Tumor-derived IL-8 facilitates lymph node metastasis of gastric cancer via PD-1 up-regulation in CD8+ T cells

Cellular and secretome profiling uncover immunological biomarkers in the prognosis of renal cell carcinoma patients

Renal cell carcinoma (RCC) is recognized as an immunogenic tumor, yet tumor-infiltrating lymphocytes often exhibit diminished effector function. However, the mechanisms underlying reduced T and NK cell activity in RCC remain unclear. Here, we examined the immune contexture in RCC patients undergoing nephrectomy to identify immune-related biomarkers associated with disease progression. Immune cell phenotypes and secretion profiles were assessed using flow cytometry and Luminex multiplex analysis. Supervised multivariate analysis revealed several changes of which frequencies of T and NK cells expressing CCR5, CXCR3, and PD-1 were elevated within tumors compared with peripheral blood. In addition, higher levels of regulatory T cells, PD-1+, and CXCR3+ T and NK cells were observed in patients with relapse following nephrectomy. With regards to soluble factors, tumor-derived CXCL8 was associated with higher Fuhrman grade and increased frequency of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs). These biomarkers demonstrate potential relevance in the progression of RCC and merit further investigation in prospective studies.

Targeting PD-1 post-translational modifications for improving cancer immunotherapy

Programmed cell death protein 1 (PD-1) is a critical immune checkpoint receptor that suppresses immune responses largely through its interaction with PD-L1. Tumors exploit this mechanism to evade immune surveillance, positioning immune checkpoint inhibitors targeting the PD-1/PD-L1 axis as groundbreaking advancements in cancer therapy. However, the overall effectiveness of these therapies is often constrained by an incomplete understanding of the underlying mechanisms. Recent research has uncovered the pivotal role of various post-translational modifications (PTMs) of PD-1, including ubiquitination, UFMylation, phosphorylation, palmitoylation, and glycosylation, in regulating its protein stability, localization, and protein-protein interactions. As much, dysregulation of these PTMs can drive PD-1-mediated immune evasion and contribute to therapeutic resistance. Notably, targeting PD-1 PTMs with small-molecule inhibitors or monoclonal antibodies (MAbs) has shown potential to bolster anti-tumor immunity in both pre-clinical mouse models and clinical trials. This review highlights recent findings on PD-1's PTMs and explores emerging therapeutic strategies aimed at modulating these modifications. By integrating these mechanistic insights, the development of combination cancer immunotherapies can be further rationally advanced, offering new avenues for more effective and durable treatments.

Immunosuppressive Effects of Multiple Myeloma-Derived Extracellular Vesicles Through T Cell Exhaustion

Extracellular vehicles (EVs) are reported to be involved in several processes relating to tumor progression, including angiogenesis, osteolysis, and drug resistance in multiple myeloma (MM). However, the role of EVs in the immune-suppressive milieu of MM is poorly understood. Here, we investigated the effects of MM-derived EVs on T cells, focusing on markers of T cell exhaustion. Using activated peripheral blood mononuclear cells from healthy donors, we observed immunosuppressive effects such as upregulated expression of immune checkpoint markers on CD8+ T cells treated with MM-derived EVs. Proteomic analysis identified several proteins, such as IL-8, SLC1A5, PIN2, and FSP1, associated with regulation of T cell exhaustion and chronic inflammation. Surprisingly, sphingosine kinase 1 (SPHK1) was enriched in MM cell line-derived EVs, implicating SPHK1/S1P signaling in the immunosuppressive effect of MM EVs. Thus, MM-derived EVs may promote T cell exhaustion via upregulating the expression of immune checkpoint markers and thereby contribute to the formation of the immune-suppressive milieu of MM, resulting in impaired T cell activity.

Regulation of the CD8⁺ T cell and PDL1/PD1 axis in gastric cancer: Unraveling the molecular landscape

Gastric cancer (GC) remains a significant global health burden, mainly due to immune evasion mechanisms within its complex tumor microenvironment (TME). The interaction between CD8⁺ T cells and the PD1/PDL1 axis is central to these mechanisms. CD8⁺ T cells, key players in antitumor immunity, often exhibit impaired functionality in the GC TME, primarily due to PD1-mediated inhibitory signaling induced by PDL1 expressed on tumor and immune cells. Recent findings have elucidated intricate molecular interactions governing PD1 expression on CD8⁺ T cells and the modulation of PDL1 on tumor cells and immune cells by diverse signals such as cytokines, metabolic factors, and noncoding RNAs. While high PD1 expression typically indicates CD8⁺ T cell exhaustion and poor clinical outcomes, recent studies highlight scenarios where elevated PD1 levels correlate with preserved or enhanced T cell cytotoxic activity, suggesting nuanced regulatory pathways. Therapeutic strategies that disrupt PD1/PDL1 interactions, through checkpoint inhibitors or pharmacological modulation, have demonstrated potential in reactivating antitumor responses. However, resistance mechanisms, including altered antigen presentation, metabolic reprogramming, and immunosuppressive cell infiltration, continue to limit efficacy. Emerging combination therapies, biomarker-driven patient stratification, and novel targets like noncoding RNAs and exosomal PDL1 represent promising avenues to enhance treatment effectiveness. This review synthesizes current insights into the molecular regulation of CD8⁺ T cell functionality and the PD1/PDL1 axis, highlighting potential therapeutic strategies to restore antitumor immunity and improve patient outcomes in gastric cancer.

EGR2 promotes liver cancer metastasis by enhancing IL-8 expression through transcription regulation of PDK4 in M2 macrophages

Liver tumor is a common digestive system tumor, and its development is closely related to complex cytokines, tumor microenvironment and immunoregulatory mechanisms. Tumor-associated macrophages play a great role in a series of liver cancer development by secreting various cytokines and transmitting multiple signals, but how macrophages regulate the various biological behaviors of liver cancer cells at the microscopic level is a challenge we still need to overcome. In this research, we first identified the Early Growth Response 2 (EGR2) gene, which exhibited significant expression in M2 macrophages in comparison to M0 and M1 cell types, utilizing RNA sequencing. Subsequently, we validated this finding through a battery of methodologies, including WB, qRT-PCR, and immunofluorescence assays. We further employed a co-culture model involving MHCC97L and macrophages to investigate the impact of EGR2 downregulation within M2 cells on the in vivo and in vitro metastatic and invasive capabilities of MHCC97L cells. Subsequently, we directed our attention to investigating the impact of EGR2 on the levels of interleukin-8 (IL-8). Through comprehensive analyses including RNA sequencing, CUT-and-Tag, and ChIP techniques, we demonstrated that EGR2 can bind to the promoter region of the Pyruvate Dehydrogenase Kinase 4 (PDK4) gene. Finally, we introduced a virus overexpressing PDK4 and demonstrated that EGR2 could regulate the transcriptional level of PDK4 to affect the expression of IL-8, and ultimately alter the metastatic ability of hepatocellular carcinoma cells. Our study demonstrates that EGR2 may be a valuable target for future intervention in the disease process of hepatocellular carcinoma and refines the mechanism at the microscopic level of Tumor-associated macrophages.

High CXCL8 expression predicting poor prognosis in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is highly prone to early relapse and metastasis following standard treatment. CXCL8 is a key factor in tumor invasion and metastasis, but its role in TNBC prognosis and clinicopathological correlations remains poorly understood. This study investigated CXCL8 expression and its clinical significance in TNBC to develop a prognostic nomogram for guiding intensive treatment and follow-up strategies. Public datasets from the gene expression omnibus public datasets platform were analyzed to assess CXCL8 expression. Additionally, paraffin-embedded TNBC specimens collected from our hospital were examined using immunohistochemistry to explore the relationship between CXCL8 expression and clinicopathological features. Survival analysis was performed to evaluate whether CXCL8 serves as an unfavorable prognostic biomarker for TNBC patients. Univariate Cox regression analysis was conducted to identify prognostic factors. Based on these findings, a nomogram was developed to predict TNBC progression risk. CXCL8 expression was significantly higher in TNBC tissues than in adjacent normal tissues ( P  < 0.05). Among 122 TNBC patients, 46 were CXCL8-positive and 76 were CXCL8-negative. CXCL8 expression was significantly associated with N stage ( P  < 0.05). Progression-free survival (PFS) was markedly shorter in the CXCL8-positive group compared with the CXCL8-negative group ( P  < 0.001). Univariate Cox regression identified N1-3, M1, and CXCL8 positivity as significant risk factors for disease progression. A nomogram incorporating these variables (N, M, and CXCL8) was constructed to predict PFS. Time-dependent receiver operating characteristic curve analysis at 12-, 36-, and 48-month demonstrated strong predictive performance, with area under the curve values of 0.857, 0.839, and 0.795, respectively. CXCL8 is highly expressed in TNBC and promotes lymphatic metastasis, serving as an unfavorable prognostic factor. The developed nomogram offers a valuable tool for guiding personalized treatment and follow-up strategies in TNBC patients.

Serum levels of oxidative stress, IL-8, and pepsinogen I/II ratio in Helicobacter pylori and gastric cancer patients: potential diagnostic biomarkers

BACKGROUND AND AIM

Helicobacter pylori (H.pylori), a gram-negative bacterial pathogen associated with an increased risk of gastric cancer. This study investigates potential factors in the incidence of gastric cancer in patients with H.pylori, including oxidative stress, inflammatory biomarkers, serum pepsinogens (PG) of I and II, and PG-I/PG-II ratio.

METHODS

The study comprised individuals with Helicobacter pylori (H.pylori) infection, gastric cancer patients, and healthy individuals. Biochemical parameters such as FBS (fasting blood sugar), lipid profile, and liver and kidney functional factors were evaluated using colorimetric techniques. Oxidative markers such as total oxidant status (TOS) and malondialdehyde (MDA) were quantified through colorimetric methods. IL-8, PG-II, and PG-II levels were also determined using the ELISA technique.

RESULTS

Individuals with H. pylori infection exhibited elevated levels of IL-8 (940.5 ± 249.7 vs. 603.4 ± 89.1 pg/ml, P < 0.0001) and oxidative species (5.47 ± 0.7 vs. 1.64 ± 0.7 nM, P < 0.05) compared to gastric cancer patients, who, despite having lower levels of IL-8 and oxidative species, showed higher levels of MDA. H.pylori patients exhibited significantly higher levels of PG-I (7.28 ± 2.1 vs. 2.61 ± 1.4 ng/ml, P < 0.001), PG-II (3.21 ± 1 vs. 2.6 ± 0.6 ng/ml, P < 0.001), and the PG-I/PG-II ratio (2.27 ± 1.2 vs. 1 ± 0.4, P < 0.001) compared to gastric cancer patients. The findings were substantiated using various data analysis platforms such as Gene Expression Profiling Interactive Analysis (GEPIA), UALCAN (The University of ALabama at Birmingham CANcer data analysis), cBioPortal, and TIMER (Tumor IMmune Estimation Resource). These parameters could serve as potential diagnostic biomarkers for screening and therapeutic interventions based on the cut-off values derived from ROC (receiver operating characteristic) curves for IL-8, PGI, PGII, and PGI/PGII across the three groups.

CONCLUSIONS

IL-8, PGI, PGII, and PGI/PGII parameters could serve as potential diagnostic markers for the screening and treatment of gastric conditions.

Tumor microenvironment: Nurturing cancer cells for immunoevasion and druggable vulnerabilities for cancer immunotherapy

The tumor microenvironment (TME) is an intricate ecosystem where cancer cells thrive, encompassing a wide array of cellular and non-cellular components. The TME co-evolves with tumor progression in a spatially and temporally dynamic manner, which endows cancer cells with the adaptive capability of evading immune surveillance. To this end, diverse cancer-intrinsic mechanisms were exploited to dampen host immune system, such as upregulating immune checkpoints, impairing antigens presentation and competing for nutrients. In this review, we discuss how cancer immunoevasion is tightly regulated by hypoxia, one of the hallmark biochemical features of the TME. Moreover, we comprehensively summarize how immune evasiveness of cancer cells is facilitated by the extracellular matrix, as well as soluble components of TME, including inflammatory factors, lactate, nutrients and extracellular vesicles. Given their important roles in dictating cancer immunoevasion, various strategies to target TME components are proposed, which holds promising translational potential in developing novel therapeutics to sensitize anti-cancer immunotherapy such as immune checkpoint blockade.

Cytoplasmic FBXO38 mediates PD-1 degradation

Comment on “FBXO38 is dispensable for PD-1 regulation” by Dibus et al,

Anlotinib inhibits cervical cancer cell proliferation and invasion by suppressing cytokine secretion in activated cancer-associated fibroblasts

Objective

The aim of this study was to investigate whether anlotinib could exert an inhibitory effect on the proliferation and invasion of cervical cancer cells by inhibiting cytokines secreted by activated cancer-associated fibroblasts (CAFs).

Methods

CAFs were isolated from cervical cancer tissues and experimentally studied in vivo and in vitro. Molecular biology experimental methods were used to verify whether anlotinib could inhibit the pro-carcinogenic effects of CAFs derived from cervical cancer tissues.

Results

CAFs promote the proliferation and invasion of cervical cancer cells. Anlotinib inhibited the activation of CAFs and suppressed the promotion of cervical cancer cells by CAFs. Anlotinib inhibited the expression of multiple cytokines within CAFs and suppressed the release of interleukin (IL)-6 (IL-6) and IL-8. In vivo studies have shown that anlotinib diminished the growth of xenografted cervical cancer cells, and treatment in combination with docetaxel had an even more significant tumor growth inhibitory effect.

Conclusion

Anlotinib inhibits the pro-cancer effects of CAFs by suppressing the activation of CAFs and the secretion of pro-cancer cytokines. Our findings suggest that the combination of anlotinib and docetaxel may be a potential strategy for the treatment of refractory cervical cancer.

CAFs and T cells interplay: The emergence of a new arena in cancer combat

The interaction between the immune system and the tumor matrix has a huge impact on the progression and treatment of cancer. This paper summarizes and discusses the crosstalk between T cells and cancer-associated fibroblasts (CAFs). CAFs can also produce inhibitors that counteract the function of T cells and promote tumor immune escape, while T cells can also engage in complex two-way interactions with CAFs through direct cell contact, the exchange of soluble factors such as cytokines, and the remodeling of the extracellular matrix. Precise targeted intervention can effectively reverse tumor-promoting crosstalk between T cells and CAFs, improve anti-tumor immune response, and provide a new perspective for cancer treatment. Therefore, it is important to deeply understand the mechanism of crosstalk between T cells and CAFs. This review aims to outline the underlying mechanisms of these interactions and discuss potential therapeutic strategies that may become fundamental tools in the treatment of cancer, especially hard-to-cure cancers.

Tumour cell-derived serglycin promotes IL-8 secretion of CAFs in gastric cancer

BACKGROUND

Cancer-associated fibroblasts (CAFs)-derived IL-8 plays important roles in chemoresistance, immunosuppression, and lymph node metastasis of gastric cancer. However, the mechanisms underlying IL-8 production in CAFs remains unclear.

METHODS

DNA pulldown assay was performed to identify the transcription factors responsible for IL-8 expression in CAFs, which was further verified using CHIP-qPCR and DNA agarose gel electrophoresis assays. The cellular localisation of IL-8 was analysed using multiplex immunofluorescence (MxIF).

RESULTS

MxIF demonstrated that IL-8 was mainly produced by CAFs in gastric cancer. Lysine[K]-specific demethylase 5B (KDM5B) was identified as an IL-8 transcription factor in CAFs, and the binding of KDM5B to phosphorylated RB1 limited the transcriptional regulation of IL-8 in gastric cancer cells. Serglycin (SRGN) secreted by tumour cells activated the CD44/c-Myc pathway to upregulate KDM5B expression, thereby promoting IL-8 production in CAFs. Furthermore, tumour-associated neutrophils (TANs)-derived regenerating family member 4 (REG4) upregulates SRGN expression by activating cAMP-responsive element binding protein 1 (CREB1) in gastric cancer cells. Thus, the SRGN-IL-8-TANs-SRGN loop, which facilitates tumour progression, has been explored in gastric cancer.

CONCLUSIONS

This study revealed the mechanisms of the preferential production of IL-8 by CAFs in gastric cancer, and paves the way for potential new therapeutic strategies for gastric cancer.

Analysis of lymph node metastasis and survival prognosis in early gastric cancer patients: A retrospective study

BACKGROUND

Early gastric cancer (EGC) is a common malignant tumor of the digestive system, and its lymph node metastasis and survival prognosis have been concerning. By retrospectively analyzing the clinical data of EGC patients, we can better understand the status of lymph node metastasis and its impact on survival and prognosis.

AIM

To evaluate the prognosis of EGC patients and the factors that affect lymph node metastasis.

METHODS

The clinicopathological data of 1011 patients with EGC admitted to our hospital between January 2015 and December 2023 were collected in a retrospective cohort study. There were 561 males and 450 females. The mean age was 58 ± 11 years. The patient underwent radical gastrectomy. The status of lymph node metastasis in each group was determined according to the pathological examination results of surgical specimens. The outcomes were as follows: (1) Lymph node metastasis in EGC patients; (2) Analysis of influencing factors of lymph node metastasis in EGC; and (3) Analysis of prognostic factors in patients with EGC. Normally distributed measurement data are expressed as mean ± SD, and a t test was used for comparisons between groups. The data are expressed as absolute numbers or percentages, and the chi-square test was used for comparisons between groups. Rank data were compared using a nonparametric rank sum test. A log-rank test and a logistic regression model were used for univariate analysis. A logistic stepwise regression model and a Cox stepwise regression model were used for multivariate analysis. The Kaplan-Meier method was used to calculate the survival rate and construct survival curves. A log-rank test was used for survival analysis.

RESULTS

Analysis of influencing factors of lymph node metastasis in EGC. The results of the multifactor analysis showed that tumor length and diameter, tumor site, tumor invasion depth, vascular thrombus, and tumor differentiation degree were independent influencing factors for lymph node metastasis in patients with EGC (odds ratios = 1.80, 1.49, 2.65, 5.76, and 0.60; 95%CI: 1.29-2.50, 1.11-2.00, 1.81-3.88, 3.87-8.59, and 0.48-0.76, respectively; P < 0.05). Analysis of prognostic factors in patients with EGC. All 1011 patients with EGC were followed up for 43 (0-13) months. The 3-year overall survival rate was 97.32%. Multivariate analysis revealed that age > 60 years and lymph node metastasis were independent risk factors for prognosis in patients with EGC (hazard ratio = 9.50, 2.20; 95%CI: 3.31-27.29, 1.00-4.87; P < 0.05). Further analysis revealed that the 3-year overall survival rates of gastric cancer patients aged > 60 years and ≤ 60 years were 99.37% and 94.66%, respectively, and the difference was statistically significant (P < 0.05). The 3-year overall survival rates of patients with and without lymph node metastasis were 95.42% and 97.92%, respectively, and the difference was statistically significant (P < 0.05).

CONCLUSION

The lymph node metastasis rate of EGC patients was 23.64%. Tumor length, tumor site, tumor infiltration depth, vascular cancer thrombin, and tumor differentiation degree were found to be independent factors affecting lymph node metastasis in EGC patients. Age > 60 years and lymph node metastasis are independent risk factors for EGC prognosis.

PD-1 regulation in immune homeostasis and immunotherapy

Harnessing the programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) axis is pivotal in autoimmunity and cancer immunotherapy. PD-1 receptors on immune cells engage with one of its ligands, PD-L1 or PD-L2, expressed on antigen-presenting cells or tumor cells, driving T-cell dysfunction and tumor immune escape. Thus, targeting PD-1/PD-L1 revitalizes cytotoxic T cells for cancer elimination. However, a majority of cancer patients don't respond to PD-1/PD-L1 blockade, and the underlying mechanisms remain partially understood. Recent studies have revealed that PD-1 expression levels or modifications impact the effectiveness of anti-PD-1/PD-L1 treatments. Therefore, understanding the molecular mechanisms governing PD-1 expression and modifications is crucial for innovating therapeutic strategies to enhance the efficacy of PD-1/PD-L1 inhibition. This article presents a comprehensive overview of advancements in PD-1 regulation and highlights their potential in modulating immune homeostasis and cancer immunotherapy, aiming to refine clinical outcomes.

Single cell deciphering of progression trajectories of the tumor ecosystem in head and neck cancer

Head and neck squamous cell carcinoma is the sixth most common cancer worldwide and has high heterogeneity and unsatisfactory outcomes. To better characterize the tumor progression trajectory, we perform single-cell RNA sequencing of normal tissue, precancerous tissue, early-stage, advanced-stage cancer tissue, lymph node, and recurrent tumors tissue samples. We identify the transcriptional development trajectory of malignant epithelial cells and a tumorigenic epithelial subcluster regulated by TFDP1. Furthermore, we find that the infiltration of POSTN+ fibroblasts and SPP1+ macrophages gradually increases with tumor progression; their interaction or interaction with malignant cells also gradually increase to shape the desmoplastic microenvironment and reprogram malignant cells to promote tumor progression. Additionally, we demonstrate that during lymph node metastasis, exhausted CD8+ T cells with high CXCL13 expression strongly interact with tumor cells to acquire more aggressive phenotypes of extranodal expansion. Finally, we delineate the distinct features of malignant epithelial cells in primary and recurrent tumors, providing a theoretical foundation for the precise selection of targeted therapy for tumors at different stages. In summary, the current study offers a comprehensive landscape and deep insight into epithelial and microenvironmental reprogramming throughout initiation, progression, lymph node metastasis and recurrence of head and neck squamous cell carcinoma.

Evolving perspectives regarding the role of the PD-1/PD-L1 pathway in gastric cancer immunotherapy

Gastric cancer (GC) is an increasing global health problem and is one of the leading cancers worldwide. Traditional therapies, such as radiation and chemotherapy, have made limited progress in enhancing their efficacy for advanced GC. The development of immunotherapy for advanced GC has considerably improved with a deeper understanding of the tumor microenvironment. Immunotherapy using checkpoint inhibitors is a new therapeutic option that has made substantial advances in the treatment of other malignancies and is increasingly used in other clinical oncology treatments. Particularly, therapeutic antibodies targeting the programmed cell death protein-1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway have been effectively used in the clinical treatment of cancer. Monoclonal antibodies blocking the PD-1/PD-L1 pathway have been developed for cancer immunotherapy to enhance T cell function to restore the immune response and represent a breakthrough in the treatment of GC. This review provides an outline of the progress of PD-1/PD-L1 blockade therapy and its expression characteristics and clinical application in advanced GC.

The role of pyroptosis and gasdermin family in tumor progression and immune microenvironment

Pyroptosis, an inflammatory programmed cell death, distinguishes itself from apoptosis and necroptosis and has drawn increasing attention. Recent studies have revealed a correlation between the expression levels of many pyroptosis-related genes and both tumorigenesis and progression. Despite advancements in cancer treatments such as surgery, radiotherapy, chemotherapy, and immunotherapy, the persistent hallmark of cancer enables malignant cells to elude cell death and develop resistance to therapy. Recent findings indicate that pyroptosis can overcome apoptosis resistance amplify treatment-induced tumor cell death. Moreover, pyroptosis triggers antitumor immunity by releasing pro-inflammatory cytokines, augmenting macrophage phagocytosis, and activating cytotoxic T cells and natural killer cells. Additionally, it transforms "cold" tumors into "hot" tumors, thereby enhancing the antitumor effects of various treatments. Consequently, pyroptosis is intricately linked to tumor development and holds promise as an effective strategy for boosting therapeutic efficacy. As the principal executive protein of pyroptosis, the gasdermin family plays a pivotal role in influencing pyroptosis-associated outcomes in tumors and can serve as a regulatory target. This review provides a comprehensive summary of the relationship between pyroptosis and gasdermin family members, discusses their roles in tumor progression and the tumor immune microenvironment, and analyses the underlying therapeutic strategies for tumor treatment based on pyroptotic cell death.

The Evolving Landscape of B Cells in Cancer Metastasis

Metastasis is the leading cause of cancer mortality. Functional and clinical studies have documented diverse B-cell and antibody responses in cancer metastasis. The presence of B cells in tumor microenvironments and metastatic sites has been associated with diverse effects that can promote or inhibit metastasis. Specifically, B cells can contribute to the spread of cancer cells by enhancing tumor cell motility, invasion, angiogenesis, lymphangiogenesis, and extracellular matrix remodeling. Moreover, they can promote metastatic colonization by triggering pathogenic immunoglobulin responses and recruiting immune suppressive cells. Contrastingly, B cells can also exhibit antimetastatic effects. For example, they aid in enhanced antigen presentation, which helps activate immune responses against cancer cells. In addition, B cells play a crucial role in preventing the dissemination of metastatic cells from the primary tumor and secrete antibodies that can aid in tumor recognition. Here, we review the complex roles of B cells in metastasis, delineating the heterogeneity of B-cell activity and subtypes by metastatic site, antibody class, antigen (if known), and molecular phenotype. These important attributes of B cells emphasize the need for a deeper understanding and characterization of B-cell phenotypes to define their effects in metastasis.

Resistance to immune checkpoint inhibitors in gastric cancer

Gastric cancer (GC) is one of the most common gastrointestinal malignancies worldwide. In the past decade, with the development of early diagnostic techniques, a clear decline in GC incidence has been observed, but its mortality remains high. The emergence of new immunotherapies such as immune checkpoint inhibitors (ICIs) has changed the treatment of GC patients to some extent. However, only a small number of patients with advanced GC have a durable response to ICI treatment, and the efficacy of ICIs is very limited. Existing studies have shown that the failure of immunotherapy is mainly related to the development of ICI resistance in patients, but the understanding of the resistance mechanism is still insufficient. Therefore, clarifying the mechanism of GC immune resistance is critical to improve its treatment and clinical benefit. In this review, we focus on summarizing the mechanisms of primary or acquired resistance to ICI immunotherapy in GC from both internal and external aspects of the tumor. At the same time, we also briefly discuss some other possible resistance mechanisms in light of current studies.

Targeting cancer-associated adipocyte-derived CXCL8 inhibits triple-negative breast cancer progression and enhances the efficacy of anti-PD-1 immunotherapy

Cancer-associated adipocytes (CAAs), one of the primary stromal components, exhibit intimate crosstalk and release multiple cell factors mediating local and systemic biological effects. However, the role of CAAs in the regulation of systemic immune responses and their potential value in the clinical treatment of triple-negative breast cancer (TNBC) are not well described. Transcriptome sequencing was performed on CAA and normal adipocyte (NA) tissues isolated from surgically resected samples from TNBC patients and healthy controls. Cytokines, including C-X-C motif chemokine ligand 8 (CXCL8, also known as IL-8), secreted from NAs and CAAs were compared by transcriptome sequencing and enzyme-linked immunosorbent assay (ELISA). Proliferation, migration and invasion assays were employed to analyze the role of CAAs and CAA-derived CXCL8 (macrophage inflammatory protein-2 (MIP2) as a functional surrogate in mice). TNBC syngraft models were established to evaluate the curative effect of targeting CXCL8 in combination with anti-PD-1 therapies. Real-time quantitative polymerase chain reaction (RT-qPCR), western blotting (WB), polymerase chain reaction (PCR) array, flow cytometry, immunohistochemistry (IHC), and immunofluorescence (IF) were applied to analyze immune cell infiltration and epithelial-mesenchymal transition (EMT) markers. Specifically, we demonstrated that CAAs and CAA-derived CXCL8 played important roles in tumor growth, EMT, metastasis and tumor immunity suppression. CAA-derived CXCL8 remodeled the tumor immune microenvironment not only by suppressing CD4+ T and CD8+ T immune cell infiltration but also by upregulating CD274 expression in TNBC. The combination of targeting the CXCL8 pathway and blocking the PD-1 pathway synergistically increased the tumor immune response and inhibited tumor progression. Thus, our results highlight the molecular mechanisms and translational significance of CAAs in tumor progression and immune ecosystem regulatory effects and provide a better understanding of the potential clinical benefit of targeting CAA-derived CXCL8 in antitumor immunity and as a new therapeutic moiety in TNBC.

Immunomodulatory properties of the lymphatic endothelium in the tumor microenvironment

The tumor microenvironment (TME) is an intricate complex and dynamic structure composed of various cell types, including tumor, stromal and immune cells. Within this complex network, lymphatic endothelial cells (LECs) play a crucial role in regulating immune responses and influencing tumor progression and metastatic dissemination to lymph node and distant organs. Interestingly, LECs possess unique immunomodulatory properties that can either promote or inhibit anti-tumor immune responses. In fact, tumor-associated lymphangiogenesis can facilitate tumor cell dissemination and metastasis supporting immunoevasion, but also, different molecular mechanisms involved in LEC-mediated anti-tumor immunity have been already described. In this context, the crosstalk between cancer cells, LECs and immune cells and how this communication can shape the immune landscape in the TME is gaining increased interest in recent years. In this review, we present a comprehensive and updated report about the immunomodulatory properties of the lymphatic endothelium within the TME, with special focus on primary tumors and tumor-draining lymph nodes. Furthermore, we outline emerging research investigating the potential therapeutic strategies targeting the lymphatic endothelium to enhance anti-tumor immune responses. Understanding the intricate mechanisms involved in LEC-mediated immune modulation in the TME opens up new possibilities for the development of innovative approaches to fight cancer.

Lymph node metastasis and tumor-educated immune tolerance: Potential therapeutic targets against distant metastasis

Lymph node metastasis has been shown to positively associated with the prognosis of many cancers. However, in clinical treatment, lymphadenectomy is not always successful, suggesting that immune cells in the tumor and sentinel lymph nodes still play a pivotal role in tumor immunosuppression. Recent studies had shown that tumors can tolerate immune cells through multiple strategies, including tumor-induced macrophage reprogramming, T cells inactivation, production of B cells pathogenic antibodies and activation of regulatory T cells to promote tumor colonization, growth, and metastasis in lymph nodes. We reviewed the bidirectional effect of immune cells on anti-tumor or promotion of cancer cell metastasis during lymph node metastasis, and the mechanisms by which malignant cancer cells modify immune cells to create a more favorable environment for the growth and survival of cancer cells. Research and treatment strategies focusing on the immune system in lymph nodes and potential immune targets in lymph node metastasis were also be discussed.

Predicting Lymph Node Metastasis Status from Primary Muscle-Invasive Bladder Cancer Histology Slides Using Deep Learning: A Retrospective Multicenter Study

BACKGROUND

Accurate prediction of lymph node metastasis (LNM) status in patients with muscle-invasive bladder cancer (MIBC) before radical cystectomy can guide the use of neoadjuvant chemotherapy and the extent of pelvic lymph node dissection. We aimed to develop and validate a weakly-supervised deep learning model to predict LNM status from digitized histopathological slides in MIBC.

METHODS

We trained a multiple instance learning model with an attention mechanism (namely SBLNP) from a cohort of 323 patients in the TCGA cohort. In parallel, we collected corresponding clinical information to construct a logistic regression model. Subsequently, the score predicted by the SBLNP was incorporated into the logistic regression model. In total, 417 WSIs from 139 patients in the RHWU cohort and 230 WSIs from 78 patients in the PHHC cohort were used as independent external validation sets.

RESULTS

In the TCGA cohort, the SBLNP achieved an AUROC of 0.811 (95% confidence interval [CI], 0.771-0.855), the clinical classifier achieved an AUROC of 0.697 (95% CI, 0.661-0.728) and the combined classifier yielded an improvement to 0.864 (95% CI, 0.827-0.906). Encouragingly, the SBLNP still maintained high performance in the RHWU cohort and PHHC cohort, with an AUROC of 0.762 (95% CI, 0.725-0.801) and 0.746 (95% CI, 0.687-0.799), respectively. Moreover, the interpretability of SBLNP identified stroma with lymphocytic inflammation as a key feature of predicting LNM presence.

CONCLUSIONS

Our proposed weakly-supervised deep learning model can predict the LNM status of MIBC patients from routine WSIs, demonstrating decent generalization performance and holding promise for clinical implementation.

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.

IL-8 Secreted by Gastric Epithelial Cells Infected with Helicobacter pylori CagA Positive Strains Is a Chemoattractant for Epstein-Barr Virus Infected B Lymphocytes

Helicobacter pylori and EBV are considered the main risk factors in developing gastric cancer. Both pathogens establish life-lasting infections and both are considered carcinogenic in humans. Different lines of evidence support that both pathogens cooperate to damage the gastric mucosa. Helicobacter pylori CagA positive virulent strains induce the gastric epithelial cells to secrete IL-8, which is a potent chemoattractant for neutrophils and one of the most important chemokines for the bacterium-induced chronic gastric inflammation. EBV is a lymphotropic virus that persists in memory B cells. The mechanism by which EBV reaches, infects and persists in the gastric epithelium is not presently understood. In this study, we assessed whether Helicobacter pylori infection would facilitate the chemoattraction of EBV-infected B lymphocytes. We identified IL-8 as a powerful chemoattractant for EBV-infected B lymphocytes, and CXCR2 as the main IL-8 receptor whose expression is induced by the EBV in infected B lymphocytes. The inhibition of expression and/or function of IL-8 and CXCR2 reduced the ERK1/2 and p38 MAPK signaling and the chemoattraction of EBV-infected B lymphocytes. We propose that IL-8 at least partially explains the arrival of EBV-infected B lymphocytes to the gastric mucosa, and that this illustrates a mechanism of interaction between Helicobacter pylori and EBV.

Tissue-resident memory T cells in gastrointestinal tumors: turning immune desert into immune oasis

Tissue-resident memory T cells (Trm) are a particular type of T cell subgroup, which stably reside in tissues and have been revealed to be the most abundant memory T cell population in various tissues. They can be activated in the local microenvironment by infection or tumor cells and rapidly clean them up to restore homeostasis of local immunity in gastrointestinal tissues. Emerging evidence has shown that tissue-resident memory T cells have great potential to be mucosal guardians against gastrointestinal tumors. Therefore, they are considered potential immune markers for immunotherapy of gastrointestinal tumors and potential extraction objects for cell therapy with essential prospects in clinical translational therapy. This paper systematically reviews the role of tissue-resident memory T cells in gastrointestinal tumors and looks to the future of their prospect in immunotherapy to provide a reference for clinical application.

Tumor microenvironment-mediated immune tolerance in development and treatment of gastric cancer

Tumor microenvironment is the general term for all non-cancer components and their metabolites in tumor tissue. These components include the extracellular matrix, fibroblasts, immune cells, and endothelial cells. In the early stages of tumors, the tumor microenvironment has a tumor suppressor function. As the tumor progresses, tumor immune tolerance is induced under the action of various factors, such that the tumor suppressor microenvironment is continuously transformed into a tumor-promoting microenvironment, which promotes tumor immune escape. Eventually, tumor cells manifest the characteristics of malignant proliferation, invasion, metastasis, and drug resistance. In recent years, stress effects of the extracellular matrix, metabolic and phenotypic changes of innate immune cells (such as neutrophils, mast cells), and adaptive immune cells in the tumor microenvironment have been revealed to mediate the emerging mechanisms of immune tolerance, providing us with a large number of emerging therapeutic targets to relieve tumor immune tolerance. Gastric cancer is one of the most common digestive tract malignancies worldwide, whose mortality rate remains high. According to latest guidelines, the first-line chemotherapy of advanced gastric cancer is the traditional platinum and fluorouracil therapy, while immunotherapy for gastric cancer is extremely limited, including only Human epidermal growth factor receptor 2 (HER-2) and programmed death ligand 1 (PD-L1) targeted drugs, whose benefits are limited. Clinical experiments confirmed that cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), vascular endothelial growth factor receptor (VEGFR) and other targeted drugs alone or in combination with other drugs have limited efficacy in patients with advanced gastric cancer, far less than in lung cancer, colon cancer, and other tumors. The failure of immunotherapy is mainly related to the induction of immune tolerance in the tumor microenvironment of gastric cancer. Therefore, solving the immune tolerance of tumors is key to the success of gastric cancer immunotherapy. In this study, we summarize the latest mechanisms of various components of the tumor microenvironment in gastric cancer for inducing immune tolerance and promoting the formation of the malignant phenotype of gastric cancer, as well as the research progress of targeting the tumor microenvironment to overcome immune tolerance in the treatment of gastric cancer.

Association of serum Interleukin-8 level with lymph node metastasis and tumor recurrence in gastric cancer

The level of pretherapeutic serum interleukin-8 (sIL-8) has been demonstrated to correlate with chemoresistance in gastric cancer. However, its clinicopathological significance of sIL-8 in gastric cancer remains unknown. Herein, a total of 335 patients diagnosed with gastric adenocarcinoma were enrolled. The clinicopathological features were collected, and the sIL-8 levels were measured using enzyme-linked immunosorbent assay. The sIL-8 levels ranged from 1.48 pg/ml to 1025.22 pg/ml with > 15.41 pg/ml defined as high according to the receiver operating characteristic analysis. sIL-8 levels were strongly associated with Lauren classification and tumor recurrence. High sIL-8 correlated with lymph node metastasis (LNM) in the intestinal- and diffuse-type tumors and acted as an independent risk factor for LNM in both types. Patients with high sIL-8 levels had worse relapse-free survival than those with low sIL-8 levels. High sIL-8 level was associated with tumor relapse in the intestinal- and diffuse-type tumors, and was also an independent risk factor in the intestinal- and mixed-type tumors. Further analysis revealed that sIL-8 levels were positively associated with LNM and tumor relapse in patients with negative carcinoembryonic antigen (CEA), but not in those with elevated serum CEA levels. In conclusion, this retrospective study demonstrated that the pretherapeutic sIL-8 level has predictive value for LNM and tumor recurrence, and may serve as a potential tumor marker in gastric cancer.