Targeting Treg cells in cancer immunotherapy

Regulatory T cells converted from Th1 cells in tumors suppress cancer immunity via CD39

Regulatory T (Treg) cells are known to impede antitumor immunity, yet the regulatory mechanisms and functional roles of these cells remain poorly understood. In this study, through the characterization of multiple cancer models, we identified a substantial presence of peripherally induced Treg cells in the tumor microenvironment (TME). Depletion of these cells triggered antitumor responses and provided potent therapeutic effects by increasing functional CD8+ T cells. Fate-mapping and transfer experiments revealed that IFN-γ-expressing T helper (Th) 1 cells differentiated into Treg cells in response to TGF-β signaling in tumors. Pseudotime trajectory analysis further revealed the terminal differentiation of Th1-like Treg cells from Th1 cells in the TME. Tumor-resident Treg cells highly expressed T-bet, which was essential for their functions in the TME. Additionally, CD39 was highly expressed by T-bet+ Treg cells in both mouse and human tumors, and was necessary for Treg cell-mediated suppression of CD8+ T cell responses. Our study elucidated the developmental pathway of intratumoral Treg cells and highlighted novel strategies for targeting them in cancer patients.

The possible anti-tumor effects of regulatory T cells plasticity / IL-35 in the tumor microenvironment of the major three cancer types

T lymphocytes are among the immunological cells that make up the tumor microenvironment (TME), and they are essential in the growth of tumors and anti-tumor reactions. Regulatory T cells (Treg cells) are a subset of CD4+ T cells in the immune system that suppress the immune system. They are distinguished by their expression of the master transcription factor forkhead box protein P3 (FOXP3). Furthermore, Treg cells are essential for maintaining immunological homeostasis, inhibiting inflammation, and maintaining self-tolerance. In a variety of malignancies within the TME, Treg cells demonstrate notable flexibility and functional diversity. Highly plastic Treg cells can change into Th-like Treg cells in specific circumstances, which allow them to secrete particular pro-inflammatory cytokines. Interleukin 35 (IL-35) is a part of the immunosuppressive cytokines that belong to the IL-12 family. Treg cells release IL-35, which was elevated in the peripheral blood and TME of numerous cancer patients, implying that IL-35 in the TME may be an intriguing target for cancer therapy. In cancer, IL-35 is a two-edged sword; it promotes tumorigenicity in cancer cells while shielding them from apoptosis. Nonetheless, other investigations have mentioned its conflicting effects on cancer prevention. Herein, we provide an updated understanding of the critical mechanisms behind the anticancer immunity mediated by Treg cells plasticity, the role of IL-35, and tactics to strengthen the immune response against malignancies, outlining major clinical trials that used Treg cells/IL-35 therapies in the three main cancer types (lung, breast, and colorectal cancers).

Nanoparticle-based drug delivery systems to modulate tumor immune response for glioblastoma treatment

Glioblastoma (GBM) is a primary central nervous system neoplasm, characterized by a grim prognosis and low survival rates. This unfavorable therapeutic outcome is partially attributed to the inadequate immune infiltration and an immunosuppressive microenvironment, which compromises the effectiveness of conventional radiotherapy and chemotherapy. To this end, precise modulation of cellular dynamics in the immune system has emerged as a promising approach for therapeutic intervention. The advent of nanoparticle-based therapies has revolutionized cancer treatment and provided highly effective options. Consequently, various strategically designed nano-delivery platforms have been established to promote the efficacy of immune therapy against GBM. This review delves into the recent advancements in nano-based delivery systems that are designed to modulate immune cells in GBM microenvironment, and explores their multifaceted mechanisms, including the blockade of immune checkpoints, the restraint of immunosuppressive cells, the coordination of tumor-associated macrophages, the activation of innate immune cells, and the stimulation of adaptive immunity. Collectively, this summary not only advances the comprehension involved in modulating antitumor immune responses in GBM, but also paves the way for the development of innovative therapeutic strategies to conquer GBM. STATEMENT OF SIGNIFICANCE: Glioblastoma (GBM) is the most lethal brain tumor, with a median survival rate of merely 12-16 months after diagnosis. Despite surgical, radiation and chemotherapy treatments, the two-year survival rate for GBM patients is less than 10 %. The treatment of GBM is challenging mainly because several issues associated with the GBM microenvironment have not yet been resolved. Most recently, novel drug delivery approaches, based on the clear understanding of the intrinsic properties of GBM, have shown promise in overcoming some of the obstacles. In particular, taking account of the highly immunosuppressive tumor microenvironment in GBM, recent advancements in nano-based delivery systems are put forward to stimulate immune cells in GBM and unravel their multifaceted mechanisms. This review summarizes the latest nanoparticle-based drug delivery systems to modulate tumor immune response for glioblastoma treatment. Moreover, the development trends and challenges of nanoparticle-based drug delivery systems in modulating the immunity of GBM are predicted, which may facilitate widespread regimens springing up for successfully treating GBM.

Disulfidptosis-related gene SLC3A2: a novel prognostic biomarker in nasopharyngeal carcinoma and head and neck squamous cell carcinoma

Introduction

Nasopharyngeal carcinoma (NPC), one of the most common malignancies of the head and neck, is characterised by a complex pathogenesis and an unfavourable prognosis. Recently, disulfidoptosis, a novel form of cell death, has been proposed. Several studies in recent years have extensively investigated the function of the disulfidoptosis-related SLC7A11 gene in cancer, but the role of its partner protein, SLC3A2, remains unknown unclear in NPC.

Methods

GEO database analysis confirmed SLC3A2's prognostic impact on nasopharyngeal carcinoma. ROC, Kaplan-Meier analyses, and stage-specific expression studies showed a strong correlation with poor HNSC prognosis. GO and KEGG analyses pinpointed relevant signaling pathways. In vitro, SLC3A2's influence on cell proliferation, migration, and invasion was evaluated through CCK8, wound healing, colony formation, transwell assays, and cell cycle analysis.

Results

In this study, we identified the high expression of SLC3A2 in NPC and head and neck squamous cell carcinoma (HNSC) and analyzed its potential mechanism and correlation with patient prognosis. Furthermore, a negative relationship was found between the expression level of SLC3A2 and the extent of immune cell infiltration and immune checkpoint. Differentially expressed genes (DEGs) between the high and low SLC3A2 expression groups were primarily involved in cytokine-cytokine receptor interaction and immune response. Finally, in vitro experiments demonstrated that SLC3A2 stimulates tumor cell proliferation and migration.

Discussion

In conclusion, these results indicated a strong association between SLC3A2 and progression in both NPC and HNSC, suggesting it as a promising biomarker for predicting adverse prognosis in NPC and HNSC patients.

The role of interleukin-17 in inflammation-related cancers

Emerging evidence indicates a correlation between inflammation and the development and progression of cancer. Among the various inflammatory signals, interleukin-17 (IL-17) family cytokines serve as a critical link between inflammation and cancer. IL-17 is a highly versatile pro-inflammatory cytokine that plays a pivotal role in host defense, tissue repair, the pathogenesis of inflammatory diseases, and cancer progression. During the early stages of tumorigenesis, IL-17 signaling directly promotes the proliferation of tumor cells. Conversely, IL-17 has been shown to exhibit antitumor immunity in several models of grafted subcutaneous tumors. Additionally, dynamic changes in the microbiome can influence the secretion of IL-17, thereby affecting tumor development. The specific role of IL-17 is contingent upon its functional classification, spatiotemporal characteristics, and the stage of tumor development. In this review, we introduce the fundamental biology of IL-17 and the expression profile of its receptors in cancer, while also reviewing and discussing recent advancements regarding the pleiotropic effects and mechanisms of IL-17 in inflammation-related cancers. Furthermore, we supplement our discussion with insights into the mechanisms by which IL-17 impacts cancer progression through interactions with the microbiota, and we explore the implications of IL-17 in cancer therapy. This comprehensive analysis aims to enhance our understanding of IL-17 and its potential role in cancer treatment.

Modulating Treg cell activity in prostate cancer via chitosan nanoparticles loaded with si-BATF/PRDM1

Prostate cancer is a significant health issue, with regulatory T (Treg) cells playing a crucial role in its progression. This study explores the potential of chitosan-modified magnetic nanoparticles loaded with si-BATF/PRDM1 to target Treg cell activity in impeding prostate cancer development. By understanding the function of BATF and PRDM1 in Treg cells, the research demonstrates their central involvement in prostate cancer progression. Through experiments in vitro and in vivo, including single-cell sequencing and gene silencing assays, chitosan nanoparticles efficiently deliver siRNA, inhibiting BATF and PRDM1 expression. This inhibition leads to suppressed tumor growth and metastasis in prostate cancer models. The findings highlight the promise of nanoparticle-based approaches in modulating Treg cell activity for prostate cancer therapy, offering a potential avenue for precision medicine interventions in combating this prevalent malignancy.

Foxp3 inhibitory peptide encapsulated in a novel CD25-targeted nanoliposome promotes efficient tumor regression in mice

P60, a Foxp3 inhibitory peptide, can hinder the regulatory T cell (Treg) activity and impair tumor proliferation. However, low systemic stability and poor specificity have led to daily dosing to achieve therapeutic effect. Therefore, this study aims to improve P60 stability and specific delivery through its encapsulation in liposomes targeting CD25, constitutively expressed in Tregs. P60 liposomes formulated with DSPE-PEG750 or DSPE-PEG2000 were incubated with DSPE-PEG2000-Maleimide micelles conjugated to Fab' fragments of anti-CD25 to develop two targeted formulations or immunoliposomes (IL): IL-P602000 (DSPE-PEG2000 only) and IL-P60750 (combining DSPE-PEG750 and DSPE-PEG2000). P60 encapsulation efficiency was 50%-60% irrespective of PEG chain length. Treg uptake was 2.5 and 14 times higher for IL-PEG750 compared with IL-PEG2000 and non-targeted liposomes, respectively, in in-vitro assays. In fact, IL-P60750 allowed CD8+  T cells ex-vivo proliferation in presence of Treg at doses 10-20 times lower than for free P60. Antitumor response of P60 and IL-P60750 in monotherapy and combined with anti-PD-1 was evaluated in MC38 and LLCOVA tumor bearing mice. In MC38 model, IL-P60750 monotherapy induced total tumor regression in 40% of mice reaching 100% for anti-PD-1 combination. This effect was associated with a significant increase in activated CD8+ T cells in tumors. Notably, IL-P60750 also inhibited human Treg in ex-vivo assay, showing the translational capability of this formulation. In conclusion, IL-P60750 formulated with different PEG chain lengths, has demonstrated antitumor efficacy by selective inhibition of Treg activity and enhances the effect of anti-PD1. Altogether, this novel IL represents a promising nanoplatform for cancer immunotherapies.

Harnessing Antitumor Immunity in Ovarian Cancer

Despite progress in other tumor types, immunotherapy is not yet part of the standard of care treatment for high-grade serous ovarian cancer patients. Although tumor infiltration by T cells is frequently observed in patients with ovarian cancer, clinical responses to immunotherapy remain low. Mechanisms for immune resistance in ovarian cancer have been explored and may provide insight into future approaches to improve response to immunotherapy agents. In this review, we discuss what is known about the immune landscape in ovarian cancer, review the available data for immunotherapy-based strategies in these patients, and provide possible future directions.

Glut3 promotes cellular O-GlcNAcylation as a distinctive tumor-supportive feature in Treg cells

Regulatory T cells (Tregs) establish dominant immune tolerance but obstruct tumor immune surveillance, warranting context-specific mechanistic insights into the functions of tumor-infiltrating Tregs (TIL-Tregs). We show that enhanced posttranslational O-linked N-acetylglucosamine modification (O-GlcNAcylation) of cellular factors is a molecular feature that promotes a tumor-specific gene expression signature and distinguishes TIL-Tregs from their systemic counterparts. We found that altered glucose utilization through the glucose transporter Glut3 is a major facilitator of this process. Treg-specific deletion of Glut3 abrogates tumor immune tolerance, while steady-state immune homeostasis remains largely unaffected in mice. Furthermore, by employing mouse tumor models and human clinical data, we identified the NF-κB subunit c-Rel as one such factor that, through Glut3-dependent O-GlcNAcylation, functionally orchestrates gene expression in Tregs at tumor sites. Together, these results not only identify immunometabolic alterations and molecular events contributing to fundamental aspects of Treg biology, specifically at tumor sites but also reveal tumor-specific cellular properties that can aid in the development of Treg-targeted cancer immunotherapies.

Crucial immunological roles of the invasion front in innate and adaptive immunity in cervical cancer

BACKGROUND

The immunostimulatory actions of innate and adaptive immune responses play a crucial role in the cancer-immunity cycle. Although cervical cancer (CC) exhibits a high recurrence rate, the relation with lymphocytes in the tumor tissue have not been analyzed.

METHODS

We analyzed NKT, NK, and T cells, not only in peripheral blood (PB), but also tumor tissue through histological analysis from 23 patients with CC collected before treatment. A correlation of them between PB and the tumor tissue were assessed.

RESULTS

We detected functional NKT and NKG2Dhi NK cells and effector CD4+ Tregs in PB. In the tumor, we detected the infiltration of LAG-3+ TIM-3+ CD4+ and CD8+ T cells rather than NK cells particularly in the invasion front (IF) by fluorescent multiplex immunohistochemistry. The heatmap and correlation analysis revealed that LAG-3+ TIM-3+ CD8+ T cells are highly associated with CD69+ CD103- exhausted CD8+ T cells. We identified the statistical relationship between CD4+Tregs in PB and the number of LAG-3+ TIM-3+ CD4+ T cells in the IF, which may be related to recurrence in patients with CC.

CONCLUSIONS

LAG-3+ TIM-3+ T cells located in the IF may play a key role in regulation of the tumor immune microenvironment.

Regulatory T cells in immune checkpoint blockade antitumor therapy

Regulatory T cells (Tregs), an essential component of the human immune system, are a heterogeneous group of T lymphocytes with the ability to suppress immune responses and maintain immune homeostasis. Recent evidence indicates that Tregs may impair antitumor immunity and facilitate cancer progression by weakening functions of effector T cells (Teffs). Consequently, targeting Tregs to eliminate them from tumor microenvironments to improve Teffs' activity could emerge as an effective strategy for cancer immunotherapy. This review outlines the biology of Tregs, detailing their origins, classification, and crucial markers. Our focus lies on the complex role of Tregs in cancer's development, progression and treatment, particularly on their suppressive role upon antitumor responses via multiple mechanisms. We delve into Tregs' involvement in immune checkpoint blockade (ICB) therapy, their dual effect on cancer immunotherapy and their potential biomarkers for ICB therapy effectiveness. We also summarize advances in the therapies that adjust Tregs to optimize ICB therapy, which may be crucial for devising innovative cancer treatment strategies.

A CD25×TIGIT bispecific antibody induces anti-tumor activity through selective intratumoral Treg cell depletion

Intratumoral regulatory T cells (Tregs) express high levels of CD25 and TIGIT, which are also recognized as markers of effector T cell (Teff) activation. Targeting these molecules each alone with monoclonal antibodies (mAbs) poses a risk of concurrently depleting both Teffs and peripheral Tregs, thereby compromising the effectiveness and selectivity of intratumoral Treg depletion. Here, leveraging the increased abundance of CD25+ TIGIT+ double-positive Tregs in the solid tumor microenvironment (but not in peripheral tissues), we explore the feasibility of using a CD25×TIGIT bispecific antibody (bsAb) to selectively deplete intratumoral Tregs. We initially constructed a bsAb co-targeting mouse CD25 and TIGIT, NSWm7210, and found that NSWm7210 conferred enhanced intratumoral Treg depletion, Teff activation, and tumor suppression as compared to the parental monotherapies in mouse models. We subsequently constructed a bsAb co-targeting human CD25 and TIGIT (NSWh7216), which preferentially eliminated CD25+ TIGIT+ double-positive cells over single-positive cells in vitro. NSWh7216 exhibited enhanced anti-tumor activity without toxicity of peripheral Tregs in CD25 humanized mice compared to the parental monotherapies. Our study illustrates the use of CD25×TIGIT bsAbs as effective agents against solid tumors based on selective depletion of intratumoral Tregs.

Development of oxidative stress- and ferroptosis-related prognostic signature in gastric cancer and identification of CDH19 as a novel biomarker

BACKGROUND

Ferroptosis is a unique mode of cell death that is iron-dependent and associated with oxidative stress and lipid peroxidation. Oxidative stress and ferroptosis are essential mechanisms leading to metabolic abnormalities in cells and have been popular areas in cancer research.

METHODS

Initially, 76 oxidative stress and ferroptosis-related genes (OFRGs) were acquired by intersecting the gene sets from oxidative stress and ferroptosis. Afterwards, optimal OFRGs were screened using PPI networks, and individuals were separated into two OFRG subtypes (K = 2). Subsequently, we successfully constructed and verified a prognostic signature comprising SLC7A2, Cadherin 19 (CDH19), and CCN1. To further uncover potential biomarkers of gastric cancer (GC), we examined the expression level of CDH19, investigated the effects of knocking down CDH19 on the biological behavior of GC cells, and explored whether CDH19 is involved in ferroptosis and oxidative stress processes.

RESULTS

According to the findings, individuals in the low-risk scoring group have less infiltration of immune suppressive cells, fewer occurrences of immune escape and dysfunction, greater efficacy in chemotherapy and immunotherapy, and better survival outcomes. The qRT-PCR assay indicated that CDH19 expression was significantly higher in GC cells. Through experiments, we demonstrated that knocking down CDH19 can affect the transcription levels of ACSL4 and GPX4, increase intracellular iron ion concentration and accumulation of reactive oxygen species (ROS), and inhibit the proliferation and migration of GC cells.

CONCLUSION

We developed an OFRG-related signature to predict the prognosis and treatment responsiveness of individuals with GC and identified CDH19 as a possible therapeutic target for GC.

Data-mining-based biomarker evaluation and experimental validation of SHTN1 for bladder cancer

BACKGROUND

Gene therapy in bladder cancer (BLCA) remains an area ripe for exploration. Recent studies have highlighted the crucial role of SHTN1 in the initiation and progression of various cancers and SHTN1 may have interacted with the FGFR gene. However, its specific function in BLCA remains unclear.

MATERIALS AND METHODS

We investigated the association between SHTN1 expression and prognosis, immune infiltration, and the tumor microenvironment (TME) across multiple malignancies using 433 BLCA samples from The Cancer Genome Atlas (TCGA). Differential gene expression analysis, functional annotation via Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) were performed for SHTN1-related genes by using R packages. Immune response and TME scores, along with drug sensitivity profiles of SHTN1, were analyzed using R packages. Immunohistochemistry (IHC) and western blotting were conducted to assess SHTN1 expression in surgical specimens from BLCA patients.CCK8 assay and cells wound healing assay were performed.The bioinformatics was analyzed by R software. Significant differences were evaluated using unpaired t test.

RESULTS

SHTN1 expression levels were significantly elevated in BLCA associated with poor prognosis (p < 0.01). Receiver operating characteristic (ROC) curves and nomograms demonstrated the diagnostic and prognostic efficacy of SHTN1 in BLCA. Notably, SHTN1 expression was higher in high-grade BLCA compared to lower-grade (p = 5.6e-10), a finding corroborated by IHC and western blotting. Pathway enrichment analysis revealed significant involvement of the Neuroactive ligand-receptor interaction and Chemical carcinogenesis - DNA adducts signaling pathways among SHTN1 differentially expressed genes. In terms of immune infiltration, T cells CD8, T cells follicular helper, and dendritic cells were predominant in the SHTN1 low-expression group, whereas macrophages M0 and M2, and mast cells were predominant in the high-expression group. Multivariate Cox regression analysis identified SHTN1 as an independent prognostic factor for overall survival (HR = 2.93; 95 % CI = 1.40-6.13; p = 0.004).CCK8 and wound healing experiments showed that SHTN1 knockdown reduced the cell proliferation and migration. Western blot showed that the EMT pathway was clearly associated with SHTN1.

CONCLUSIONS

Our findings suggest that SHTN1 holds promise as a prognostic and diagnostic biomarker for BLCA. Moreover, it is closely associated with elevated immune infiltration and distinct characteristics of the tumor microenvironment in BLCA.

Deciphering the prognostic and therapeutic significance of BAG1 and BAG2 for predicting distinct survival outcome and effects on liposarcoma

Liposarcoma (LPS) is the second most common kind of soft tissue sarcoma, and a heterogeneous malignant tumor derived from adipose tissue. Up to now, the prognostic value of BAG1 or BAG2 in LPS has not been defined yet. Expression profiling data of LPS patients were collected from TCGA and GEO database. Survival curves were plotted to verify the outcome differences of patients based on BAG1 or BAG2 expression. Univariate and multivariate Cox regression models were used to analyze the prognostic ability of BAG1 or BAG2. Chaperone's regulators BAG1 and BAG2 were identified as prognostic biomarkers for LPS patients, which exhibited distinct expression patterns and survival outcome prediction performances. Patients with high BAG2 expression and/or low BAG1 expression had worse prognosis. Enrichment analysis showed that BAG1 was involved in negative regulation of TGF-β signaling. Low expression of BAG1 was associated with high abundance of regulatory T cells (Tregs). The 2-gene signature model further confirmed the improved risk assessment performance of BAG1 and BAG2: high risk patients displayed poor prognosis. BAG1 and BAG2 are supposed to be potential prognostic biomarkers for LPS and have impacts on liposarcomagenesis and immune infiltration in distinctive manners, which may function as potential therapy targets (BAG1 agonists/BAG2 inhibitors) for LPS.

Opportunities and challenges for targeting HPK1 in cancer immunotherapy

Hematopoietic Progenitor Kinase 1 (HPK1, also known as MAP4K1) is a hematopoiesis-specific serine/threonine kinase that belongs to the MAP4K family of Ste20-related protein kinases. HPK1 has been identified as a negative regulator of T-cell receptor signaling. Recent studies have indicated that the inhibition or knockout of HPK1 kinase function can effectively alleviate T cell exhaustion, enhance T cell functionality, and improve the therapeutic efficacy of tumor immunotherapy. In recent years, small molecule chemical drugs targeting HPK1 have made significant progress and have become a hot topic in the research and development of tumor immunotherapy drugs. However, the advancement of small molecule drugs that target HPK1 is hindered by various challenges, including the limited selectivity, insufficient immune stimulation, and the ambiguity surrounding role of non-kinase scaffold functions of HPK1 in tumor immune responses. This review briefly describes the biological structure of HPK1 and its related signaling pathways in tumor immunity, systematically discusses the latest research progress in small molecule chemical drugs targeting HPK1. Finally, we summarize and prospect the opportunities and challenges in the drug development of small molecule chemical drugs targeting HPK1 in tumor immunity.

Targeting the Dendritic Cell-Secreted Immunoregulatory Cytokine CCL22 Alleviates Radioresistance

PURPOSE

Radiation-mediated immune suppression limits efficacy and is a barrier in cancer therapy. Radiation induces negative regulators of tumor immunity including regulatory T cells (Treg). Mechanisms underlying Treg infiltration after radiotherapy (RT) are poorly defined. Given that conventional dendritic cells (cDC) maintain Treg, we sought to identify and target cDC signaling to block Treg infiltration after radiation.

EXPERIMENTAL DESIGN

Transcriptomics and high dimensional flow cytometry revealed changes in murine tumor cDC that not only mediate Treg infiltration after RT but also associate with worse survival in human cancer datasets. Antibodies perturbing a cDC-CCL22-Treg axis were tested in syngeneic murine tumors. A prototype interferon-anti-epidermal growth factor receptor fusion protein (αEGFR-IFNα) was examined to block Treg infiltration and promote a CD8+ T cell response after RT.

RESULTS

Radiation expands a population of mature cDC1 enriched in immunoregulatory markers that mediates Treg infiltration via the Treg-recruiting chemokine CCL22. Blocking CCL22 or Treg depletion both enhanced RT efficacy. αEGFR-IFNα blocked cDC1 CCL22 production while simultaneously inducing an antitumor CD8+ T cell response to enhance RT efficacy in multiple EGFR-expressing murine tumor models, including following systemic administration.

CONCLUSIONS

We identify a previously unappreciated cDC mechanism mediating Treg tumor infiltration after RT. Our findings suggest blocking the cDC1-CCL22-Treg axis augments RT efficacy. αEGFR-IFNα added to RT provided robust antitumor responses better than systemic free interferon administration and may overcome clinical limitations to interferon therapy. Our findings highlight the complex behavior of cDC after RT and provide novel therapeutic strategies for overcoming RT-driven immunosuppression to improve RT efficacy. See related commentary by Kalinski et al., p. 4260.

Abscopal effect: from a rare phenomenon to a new frontier in cancer therapy

Radiotherapy (RT) controls local lesions, meantime it has the capability to induce systemic response to inhibit distant, metastatic, non-radiated tumors, which is referred to as the "abscopal effect". It is widely recognized that radiotherapy can stimulate systemic immune response. This provides a compelling theoretical basis for the combination of immune therapy combined with radiotherapy(iRT). Indeed, this phenomenon has also been observed in clinical treatment, bringing significant clinical benefits to patients, and a series of basic studies are underway to amplify this effect. However, the molecular mechanisms of immune response induced by RT, determination of the optimal treatment regimen for iRT, and how to amplify the abscopal effect. In order to amplify and utilize this effect in clinical management, these key issues require to be well addressed; In this review, we comprehensively summarize the growing consensus and emphasize the emerging limitations of enhancing the abscopal effect with radiotherapy or immunotherapy. Finally, we discuss the prospects and barriers to the current clinical translational applications.

Sialic acid-modified doxorubicin liposomes target tumor-related immune cells to relieve multiple inhibitions of CD8+ T cells

In different types of cancer treatments, cancer-specific T cells are required for effective anticancer immunity, which has a central role in cancer immunotherapy. However, due to the multiple inhibitions of CD8+ T cells by tumor-related immune cells, CD8+ T-cell mediated antitumor immunotherapy has not achieved breakthrough progress in the treatment of solid tumors. Receptors for sialic acid (SA) are highly expressed in tumor-associated immune cells, so SA-modified nanoparticles are a drug delivery nanoplatform using tumor-associated immune cells as vehicles. To relieve the multiple inhibitions of CD8+ T cells by tumor-associated immune cells, we prepared SA-modified doxorubicin liposomes (SL-DOX, Scheme 1A). In our study, free SA decreased the toxicity of SL-DOX to tumor-associated immune cells. Compared with common liposomes, SL-DOX could inhibit tumor growth more effectively. It is worth noting that SL-DOX could not only kill tumor-related neutrophils and monocytes to relieve the multiple inhibitions of CD8+ T cells but also induce immunogenic death of tumor cells to promote the infiltration and differentiation of CD8+ T cells (Scheme 1B). Therefore, SL-DOX has potential value for the clinical therapeutic effect of CD8+ T cells mediating anti-tumor immunotherapy.

Optimizing Early Clinical Investigations in Cancer Immunotherapy: The Translational Journey of RG6292, a Novel, Selective Treg-Depleting Antibody

The multifaceted IL-2/IL-2R biology and its modulation by promising therapeutic agents are highly relevant topics in the cancer immunotherapy field. A novel CD25-Treg-depleting antibody (Vopikitug, RG6292) has been engineered to preserve IL-2 signaling on effector T cells to enhance effector activation and antitumor immunity, and is currently being evaluated in the clinic. The Entry into Human-enabling framework described here investigated the characteristics of RG6292, from in vitro quantification of CD25 and RG6292 pharmacology using human tissues to in vivo assessment of PK/PD/safety relationships in cynomolgus monkeys as non-human primate species (NHP). Fundamental knowledge on CD25 and Treg biology in healthy and diseased tissues across NHP and human highlighted the commonalities between these species in regard to the target biology and demonstrated the conservation of RG6292 properties between NHP and human. The integration of in vitro and in vivo PK/PD/safety data from these species enabled the identification of human relevant safety risks, the selection of the most appropriate safe starting dose and the projection of the pharmacologically-relevant dose range. The first clinical data obtained for RG6292 in patients verified the appropriateness of the described approaches as well as validated the full clinical relevance of the projected safety, PK, and PD profiles from animal to man. This work shows how the integration of mechanistic non-clinical data increases the predictive value for human, allowing efficient transition of drug candidates and optimizations of early clinical investigations.

Lymphocyte T Subsets and Outcome of Immune Checkpoint Inhibitors in Melanoma Patients: An Oncologist's Perspective on Current Knowledge

Melanoma is the most aggressive and deadly form of skin cancer, and its incidence has been steadily increasing over the past few decades, particularly in the Caucasian population. Immune checkpoint inhibitors (ICI), anti-PD-1 monotherapy or in combination with anti-CTLA-4, and more recently, anti-PD-1 plus anti-LAG-3 have changed the clinical evolution of this disease. However, a significant percentage of patients do not benefit from these therapies. Therefore, to improve patient selection, it is imperative to look for novel biomarkers. Immune subsets, particularly the quantification of lymphocyte T populations, could contribute to the identification of ICI responders. The main purpose of this review is to thoroughly examine significant published data on the potential role of lymphocyte T subset distribution in peripheral blood (PB) or intratumorally as prognostic and predictive of response biomarkers in advanced melanoma patients treated with ICI regardless of BRAFV600 mutational status.

The Major Role of T Regulatory Cells in the Efficiency of Vaccination in General and Immunocompromised Populations: A Review

Since their conception with the smallpox vaccine, vaccines used worldwide have mitigated multiple pandemics, including the recent COVID-19 outbreak. Insightful studies have uncovered the complexities of different functional networks of CD4 T cells (T helper 1 (Th1); Th2, Th17) and CD8 T cells (T cytotoxic; Tc), as well as B cell (BIgM, BIgG, BIgA and BIgE) subsets, during the response to vaccination. Both T and B cell subsets form central, peripheral, and tissue-resident subsets during vaccination. It has also become apparent that each vaccination forms a network of T regulatory subsets, namely CD4+ CD25+ Foxp3+ T regulatory (Treg) cells and interleukin-10 (IL-10)-producing CD4+ Foxp3- T regulatory 1 (Tr1), as well as many others, which shape the quality/quantity of vaccine-specific IgM, IgG, and IgA antibody production. These components are especially critical for immunocompromised patients, such as older individuals and allograft recipients, as their vaccination may be ineffective or less effective. This review focuses on considering how the pre- and post-vaccination Treg/Tr1 levels influence the vaccination efficacy. Experimental and clinical work has revealed that Treg/Tr1 involvement evokes different immune mechanisms in diminishing vaccine-induced cellular/humoral responses. Alternative steps may be considered to improve the vaccination response, such as increasing the dose, changing the delivery route, and/or repeated booster doses of vaccines. Vaccination may be combined with anti-CD25 (IL-2Rα chain) or anti-programmed cell death protein 1 (PD-1) monoclonal antibodies (mAb) to decrease the Tregs and boost the T/B cell immune response. All of these data and strategies for immunizations are presented and discussed, aiming to improve the efficacy of vaccination in humans and especially in immunocompromised and older individuals, as well as organ transplant patients.

Anoikis-Related Genes Impact Prognosis and Tumor Microenvironment in Bladder Cancer

Anoikis tolerance is an important biological process of tumor colonization and metastasis outside the primary tumor. Recent research has progressively elucidated the function and underlying mechanisms of anoikis in the metastasis of various solid tumors. Nevertheless, the specific mechanisms of anoikis in bladder cancer and its consequent effects on the tumor immune microenvironment remain ambiguous. In this study, we developed an anoikis score based on five genes (ETV7, NGF, SCD, LAMC1, and CASP6) and categorized subjects into high and low-risk groups using the median score from the TCGA database. Our findings indicate that SCD enhances the proliferation of bladder cancer cells in vitro. Furthermore, integrating the anoikis score with clinicopathological features to construct a prognostic nomogram demonstrated precision in assessing patient outcomes. Immune cell analysis revealed elevated infiltration levels of Treg cells and M2 macrophages in the high anoikis score group, whereas CD8+ T cell levels were reduced. This study highlights the importance of anoikis score in predicting patient prognosis, immune cell infiltration, and drug response, which may provide a treatment modality worth exploring in depth for the study of bladder cancer.

Antisense targeting of FOXP3+ Tregs to boost anti-tumor immunity

Our goal is to improve the outcomes of cancer immunotherapy by targeting FOXP3+ T-regulatory (Treg) cells with a next generation of antisense oligonucleotides (ASO), termed FOXP3 AUMsilence ASO. We performed in vitro experiments with human healthy donor PBMC and clinical samples from patients with lung cancer, mesothelioma and melanoma, and tested our approach in vivo using ASO FOXP3 in syngeneic murine cancer models and in humanized mice. ASO FOXP3 had no effects on cell viability or cell division, did not affect expression of other FOXP members, but decreased expression of FOXP3 mRNA in PBMC by 54.9% and in cancer samples by 64.7%, with corresponding 41.0% (PBMC) and 60.0% (cancer) decreases of Treg numbers (all p<0.0001). Hence, intratumoral Treg were more sensitive to the effects of ASO FOXP3 than peripheral blood Tregs. Isolated human Treg, incubated with ASO FOXP3 for 3.5 hours, had significantly impaired suppressive function (66.4%) versus Scramble control. In murine studies, we observed a significant inhibition of tumor growth, while 13.6% (MC38) to 22% (TC1) of tumors were completely resorbed, in conjunction with ~50% decrease of Foxp3 mRNA by qPCR and decreased numbers of intratumoral Tregs. In addition, there were no changes in FOXP3 mRNA expression or in the numbers of Tregs in draining lymph nodes and in spleens of tumor bearing mice, confirming that intratumoral Treg had enhanced sensitivity to ASO FOXP3 in vivo compared to other Treg populations. ASO FOXP3 Treg targeting in vivo and in vitro was accompanied by significant downregulation of multiple exhaustion markers, and by increased expression of perforin and granzyme-B by intratumoral T cells. To conclude, we report that targeting the key Treg transcription factor FOXP3, with ASO FOXP3, has a powerful anti-tumoral effect and enhances T cell response in vitro and in vivo.

Immunohistochemical analyses reveal FoxP3 expressions in spleen and colorectal cancer in mice treated with AOM/DSS, and their suppression by glycyrrhizin

We previously demonstrated that glycyrrhizin (GL) suppressed inflammation and carcinogenesis in an azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced murine model of colorectal cancer (CC). In this study, we found an accumulation of regulatory T cells (Tregs) in the spleen and suppression by GL in model mice. ICR mice were divided into four groups: Control, GL, CC, and GL-treated CC (CC+GL), and were sacrificed 20 weeks after AOM/DSS treatment. We measured spleen weight, areas of white and red pulp, and CD8+ T cells (cytotoxic T lymphocytes, CTL), and CD11c-positive cells (dendritic cells) in splenic tissues and forkhead box protein 3 (FoxP3)-positive cells (Tregs) in colorectal and splenic tissues. In all cases, the CC group showed a significant increase compared with those in Control group, and GL administration significantly attenuated this increase. These results indicate that Tregs accumulated in the spleen may participate in inflammation-related carcinogenesis by suppressing CTL. We also suggest that GL which binds to high-mobility group box 1 (HMGB1), suppresses carcinogenesis with decreasing Tregs in the spleen. Furthermore, there was an expression of FoxP3 in cancer cells, indicating that it may be involved in the malignant transformation of cancer cells.

ncRNA-mediated SOX4 overexpression correlates with unfavorable outcomes and immune infiltration in hepatocellular carcinoma

BACKGROUND

The activity and number of immune cells in the tumor microenvironment are closely related to the overall survival of patients with hepatocellular carcinoma (HCC). The sex-determining region Y-box 4 (SOX4) gene is abnormally expressed in various tumor tissues and is critical for tumor development. However, the correlation between SOX4 expression in HCC and tumor immunity is unclear.

METHODS

SOX4 expression was explored using data from The Cancer Genome Atlas, and UALCAN databases. Real-time reverse transcription quantitative and western blotting were used to analyze SOX4 expression in several liver cancer cell lines. Additionally, correlations among SOX4 expression, cancer immune characteristics, and infiltrated immune cell gene marker sets in patients with HCC were analyzed using data from the Tumor Immune Estimation Resource, Gene Expression Profiling Interactive Analysis, and Tumor-Immune System Interactions databases. Moreover, we evaluated SOX4 expression in HCC tissues and the correlation of SOX4 expression with survival rate. Subsequently, noncoding RNAs (ncRNAs) responsible for SOX4 overexpression were identified using expression, correlation, and survival analyses.

RESULTS

SOX4 expression was significantly upregulated in HCC and correlated with a poor prognosis. Additionally, SOX4 upregulation in HCC positively correlated with immune cell infiltration, several biomarkers of immune cells, and immune checkpoint expression. Finally, the MCM3AP-AS1/hsa-miR-204-5p axis was identified as the most likely upstream ncRNA-related pathway for SOX4 in HCC. These results indicated that ncRNA-mediated upregulation of SOX4 correlated with the immune infiltration level and poor prognosis in HCC. Our findings provide new directions for the development of novel immunotherapeutic targets for HCC.

A bibliometric analysis of drug resistance in immunotherapy for breast cancer: trends, themes, and research focus

While breast cancer treatments have advanced significantly nowadays, yet metastatic, especially triple-negative breast cancer (TNBC), remains challenging with low survival. Cancer immunotherapy, a promising approach for HER2-positive and TNBC, still faces resistance hurdles. Recently, numerous studies have set their sights on the resistance of immunotherapy for breast cancer. Our study provides a thorough comprehension of the current research landscape, hotspots, and emerging breakthroughs in this critical area through a meticulous bibliometric analysis. As of March 26, 2024, a total of 1341 articles on immunology resistance in breast cancer have been gathered from Web of Science Core Collection, including 765 articles and 576 reviews. Bibliometrix, CiteSpace and VOSviewer software were utilized to examine publications and citations per year, prolific countries, contributive institutions, high-level journals and scholars, as well as highly cited articles, references and keywords. The research of immunotherapy resistance in breast cancer has witnessed a remarkable surge over the past seven years. The United States and China have made significant contributions, with Harvard Medical School being the most prolific institution and actively engaging in collaborations. The most contributive author is Curigliano, G from the European Institute of Oncology in Italy, while Wucherpfennig, K. W. from the Dana-Farber Cancer Institute in the USA, had the highest citations. Journals highly productive primarily focus on clinical, immunology and oncology research. Common keywords include "resistance", "expression", "tumor microenvironment", "cancer", "T cell", "therapy", "chemotherapy" and "cell". Current research endeavors to unravel the mechanisms of immune resistance in breast cancer through the integration of bioinformatics, basic experiments, and clinical trials. Efforts are underway to develop strategies that improve the effectiveness of immunotherapy, including the exploration of combination therapies and advancements in drug delivery systems. Additionally, there is a strong focus on identifying novel biomarkers that can predict patient response to immunology. This study will provide researchers with an up-to-date overview of the present knowledge in drug resistance of immunology for breast cancer, serving as a valuable resource for informed decision-making and further research on innovative approaches to address immunotherapy resistance.

Establishment of a chemokine-based prognostic model and identification of CXCL10+ M1 macrophages as predictors of neoadjuvant therapy efficacy in colorectal cancer

Background

Although neoadjuvant therapy has brought numerous benefits to patients, not all patients can benefit from it. Chemokines play a crucial role in the tumor microenvironment and are closely associated with the prognosis and treatment of colorectal cancer. Therefore, constructing a prognostic model based on chemokines will help risk stratification and providing a reference for the personalized treatment.

Methods

Employing LASSO-Cox predictive modeling, a chemokine-based prognostic model was formulated, harnessing the data from TCGA and GEO databases. Then, our exploration focused on the correlation between the chemokine signature and elements such as the immune landscape, somatic mutations, copy number variations, and drug sensitivity. CXCL10+M1 macrophages identified via scRNA-seq. Monocle2 showed cell pseudotime trajectories, CellChat characterized intercellular communication. CytoTRACE analyzed neoadjuvant therapy stemness, SCENIC detected cell type-specific regulation. Lastly, validation was performed through multiplex immunofluorescence experiments.

Results

A model based on 15 chemokines was constructed and validated. High-risk scores correlated with poorer prognosis and advanced TNM and clinical stages. Individuals presenting elevated risk scores demonstrated an increased propensity towards the development of chemotherapy resistance. Subsequent scRNA-seq data analysis indicated that patients with higher presence of CXCL10+ M1 macrophages in tumor tissues are more likely to benefit from neoadjuvant therapy.

Conclusion

We developed a chemokine-based prognostic model by integrating both single-cell and bulk RNA-seq data. Furthermore, we revealed epithelial cell heterogeneity in neoadjuvant outcomes and identified CXCL10+ M1 macrophages as potential therapy response predictors. These findings could significantly contribute to risk stratification and serve as a key guide for the advancement of personalized therapeutic approaches.

A real-time antibody-dependent cellular phagocytosis assay by live cell imaging

Antibody-dependent cellular phagocytosis (ADCP) is a cellular process by which antibody-opsonized targets (pathogens or cells) activate the Fc receptors on the surface of phagocytes to induce phagocytosis, resulting in internalization and degradation of pathogens or target cells through phagosome acidification. Besides NK cells-mediated antibody-dependent cellular cytotoxicity (ADCC), tumor-infiltrated monocytes and macrophages can directly kill tumor cells in the presence of tumor antigen-specific antibodies through ADCP, representing another attractive strategy for cancer immunotherapy. Even though several methods have been developed to measure ADCP, an automated and high-throughput quantitative assay should offer highly desirable advantages for drug discovery. In this study we established a new ADCP assay to identify therapeutical monoclonal antibodies (mAbs) that facilitate macrophages phagocytosis of live target cells. We used Incucyte, an imaging system for live cell analysis. By labeling the live target cells with a pH sensitive dye (pHrodo), we successfully monitored the ADCP in real time. We demonstrated that our image-based assay is robust and quantitative, suitable for screening and characterization of therapeutical mAbs that directly kill target cells through ADCP. Furthermore, we found different subtypes of macrophages have distinct ADCP activities using both mouse and human primary macrophages differentiated in vitro. By studying various mAbs with mutations in their Fc regions using our assay, we showed that the variants with increased binding to Fc gamma receptors (FcγRs) have enhanced ADCP activities.

The immune landscape of uterine fibroids as determined by mass cytometry

OBJECTIVE

To study the differences in immune cell profiles in uterine fibroids (Fibs) and matched myometrium (Myo).

DESIGN

Observational study.

SETTING

Laboratory study.

PATIENT(S)

The study included tissue that was collected from 10 pairs of Fib and matched Myo from women, not on hormonal medications, undergoing hysterectomy and myomectomy.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Differences in immune cell and cytokine composition between Fib and matched Myo.

RESULT(S)

The mass cytometry analysis indicated that Fibs had a significantly higher number of natural killer (NK) cells, total macrophages, M2 macrophages, and conventional dendritic cells when compared with matched Myo from the same patient. In contrast, Fibs had significantly fewer CD3 and CD4 T cells when compared with Myo. The mass cytometry analysis results did not show any significant difference in the number of resting mast cells. Immunoflurorescent and immunohistochemical imaging confirmed the cytometry by time of flight results, showing a significantly higher number of NK cells, tryptase-positive mast cells indicative of mast cell activation, total macrophages, and M2 cells in Fibs and a significantly lower number of CD3 and CD4 T cells. The cytokine assay revealed significantly increased levels of human interferon α2, interleukin (IL)-1α, and platelet-derived growth factor AA and significantly lower levels of macrophage colony-stimulating factor and IL-1 receptor antagonist in Fib.

CONCLUSION(S)

Our results show significant differences in immune cell populations and cytokine levels between Fib and Myo. These differences could account for the increased inflammation in fib and a potential mechanism by which these tumors evade the immune system. These findings provide a foundation for further studies exploring the role of immune cells in Fib development.

Role of Forkhead Box P3 in IFNγ-Mediated PD-L1 Expression and Bladder Cancer Epithelial-to-Mesenchymal Transition

Antagonism of the PD-1/PD-L1 axis is a critical therapeutic strategy for patients with advanced bladder cancer. IFNγ functions as a key regulator of PD-L1 in both immune as well as cancer cells. Forkhead box P3 (FOXP3) is a transcription factor synonymous in T regulatory cell function but with increasingly described functions in cancer cells. Here, we investigated the relationship between FOXP3 and PD-L1 in bladder cancer. We showed that FOXP3 is critical in the ability for IFNγ to activate PD-L1 in bladder cancer cells. FOXP3 can bind to the PD-L1 promoter and induces a gene program that leads to regulation of multiple immune-related genes and genes involved in epithelial-to-mesenchymal transition (EMT). Using in vitro and in vivo human and murine models, we showed that FOXP3 can influence bladder cancer EMT as well as promote cancer metastases. Furthermore, FOXP3 may be a convergent factor for multiple activators of PD-L1, including the chemotherapeutic drug cisplatin.

SIGNIFICANCE

Historically a key transcription factor driving T regulatory cell function, FOXP3 has an increasingly recognized role in cancer cells. In bladder cancer, we defined a novel mechanism whereby FOXP3 mediates the activation of the immune checkpoint PD-L1 by the cytokine IFNγ. We also showed that FOXP3 induces other immune checkpoints as well as genes involved in EMT, promoting immune resistance and cancer metastases.

RAB42 overexpression correlates with poor prognosis, immune cell infiltration and chemoresistance

Background

RAB42 (Ras-related protein 42) is a new small GTPase that controls the vesicular trafficking from endosomes to trans-Golgi network in mammalian cells. However, the role of RAB42 in multiple cancers, especially in liver hepatocellular carcinoma (LIHC), has not been well investigated.

Methods

A variety of cancer-related databases and online tools, including TCGA, GTEx, TARGET, QUANTISEQ, EPIC, RNAactDrug, CTR-DB, TIMER algorithms and Sangerbox, were applied to explore the correlation of RAB42 expression with prognosis, immune microenvironment, immune regulatory network, RNA modification, pathway activation and drug sensitivity in pan-cancer. The prognostic, immunomodulatory and tumor-promoting effects of RAB42 were verified in various malignancies and determined by a series of in vitro cellular experiments.

Results

RAB42 is significantly overexpressed in most cancers with advanced pathological stages. Its overexpression is correlated with poor survival in pan-cancer. RAB42 overexpression has a high diagnostic accuracy of various cancers (AUC > 0.80). RAB42 overexpression not only correlates with distinct stromal immune infiltration and level of immune checkpoint molecules, but also associates with weak immune cell infiltration, immunomodulatory genes expression, and immunotherapeutic response to immune checkpoint inhibitors (ICIs). Additionally, RAB42 overexpression correlates with enhanced expression of m6A RNA methylation-related genes (MRGs) and its interactors. Moreover, overexpression of RAB42 serves as a drug-resistant marker to certain chemotherapies and acts as a potential biomarker for LIHC. Notably, RAB42 overexpression or activation promotes the cellular proliferation, migration and invasion of LIHC.

Conclusion

Overexpressed RAB42 serves as a potential prognostic biomarker and therapeutic target in pan-cancer, especially in LIHC.

Tebentafusp Induces a T-Cell-Driven Rash in Melanocyte-Bearing Skin as an Adverse Event Consistent with the Mechanism of Action

Tebentafusp is a gp100xCD3-bispecific ImmTAC designed to redirect polyclonal T cells against cells presenting the melanocyte lineage-specific antigen gp100 on HLA-A∗02:01. Skin-related adverse events, predominantly rash, are frequent and occur within a few hours after initial infusions; yet, the mechanisms are unknown. In this study, we analyzed clinical data from the randomized phase 3 trial (NCT03070392) of tebentafusp (n = 252) versus investigator's choice (n = 126). Translational analyses were performed on paired on-treatment skin samples from 19 patients collected in the phase 1 trial (NCT01211262). Our analyses showed that rash is a clinical manifestation of tebentafusp-induced recruitment of T cells to cutaneous melanocytes. Development of rash depended on baseline expression levels of gp100 and other melanin pathway genes in the skin. On treatment, melanocyte number was reduced, and expression of melanocytic genes decreased, whereas gene expression related to immunity and cytokine signaling increased. When adjusted for baseline prognostic features, patients with rash within the first week of tebentafusp treatment had the same overall survival as patients without a rash in the phase 3 randomized trial IMCgp100-202 (hazard ratio = 0.84, 95% confidence interval = 0.53-1.32). In summary, skin rash is an off-tumor, on-target effect of tebentafusp against gp100+ melanocytes, in line with the mechanism of action.

E3 ubiquitin ligase RNF180 mediates the ALKBH5/SMARCA5 axis to promote colon inflammation and Th17/Treg imbalance in ulcerative colitis mice

SMARCA5, a protein in the SWI/SNF family, has been previously implicated in the development of ulcerative colitis (UC) through methylation. However, the specific molecular mechanisms by which SMARCA5 contributes to colonic inflammation and the imbalance between Th17 and Treg cells remain unclear. This study was designed to explore these molecular mechanisms. A UC mouse model was established using dextran sulfate sodium induction, followed by measurements of mouse weight, disease activity index (DAI) score, colon length, pathological changes in the colon, and FITC-dextran concentration. The levels of IL-17a, IFN-γ, IL-6, TNF-α, TGF-β, and IL-10 were measured, along with the protein expression of ZO-1 and Occludin. Flow cytometry was used to assess the presence of IL-17 + CD4 + (Th17 +) cells and FOXP3 + CD25 + CD4 + (Treg +) cells in the spleen and mesenteric lymph nodes of UC mice. We observed that SMARCA5 and RNF180 were increased, while ALKBH5 was downregulated in UC mouse colon tissue. SMARCA5 or RNF180 knockdown or ALKBH5 overexpression ameliorated the colon inflammation and Th17/Treg cell imbalance in UC mice, shown by increased body weight, colon length, FOXP3 + CD25 + CD4 + T cells, and the levels of ZO-1, Occludin, TGF-β, IL-10, and FOXP3. It decreased DAI scores, IL-17 + CD4 + T cells, and levels of IL-17a, IFN-γ, IL-6, TNF-α, and ROR-γt. ALKBH5 inhibited SMARCA5 expression via m6A modification, while RNF180 reduced ALKBH5 expression via ubiquitination. Our findings indicate that RNF180 aggravated the colon inflammation and Th17/Treg cell imbalance in UC mice by regulating the ALKBH5/SMARCA5 axis.

BET Inhibitor JQ1 Selectively Reduce Tregs by Upregulating STAT3 and Suppressing PD-1 Expression in Patients with Multiple Myeloma

Multiple myeloma (MM) stands as a prevalent hematological malignancy, primarily incurable, originating from plasma cell clones. MM's progression encompasses genetic abnormalities and disruptions in the bone marrow microenvironment, leading to tumor proliferation, immune dysfunction, and compromised treatment outcomes. Emerging evidence highlights the critical role of regulatory T cells (Tregs) in MM progression, suggesting that targeting Tregs could enhance immune functionality and treatment efficacy. In this study, a notable increase in Treg proportions within MM patients' bone marrow (BM) compared to healthy individuals is observed. Additionally, it is found that the bromodomain and extraterminal domain (BET) inhibitor JQ1 selectively diminishes Treg percentages in MM patients' BM and reduces TGF-β1-induced Tregs. This reduction occurs via inhibiting cell viability and promoting apoptosis. RNA sequencing further indicates that JQ1's inhibitory impact on Tregs likely involves upregulating STAT3 and suppressing PD-1 expression. Collectively, these findings suggest JQ1's potential to modulate Tregs, bolstering the immune response in MM and introducing a promising avenue for MM immunotherapy.

Current and future perspectives on the regulation and functions of miR-545 in cancer development

Micro ribonucleic acids (miRNAs) are a highly conserved class of single-stranded non-coding RNAs. Within the miR-545/374a cluster, miR-545 resides in the intron of the long non-coding RNA (lncRNA) FTX on Xq13.2. The precursor form, pre-miR-545, is cleaved to generate two mature miRNAs, miR-545-3p and miR-545-5p. Remarkably, these two miRNAs exhibit distinct aberrant expression patterns in different cancers; however, their expression in colorectal cancer remains controversial. Notably, miR-545-3p is affected by 15 circular RNAs (circRNAs) and 10 long non-coding RNAs (lncRNAs), and it targets 27 protein-coding genes (PCGs) that participate in the regulation of four signaling pathways. In contrast, miR-545-5p is regulated by one circRNA and five lncRNAs, it targets six PCGs and contributes to the regulation of one signaling pathway. Both miR-545-3p and miR-545-5p affect crucial cellular behaviors, including cell cycle, proliferation, apoptosis, epithelial-mesenchymal transition, invasion, and migration. Although low miR-545-3p expression is associated with poor prognosis in three cancer types, studies on miR-545-5p are yet to be reported. miR-545-3p operates within a diverse range of regulatory networks, thereby augmenting the efficacy of cancer chemotherapy, radiotherapy, and immunotherapy. Conversely, miR-545-5p enhances immunotherapy efficacy by inhibiting T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) expression. In summary, miR-545 holds immense potential as a cancer biomarker and therapeutic target. The aberrant expression and regulatory mechanisms of miR-545 in cancer warrant further investigation.

Tumor mutational burden adjusted by neutrophil-to-lymphocyte ratio serves as a potential biomarker for atezolizumab-treated patients with extensive stage small cell lung cancer

BACKGROUND

There is a desperate for the identification of more accurate and efficient biomarkers for ICI responses in patients with SCLC.

METHODS

The data of our study was obtained from IMpower133 study. A total of 202 patients with SCLC received the treatment of placebo plus carboplatin plus etoposide (EC) while a total of 201 patients with SCLC received the treatment of atezolizumab plus EC. Overall survival (OS) was compared using Kaplan Meier analyses. Univariate and multivariate Cox regression analysis were used to determine independent prognostic variables affecting OS in patients with SCLC.

RESULTS

We have demonstrated that a higher TMB adjusted by a lower neutrophil-to-lymphocyte ratio (NLR) is significantly correlated with improved OS, in patients with SCLC subject to either atezolizumab or placebo (P = 0.001 for atezolizumab and P = 0.034 for placebo). Moreover, Cox model showed that TMB < 10 mut/Mb adjusted by NLR ≥ median was an independent factor of OS for atezolizumab-treated SCLC patients (hazard ratio [HR], 2.82; 95% confidence interval; 1.52-5.24; P = 0.001). Both univariate and multivariate cox regression analysis showed that for patients with SCLC harboring low NLR and high TMB, survival is significantly longer in those treated with atezolizumab than those treated with placebo. Survival benefit is significantly higher in atezolizumab-treated patients with SCLC than those treated with placebo (P = 0.018 for TMB cutoff = 10 mut/Mb, P = 0.034 for TMB cutoff = 16 mut/Mb).

CONCLUSION

Our findings provide a promising insight into the utility of NLR-adjusted TMB in the prognosis and immune responses in patients with SCLC.

The role of KLRG1: a novel biomarker and new therapeutic target

Killer cell lectin-like receptor G1 (KLRG1) is an immune checkpoint receptor expressed predominantly in NK and T-cell subsets that downregulates the activation and proliferation of immune cells and participates in cell-mediated immune responses. Accumulating evidence has demonstrated the importance of KLRG1 as a noteworthy disease marker and therapeutic target that can influence disease onset, progression, and prognosis. Blocking KLRG1 has been shown to effectively mitigate the effects of downregulation in various mouse tumor models, including solid tumors and hematologic malignancies. However, KLRG1 inhibitors have not yet been approved for human use, and the understanding of KLRG1 expression and its mechanism of action in various diseases remains incomplete. In this review, we explore alterations in the distribution, structure, and signaling pathways of KLRG1 in immune cells and summarize its expression patterns and roles in the development and progression of autoimmune diseases, infectious diseases, and cancers. Additionally, we discuss the potential applications of KLRG1 as a tool for tumor immunotherapy.

Immune landscape and response to oncolytic virus-based immunotherapy

Oncolytic virus (OV)-based immunotherapy has emerged as a promising strategy for cancer treatment, offering a unique potential to selectively target malignant cells while sparing normal tissues. However, the immunosuppressive nature of tumor microenvironment (TME) poses a substantial hurdle to the development of OVs as effective immunotherapeutic agents, as it restricts the activation and recruitment of immune cells. This review elucidates the potential of OV-based immunotherapy in modulating the immune landscape within the TME to overcome immune resistance and enhance antitumor immune responses. We examine the role of OVs in targeting specific immune cell populations, including dendritic cells, T cells, natural killer cells, and macrophages, and their ability to alter the TME by inhibiting angiogenesis and reducing tumor fibrosis. Additionally, we explore strategies to optimize OV-based drug delivery and improve the efficiency of OV-mediated immunotherapy. In conclusion, this review offers a concise and comprehensive synopsis of the current status and future prospects of OV-based immunotherapy, underscoring its remarkable potential as an effective immunotherapeutic agent for cancer treatment.

Sarcoid-like reactions to immune checkpoint inhibitors: Incidence, treatment course, and impact on cancer progression and survival

INTRODUCTION

Sarcoid-like reactions (SLRs) to immune checkpoint inhibitors (ICIs) are a rare but increasingly recognized immune-related adverse event of which the clinical significance is unclear.

METHODS

We conducted a retrospective cohort study at a tertiary academic center of consecutive patients who received at least one dose of ICI from 2013 to 2020. Patient characteristics, risk factors, and outcomes were compared between patients with and without SLR following ICI treatment.

RESULTS

A total of 2963 cancer patients received at least 1 dose of ICI between 2013 and 2020, and 7 patients (0.24 %) developed SLR. There were no significant demographic differences between patients with and without SLR following ICI. SLRs occurred in 5 of 451 (1.07 %) melanoma patients and 2 of 840 (0.24 %) non-small cell lung cancer patients. Two of the 7 patients had multi-organ SLR, and both were symptomatic requiring systemic corticosteroids and permanent ICI discontinuation, while single organ SLR patients did not require immune suppression. Development of SLR did not appear to have negative impact on cancer progression or overall survival; in fact, a trend towards improved progression-free and overall survival was observed (median time: 1363 days vs 127 days, p = 0.091; 1387 days vs 428.5 days, p = 0.19, respectively).

CONCLUSIONS

SLRs are a known but understudied complication associated with ICI therapy. Multisystem SLR patients were more symptomatic and required ICI discontinuation and immune suppression. Larger studies are needed to fully evaluate the impact of SLR on cancer outcomes.

Converting "cold" to "hot": epigenetics strategies to improve immune therapy effect by regulating tumor-associated immune suppressive cells

Significant developments in cancer treatment have been made since the advent of immune therapies. However, there are still some patients with malignant tumors who do not benefit from immunotherapy. Tumors without immunogenicity are called "cold" tumors which are unresponsive to immunotherapy, and the opposite are "hot" tumors. Immune suppressive cells (ISCs) refer to cells which can inhibit the immune response such as tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), regulatory T (Treg) cells and so on. The more ISCs infiltrated, the weaker the immunogenicity of the tumor, showing the characteristics of "cold" tumor. The dysfunction of ISCs in the tumor microenvironment (TME) may play essential roles in insensitive therapeutic reaction. Previous studies have found that epigenetic mechanisms play an important role in the regulation of ISCs. Regulating ISCs may be a new approach to transforming "cold" tumors into "hot" tumors. Here, we focused on the function of ISCs in the TME and discussed how epigenetics is involved in regulating ISCs. In addition, we summarized the mechanisms by which the epigenetic drugs convert immunotherapy-insensitive tumors into immunotherapy-sensitive tumors which would be an innovative tendency for future immunotherapy in "cold" tumor.

Prognostic role of MUCIN family and its relationship with immune characteristics and tumor biology in diffuse-type gastric cancer

The main component of O-glycoproteins, mucin, is known to play important roles in physiological conditions and oncogenic processes, particularly correlated with poor prognosis in different carcinomas. Diffuse-type gastric cancer (DGC) has long been associated with genomic stability and unfavorable clinical outcomes. To investigate further, we obtained clinical information and the RNA-seq data of the TCGA-STAD cohort. Through the use of unsupervised clustering methods and GSEA, we identified two distinct clusters, characterized by higher and lower expression of MUC2 and MUC20, denoted as cluster 1 and cluster 2, respectively. Subsequently, employing CIBERSORT, it was determined that cluster 2 exhibited a higher tumor mutation burden (TMB) and a greater abundance of CD8+ T cells and activated CD4+ memory T cells, in addition to immune checkpoints (ICPs). On the other hand, cluster 1 showed a lower TIDE score estimation, indicating a higher probability of tumor immune escape. Furthermore, overexpression of MUC15 and MUC20 was confirmed through qPCR and Western blotting, and their specific roles in mediating the epithelial-mesenchymal transition (EMT) process of GC cells (SNU484 and Hs746t) were validated via CCK-8 assay and wound healing assay in vitro. These findings highlight the potential prognostic value of MUC20 and offer insights into the prospects of immunotherapy for DGC by targeting MUC20.

Spatial and functional targeting of intratumoral Tregs reverses CD8+ T cell exhaustion and promotes cancer immunotherapy

Intratumoral Tregs are key mediators of cancer immunotherapy resistance, including anti-programmed cell death (ligand) 1 [anti-PD-(L)1] immune checkpoint blockade (ICB). The mechanisms driving Treg infiltration into the tumor microenvironment (TME) and the consequence on CD8+ T cell exhaustion remain elusive. Here, we report that heat shock protein gp96 (also known as GRP94) was indispensable for Treg tumor infiltration, primarily through the roles of gp96 in chaperoning integrins. Among various gp96-dependent integrins, we found that only LFA-1 (αL integrin), and not αV, CD103 (αE), or β7 integrin, was required for Treg tumor homing. Loss of Treg infiltration into the TME by genetic deletion of gp96/LFA-1 potently induced rejection of tumors in multiple ICB-resistant murine cancer models in a CD8+ T cell-dependent manner, without loss of self-tolerance. Moreover, gp96 deletion impeded Treg activation primarily by suppressing IL-2/STAT5 signaling, which also contributed to tumor regression. By competing for intratumoral IL-2, Tregs prevented the activation of CD8+ tumor-infiltrating lymphocytes, drove thymocyte selection-associated high mobility group box protein (TOX) induction, and induced bona fide CD8+ T cell exhaustion. By contrast, Treg ablation led to striking CD8+ T cell activation without TOX induction, demonstrating clear uncoupling of the 2 processes. Our study reveals that the gp96/LFA-1 axis plays a fundamental role in Treg biology and suggests that Treg-specific gp96/LFA-1 targeting represents a valuable strategy for cancer immunotherapy without inflicting autoinflammatory conditions.

Optimizing cancer therapy: a review of the multifaceted effects of metronomic chemotherapy

Metronomic chemotherapy (MCT), characterized by the continuous administration of chemotherapeutics at a lower dose without prolonged drug-free periods, has garnered significant attention over the last 2 decades. Extensive evidence from both pre-clinical and clinical settings indicates that MCT induces distinct biological effects than the standard Maximum Tolerated Dose (MTD) chemotherapy. The low toxicity profile, reduced likelihood of inducing acquired therapeutic resistance, and low cost of MCT render it an attractive chemotherapeutic regimen option. One of the most prominent aspects of MCT is its anti-angiogenesis effects. It has been shown to stimulate the expression of anti-angiogenic molecules, thereby inhibiting angiogenesis. In addition, MCT has been shown to decrease the regulatory T-cell population and promote anti-tumor immune response through inducing dendritic cell maturation and increasing the number of cytotoxic T-cells. Combination therapies utilizing MCT along with oncolytic virotherapy, radiotherapy or other chemotherapeutic regimens have been studied extensively. This review provides an overview of the current status of MCT research and the established mechanisms of action of MCT treatment and also offers insights into potential avenues of development for MCT in the future.

Identification of the new molecular subtypes related to inflammation in breast cancer

Breast cancer is a prevalent ailment among women, and the inflammatory response plays a crucial role in the management and prediction of breast cancer (BRCA). However, the new subtypes based on inflammation in BRCA research are still undefined. The databases including The Cancer Genome Atlas and gene expression omnibus were utilized to gather clinical data and somatic mutation information for approximately 1069 BRCA patients. Through Consensus Clustering, novel subtypes linked to inflammation were identified. A comparative analysis was conducted on the prognosis, and immune cell infiltration, and somatic mutation of the new subtypes. Additionally, an investigation into drug therapy and immunotherapy was conducted to distinguish high-risk individuals from low-risk ones. The findings of this investigation proposed the categorization of BRCA into innovative subtypes predicated on the inflammatory response and 6 key genes were a meaningful approach. Specifically, the low-, medium-, and high-inflammation subtypes exhibited varying degrees of association with clinicopathological features, tumor microenvironment, and prognosis. Notably, the high-inflammation subtype was characterized by a strong correlation with immunosuppressive microenvironments and a higher frequency of somatic mutations, which was an indication of poorer health. This study revealed that a brand-new classification could throw new light on the effective prognosis. The integration of multiple key genes was a new characterization that could promote more immunotherapy strategies and contribute to predicting the efficacy of the chemotherapeutic drugs.

Activating CD8+ T Cells by Pt(IV) Prodrug-Based Nanomedicine and aPD-L1 Antibody for Enhanced Cancer Immunotherapy

Recent years have witnessed substantial progress in cancer immunotherapy, specifically T cell-based therapies. However, the application of T cell therapies has been primarily limited to hematologic malignancies, with limited success in the treatment of solid tumors. The main challenge in treating solid tumor is immune escape, which is characterized by reduced antigenicity, diminished immunogenicity, and the development of suppressive tumor immune microenvironments. To address these obstacles and restore T cell-mediated anti-tumor responses, a novel nanoparticle formulation known as PRA@Oxa-c16 is developed. This innovative approach combines retinoic acid and Pt(IV) to specifically target and overcome immune escape. Notably, the therapeutic efficacy of PRA@Oxa-c16 primarily relies on its ability to induce anti-tumor T cell responses, in contrast to the cytotoxicity associated with conventional chemotherapeutic agents. When combined with an immune checkpoint blockade, anti-programmed death-ligand 1 antibody, PRA@Oxa-c16 effectively eliminates solid tumors and induces immune memory responses, which prevent tumor metastasis and recurrence. This promising approach holds great potential for enhancing the treatment of solid tumors with T cell-based immunotherapy.

Evolving Tumor Characteristics and Smart Nanodrugs for Tumor Immunotherapy

Typical physiological characteristics of tumors, such as weak acidity, low oxygen content, and upregulation of certain enzymes in the tumor microenvironment (TME), provide survival advantages when exposed to targeted attacks by drugs and responsive nanomedicines. Consequently, cancer treatment has significantly progressed in recent years. However, the evolution and adaptation of tumor characteristics still pose many challenges for current treatment methods. Therefore, efficient and precise cancer treatments require an understanding of the heterogeneity degree of various factors in cancer cells during tumor evolution to exploit the typical TME characteristics and manage the mutation process. The highly heterogeneous tumor and infiltrating stromal cells, immune cells, and extracellular components collectively form a unique TME, which plays a crucial role in tumor malignancy, including proliferation, invasion, metastasis, and immune escape. Therefore, the development of new treatment methods that can adapt to the evolutionary characteristics of tumors has become an intense focus in current cancer treatment research. This paper explores the latest understanding of cancer evolution, focusing on how tumors use new antigens to shape their "new faces"; how immune system cells, such as cytotoxic T cells, regulatory T cells, macrophages, and natural killer cells, help tumors become "invisible", that is, immune escape; whether the diverse cancer-associated fibroblasts provide support and coordination for tumors; and whether it is possible to attack tumors in reverse. This paper discusses the limitations of targeted therapy driven by tumor evolution factors and explores future strategies and the potential of intelligent nanomedicines, including the systematic coordination of tumor evolution factors and adaptive methods, to meet this therapeutic challenge.

Stroma-infiltrating T cell spatiotypes define immunotherapy outcomes in adolescent and young adult patients with melanoma

The biological underpinnings of therapeutic resistance to immune checkpoint inhibitors (ICI) in adolescent and young adult (AYA) melanoma patients are incompletely understood. Here, we characterize the immunogenomic profile and spatial architecture of the tumor microenvironment (TME) in AYA (aged ≤ 30 years) and older adult (aged 31-84 years) patients with melanoma, to determine the AYA-specific features associated with ICI treatment outcomes. We identify two ICI-resistant spatiotypes in AYA patients with melanoma showing stroma-infiltrating lymphocytes (SILs) that are distinct from the adult TME. The SILhigh subtype was enriched in regulatory T cells in the peritumoral space and showed upregulated expression of immune checkpoint molecules, while the SILlow subtype showed a lack of immune activation. We establish a young immunosuppressive melanoma score that can predict ICI responsiveness in AYA patients and propose personalized therapeutic strategies for the ICI-resistant subgroups. These findings highlight the distinct immunogenomic profile of AYA patients, and individualized TME features in ICI-resistant AYA melanoma that require patient-specific treatment strategies.

The rising roles of exosomes in the tumor microenvironment reprogramming and cancer immunotherapy

Exosomes are indispensable for intercellular communications. Tumor microenvironment (TME) is the living environment of tumor cells, which is composed of various components, including immune cells. Based on TME, immunotherapy has been recently developed for eradicating cancer cells by reactivating antitumor effect of immune cells. The communications between tumor cells and TME are crucial for tumor development, metastasis, and drug resistance. Exosomes play an important role in mediating these communications and regulating the reprogramming of TME, which affects the sensitivity of immunotherapy. Therefore, it is imperative to investigate the role of exosomes in TME reprogramming and the impact of exosomes on immunotherapy. Here, we review the communication role of exosomes in regulating TME remodeling and the efficacy of immunotherapy, as well as summarize the underlying mechanisms. Furthermore, we also introduce the potential application of the artificially modified exosomes as the delivery systems of antitumor drugs. Further efforts in this field will provide new insights on the roles of exosomes in intercellular communications of TME and cancer progression, thus helping us to uncover effective strategies for cancer treatment.

Non-coding RNAs in cancer immunotherapy: A solution to overcome immune resistance?

With the rapid advancement in immunotherapy, cancer immune resistance has become more evident, which demands new treatment approaches to achieve greater efficacy. Non-coding RNAs (ncRNAs) are a heterogeneous group of RNAs that are not translated to proteins but instead regulate different stages of gene expression. Recent studies have increasingly supported the critical role of ncRNAs in immune cell-cancer cell cross-talk, and numerous ncRNAs have been implicated in the immune evasion of cancer cells. Cancer cells take advantage of ncRNAs to modulate several signaling pathways and upregulate the expression of immune checkpoints and anti-inflammatory mediators, thereby dampening the anti-tumor response of M1 macrophages, dendritic cells, cytotoxic T cells, and natural killer cells or potentiating the immunosuppressive properties of M2 macrophages, regulatory T cells, and myeloid-derived suppressive cells. Upregulation of immunosuppressive ncRNAs or downregulation of immunogenic ncNRAs is a major driver of resistance to immune checkpoint inhibitors, cancer vaccines, and other means of cancer immunotherapy, making ncRNAs ideal targets for treatment. In addition, ncRNAs released by cancer cells have been demonstrated to possess prognostic values for patients who undergo cancer immunotherapy. Future clinical trials are urged to consider the potential of ncRNAs in cancer immunotherapy.