverse outcomes and immune evasion in CRC patients, showing strong associations with immune checkpoint proteins and modest correlations with CD8+ T cell infiltration. Co-culture experiments demonstrated YWHAH-induced CD8+ T cell exhaustion, characterized by decreased proliferation and increased exhaustion markers. NAT10-mediated ac4C modification enhanced YWHAH stability in CRC. The involvement of YWHAH in CD8 + T cell exhaustion suggests its potential as a therapeutic target and prognostic marker in CRC immunotherapy, highlighting the intricate interplay between epitranscriptomic modifications, the tumor microenvironment, and immune responses in CRC progression.

Role of T cells in liver metastasis

The liver is a major metastatic site (organ) for gastrointestinal cancers (such as colorectal, gastric, and pancreatic cancers) as well as non-gastrointestinal cancers (such as lung, breast, and melanoma cancers). Due to the innate anatomical position of the liver, the apoptosis of T cells in the liver, the unique metabolic regulation of hepatocytes and other potential mechanisms, the liver tends to form an immunosuppressive microenvironment and subsequently form a pre-metastatic niche (PMN), which can promote metastasis and colonization by various tumor cells(TCs). As a result, the critical role of immunoresponse in liver based metastasis has become increasingly appreciated. T cells, a centrally important member of adaptive immune response, play a significant role in liver based metastases and clarifying the different roles of the various T cells subsets is important to guide future clinical treatment. In this review, we first introduce the predisposing factors and related mechanisms of liver metastasis (LM) before introducing the PMN and its transition to LM. Finally, we detail the role of different subsets of T cells in LM and advances in the management of LM in order to identify potential therapeutic targets for patients with LM.

The Usefulness of Vitamin K-Dependent Proteins in the Diagnosis of Colorectal Carcinoma

Colorectal cancer (CRC) is one of the most common neoplasms in developed countries, with increasing incidence and mortality, even in young people. A variety of serum markers have been associated with CRC (CEA, CA 19-9), but neither should be used as a screening tool for the diagnosis or evolution staging of CRC. The sensitivity and specificity of these markers are not as good as is required, so new ones need to be found. Matrix Gla protein and PIVKA II are involved in carcinogenesis, but few studies have evaluated their usefulness in predicting the presence and severity of CRC. Two hundred patients were divided into three groups: 80 patients were included in the control group; 80 with CRC and without hepatic metastasis were included in Group 1; 40 patients with CRC and hepatic metastasis were included in Group 2. Vitamin K-dependent proteins (VKDPs) levels in plasma were determined. Patients with CRC without methastasis (Group 1) and CRC patients with methastasis (Group 2) presented significantly higher values of CEA, CA 19-9, PIVKA II (310.05 ± 38.22 vs. 430.13 ± 122.13 vs. 20.23 ± 10.90), and ucMGP (14,300.00 ± 2387.02 vs. 13,410.52 ± 2243.16 vs. 1780.31 ± 864.70) compared to control group (Group 0). Interestingly, Group 1 presented the greatest PIVKA II values. Out of all the markers, significant differences between the histological subgroups were found only for ucMGP, but only in non-metastatic CRC. Studying the discrimination capacity between the patients with CRC vs. those without, no significant differences were found between the classical tumor markers and the VKDP AUROC curves (PIVKA II and ucMGP AUROCs = 1). For the metastatic stage, the sensitivity and specificity of the VKDPs were lower in comparison with those of CA 19-9 and CEA, respectively (PIVKA II AUROC = 0.789, ucMGP AUROC = 0.608). The serum levels of these VKDPs are significantly altered in patients with colorectal carcinoma; it is possible to find additional value of these in the early stages of the disease.

Feasibility of Hepatic Artery Infusion Chemotherapy for Colorectal Liver Metastasis in an Indian Setting

Hepatic artery infusion chemotherapy (HAIC) is a popular treatment modality for the treatment of colorectal liver metastasis (CRLM). The aim of this study was to determine the feasibility of HAIC for high-risk resected CRLM delivered using repeated femoral puncture and delivering 5-fluorouracil infusional chemotherapy along with systemic adjuvant chemotherapy. The present study is a retrospective review of a prospectively maintained database. All patients who underwent HAIC for colorectal liver metastases between July 2022 and July 2023 were included. A total of 12 patients were included in the study of which 11 completed four sessions as planned. The median age was 47 (29-73) years with nine male (81%) and two female (18%) patients. Rectum (n = 7, 63%) was the most common primary location. All patients received systemic chemotherapy with 5-fluorouracil-based regimens prior to HAIC (median 12 cycles). The median number of metastasis was 2 (1-8). Eight patients had metastasis in unilobar distribution (73%). On completion of HAIC treatment, nine patients (64%) were completely disease free with a median follow-up of 8 months. None of the patients experienced any immediate adverse events during or after completion of the procedure. Conventional HAIC comes with various challenges such as unavailability of the agent floxuridine and the specialized HAIC pump. Percutaneous HAIC has a lower chance of infection. The delivery of HAIC using repeated femoral punctures and 5FU chemotherapy was successful in over 90% of the patients making it a feasible option in the treatment of CRLM.

MGP+ and IDO1+ tumor-associated macrophages facilitate immunoresistance in breast cancer revealed by single-cell RNA sequencing

Immunotherapy is widely applied for the treatment of breast cancer, but to which some patients respond poorly or develop resistance. Therefore, the mechanism needs to be further studied. Transcriptomic data of 31 breast cancer patients treated with anti-programmed death receptor 1 (PD-1) was downloaded from the VIB-KULeuven Center for Cancer Biology to analyze the changes in myeloid cells in tumor tissues before and after immunotherapy. And 24 cell populations that may be immune-related were further identified. Representative cell populations were also screened and validated through cellular and animal experiments to evaluate the relevant molecular expression and pathways of tumor-associated macrophages (TAMs) in the tumor microenvironment. The results demonstrated that MGP+ TAMs and IDO1+ TAMs influenced the efficacy of immunotherapy in breast cancer patients. After anti-PD-1 treatment, Increased numbers of MGP+ TAMs and IDO1+ TAMs in breast cancer patients upregulated pro-tumorigenic factors associated with resistance to immunosuppressive therapy. This study provides new biomarkers for immunotherapy to predict therapeutic responses and overcome potential resistance to immunotherapy. It is an important complement to the immunosuppression caused by TAMs after immunotherapy for breast cancer.

Suppression of AGRN enhances CD8+ T cell recruitment and inhibits breast cancer progression

Breast cancer (BC) stands as a prominent contributor to global cancer-related mortality, with an increasing incidence annually. This study aims to investigate AGRN gene expression in BC, as well as explore its influence on the tumor immune microenvironment. AGRN displayed a pronounced upregulation in BC tissues relative to paracancerous tissues. Single-cell RNA analysis highlighted AGRN-specific elevation within cancer cell clusters and also showed expression expressed in stromal as well as immune cell clusters. AGRN upregulation was positively correlated with clinicopathological stage and negatively correlated with BC prognosis. As revealed by the in vitro experiment, AGRN knockdown effectively hinders BC cells in terms of proliferation, invasion as well as migration. AGRN protein, which may interact with EXT1, LRP4, RAPSN, etc., was primarily distributed in the cell cytoplasm. Notably, immune factors might interact with AGRN in BC, evidenced by its discernible associations with immunofactors like IL10, CD274, and PVRL2. Mass spectrometry and immunohistochemistry revealed that the reduction of AGRN led to an increase in CD8+ T cells with triple-negative breast cancer (TNBC). Mechanistically, the connection between TRIM7 and PD-L1 is improved by AGRN, acting as a scaffold, thereby facilitating the accelerated degradation of PD-L1 by TRIM7. Downregulation of AGRN inhibits BC progression and increases CD8+ T cell recruitment. Targeting AGRN may contribute to BC treatment. The biomarker AGRN, serving as a therapeutic target for BC, emerges as a prospective avenue for enhancing both diagnosis and prognosis in BC cases.

FSTL3 promotes tumor immune evasion and attenuates response to anti-PD1 therapy by stabilizing c-Myc in colorectal cancer

Programmed cell death 1 ligand 1 (PDL1)/programmed cell death 1 (PD1) blockade immunotherapy provides a prospective strategy for the treatment of colorectal cancer (CRC), but various constraints on the effectiveness of the treatment are still remaining. As reported in previous studies, follistatin-like 3 (FSTL3) could mediate inflammatory response in macrophages by induction lipid accumulation. Herein, we revealed that FSTL3 were overexpressed in malignant cells in the CRC microenvironment, notably, the expression level of FSTL3 was related to tumor immune evasion and the clinical efficacy of anti-PD1 therapy. Further studies determined that hypoxic tumor microenvironment induced the FSTL3 expression via HIF1α in CRC cells, FSTL3 could bind to the transcription factor c-Myc (354-406 amino acids) to suppress the latter's ubiquitination and increase its stability, thereby to up-regulated the expression of PDL1 and indoleamine 2,3-dioxygenase 1 (IDO1). The results in the immunocompetent tumor models verified that FSLT3 knockout in tumor cells increased the proportion of CD8+ T cells in the tumor microenvironment, reduced the proportion of regulatory T cells (CD25+ Foxp3+) and exhausted T cells (PD1+ CD8+), and synergistically improved the anti-PD1 therapy efficacy. To sum up, FSTL3 enhanced c-Myc-mediated transcriptional regulation to promote immune evasion and attenuates response to anti-PD1 therapy in CRC, suggesting the potential of FSTL3 as a biomarker of immunotherapeutic efficacy as well as a novel immunotherapeutic target in CRC.

ABLIM1, a novel ubiquitin E3 ligase, promotes growth and metastasis of colorectal cancer through targeting IĸBα ubiquitination and activating NF-ĸB signaling

Actin-binding LIM protein 1 (ABLIM1), a member of the LIM-domain protein family, has been reported as a suppressor in several tumors whereas its role in colorectal cancer (CRC) remains unknown. In this study, we find that ABLIM1 is up-regulated in CRC patients and high levels of ABLIM1 predict short disease-free survival time. Knock-down of ABLIM1 in CRC cell lines by lenti-virus leads to inhibited cell proliferation, migration, and invasion capabilities in vitro and impaired growth of tumor xenografts and liver metastasis lesions in vivo, while ABLIM1 overexpression accelerates tumor growth and invasion in vitro. Mechanistically, we uncover that ABLIM1 activates the NF-ĸB/CCL-20 signaling through modulating IĸBα ubiquitination and proteasomal-mediated degradation. Further co-immunoprecipitation, in vivo and in vitro ubiquitination assays reveal ABLIM1 as a novel ubiquitin E3 ligase binding to IĸBα. Interestingly, The E3 ligase catalysis activity of ABLIM1 depends on its 402-778aa rather than its LIM domains and its interaction with IĸBα relies on the HP domain. Our findings delineate the oncogenic role of ABLIM1 in CRC progression and reveal it as a novel E3 ligase targeting IĸBα, providing new insights into the regulation of NF-ĸB signaling in tumors.

The Inhibitory Effects of Propofol on Colorectal Cancer Progression through the NF-κB/HIF-1α Signaling Pathway

BACKGROUND AND OBJECTIVE

Colorectal cancer (CRC) is a neoplastic disease that gradually develops due to genetic variations and epigenetic changes. Surgical excision is the first-line treatment for CRC. Accumulating evidence has shown that total intravenous anesthesia has beneficial effects for CRC patients as it decreases the probability of tumor recurrence and metastasis. Propofol is one of the most frequently used intravenous anesthetics in clinical practice. However, it remains unknown whether it can reduce recurrence and metastasis after surgery in cancer patients.

METHODS

CRC cell lines (HCT116 and SW480) were cultured in vitro, and different concentrations of propofol were added to the cell culture medium. The proliferation effect of propofol on CRC cell lines was evaluated by CCK-8 assay. The effect of propofol on the migration and invasion of CRC cells was evaluated by scratch healing and Transwell experiments. The inhibitory effects of propofol on NF-κB and HIF-1α expressions in CRC cell lines were determined by Western blotting and immunofluorescence assays to further clarify the regulatory effects of propofol on NF-κB and HIF-1α.

RESULTS

Compared to the control, propofol significantly inhibited the proliferation, migration, and invasion abilities of CRC cells (HCT116 and SW480) (p < 0.0001). The expression levels of NF-κB and HIF-1α gradually decreased with increasing propofol concentration in both cell lines. After activation and inhibition of NF-κB, the expression of HIF-1α changed. Further studies showed that propofol inhibited LPS-activated NF-κB-induced expression of HIF-1α, similar to the NF-κB inhibitor Bay17083 (p < 0.0001).

CONCLUSION

In vitro, propofol inhibited the proliferation, migration, and invasion of CRC cells (HCT116 and SW480) in a dose-dependent manner, possibly by participating in the regulation of the NF-κB/HIF-1α signaling pathway.

The current status and future of PD-L1 in liver cancer

The application of immunotherapy in tumor, especially immune checkpoint inhibitors (ICIs), has played an important role in the treatment of advanced unresectable liver cancer. However, the efficacy of ICIs varies greatly among different patients, which has aroused people's attention to the regulatory mechanism of programmed death ligand-1 (PD-L1) in the immune escape of liver cancer. PD-L1 is regulated by multiple levels and signaling pathways in hepatocellular carcinoma (HCC), including gene variation, epigenetic inheritance, transcriptional regulation, post-transcriptional regulation, and post-translational modification. More studies have also found that the high expression of PD-L1 may be the main factor affecting the immunotherapy of liver cancer. However, what is the difference of PD-L1 expressed by different types of cells in the microenvironment of HCC, and which type of cells expressed PD-L1 determines the effect of tumor immunotherapy remains unclear. Therefore, clarifying the regulatory mechanism of PD-L1 in liver cancer can provide more basis for liver cancer immunotherapy and combined immune treatment strategy. In addition to its well-known role in immune regulation, PD-L1 also plays a role in regulating cancer cell proliferation and promoting drug resistance of tumor cells, which will be reviewed in this paper. In addition, we also summarized the natural products and drugs that regulated the expression of PD-L1 in HCC.

Aldehyde dehydrogenase 2-mediated aldehyde metabolism promotes tumor immune evasion by regulating the NOD/VISTA axis

BACKGROUND

Aldehyde dehydrogenase 2 (ALDH2) is a crucial enzyme involved in endogenous aldehyde detoxification and has been implicated in tumor progression. However, its role in tumor immune evasion remains unclear.

METHODS

Here, we analyzed the relationship between ALDH2 expression and antitumor immune features in multiple cancers. ALDH2 knockout tumor cells were then established using CRISPR/Cas9 system. In immunocompetent breast cancer EMT6 and melanoma B16-F10 mouse models, we investigated the impact of ALDH2 blockade on cytotoxic T lymphocyte function and tumor immune microenvironment by flow cytometry, mass cytometry, Luminex liquid suspension chip detection, and immunohistochemistry. Furthermore, RNA sequencing, flow cytometry, western blot, chromatin immunoprecipitation assay, and luciferase reporter assays were employed to explore the detailed mechanism of ALDH2 involved in tumor immune evasion. Lastly, the synergistic therapeutic efficacy of blocking ALDH2 by genetic depletion or its inhibitor disulfiram in combination with immune checkpoint blockade (ICB) was investigated in mouse models.

RESULTS

In our study, we uncovered a positive correlation between the expression level of ALDH2 and T-cell dysfunction in multiple cancers. Furthermore, blocking ALDH2 significantly suppressed tumor growth by enhancing cytotoxic activity of CD8+ T cells and reshaping the immune landscape and cytokine milieu of tumors in vivo. Mechanistically, inhibiting ALDH2-mediated metabolism of aldehyde downregulated the expression of V-domain Ig suppressor of T-cell activation (VISTA) via inactivating the nucleotide oligomerization domain (NOD)/nuclear factor kappa-B (NF-κB) signaling pathway. As a result, the cytotoxic function of CD8+ T cells was revitalized. Importantly, ALDH2 blockade markedly reinforced the efficacy of ICB treatment.

CONCLUSIONS

Our data delineate that ALDH2-mediated aldehyde metabolism drives tumor immune evasion by activating the NOD/NF-κB/VISTA axis. Targeting ALDH2 provides an effective combinatorial therapeutic strategy for immunotherapy.

Single-cell RNA-sequencing atlas reveals an FABP1-dependent immunosuppressive environment in hepatocellular carcinoma

BACKGROUND

Single-cell RNA sequencing, also known as scRNA-seq, is a method profiling cell populations on an individual cell basis. It is particularly useful for more deeply understanding cell behavior in a complicated tumor microenvironment. Although several previous studies have examined scRNA-seq for hepatocellular carcinoma (HCC) tissues, no one has tested and analyzed HCC with different stages.

METHODS

In this investigation, immune cells isolated from surrounding normal tissues and cancer tissues from 3 II-stage and 4 III-stage HCC cases were subjected to deep scRNA-seq. The analysis included 15 samples. We distinguished developmentally relevant trajectories, unique immune cell subtypes, and enriched pathways regarding differential genes. Western blot and co-immunoprecipitation were performed to demonstrate the interaction between fatty acid binding protein 1 (FABP1) and peroxisome proliferator-activated receptor gamma(PPARG). In vivo experiments were performed in a C57BL/6 mouse model of HCC established via subcutaneous injection.

RESULTS

FABP1 was discovered to be overexpressed in tumor-associated macrophages (TAMs) with III-stage HCC tissues compared with II-stage HCC tissues. This finding was fully supported by immunofluorescence detection in significant amounts of HCC human samples. FABP1 deficiency in TAMs inhibited HCC progression in vitro. Mechanistically, FABP1 interacted with PPARG/CD36 in TAMs to increase fatty acid oxidation in HCC. When compared with C57BL/6 mice of the wild type, tumors in FABP1-/- mice consistently showed attenuation. The FABP1-/- group's relative proportion of regulatory T cells and natural killer cells showed a downward trend, while dendritic cells, M1 macrophages, and B cells showed an upward trend, according to the results of mass cytometry. In further clinical translation, we found that orlistat significantly inhibited FABP1 activity, while the combination of anti-programmed cell death 1(PD-1) could synergistically treat HCC progression. Liposomes loaded with orlistat and connected with IR780 probe could further enhance the therapeutic effect of orlistat and visualize drug metabolism in vivo.

CONCLUSIONS

ScRNA-seq atlas revealed an FABP1-dependent immunosuppressive environment in HCC. Orlistat significantly inhibited FABP1 activity, while the combination of anti-PD-1 could synergistically treat HCC progression. This study identified new treatment targets and strategies for HCC progression, contributing to patients with advanced HCC from new perspectives.

Grid2 interacting protein is a potential biomarker related to immune infiltration in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the three deadliest malignant tumors in the world, posing a severe hazard to human health. Nonetheless, the 5-year survival rate for advanced CRC remains unsatisfactory. Grid2 interacting protein (GRID2IP) is a Purkinje fiber postsynaptic scaffold protein implicated in a number of signal transduction pathways in the nervous system. Previous studies have shown that Grid2 is closely related to the occurrence and prognosis of gastric cancer and many other diseases. Therefore, we aim to identify the relationship between GRID2IP and the occurrence and prognosis of CRC.

METHODS

Transcriptome data were retrieved from The Cancer Genome Atlas (TCGA) database to analyze the differential expression of GRID2IP in a variety of malignant tumors and then validate it by quantitative real time polymerase chain reaction(Q-PCR) and Western Blot in HT29 and SW480 cells. "DESeq2" package was used to analyze the differentially expressed genes (DEGs) between the high- and low-GRID2IP subgroups. In relation to DEGs, Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed. In addition, gene set enrichment analysis (GSEA) and single-sample gene set enrichment analysis (ssGSEA) were employed to examine DEGs-associated signaling pathways and GRID2IP-associated immune cell infiltration levels. Besides, overall survival (OS), disease-specific survival (DSS), and progression-free interval (PFI) were compared between the two subgroups using a Kaplan-Meier analysis. In addition, a prognostic model for GRID2IP and clinical characteristics was developed using the univariate Cox regression method. The "pRRophetic" package was applied to predict the drug sensitivity of different subgroups. Moreover, we also performed single-cell analysis of GRID2IP using the TISCH database.

RESULTS

GRID2IP is upregulated in CRC patients. The rise of GRID2IP inhibits the invasion of tumor-associated immune cells resulting in a lower immune score. In addition, high GRID2IP expression was associated with poor prognosis in different clinical subgroups. Analysis of single cells revealed that GRID2IP was predominantly expressed in immune cells, myofibroblasts, and cancerous cells. In terms of chemotherapy drug sensitivity, the subgroup with high GRID2IP expression was less sensitive to gemcitabine.

CONCLUSIONS

Our results suggest that rising GRID2IP promotes tumor-associated immune cell infiltration and suggests adverse outcomes in CRC patients, which may be a useful biomarker for determining the prognosis of CRC and a potential target molecule for CRC therapy.

Toxicity induced by orellanine from the mushroom Cortinarius orellanus in primary renal tubular proximal epithelial cells (RPTEC): Novel mechanisms of action

The toxicity of Orellanine (OR), a significant factor in mushroom poisoning, has severe effects on the kidneys, particularly the proximal tubules. This study investigated the acute toxicity of OR from the Cortinarius orellanus mushroom in human Primary Renal Tubular Proximal Epithelial Cells (RPTEC). Additionally, the half maximal inhibitory concentration (IC50) of OR in MCF-7 cells was established. RPTEC were subjected to a 6.25 μg/ml dose of orellanine for 24 h, while Control cells were exposed to 0.05% DMSO (vehicle). The RT2 Profiler™ PCR Array Human Nephrotoxicity was utilized to identify genes that were upregulated or downregulated. Western blotting confirmed the protein product of some significantly regulated genes compared to control cells. The IC50 of OR was found to be 319.2 μg/ml. The mechanism of OR toxicity involved several pathways including apoptosis, metal ion binding, cell proliferation, tissue remodeling, xenobiotic metabolism, transporters, extracellular matrix molecules, and cytoskeleton pathways. Other genes from non-specific pathways were also identified. These findings enhance our understanding of OR nephrotoxicity and pave the way for future research into potential treatments or antidotes for natural mushroom poisoning.

Crosstalk between gut microbiota and metastasis in colorectal cancer: implication of neutrophil extracellular traps

Primary colorectal cancer (CRC) often leads to liver metastasis, possibly due to the formation of pre-metastatic niche (PMN) in liver. Thus, unravelling the key modulator in metastasis is important for the development of clinical therapies. Gut microbiota dysregulation is a key event during CRC progression and metastasis. Numerous studies have elucidated the correlation between specific gut bacteria strains (e.g., pks + E. coli and Bacteroides fragilis) and CRC initiation, and gut bacteria translocation is commonly witnessed during CRC progression. Gut microbiota shapes tumor microenvironment (TME) through direct contact with immune cells or through its functional metabolites. However, how gut microbiota facilitates CRC metastasis remains controversial. Meanwhile, recent studies identify the dissemination of bacteria from gut lumen to liver, suggesting the role of gut microbiota in shaping tumor PMN. A pro-tumoral PMN is characterized by the infiltration of immunosuppressive cells and increased pro-inflammatory immune responses. Notably, neutrophils form web-like structures known as neutrophil extracellular traps (NETs) both in primary TME and metastatic sites, NETs are involved in cancer progression and metastasis. In this review, we focus on the role of gut microbiota in CRC progression and metastasis, highlight the multiple functions of different immune cell types in TME, especially neutrophils and NETs, discuss the possible mechanisms of gut microbiota in shaping PMN formation, and provide therapeutical indications in clinic.

S100P as a potential biomarker for immunosuppressive microenvironment in pancreatic cancer: a bioinformatics analysis and in vitro study

BACKGROUND

Immunosuppression is a significant factor contributing to the poor prognosis of cancer. S100P, a member of the S100 protein family, has been implicated in various cancers. However, its role in the tumor microenvironment (TME) of pancreatic cancer remains unclear. This study aimed to investigate the potential impact of S100P on TME characteristics in patients with pancreatic cancer.

METHODS

Multiple data (including microarray, RNA-Seq, and scRNA-Seq) were obtained from public databases. The expression pattern of S100P was comprehensively evaluated in RNA-Seq data and validated in four different microarray datasets. Prognostic value was assessed through Kaplan-Meier plotter and Cox regression analyses. Immune infiltration levels were determined using the ESTIMATE and ssGSEA algorithms and validated at the single-cell level. Spearman correlation test was used to examine the correlation between S100P expression and immune checkpoint genes, and tumor mutation burden (TMB). DNA methylation analysis was performed to investigate the change in mRNA expression. Reverse transcription PCR (RT-PCR) and immunohistochemical (IHC) were utilized to validate the expression using five cell lines and 60 pancreatic cancer tissues.

RESULTS

This study found that S100P was differentially expressed in pancreatic cancer and was associated with poor prognosis (P < 0.05). Notably, S100P exhibited a significant negative-correlation with immune cell infiltration, particularly CD8 + T cells. Furthermore, a close association between S100P and immunotherapy was observed, as it strongly correlated with TMB and the expression levels of TIGIT, HAVCR2, CTLA4, and BTLA (P < 0.05). Intriguingly, higher S100P expression demonstrated a negative correlation with methylation levels (cg14323984, cg27027375, cg14900031, cg14140379, cg25083732, cg07210669, cg26233331, and cg22266967), which were associated with CD8 + T cells. In vitro RT-PCR validated upregulated S100P expression across all five pancreatic cancer cell lines, and IHC confirmed high S100P levels in pancreatic cancer tissues (P < 0.05).

CONCLUSION

These findings suggest that S100P could serve as a promising biomarker for immunosuppressive microenvironment, which may provide a novel therapeutic way for pancreatic cancer.

CHSY1 promotes CD8+ T cell exhaustion through activation of succinate metabolism pathway leading to colorectal cancer liver metastasis based on CRISPR/Cas9 screening

BACKGROUND

The most common site of metastasis in colorectal cancer (CRC) is the liver and liver metastases occur in more than 50% of patients during diagnosis or treatment. The occurrence of metastasis depends on a series of events known as the invasive-metastasis cascade. Currently, the underlying genes and pathways regulating metastasis initiation in the liver microenvironment are unknown.

METHODS

We performed systematic CRISPR/Cas9 screening using an in vivo mouse model of CRC liver metastasis to identify key regulators of CRC metastasis. We present the full results of this screen,which included a list of genes that promote or repress CRC liver colonization. By silencing these genes individually, we found that chondroitin sulfate synthase 1 (CHSY1) may be involved in CRC metastasis. We verified the function of CHSY1 and its involvement in liver metastasis of CRC through in vivo and in vitro experiments.

RESULT

The results of TCGA and CRISPR/Cas9 showed that CHSY1 was overexpressed in CRC primary and liver metastasis tissues and indicated a worse clinical prognosis. In vitro and in vivo experiments confirmed that CHSY1 facilitated the liver metastasis of CRC and CHSY1 induced CD8+ T cell exhaustion and upregulated PD-L1 expression. The metabolomic analysis indicated that CHSY1 promoted CD8+ T cell exhaustion by activating the succinate metabolism pathway leading to liver metastasis of CRC. Artemisinin as a CHSY1 inhibitor reduced liver metastasis and enhanced the effect of anti-PD1 in CRC. PLGA-loaded Artemisinin and ICG probe reduced liver metastasis and increased the efficiency of anti-PD1 treatment in CRC.

CONCLUSION

CHSY1 could promote CD8+ T cell exhaustion through activation of the succinate metabolic and PI3K/AKT/HIF1A pathway, leading to CRC liver metastasis. The combination of CHSY1 knockdown and anti-PD1 contributes to synergistic resistance to CRC liver metastasis. Artemisinin significantly inhibits CHSY1 activity and in combination with anti-PD1 could synergistically treat CRC liver metastases. This study provides new targets and specific strategies for the treatment of CRC liver metastases, bringing new hope and benefits to patients.

NF-κB in Cell Deaths, Therapeutic Resistance and Nanotherapy of Tumors: Recent Advances

The transcription factor nuclear factor-κB (NF-κB) plays a complicated role in multiple tumors. Mounting evidence demonstrates that NF-κB activation supports tumorigenesis and development by enhancing cell proliferation, invasion, and metastasis, preventing cell death, facilitating angiogenesis, regulating tumor immune microenvironment and metabolism, and inducing therapeutic resistance. Notably, NF-κB functions as a double-edged sword exerting positive or negative influences on cancers. In this review, we summarize and discuss recent research on the regulation of NF-κB in cancer cell deaths, therapy resistance, and NF-κB-based nano delivery systems.

Landscapes and mechanisms of CD8+ T cell exhaustion in gastrointestinal cancer

CD8+ T cells, a cytotoxic T lymphocyte, are a key component of the tumor immune system, but they enter a hyporeactive T cell state in long-term chronic inflammation, and how to rescue this depleted state is a key direction of research. Current studies on CD8+ T cell exhaustion have found that the mechanisms responsible for their heterogeneity and differential kinetics may be closely related to transcription factors and epigenetic regulation, which may serve as biomarkers and potential immunotherapeutic targets to guide treatment. Although the importance of T cell exhaustion in tumor immunotherapy cannot be overstated, studies have pointed out that gastric cancer tissues have a better anti-tumor T cell composition compared to other cancer tissues, which may indicate that gastrointestinal cancers have more promising prospects for the development of precision-targeted immunotherapy. Therefore, the present study will focus on the mechanisms involved in the development of CD8+ T cell exhaustion, and then review the landscapes and mechanisms of T cell exhaustion in gastrointestinal cancer as well as clinical applications, which will provide a clear vision for the development of future immunotherapies.

Establishment and validation of exhausted CD8+ T cell feature as a prognostic model of HCC

Objectives

The exhausted CD8+T (Tex) cells are a unique cell population of activated T cells that emerges in response to persistent viral infection or tumor antigens. Tex cells showed the characteristics of aging cells, including weakened self-renewal ability, effector function inhibition, sustained high expression of inhibitory receptors including PD-1, TIGIT, TIM-3, and LAG-3, and always accompanied by metabolic and epigenetic reprogramming. Tex cells are getting more and more attention in researching immune-related diseases and tumor immunotherapy. However, studies on Tex-related models for tumor prognosis are still lacking. We hope to establish a risk model based on Tex-related genes for HCC prognosis.

Methods

Tex-related GEO datasets from different pathologic factors (chronic HBV, chronic HCV, and telomere shortening) were analyzed respectively to acquire differentially expressed genes (DEGs) by the ‘limma’ package of R. Genes with at least one intersection were incorporated into Tex-related gene set. GO, KEGG, and GSEA enrichment analyses were produced. Hub genes and the PPI network were established and visualized by the STRING website and Cytoscape software. Transcription factors and targeting small molecules were predicted by the TRUST and CLUE websites. The Tex-related HCC prognostic model was built by Cox regression and verified based on different datasets. Tumor immune dysfunction and exclusion (TIDE) and SubMap algorithms tested immunotherapy sensitivity. Finally, qRT-PCR and Flow Cytometry was used to confirm the bioinformatic results.

Results

Hub genes such as AKT1, CDC6, TNF and their upstream transcription factor ILF3, Regulatory factor X-associated protein, STAT3, JUN, and RELA/NFKB1 were identified as potential motivators for Tex. Tex-related genes SLC16A11, CACYBP, HSF2, and ATG10 built the HCC prognostic model and helped with Immunotherapy sensitivity prediction.

Conclusion

Our study demonstrated that Tex-related genes might provide accurate prediction for HCC patients in clinical decision-making, prognostic assessment, and immunotherapy. In addition, targeting the hub genes or transcription factors may help to reverse T cell function and enhance the effect of tumor immunotherapy.

Unraveling the function of epithelial-mesenchymal transition (EMT) in colorectal cancer: Metastasis, therapy response, and revisiting molecular pathways

Colorectal cancer (CRC) is a dangerous form of cancer that affects the gastrointestinal tract. It is a major global health concern, and the aggressive behavior of tumor cells makes it difficult to treat, leading to poor survival rates for patients. One major challenge in treating CRC is the metastasis, or spread, of the cancer, which is a major cause of death. In order to improve the prognosis for patients with CRC, it is necessary to focus on ways to inhibit the cancer's ability to invade and spread. Epithelial-mesenchymal transition (EMT) is a process that is linked to the spread of cancer cells, also known as metastasis. The process transforms epithelial cells into mesenchymal ones, increasing their mobility and ability to invade other tissues. This has been shown to be a key mechanism in the progression of colorectal cancer (CRC), a particularly aggressive form of gastrointestinal cancer. The activation of EMT leads to increases in the spread of CRC cells, and during this process, levels of the protein E-cadherin decrease while levels of N-cadherin and vimentin increase. EMT also contributes to the development of resistance to chemotherapy and radiation therapy in CRC. Non-coding RNAs, such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), play a role in regulating EMT in CRC, often through their ability to "sponge" microRNAs. Anti-cancer agents have been shown to suppress EMT and reduce the progression and spread of CRC cells. These findings suggest that targeting EMT or related mechanisms may be a promising approach for treating CRC patients in the clinic.

Up-regulation of PUM1 by miR-218-5p promotes colorectal tumor-initiating cell properties and tumorigenesis by regulating the PI3K/AKT axis

Background

Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of cancer-related death worldwide. Advanced stage CRC, during the recent past, had a dismal prognosis and only a few available treatments. Pumilio homologous protein 1 (PUM1) is reportedly aberrant in human malignancies, including CRC. However, the role of PUM1 in the regulation of tumor-initiating cells (T-ICs) remains unknown.

Methods

The levels of messenger RNAs (mRNAs) were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunoblot analyses. Statistical analyses were performed to determine the associations between the levels of PUM1 and tumor features and patient outcomes. Whether PUM1 is a downstream target of miR-218-5p was verified by bioinformatics target gene prediction and qRT-PCR.

Results

Herein, it was found that T-ICs, chemoresistance, and recurrent CRC samples all manifest increased PUM1 expression. Functional investigations have shown that PUM1 increased the self-renewal, tumorigenicity, malignant proliferation, and chemoresistance of colorectal cells. PUM1 activates the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) signaling pathway biochemically. Furthermore, it was discovered that miR-218-5p specifically targets T-ICs' PUM1 3'-untranslated region (3'-UTR). More importantly, the PUM1/PI3K/AKT axis regulates CRC cells' responses to treatment with cetuximab, and PUM1 overexpression increased cetuximab resistance. More evidence points to the possibility that low PUM1 may predict cetuximab benefits in CRC patients after analysis of the patient cohort, patient-derived tumor organoids, and patient-derived xenografts (PDXs).

Conclusions

Taken together, the result of this work points to the critical function of the miR-218-5p/PUM1/PI3K/AKT regulatory circuit in regulating T-ICs characteristics and thus suggests possible therapeutic targets for CRC.