Colorectal Cancer-Associated Immune Exhaustion Involves T and B Lymphocytes and Conventional NK Cells and Correlates With a Shorter Overall Survival

Developing and experimental validating a B cell exhaustion-related gene signature to assess prognosis and immunotherapeutic response in bladder cancer

BACKGROUND

B cell exhaustion (BEX) refers to the impairment of normal B cell functions and decreased proliferation capability. However, the prognostic value of BEX-related genes in bladder cancer (BLCA) remains unclear.

METHODS

BLCA cases from TCGA were used for training, while GSE5287, GSE13507, GSE31684, and GSE32894 cohorts from GEO were used for external validation. BEX-related genes were identified through literature retrieval, unsupervised clustering, and genomic difference detection. Gene pairing, LASSO, random forest, and Cox regression were employed to construct a predictive model. B cell samples from scRNAseqDB, GSE111636, and IMvigor210 were utilized to explore immunoprofiles and the predictive ability of the model in immunotherapeutic response. Additionally, 21 pairs of BLCA and paracarcinoma samples from Nanfang Hospital were used to re-confirm our findings through RT-qPCR, immunofluorescence, and flow cytometry.

RESULTS

39 BEX-related genes were identified. A 4-gene-pair signature was constructed and served as a reliable prognostic predictor across multiple datasets (pooled HR = 2.32; 95 % CI = 1.81-2.98). The signature reflected the BEX statuses of B cells (FDR < 0.05) and showed promise in evaluating immunotherapeutic sensitivity (P < 0.001). In the local cohort, CD52, TUBB6, and CAV1 were down-regulated in BLCA tissues, while TGFBI, UBE2L6, TINAGL1, and IL32 were up-regulated (all P < 0.05). Furthermore, the infiltration levels of CD19 + CD52 + and CD19 + TUBB6 + B cells in paracarcinoma samples were higher than those in BLCA samples (all P < 0.05).

CONCLUSION

A BEX-related gene signature was developed to predict prognosis and immunotherapeutic sensitivity in BLCA, providing valuable guidance for personalized treatment.

Ferroptosis and immunosenescence in colorectal cancer

Colorectal cancer (CRC), ranked as the globe's third leading malignancy. Despite advancements in therapeutic approaches, the mortality rate remains distressingly high for those afflicted with advanced stages of the disease. Ferroptosis is a programmed form of cell death. The ways of ferroptosis mainly include promoting the accumulation of cellular ROS and increasing the level of cellular Labile iron pool (LIP). Immunosenescence is characterized by a gradual deterioration of the immune system's ability to respond to pathogens and maintain surveillance against cancer cells. In CRC, this decline is exacerbated by the tumor microenvironment, which can suppress the immune response and promote tumor progression. This paper reviews the relationship between iron prolapse and immune senescence in colorectal cancer, focusing on the following aspects: firstly, the different pathways that induce iron prolapse in colorectal cancer; secondly, immune-immune senescence in colorectal cancer; and lastly, the interactions between immune senescence and iron prolapse in colorectal cancer, e.g., immune-immune senescent cells often exhibit increased oxidative stress, leading to the accumulation of ROS, and consequently to lipid peroxidation and induction of iron-induced cell death. At the same time, ferroptosis induces immune cell senescence as well as alterations in the immune microenvironment by promoting the death of damaged or diseased cells and leading to the inflammation usually associated with it. In conclusion, by exploring the potential targets of ferroptosis and immune senescence in colorectal cancer therapy, we hope to provide a reference for future research.

Involvement of SIRT1-mediated cellular immune response in cancer

The morbidity and mortality of cancer are rising rapidly worldwide and immunotherapy has become an effective means to curb the progress of cancer. Sirtuin-1(SIRT1) is a NAD+ -dependent deacetylase that plays a key role in cancer development and immune regulation through mediating a variety of signaling pathways. Targeting SIRT1 in immunotherapy could enhance or erod immune responses against cancer cells, while SIRT1 activator and inhibitors are being developed as potential antineoplastic agents with important implications in clinic. This review summarizes the impact of SIRT1 in different types of immune cells and mechanism of SIRT1-mediated immune responses in tumor progression as well as its therapeutic perspectives.

T cell exhaustion in human cancers

T cell exhaustion refers to a progressive state in which T cells become functionally impaired due to sustained antigenic stimulation, which is characterized by increased expression of immune inhibitory receptors, but weakened effector functions, reduced self-renewal capacity, altered epigenetics, transcriptional programme and metabolism. T cell exhaustion is one of the major causes leading to immune escape of cancer, creating an environment that supports tumor development and metastatic spread. In addition, T cell exhaustion plays a pivotal role to the efficacy of current immunotherapies for cancer. This review aims to provide a comprehensive view of roles of T cell exhaustion in cancer development and progression. We summerized the regulatory mechanisms that involved in T cell exhaustion, including transcription factors, epigenetic and metabolic reprogramming events, and various microenvironmental factors such as cytokines, microorganisms, and tumor autocrine substances. The paper also discussed the challenges posed by T cell exhaustion to cancer immunotherapies, including immune checkpoint blockade (ICB) therapies and chimeric antigen receptor T cell (CAR-T) therapy, highlightsing the obstacles encountered in ICB therapies and CAR-T therapies due to T cell exhaustion. Finally, the article provides an overview of current therapeutic options aimed to reversing or alleviating T cell exhaustion in ICB and CAR-T therapies. These therapeutic approaches seek to overcome T cell exhaustion and enhance the effectiveness of immunotherapies in treating tumors.

Pan-cancer single-cell dissection reveals phenotypically distinct B cell subtypes

Characterizing the compositional and phenotypic characteristics of tumor-infiltrating B cells (TIBs) is important for advancing our understanding of their role in cancer development. Here, we establish a comprehensive resource of human B cells by integrating single-cell RNA sequencing data of B cells from 649 patients across 19 major cancer types. We demonstrate substantial heterogeneity in their total abundance and subtype composition and observe immunoglobulin G (IgG)-skewness of antibody-secreting cell isotypes. Moreover, we identify stress-response memory B cells and tumor-associated atypical B cells (TAABs), two tumor-enriched subpopulations with prognostic potential, shared in a pan-cancer manner. In particular, TAABs, characterized by a high clonal expansion level and proliferative capacity as well as by close interactions with activated CD4 T cells in tumors, are predictive of immunotherapy response. Our integrative resource depicts distinct clinically relevant TIB subsets, laying a foundation for further exploration of functional commonality and diversity of B cells in cancer.

Lipopolysaccharide-responsive beige-like anchor is involved in regulating NF-κB activation in B cells

Introduction

Lipopolysaccharide-responsive and beige-like anchor (LRBA) is a scaffolding protein that interacts with proteins such as CTLA-4 and PKA, the importance of which has been determined in various cell types, including T regulatory cells, B cells, and renal cells. LRBA deficiency is associated with an inborn error in immunity characterized by immunodeficiency and autoimmunity. In addition to defects in T regulatory cells, patients with LRBA deficiency also exhibit B cell defects, such as reduced cell number, low memory B cells, hypogammaglobulinemia, impaired B cell proliferation, and increased autophagy. Although Lrba-/- mice do not exhibit the immunodeficiency observed in humans, responses to B cell receptors (BCR) in B cells have not been explored. Therefore, a murine model is for elucidating the mechanism of Lrba mechanism in B cells.

Aim

To compare and evaluate spleen-derived B cell responses to BCR crosslinking in C57BL6 Lrba-/- and Lrba+/+ mice.

Materials and methods

Spleen-derived B cells were obtained from 8 to 12-week-old mice. Subpopulations were determined by immunostaining and flow cytometry. BCR crosslinking was assessed by the F(ab')2 anti-μ chain. Activation, proliferation and viability assays were performed using flow cytometry and protein phosphorylation was evaluated by immunoblotting. The nuclear localization of p65 was determined using confocal microscopy. Nur77 expression was evaluated by Western blot.

Results

Lrba-/- B cells showed an activated phenotype and a decreased proportion of transitional 1 B cells, and both proliferation and survival were affected after BCR crosslinking in the Lrba-/- mice. The NF-κB pathway exhibited a basal activation status of several components, resulting in increased activation of p50, p65, and IκBα, basal p50 activation was reduced by the Plcγ2 inhibitor U73122. BCR crosslinking in Lrba-/ - B cells resulted in poor p50 phosphorylation and p65 nuclear localization. Increased levels of Nur77 were detected.

Discussion

These results indicate the importance of Lrba in controlling NF-κB activation driven by BCR. Basal activation of NF-κB could impact cellular processes, such as, activation, differentiation, proliferation, and maintenance of B cells after antigen encounter.

Canopy FGF signaling regulator 3 affects prognosis, immune infiltration, and PI3K/AKT pathway in colon adenocarcinoma

BACKGROUND

Colon adenocarcinoma (COAD) is a malignant tumor of the digestive system. The mechanisms underlying COAD development and progression are still largely unknown.

AIM

To identify the role of canopy FGF signaling regulator 3 (CNPY3) in the development and progression of COAD by using bioinformatic tools and functional experiments.

METHODS

Bioinformatic data were downloaded from public databases. The associations of clinicopathological features, survival, and immune function with the expression of CNPY3 were analyzed. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses and Gene Set Enrichment Analysis were used to explore the related pathways. Then, quantitative real-time PCR and immunohistochemistry were used for validation of CNPY3 expression in clinical samples and tumor cell lines. Cell lines with CNPY3 knockdown were constructed to further analyze gene functions. The functional experiments included proliferation, invasion, migration and apoptosis assays.

RESULTS

In both the TCGA cohort and the merged dataset, elevated CNPY3 expression was observed in tumor tissues. High CNPY3 expression correlated with adverse survival and compromised immune functions. Functional enrichment analysis suggested that the pro-oncogenic properties of CNPY3 might be linked to the PI3K-AKT signaling pathway. CNPY3 expression was validated at both the RNA and protein levels. Functional assays indicated that cell proliferation, invasion, and migration were inhibited and cell apoptosis was promoted after CNPY3 knockdown. Additionally, Western blot results revealed the downregulation of key proteins in the PI3K/AKT pathway following CNPY3 knockdown. PI3K/AKT pathway activator reversed the decrease in proliferation, invasion, and migration and the increase in apoptosis. Notably, CNPY3 knockdown still affected the cells when the pathway was inhibited.

CONCLUSION

This study showed that CNPY3 is upregulated in COAD and might regulate COAD development and progression by the PI3K/AKT pathway. Thus, CNPY3 might be a promising therapeutic target.

The role of extracellular vesicles in immune cell exhaustion and resistance to immunotherapy

INTRODUCTION

Extracellular vesicles (EVs) are membrane-bound nanoparticles for intercellular communication. Subtypes of EVs, namely exosomes and microvesicles transfer diverse, bioactive cargo to their target cells and eventually interfere with immune responses. Despite being a promising approach, cancer immunotherapy currently faces several challenges including immune resistance. EVs secreted from various sources in the tumor microenvironment provoke immune cell exhaustion and lower the efficacy of immunological treatments, such as CAR T cells and immune checkpoint inhibitors.

AREAS COVERED

This article goes through the mechanisms of action of various types of EVs in inhibiting immune response and immunotherapies, and provides a comprehensive review of EV-based treatments.

EXPERT OPINION

By making use of the distinctive features of EVs, natural or modified EVs are innovatively utilized as novel cancer therapeutics. They are occasionally coupled with currently established treatments to overcome their inadequacies. Investigating the properties and interactions of EVs and EV-based treatments is crucial for determining future steps in cancer therapeutics.

Novel hypoxia- and lactate metabolism-related molecular subtyping and prognostic signature for colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a serious global health burden because of its high morbidity and mortality rates. Hypoxia and massive lactate production are hallmarks of the CRC microenvironment. However, the effects of hypoxia and lactate metabolism on CRC have not been fully elucidated. This study aimed to develop a novel molecular subtyping based on hypoxia-related genes (HRGs) and lactate metabolism-related genes (LMRGs) and construct a signature to predict the prognosis of patients with CRC and treatment efficacy.

METHODS

Bulk and single-cell RNA-sequencing and clinical data of CRC were downloaded from the TCGA and GEO databases. HRGs and LMRGs were obtained from the Molecular Signatures Database. The R software package DESeq2 was used to perform differential expression analysis. Molecular subtyping was performed using unsupervised clustering. A predictive signature was developed using univariate Cox regression, random forest model, LASSO, and multivariate Cox regression analyses. Finally, the sensitivity of tumor cells to chemotherapeutic agents before and after hypoxia was verified using in vitro experiments.

RESULTS

We classified 575 patients with CRC into three molecular subtypes and were able to distinguish their prognoses clearly. The C1 subtype, which exhibits high levels of hypoxia, has a low proportion of CD8 + T cells and a high proportion of macrophages. The expression of immune checkpoint genes is generally elevated in C1 patients with severe immune dysfunction. Subsequently, we constructed a predictive model, the HLM score, which effectively predicts the prognosis of patients with CRC and the efficacy of immunotherapy. The HLM score was validated in GSE39582, GSE106584, GSE17536, and IMvigor210 datasets. Patients with high HLM scores exhibit high infiltration of CD8 + exhausted T cells (Tex), especially terminal Tex, and oxidative phosphorylation (OXPHOS)-Tex in the immune microenvironment. Finally, in vitro experiments confirmed that CRC cell lines were less sensitive to 5-fluorouracil, oxaliplatin, and irinotecan under hypoxic conditions.

CONCLUSION

We constructed novel hypoxia- and lactate metabolism-related molecular subtypes and revealed their immunological and genetic characteristics. We also developed an HLM scoring system that could be used to predict the prognosis and efficacy of immunotherapy in patients with CRC.

Key role of interferon regulatory factor 1 (IRF-1) in regulating liver disease: progress and outlook

Interferon regulatory factor 1 (IRF-1) is a member of the IRF family. It is the first transcription factor to be identified that could bind to the interferon-stimulated response element (ISRE) on the target gene and displays crucial roles in the interferon-induced signals and pathways. IRF-1, as an important medium, has all of the advantages of full cell cycle regulation, cell death signaling transduction, and reinforcing immune surveillance, which are well documented. Current studies indicate that IRF-1 is of vital importance to the occurrence and evolution of multifarious liver diseases, including but not limited to inhibiting the replication of the hepatitis virus (A/B/C/E), alleviating the progression of liver fibrosis, and aggravating hepatic ischemia-reperfusion injury (HIRI). The tumor suppression of IRF-1 is related to the clinical characteristics of liver cancer patients, which makes it a potential indicator for predicting the prognosis and recurrence of liver cancer; additionally, the latest studies have revealed other effects of IRF-1 such as protection against alcoholic/non-alcoholic fatty liver disease (AFLD/NAFLD), cholangiocarcinoma suppression, and uncommon traits in other liver diseases that had previously received little attention. Intriguingly, several compounds and drugs have featured a protective function in specific liver disease models in which there is significant involvement of the IRF-1 signal. In this paper, we hope to propose a prospective research basis upon which to help decipher translational medicine applications of IRF-1 in liver disease treatment.

Construction and analysis of a reliable five-gene prognostic signature for colon adenocarcinoma associated with the wild-type allelic state of the COL6A6 gene

Background

Tumors emerge by acquiring a number of mutations over time. The first mutation provides a selective growth advantage compared to adjacent epithelial cells, allowing the cell to create a clone that can outgrow the cells that surround it. Subsequent mutations determine the risk of the tumor progressing to metastatic cancer. Some secondary mutations may inhibit the aggressiveness of the tumor while still increasing the survival of the clone. Meaningful mutations in genes may provide a strong molecular foundation for developing novel therapeutic strategies for cancer.

Methods

The somatic mutation and prognosis in colon adenocarcinoma (COAD) were analyzed. The copy number variation (CNV) and differentially expressed genes (DEGs) between the collagen type VI alpha 6 chain (COL6A6) mutation (COL6A6-MUT) and the COL6A6 wild-type (COL6A6-WT) subgroups were evaluated. The independent prognostic signatures based on COL6A6-allelic state were determined to construct a Cox model. The biological characteristics and the immune microenvironment between the two risk groups were compared.

Results

COL6A6 was found to be highly mutated in COAD at a frequency of 9%. Patients with COL6A6-MUT had a good overall survival (OS) compared to those with COL6A6-WT, who had a different CNV pattern. Significant differences in gene expression were established for 593 genes between the COL6A6-MUT and COL6A6-WT samples. Among them, MUC16, ASNSP1, PRR18, PEG10, and RPL26P8 were determined to be independent prognostic factors. The internally validated prognostic risk model, constructed using these five genes, demonstrated its value by revealing a significant difference in patient prognosis between the high-risk and low-risk groups. Specifically, patients in the high-risk group exhibited a considerably worse prognosis than did those in the low-risk group. The high-risk group had a significantly higher proportion of patients over 60 years of age and patients in stage III. Moreover, the tumor immune dysfunction and exclusion (TIDE) score and the expression of human leukocyte antigen (HLA) family genes were all higher in the high-risk group than that in the low-risk group.

Conclusions

The allelic state of COL6A6 and the five associated DEGs were identified as novel biomarkers for the diagnosis and prognosis of COAD and may be therapeutic targets in COAD.

Identification of ROS and KEAP1-related genes and verified targets of α-hederin induce cell death for CRC

In this study, we analyzed and verified differentially expressed genes (DEGs) in ROS and KEAP1 crosstalk in oncogenic signatures using GEO data sets (GSE4107 and GSE41328). Multiple pathway enrichment analyses were finished based on DEGs. The genetic signature for colorectal adenocarcinoma (COAD) was identified by using the Cox regression analysis. Kaplan-Meier survival and receiver operating characteristic curve analysis were used to explore the prognosis value of specific genes in COAD. The potential immune signatures and drug sensitivity prediction were also analyzed. Promising small-molecule agents were identified and predicted targets of α-hederin in SuperPred were validated by molecular docking. Also, expression levels of genes and Western blot analysis were conducted. In total, 48 genes were identified as DEGs, and the hub genes such as COL1A1, CXCL12, COL1A2, FN1, CAV1, TIMP3, and IGFBP7 were identified. The ROS and KEAP1-associated gene signatures comprised of hub key genes were developed for predicting the prognosis and evaluating the immune cell responses and immune infiltration in COAD. α-hederin, a potential anti-colorectal cancer (CRC) agent, was found to enhance the sensitivity of HCT116 cells, regulate CAV1 and COL1A1, and decrease KEAP1, Nrf2, and HO-1 expression significantly. KEAP1-related genes could be an essential mediator of ROS in CRC, and KEAP1-associated genes were effective in predicting prognosis and evaluating individualized CRC treatment. Therefore, α-hederin may be an effective chemosensitizer for CRC treatments in clinical settings.

Associations of PD-1 and PD-L1 gene polymorphisms with cancer risk: a meta-analysis based on 50 studies

Programmed death-1 and its ligand-1 (PD-1/PD-L1), immune checkpoints proteins, play a crucial role in anti-tumor responses. A large number of studies have evaluated the relationships of PD-1/PD-L1 polymorphisms with risk of cancer, but evidence for the associations remains inconsistent. Therefore, we performed a meta-analysis to examine the associations between PD-1/PD-L1 single nucleotide polymorphisms (SNPs) and cancer predisposition. Results showed that PD-1.3 and PD-L1 rs17718883 were significantly correlated with overall cancer risk. PD-1.5 was prominently linked with cervical cancer (CC), non-small cell lung cancer (NSCLC), TC (thyroid cancer), brain tumor, AML (acute myelocytic leukemia) and UCC (urothelial cell carcinoma) risk, PD-1.9 with breast cancer (BC), AML, esophageal cancer (EC) and ovarian cancer (OC) risk, and PD-1.3 with colorectal cancer (CRC) and BCC (basal cell carcinoma) risk. PD-1.1 polymorphism slightly elevated BC and OC susceptibility, whereas the rs4143815 variant notably decreased the risk of gastric cancer (GC), hepatocellular carcinoma (HCC) and OC, but increased the risk of BC. PD-1.6 was closely linked with AML risk, PD-L1 rs2890658 with NSCLC, HCC and BC risk, rs17718883 with HCC and GC risk, rs10815225 with GC risk, and rs2297136 with NSCLC and HCC risk. Interestingly, the rs7421861, rs10815225, and rs10815225 markedly reduced cancer susceptibility among Asians. The rs7421861 polymrophism decreased cancer risk among Caucasians, rather than the rs10815225 elevated cancer risk. Our results supported that PD-1 and PD-L1 SNPs were dramatically correlated with cancer risk.

B cell clonality in cancer

Carcinogenesis in the process of long-term co-evolution of tumor cells and immune environment essentially becomes possible due to incorrect decisions made, remembered, and reproduced by the immune system at the level of clonal populations of antigen-specific T- and B-lymphocytes. Tumor-immunity interaction determines the nature of such errors and, consequently, delineates the possible ways of successful immunotherapeutic intervention. It is generally recognized that tumor-infiltrating B cells (TIL-B) can play both pro-tumor and anti-tumor roles. However, the exact mechanisms that determine the contribution of clonal B cell lineages with different specificities and functions remain largely unclear. This is due to the variability of cancer types, the molecular heterogeneity of tumor cells, and, to a large extent, the individual pattern of each immune response. Further progress requires detailed investigation of the functional properties and phenotypes of clonally heterogeneous B cells in relation to their antigenic specificities, which determine the functionality of both effector B lymphocytes and immunoglobulins produced in the tumor environment. Based on a real understanding of the role of clonal antigen-specific populations of B lymphocytes in the tumor microenvironment, we need to learn how to develop new methods of targeted immunotherapy, as well as adapt existing treatment options to the specific needs of different patients and patient subgroups. In this review, we will cover B cells functional diversity and their multifaceted roles in the tumor environment.

An Analysis Regarding the Association Between DAZ Interacting Zinc Finger Protein 1 (DZIP1) and Colorectal Cancer (CRC)

Colorectal cancer (CRC) is the third most common malignant disease worldwide, and its incidence is increasing, but the molecular mechanisms of this disease are highly heterogeneous and still far from being fully understood. Increasing evidence suggests that fibrosis mediated by abnormal activation of fibroblasts based in the microenvironment is associated with a poor prognosis. However, the function and pathogenic mechanisms of fibroblasts in CRC remain unclear. Here, combining scrna-seq and clinical specimen data, DAZ Interacting Protein 1 (DZIP1) was found to be expressed on fibroblasts and cancer cells and positively correlated with stromal deposition. Importantly, pseudotime-series analysis showed that DZIP1 levels were up-regulated in malignant transformation of fibroblasts and experimentally confirmed that DZIP1 modulates activation of fibroblasts and promotes epithelial-mesenchymal transition (EMT) in tumor cells. Further studies showed that DZIP1 expressed by tumor cells also has a driving effect on EMT and contributes to the recruitment of more fibroblasts. A similar phenomenon was observed in xenografted nude mice. And it was confirmed in xenograft mice that downregulation of DZIP1 expression significantly delayed tumor formation and reduced tumor size in CRC cells. Taken together, our findings suggested that DZIP1 was a regulator of the CRC mesenchymal phenotype. The revelation of targeting DZIP1 provides a new avenue for CRC therapy.

Crosstalk between colorectal CSCs and immune cells in tumorigenesis, and strategies for targeting colorectal CSCs

Cancer immunotherapy has emerged as a promising strategy in the treatment of colorectal cancer, and relapse after tumor immunotherapy has attracted increasing attention. Cancer stem cells (CSCs), a small subset of tumor cells with self-renewal and differentiation capacities, are resistant to traditional therapies such as radiotherapy and chemotherapy. Recently, CSCs have been proven to be the cells driving tumor relapse after immunotherapy. However, the mutual interactions between CSCs and cancer niche immune cells are largely uncharacterized. In this review, we focus on colorectal CSCs, CSC-immune cell interactions and CSC-based immunotherapy. Colorectal CSCs are characterized by robust expression of surface markers such as CD44, CD133 and Lgr5; hyperactivation of stemness-related signaling pathways, such as the Wnt/β-catenin, Hippo/Yap1, Jak/Stat and Notch pathways; and disordered epigenetic modifications, including DNA methylation, histone modification, chromatin remodeling, and noncoding RNA action. Moreover, colorectal CSCs express abnormal levels of immune-related genes such as MHC and immune checkpoint molecules and mutually interact with cancer niche cells in multiple tumorigenesis-related processes, including tumor initiation, maintenance, metastasis and drug resistance. To date, many therapies targeting CSCs have been evaluated, including monoclonal antibodies, antibody‒drug conjugates, bispecific antibodies, tumor vaccines adoptive cell therapy, and small molecule inhibitors. With the development of CSC-/niche-targeting technology, as well as the integration of multidisciplinary studies, novel therapies that eliminate CSCs and reverse their immunosuppressive microenvironment are expected to be developed for the treatment of solid tumors, including colorectal cancer.

BTLA biology in cancer: from bench discoveries to clinical potentials

Immune checkpoints play a critical role in maintaining the delicate balance of immune activation in order to prevent potential harm caused by excessive activation, autoimmunity, or tissue damage. B and T lymphocyte attenuator (BTLA) is one of crucial checkpoint, regulating stimulatory and inhibitory signals in immune responses. Its interaction with the herpes virus entry mediator (HVEM) plays an essential role in negatively regulating immune responses, thereby preserving immune homeostasis. In cancer, abnormal cells evade immune surveillance by exploiting checkpoints like BTLA. Upregulated BTLA expression is linked to impaired anti-tumor immunity and unfavorable disease outcomes. In preclinical studies, BTLA-targeted therapies have shown improved treatment outcomes and enhanced antitumor immunity. This review aims to provide an in-depth understanding of BTLA's biology, its role in various cancers, and its potential as a prognostic factor. Additionally, it explores the latest research on BTLA blockade in cancer immunotherapy, offering hope for more effective cancer treatments.

Prognosis and therapy in thyroid cancer by gene signatures related to natural killer cells

BACKGROUND

Natural killer (NK) cells are crucial to cancer development and prognosis. However, the role of NK cell-related genes in immunotherapy and the tumor immune microenvironment (TIME) is not well understood. This study aimed to develop reliable risk signatures associated with NK cell-related genes for predicting thyroid cancer (THCA).

METHODS

The single-cell RNA sequencing (scRNA-seq) data from seven THCA samples (GSE184362) and bulk-RNA-seq data of 502 THCA patients (TCGA-THCA) were included. The scRNA-seq data was analyzed using the "Seurat" R package to identify differentially expressed genes in NK cells. The clustering analysis was carried out using the R package "ConsensusClusterPlus". The gene set variation analysis (GSVA) algorithm was applied to assess the variations in biological pathways among subtypes. The ESTIMATE algorithm was utilized to calculate the scores for stromal, immune and estimate variables. In addition, we used the single sample Gene Set Enrichment Analysis and CIBERSORT algorithms to assess the degree to which immune cells and pathways related to immunity were enriched based on the meta-cohort. In the TCGA-THCA cohort, the "glmnet" R package was used for the gene selection, and LASSO Cox analysis was used to construct prognostic features. The "maftools" R package was used to examine the somatic mutation landscape of THCA in both low- and high-risk groups.

RESULTS

One-hundred and eighty-five NK cell marker genes were screened, and nine genes were associated with the THCA prognosis. KLF2, OSTF1 and TAPBP were finally identified and constructed a risk signature with significant prognostic value. KLF2 and OSTF1 were protective genes, and TAPBP was a risk gene. Patients at high risk had a considerably lower overall survival compared with those at low risk. Mutations in the TCGA-THCA cohort were predominantly C > T. Increased tumor mutation burden (TMB) levels were linked to overall survival. The low-risk H-TMB+ group had a better prognosis, while the high-risk L-TMB+ group had the worst prognosis.

CONCLUSION

Natural killer cell-related genes KLF2, OSTF1 and TAPBP were used to develop a novel prognostic risk signature, offering a new perspective on the prognosis and treatment of THCA.

Evaluation of the presence of Th1 response through T-bet and IFN-gamma immunohistochemical expression in lower lip and oral tongue squamous cell carcinomas

INTRODUCTION

Evaluate the immunohistochemical expression of T-bet and IFN-γ in lower lip (LLSCC) and oral tongue squamous cell carcinoma (OTSCC), verifying the presence of Th1 responses in lesions with different clinical conditions.

METHODS AND MATERIALS

Thirty OTSCC and 30 LLSCC were analyzed by immunohistochemistry. T-bet was quantitatively assessed by parenchyma cell and stroma quantification, and IFN-γ was semi-quantitatively analyzed: 1:0-25%; 2:26-50%; 3:51-75%; 4:> 75% immunopositive cells. Histological differentiation degrees were categorized as well differentiated (WD), moderately differentiated (MD), or poorly differentiated (PD).

RESULTS

OTSCC presented the highest number of T-bet+, parenchyma (p: 0.006), stroma (p: 0.156), parenchyma/stroma (p: 0.015), with no relationship to histological malignancy grade. IFN-γ higher concentrations in LLSCC were detected in parenchyma, stroma and in parenchyma/stroma (p: 0.000), as well as greater immunoreactivity in WD and MD (p: 0.001). In OTSCC, a positive and statistically significant correlation was observed between T-bet+ in parenchyma and IFN-γ in stroma(r: 0.388; p: 0.034), in addition to a statistically significant positive correlation between T-bet in parenchyma compared to stroma(r: 0.411; p: 0.024) and for IFN-γ in both parenchyma and stroma(r: 0.775; p: 0.000) in LLSCC. Higher T-bet+ was observed in OTSCCs, although higher IFN-γ was detected in LLSCCs.

CONCLUSION

Thus, we suggest that, even though LLSCC presented lower T-bet+, the favorable microenvironment in these lesions led to an expressive activation of IFN-γ by T-bet+, considerably acting on Th1 differentiation and in antitumor activity, which, admittedly, present less aggressive behavior, reinforcing once again the important role of this cytokine and its use in strategy to fight cancer.

Mediastinal lymph node removal modulates natural killer cell exhaustion in patients with non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death globally. In this study, the effect of complete removal of mediastinal lymph nodes by video-assisted mediastinoscopic lymphadenectomy (VAMLA) on natural killer (NK) cell phenotype and functions in patients with NSCLC was evaluated. The study included 21 NSCLC patients (cIA-IVA) undergoing VAMLA staging and 33 healthy controls. Mononuclear cells were isolated from peripheral blood of all participants and mediastinal lymph nodes of the patients. NK cells were analyzed by flow cytometry to define NK subsets, expressions of PD-1, CTLA-4, activating/inhibitory receptors, granzyme A, and CD107a. The plasma levels of soluble PD-1, PDL-1, and CTLA-4 were measured by ELISA. Mediastinal lymph nodes of NSCLC patients had increased ratios of exhausted NK cells, increased expression of PD-1 and IL-10, and impaired cytotoxicity. Mediastinal lymph nodes removal increased CD56dimCD16bright cytotoxic effector phenotype and reduced exhausted NK cells. PD-1+ NK cells were significantly more abundant in patients' blood, and VAMLA significantly reduced their ratio as well. The ratio of IL-10 secreting regulatory NK cells was also reduced after VAMLA. Blood NK cells had increased cytotoxic functions and spontaneous IFN-γ secretion, and these NK cell functions were also recovered by VAMLA. Mediastinal lymph node removal reversed NK cell exhaustion, reduced regulatory NK cells, and improved antitumoral functions of NK cells. Tumor-draining lymph nodes may contribute to tumor evasion from antitumoral immune responses. The role of their removal needs to be further studied both to better understand this mechanism and as a potential immunotherapeutic approach.

[Multistain deep learning as a prognostic and predictive biomarker in colorectal cancer]

The tumor immune microenvironment (TIME) plays a crucial prognostic and predictive role in solid malignancies such as colorectal cancer (CRC). Nevertheless, scoring systems based on TIME such as the Immunoscore (IS) are rarely used in clinical practice. Among other reasons, this might be due to the additional time required for manual quantification of tumor-associated immune cells or costs associated with proprietary/commercial solutions. To address these issues, we developed a multistain deep learning model (MSDLM) and trained, validated, and tested it on immunohistochemical image data of different immune cell subtypes from over 1000 patients with CRC. Our model showed high prognostic accuracy and outperformed other clinical, molecular, and immune cell-based parameters. It might also be used for therapy response prediction in rectal cancer patients undergoing neoadjuvant therapy. Leveraging artificial intelligence interpretability/explainability methods, we ascertained that the MSDLM's predictions align with recognized antitumor immune response patterns. Consequently, the AImmunoscore (AIS) could emerge as a potential TIME-based decision-making tool for clinicians.

Natural killer cell-related prognosis signature predicts immune response in colon cancer patients

Background: Natural killer (NK) cells are crucial components of the innate immune system that fight tumors and viral infections. Patients with colorectal cancer (CRC) have a poor prognosis, and immunotherapeutic tools play a key role in the treatment of CRC. Methods: Public data on CRC patients was collected from the TCGA and the GEO databases. Tissue data of CRC patients were collected from Guangxi Medical University Affiliated Cancer Hospital. An NK-related prognostic model was developed by the least absolute shrinkage and selection operator (LASSO) and Cox regression method. Validation data were collected from different clinical subgroups and an external independent validation cohort to verify the model's accuracy. In addition, multiple external independent immunotherapy datasets were collected to further examine the value of NK-related risk scores (NKRS) in the prediction of immunotherapy response. Potential biological functions of key genes were examined by methods of cell proliferation, apoptosis and Western blotting. Results: A novel prognostic model for CRC patients based on NK-related genes was developed and NKRS was generated. There was a significantly poorer prognosis among the high-NKRS group. Based on immune response prediction, patients with low NKRS may be more suitable for immunotherapy and they are more sensitive to immunotherapy. The proliferation rate of CRC cells was significantly reduced and apoptosis of CRC cells was increased after SLC2A3 was knocked down. SLC2A3 was also found to be associated with the TGF-β signaling pathway. Conclusion: NKRS has potential applications for predicting prognostic status and response to immunotherapy in CRC patients. SLC2A3 has potential as a therapeutic target for CRC.

Sirtuin 2 up-regulation suppresses the anti-tumour activity of exhausted natural killer cells in mesenteric lymph nodes in murine colorectal carcinoma

Natural killer (NK) cells inhibit colorectal carcinoma (CRC) initiation and progression through their tumoricidal activity. However, cumulative evidence suggests that NK cells become functionally exhausted in patients with CRC. To deepen the understanding of the mechanisms underlying CRC-associated NK cell exhaustion, we explored the expression and effect of Sirtuin 2 (Sirt2) in mesenteric lymph node (mLN) NK cells in a murine colitis-associated CRC model. Sirt2 was remarkably up-regulated in mLN NK cells after CRC induction. Particularly, Sirt2 was increased in mLN NK cells expressing high T cell immunoglobulin and mucin domain-3 (TIM3), high lymphocyte activation protein-3 (LAG3), high programmed death-1 (PD-1), high T cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT), high NK group 2 member A (NKG2A), but low tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), low interferon-gamma and low granzyme B. In addition, Sirt2 was also increased in NK cells after induction of exhaustion in vitro. Lentivirus-mediated Sirt2 silencing did not affect the acute activation and cytotoxicity of non-exhausted NK cells. However, Sirt2 silencing partially restored the expression of interferon-gamma, granzyme B and CD107a in exhausted NK cells. Meanwhile, Sirt2 silencing down-regulated TIM3, LAG3, TIGIT and NKG2A while up-regulated TRAIL on exhausted NK cells. Consequently, Sirt2 silencing restored the cytotoxicity of exhausted NK cells. Moreover, Sirt2 silencing partially ameliorates the defects in glycolysis and mitochondrial respiration of exhausted NK cells, as evidenced by increases in glycolytic capacity, glycolytic reserve, basal respiration, maximal respiration and spare respiration capacity. Accordingly, Sirt2 negatively regulates the tumoricidal activity of exhausted NK cells in CRC.

Attenuated Salmonella-delivered PD-1 siRNA enhances the antitumor effects of EZH2 inhibitors in colorectal cancer

Immunotherapy has made significant progress in the treatment of malignant tumors. However, strategies to combine immunotherapy with anticancer drugs have attracted great attention due to the low response rate and unique toxicity profile of immunotherapies and the subsequent development of acquired resistance in some initial responders. EZH2, a histone methyl transferase subunit of a Polycomb repressor complex,is highly expressed in a variety of tumors, and targeting EZH2 has become a new strategy for tumor therapy and drug combination. Here，we studied the effect of EZH2 inhibitors on colorectal cancer cells and their combination with immunotherapy. Our results demonstrated that EZH2 inhibitors can not only significantly inhibit the survival of colorectal cancer (CRC) cells and induce apoptosis, effectively inhibit cell invasion and migration, but also cause an increase in the expression of PD-L1 receptors on the cell surface. To determine the effect of EZH2 in combination with immunotherapy, we combine EZH2 inhibitors with PD-1 siRNA delivered by attenuated Salmonella. The vivo experiments have shown that the combination of EZH2 inhibitors and Salmonella-delivered PD-1 siRNA can further inhibit the development of CRC, trigger effective anti-tumor immunity, and improve therapeutic efficacy. Its underlying mechanisms mainly involve synergistic immunomodulation and apoptosis. This study suggests an emerging strategy based on a combination of EZH2 inhibitor and immunotherapy based on PD-1 inhibition.

B- and T-lymphocyte attenuator could be a new player in accelerated atherosclerosis associated with chronic kidney disease

BACKGROUND

In chronic kidney disease (CKD), cardiovascular morbi-mortality is higher than in general population. Atherosclerotic cardiovascular disease is accelerated in CKD, but specific CKD-related risk factors for atherosclerosis are unknown.

METHODS

CKD patients from the NEFRONA study were used. We performed mRNA array from blood of patients free from atheroma plaque at baseline, with (n=10) and without (n=10) de novo atherosclerotic plaque development 2 years later. Selected mRNA candidates were validated in a bigger sample (n=148). Validated candidates were investigated in vivo in an experimental model of CKD-accelerated atherosclerosis, and in vitro in murine macrophages.

RESULTS

mRNA array analysis showed 92 up-regulated and 67 down-regulated mRNAs in samples from CKD patients with de novo plaque development. The functional analysis pointed to a paramount role of the immune response. The validation in a bigger sample confirmed that B- and T-lymphocyte co-inhibitory molecule (BTLA) down-regulation was associated with de novo plaque presence after 2 years. However, BTLA down-regulation was not found to be associated with atherosclerotic progression in patients with plaque already present at baseline. In a model of CKD-accelerated atherosclerosis, mRNA and protein expression levels of BTLA were significantly decreased in blood samples and atheroma plaques. Plaques from animals with CKD were bigger, had more infiltration of inflammatory cells, higher expression of IL6 and IL17 and less presence of collagen than plaques from control animals. Incubation of macrophages with rat uremic serum decreased BTLA expression.

CONCLUSIONS

BTLA could be a potential biomarker or therapeutic target for atherosclerosis incidence in CKD patients.

A novel 4-1BB/HER2 bispecific antibody shows potent antitumor activities by increasing and activating tumor-infiltrating T cells

Resistance to HER2-targeted therapy narrows the efficacy of cancer immunotherapy. Although 4-1BB/CD137 is a promising drug target as a costimulatory molecule of immune cells, no therapeutic drug has been approved in the clinic because of systemic toxicity or limited efficacy. Previously, we developed a humanized anti-HER2 monoclonal antibody (mAb) HuA21 and anti-4-1BB mAb HuB6 with distinct antigen epitopes for cancer therapy. Here, we generated an Fc-muted IgG4 HER2/4-1BB bispecific antibody (BsAb) HK006 by the fusion of HuB6 scFv and HuA21 Fab. HK006 exhibited synergistic antitumor activity by blocking HER2 signal transduction and stimulating the 4-1BB signaling pathway simultaneously and strictly dependent on HER2 expression in vitro and in vivo. Strikingly, HK006 treatment enhanced antitumor immunity by increasing and activating tumor-infiltrating T cells. Moreover, HK006 did not induce nonspecific production of proinflammatory cytokines and had no obvious toxicity in mice. Overall, these data demonstrated that HK006 should be a promising candidate for HER2-positive cancer immunotherapy.

An Fc-muted bispecific antibody targeting PD-L1 and 4-1BB induces antitumor immune activity in colorectal cancer without systemic toxicity

BACKGROUND

Resistance to immune checkpoint inhibitor (ICI) therapy narrows the efficacy of cancer immunotherapy. Although 4-1BB is a promising drug target as a costimulatory molecule of immune cells, no 4-1BB agonist has been given clinical approval because of severe liver toxicity or limited efficacy. Therefore, a safe and efficient immunostimulatory molecule is urgently needed for cancer immunotherapy.

METHODS

HK010 was generated by antibody engineering, and the Fab/antigen complex structure was analyzed using crystallography. The affinity and activity of HK010 were detected by multiple in vitro bioassays, including enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance (SPR), flow cytometry, and luciferase-reporter assays. Humanized mice bearing human PD-L1-expressing MC38 (MC38/hPDL1) or CT26 (CT26/hPDL1) tumor transplants were established to assess the in vivo antitumor activity of HK010. The pharmacokinetics (PK) and toxicity of HK010 were evaluated in cynomolgus monkeys.

RESULTS

HK010 was generated as an Fc-muted immunoglobulin (Ig)G4 PD-L1x4-1BB bispecific antibody (BsAb) with a distinguished Fab/antigen complex structure, and maintained a high affinity for human PD-L1 (KD: 2.27 nM) and low affinity for human 4-1BB (KD: 493 nM) to achieve potent PD-1/PD-L1 blockade and appropriate 4-1BB agonism. HK010 exhibited synergistic antitumor activity by blocking the PD-1/PD-L1 signaling pathway and stimulating the 4-1BB signaling pathway simultaneously, and being strictly dependent on the PD-L1 receptor in vitro and in vivo. In particular, when the dose was decreased to 0.3 mg/kg, HK010 still showed a strong antitumor effect in a humanized mouse model bearing MC38/hPDL1 tumors. Strikingly, HK010 treatment enhanced antitumor immunity and induced durable antigen-specific immune memory to prevent rechallenged tumor growth by recruiting CD8+ T cells and other lymphocytes into tumor tissue and activating tumor-infiltrating lymphocytes. Moreover, HK010 not only did not induce nonspecific production of proinflammatory cytokines but was also observed to be well tolerated in cynomolgus monkeys in 5 week repeated-dose (5, 15, or 50 mg/kg) and single-dose (75 or 150 mg/kg) toxicity studies.

CONCLUSION

We generated an Fc-muted anti-PD-L1x4-1BB BsAb, HK010, with a distinguished structural interaction with PD-L1 and 4-1BB that exhibits a synergistic antitumor effect by blocking the PD-1/PD-L1 signaling pathway and stimulating the 4-1BB signaling pathway simultaneously. It is strictly dependent on the PD-L1 receptor with no systemic toxicity, which may offer a new option for cancer immunotherapy.

Navigating the immunometabolic heterogeneity of B cells in murine hepatocellular carcinoma at single cell resolution

Induction of antitumor immunity is critical for the therapeutic efficacy of hepatocellular carcinoma (HCC) immunotherapy. The cellular metabolic state underpins the effector function of immune cells, yet our understanding of the phenotypic and metabolic heterogeneity of B cells within HCC microenvironment is poorly developed. Herein, we investigated the composition, distribution, phenotype, function and metabolic profiles of B-cell subsets in HCC and adjacent liver tissues from an orthotopic HCC mouse model using single-cell RNA sequencing (scRNA-seq). Our results identified six B-cell clusters, which can be classified into plasma cells and activated and exhausted B cells according to marker expression, functional and temporal distribution. Exhausted B cells exhibited low metabolic activities and impaired effector functions. Activated B and plasma cells showed higher metabolic activity than exhausted B cells, but there were clear differences in their metabolic profiles. In addition, we found that the effector function of exhausted B cells was further diminished in HCC tissues compared with adjacent liver tissues, but their metabolic activity was significantly enhanced. Collectively, we comprehensively characterized the metabolic profile and alterations in B-cell subsets in HCC, which contributes to the understanding of B-cell immunology in HCC and lays the foundation for exploring novel targets in HCC immunotherapy.

Sirtuin 6 is a negative regulator of the anti-tumor function of natural killer cells in murine inflammatory colorectal cancer

The immune system plays a crucial role in controlling colorectal cancer (CRC) development. Natural killer (NK) cells are tumoricidal but undergo exhaustion in CRC patients. The current research aims to understand the role of sirtuin 6 (SIRT6) in CRC-associated NK cell exhaustion in a murine inflammatory colorectal cancer model. To this end, inflammatory CRC was induced by treating mice with azoxymethane plus dextran sulfate sodium. The expression of SIRT6 in NK cells in murine mesenteric lymph nodes (mLNs) and the CRC tissue was characterized by Immunoblotting. SIRT6 knockdown was achieved by lentiviral transduction of murine splenic NK cells, followed by evaluation of NK cell proliferation and the expression of cytotoxic mediators using flow cytometry. NK cell cytotoxicity was measured by cytotoxicity assays. Adoptive transfer of murine NK cells was applied to analyze the effect of SIRT6 knockdown in vivo. We found that SIRT6 was up-regulated in infiltrating NK cells in the murine CRC tissue, especially NK cells with an exhausted phenotype and impaired cytotoxicity. SIRT6 knockdown significantly boosted murine splenic NK cell functionality, as evidenced by accelerated proliferation, increased production of cytotoxic mediators, and higher tumoricidal activity both in vitro and in vivo. Furthermore, the adoptive transfer of SIRT6-knockdown NK cells into CRC-bearing mice effectively suppressed CRC progression. Therefore, SIRT6 up-regulation is essential for murine NK cell exhaustion in CRC because it impedes the tumoricidal activity of murine NK cells. Artificial SIRT6 down-regulation could boost the function of infiltrating NK cells to oppress CRC progression in mice.

Inactivation of interleukin-30 in colon cancer stem cells via CRISPR/Cas9 genome editing inhibits their oncogenicity and improves host survival

BACKGROUND

Progression of colorectal cancer (CRC), a leading cause of cancer-related death worldwide, is driven by colorectal cancer stem cells (CR-CSCs), which are regulated by endogenous and microenvironmental signals. Interleukin (IL)-30 has proven to be crucial for CSC viability and tumor progression. Whether it is involved in CRC tumorigenesis and impacts clinical behavior is unknown.

METHODS

IL30 production and functions, in stem and non-stem CRC cells, were determined by western blot, immunoelectron microscopy, flow cytometry, cell viability and sphere formation assays. CRISPR/Cas9-mediated deletion of the IL30 gene, RNA-Seq and implantation of IL30 gene transfected or deleted CR-CSCs in NSG mice allowed to investigate IL30's role in CRC oncogenesis. Bioinformatics and immunopathology of CRC samples highlighted the clinical implications.

RESULTS

We demonstrated that both CR-CSCs and CRC cells express membrane-anchored IL30 that regulates their self-renewal, via WNT5A and RAB33A, and/or proliferation and migration, primarily by upregulating CXCR4 via STAT3, which are suppressed by IL30 gene deletion, along with WNT and RAS pathways. Deletion of IL30 gene downregulates the expression of proteases, such as MMP2 and MMP13, chemokine receptors, mostly CCR7, CCR3 and CXCR4, and growth and inflammatory mediators, including ANGPT2, CXCL10, EPO, IGF1 and EGF. These factors contribute to IL30-driven CR-CSC and CRC cell expansion, which is abrogated by their selective blockade. IL30 gene deleted CR-CSCs displayed reduced tumorigenicity and gave rise to slow-growing and low metastatic tumors in 80% of mice, which survived much longer than controls. Bioinformatics and CIBERSORTx of the 'Colorectal Adenocarcinoma TCGA Nature 2012' collection, and morphometric assessment of IL30 expression in clinical CRC samples revealed that the lack of IL30 in CRC and infiltrating leucocytes correlates with prolonged overall survival.

CONCLUSIONS

IL30 is a new CRC driver, since its inactivation, which disables oncogenic pathways and multiple autocrine loops, inhibits CR-CSC tumorigenicity and metastatic ability. The development of CRISPR/Cas9-mediated targeting of IL30 could improve the current therapeutic landscape of CRC.

Exosomal lncRNA HOTAIR induces PDL1+ B cells to impede anti-tumor immunity in colorectal cancer

Regulatory B cells (Bregs) contribute to tumor immunosuppression. However, how B cells acquire their regulatory features in tumors remain unclear. Exosomes are important messengers that transmit tumor information to remodel tumor immunity. Here we revealed that tumor-derived exosomes drive Bregs to suppress anti-tumor immunity by delivering long non-coding RNAs (lncRNAs). HOTAIR was screened by lncRNA profiling in both colorectal cancer (CRC)-derived exosomes and infiltrating B cells. Tumor-derived HOTAIR polarized B cells toward a regulatory feature marked by programmed cell death-ligand 1 (PDL1) in CRC, and induced PDL1⁺ B cells to suppress CD8⁺ T cell activity. Exosomal HOTAIR bound to and protected pyruvate kinase M2 (PKM2) against ubiquitination degradation, resulting in STAT3 activation and PDL1 expression. Results from CRC patients showed a positive correlation between exosomal HOTAIR and tumor-infiltrating PDL1⁺ B cells. These findings reveal how B cells acquire PDL1-dominant regulatory feature in CRC, implying the clinical significance of exosomal therapy targeting HOTAIR.

Harnessing Engineered Immune Cells and Bacteria as Drug Carriers for Cancer Immunotherapy

Immunotherapy continues to be in the spotlight of oncology therapy research in the past few years and has been proven to be a promising option to modulate one's innate and adaptive immune systems for cancer treatment. However, the poor delivery efficiency of immune agents, potential off-target toxicity, and nonimmunogenic tumors significantly limit its effectiveness and extensive application. Recently, emerging biomaterial-based drug carriers, including but not limited to immune cells and bacteria, are expected to be potential candidates to break the dilemma of immunotherapy, with their excellent natures of intrinsic tumor tropism and immunomodulatory activity. More than that, the tiny vesicles and physiological components derived from them have similar functions with their source cells due to the inheritance of various surface signal molecules and proteins. Herein, we presented representative examples about the latest advances of biomaterial-based delivery systems employed in cancer immunotherapy, including immune cells, bacteria, and their derivatives. Simultaneously, opportunities and challenges of immune cells and bacteria-based carriers are discussed to provide reference for their future application in cancer immunotherapy.

The prometastatic relevance of tumor-infiltrating B lymphocytes in laryngeal squamous cell carcinoma

Objectives

Laryngeal squamous cell carcinomas (LSCCs) typically have an excellent prognosis for stage I tumors but a significant risk of locoregional and distant recurrence for intermediate to advanced disease. This study will investigate the clinical relevance of the tumor microenvironment in a large cohort of treatment-naïve patients affected by stage II-IV LSCC.

Methods

Whole slide-based digital pathology analysis was applied to measure six immune cell populations identified by immunohistochemistry (IHC) staining for CD3, CD8, CD20, CD66b, CD163 and CD38. Survival analysis was performed by Cox proportional hazards models and unsupervised hierarchical clustering using the k-means method. Double IHC staining and in-situ hybridisation by RNAscope allowed further analysis of a protumoral B cell population.

Results

A cohort of 98 patients was enrolled and analysed. The cluster of immune-infiltrated LSCCs demonstrated a significantly worse disease-specific survival rate. We also discovered a new association between high CD20⁺ B cells and a greater risk of distant recurrence. The phenotypic analysis of infiltrating CD20⁺ B cells showed a naïve (BCL6^-CD27^-Mum1^-) regulatory phenotype, producing TGFβ but not IL10, according to an active TGFβ pathway, as proved by positive pSMAD2 staining.

Conclusion

The identification of regulatory B cells in the context of LSCC, along with the activation of the TGFβ pathway, could provide the basis for new trials investigating the efficacy of already available molecules targeting the TGFβ pathway in the treatment of LSCC.

Characteristics of circulating adaptive immune cells in patients with colorectal cancer

Adaptive immune cells prevent solid tumor progression by targeting and killing tumor cells. However, there are no comprehensive studies on peripheral circulating adaptive immune cell characterization in colorectal cancer (CRC) patients or the effect of tumor-node-metastasis (TNM) stages on these cells. In this study, the number, phenotype, and function of different subsets of circulating adaptive immune cells in peripheral blood of CRC patients were analyzed. We found remarkable differences in CRC patients compared with those in healthy controls, including reduced absolute counts of total T cells, helper T lymphocytes (Th), cytotoxic T lymphocytes (Tc), and double-negative T lymphocytes, a decreased proportion of INF-γ⁺ cells in total T cells and Th, and increased percentages of B cells, plasmablasts, and activated T cells. Compared with early-stage CRC patients, advanced-stage CRC patients showed more severe immunosenescence, which manifested as decreased proportions of CD8⁺ naive T cells with strong proliferative ability and CD8⁺ central memory T cells with immune surveillance function. Proportions and absolute counts of CD8⁺ and CD4⁺ terminally differentiated effector memory T cells were increased, indicating immunosenescence. The immune cell characteristics analyzed in this study serve as a starting point for further research to determine potential clinical implications.

Regulation of CD4 T Cell Responses by the Transcription Factor Eomesodermin

Central to the impacts of CD4 T cells, both positive in settings of infectious disease and cancer and negative in the settings of autoimmunity and allergy, is their ability to differentiate into distinct effector subsets with specialized functions. The programming required to support such responses is largely dictated by lineage-specifying transcription factors, often called ‘master regulators’. However, it is increasingly clear that many aspects of CD4 T cell immunobiology that can determine the outcomes of disease states involve a broader transcriptional network. Eomesodermin (Eomes) is emerging as an important member of this class of transcription factors. While best studied in CD8 T cells and NK cells, an increasing body of work has focused on impacts of Eomes expression in CD4 T cell responses in an array of different settings. Here, we focus on the varied impacts reported in these studies that, together, indicate the potential of targeting Eomes expression in CD4 T cells as a strategy to improve a variety of clinical outcomes.

Regulator of telomere elongation helicase 1 gene and its association with malignancy

BACKGROUND

With the progression of next-generation sequencing technologies, researchers have identified numerous variants of the regulator of telomere elongation helicase 1 (RTEL1) gene that are associated with a broad spectrum of phenotypic manifestations, including malignancies. At the molecular level, RTEL1 is involved in the regulation of the repair, replication, and transcription of deoxyribonucleic acid (DNA) and the maintenance of telomere length. RTEL1 can act both as a promotor and inhibitor of tumorigenesis. Here, we review the potential mechanisms implicated in the malignant transformation of tissues under conditions of RTEL1 deficiency or its aberrant overexpression.

RECENT FINDINGS

A major hemostatic challenge during RTEL1 dysfunction could arise from its unbalanced activity for unwinding guanine-rich quadruplex DNA (G4-DNA) structures. In contrast, RTEL1 deficiency leads to alterations in telomeric and genome-wide DNA maintenance mechanisms, ribonucleoprotein metabolism, and the creation of an inflammatory and immune-deficient microenvironment, all promoting malignancy. Additionally, we hypothesize that functionally similar molecules could act to compensate for the deteriorated functions of RTEL1, thereby facilitating the survival of malignant cells. On the contrary, RTEL1 over-expression was directed toward G4-unwinding, by promoting replication fork progression and maintaining intact telomeres, may facilitate malignant transformation and proliferation of various pre-malignant cellular compartments.

CONCLUSIONS

Therefore, restoring the equilibrium of RTEL1 functions could serve as a therapeutic approach for preventing and treating malignancies.

Deciphering colorectal cancer immune microenvironment transcriptional landscape on single cell resolution - A role for immunotherapy

Single cell RNA sequencing (scRNA-seq) is a novel high-throughput technique that enables the investigation of a single cell's entire transcriptome. It elucidates intricate cellular networks and generates indices that will eventually enable the development of more targeted and personalized medications. The importance of scRNA-seq has been highlighted in complex biological systems such as cancer and the immune system, which exhibit significant cellular heterogeneity. Colorectal cancer (CRC) is the third most common type of cancer and the second leading cause of cancer-related death globally. Chemotherapy continues to be used to treat these patients. However, 5-FU has been utilized in chemotherapy regimens with oxaliplatin and irinotecan since the 1960s and is still used today. Additionally, chemotherapy-resistant metastatic CRCs with poor prognoses have been treated with immunotherapy employing monoclonal antibodies, immune checkpoint inhibitors, adoptive cell therapy and cancer vaccines. Personalized immunotherapy employing tumor-specific neoantigens allows for treating each patient as a distinct group. Sequencing and multi-omics approaches have helped us identify patients more precisely in the last decade. The introduction of modern methods and neoantigen-based immunotherapy may usher in a new era in treating CRC. The unmet goal is to better understand the cellular and molecular mechanisms that contribute to CRC pathogenesis and resistance to treatment, identify novel therapeutic targets, and make more stratified and informed treatment decisions using single cell approaches. This review summarizes current scRNA-seq utilization in CRC research, examining its potential utility in the development of precision immunotherapy for CRC.

Study of PD-1 Customization and Autoimmune T Cells for Advanced Colorectal Cancer with High MSI Expression

Objective

To evaluate the significance of PD-1 customization and autoimmune T-cell therapy for advanced colorectal cancer with high MSI expression.

Methods

One hundred and eight patients with advanced colorectal cancer with high MSI expression admitted to our hospital between August 2019 and January 2022 were divided into control and study groups, and PD-1 customization and autoimmune T-cell therapy were administered to the two groups, respectively. Trends in immune indexes, PD-1 exposure, and survival rates were studied in both groups.

Results

The treatment efficiency of the study group was 90.74%, which was higher than that of the control group (61.11%) (P < 0. 05); after treatment, the presence of CDl07a, perforin, and GranB cells was significantly higher in both groups compared with that before treatment, but the expression of PD-1 was more pronounced in the study group (P < 0. 05); that is, the expression of PD-1 in peripheral T lymphocytes in the study group compared with that of the control group was higher in patients with grade III-IV, and peripheral T lymphocytes were also higher in patients with grade III-IV compared with patients with grade I-II (P < 0. 05).

Conclusion

PD-1 customization combined with autoimmune T-cell therapy is a novel therapeutic modality that can substantially improve.