Characterizing caspase-1 involvement during esophageal disease progression

Promises and Limitations of Current Models for Understanding Barrett's Esophagus and Esophageal Adenocarcinoma

BACKGROUND & AIMS

This review was developed to provide a thorough and effective update on models relevant to esophageal metaplasia, dysplasia, and carcinogenesis, focusing on the advantages and limitations of different models of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC).

METHODS

This expert review was written on the basis of a thorough review of the literature combined with expert interpretation of the state of the field. We emphasized advances over the years 2012-2023 and provided detailed information related to the characterization of established human esophageal cell lines.

RESULTS

New insights have been gained into the pathogenesis of BE and EAC using patient-derived samples and single-cell approaches. Relevant animal models include genetic as well as surgical mouse models and emphasize the development of lesions at the squamocolumnar junction in the mouse stomach. Rat models are generated using surgical approaches that directly connect the small intestine and esophagus. Large animal models have the advantage of including features in human esophagus such as esophageal submucosal glands. Alternatively, cell culture approaches remain important in the field and allow for personalized approaches, and scientific rigor can be ensured by authentication of cell lines.

CONCLUSIONS

Research in BE and EAC remains highly relevant given the morbidity and mortality associated with cancers of the tubular esophagus and gastroesophageal junction. Careful selection of models and inclusion of human samples whenever possible will ensure relevance to human health and disease.

Recent updates on pyroptosis in tumors of the digestive tract

Pyroptosis is an inflammasome-dependent form of programmed cell death that is mediated by caspases-1, -4, -5, and -11, and the gasdermin protein family. It is characterized by the rupture of cell membrane and the subsequent release of cell contents and interleukins, leading to inflammatory reaction and activation of the immune system. Recent studies have suggested that pyroptosis plays a role in the development of gastrointestinal tumors, impeding tumor generation and progression as well as providing a favorable microenvironment for tumor growth. In this review we outlined the current knowledge regarding the implications of pyroptosis in gastrointestinal cancers.

Expression of pyroptosis-related genes are correlated with immune microenvironment and predict prognosis in ESCA

OBJECTIVES

Pyroptosis-related genes (PRGs) are abnormally expressed in a variety of gastrointestinal tumors, this study aimed to investigate the role of pyroptosis genes in assessing the prognosis of esophageal cancer (ESCA).

METHODS

Through consensus clustering, we identified two subtypes associated with PRGs. After Lasso regression and multivariate Cox regression analysis, a polygenic signature based on six prognostic PRGS was constructed. Afterwards, we combined the risk score with clinical predictors to construct and validate a PRGs-associated ESCA prognostic model.

RESULTS

Through analysis, we Successfully constructed and validated a PRGs-associated ESCA prognostic model that predicts ESCA survival and correlates with the tumor immune microenvironment.

CONCLUSION

Based on PRGs features, we established a new ESCA hierarchical model. This model has important clinical implications for ESCA patients, both in terms of assessing prognosis and in terms of targeted and immunotherapy.

Regulation of dietary polyphenols on cancer cell pyroptosis and the tumor immune microenvironment

Cancer is a major public health problem that threatens human life worldwide. In recent years, immunotherapy has made great progress in both clinical and laboratory research. But the high heterogeneity and dynamics of tumors makes immunotherapy not suitable for all cancers. Dietary polyphenols have attracted researchers' attention due to their ability to induce cancer cell pyroptosis and to regulate the tumor immune microenvironment (TIME). This review expounds the regulation of dietary polyphenols and their new forms on cancer cell pyroptosis and the TIME. These dietary polyphenols include curcumin (CUR), resveratrol (RES), epigallocatechin gallate (EGCG), apigenin, triptolide (TPL), kaempferol, genistein and moscatilin. New forms of dietary polyphenols refer to their synthetic analogs and nano-delivery, liposomes. Studies in the past decade are included. The result shows that dietary polyphenols induce pyroptosis in breast cancer cells, liver cancer cells, oral squamous cells, carcinoma cells, and other cancer cells through different pathways. Moreover, dietary polyphenols exhibit great potential in the TIME regulation by modulating the programmed cell death protein 1(PD-1)/programmed death-ligand 1 (PD-L1) axis, enhancing antitumor immune cells, weakening the function and activity of immunosuppressive cells, and targeting tumor-associated macrophages (TAMs) to reduce their tumor infiltration and promote their polarization toward the M1 type. Dietary polyphenols are also used with radiotherapy and chemotherapy to improve antitumor immunity and shape a beneficial TIME. In conclusion, dietary polyphenols induce cancer cell pyroptosis and regulate the TIME, providing new ideas for safer cancer cures.

A Predictive Model Based on Pyroptosis-Related Gene Features Can Effectively Predict Clear Cell Renal Cell Carcinoma Prognosis and May Be an Underlying Target for Immunotherapy

Methods

The clinical information and RNA-seq data of ccRCC patients were collected from the TCGA dataset to first explore differential pyroptosis-related genes (PRGs). Univariate Cox regression and consensus clustering were applied to identify ccRCC subtypes. The prognostic PRGs were subjected to LASSO regression analysis to establish a prognostic model and to investigate its value and function. Finally, the relationship of the model immunity checkpoints and immunity infiltration was assessed.

Results

The receiver operating characteristic (ROC) showed that the 1-year, 3-year, and 5-year prediction rates of the prognostic model were 0.715, 0.693, and 0.732, respectively. The high-risk group had lower overall survival and higher stage than the low-risk group. Functional enrichment analysis showed that PRGs were significantly enriched mainly in the PPAR pathway, inflammatory pathway, and immune activity. ccRCC patient prognosis correlates with immune components in the microenvironment, and immune checkpoint molecules are significantly expressed in the high-risk group. Immunotherapy may be effective in the high-risk group.

Conclusion

Pyroptosis-related gene has an important impact on the progression of ccRCC and can be used as an independent predictor of patient prognosis. In addition, immune checkpoint molecules are significantly upregulated in high-risk populations, which may be a potential target for immunotherapy.

Cell pyroptosis in health and inflammatory diseases

Inflammation is a defense mechanism that can protect the host against microbe invasion. A proper inflammatory response can maintain homeostasis, but continuous inflammation can cause many chronic inflammatory diseases. To properly treat inflammatory disorders, the molecular mechanisms underlying the development of inflammation need to be fully elucidated. Pyroptosis is an inflammation-related cell death program, that is different from other types of cell death. Pyroptosis plays crucial roles in host defense against infections through the release of proinflammatory cytokines and cell lysis. Accumulating evidence indicates that pyroptosis is associated with inflammatory diseases, such as arthritis, pneumonia, and colonitis. Furthermore, pyroptosis is also closely involved in cancers that develop as a result of inflammation, such as liver cancer, esophageal cancer, pancreatic cancer, and colon cancer. Here, we review the function and mechanism of pyroptosis in inflammatory disease development and provide a comprehensive description of the potential role of pyroptosis in inflammatory diseases.

Pyroptosis, a new bridge to tumor immunity

Pyroptosis refers to the process of gasdermin (GSDM)‐mediated programmed cell death (PCD). Our understanding of pyroptosis has expanded beyond cells and is known to involve extracellular responses. Recently, there has been an increasing interest in pyroptosis due to its emerging role in activating the immune system. In the meantime, pyroptosis‐mediated therapies, which use the immune response to kill cancer cells, have also achieved notable success in a clinical setting. In this review, we discuss that the immune response induced by pyroptosis activation is a double‐edged sword that affects all stages of tumorigenesis. On the one hand, the activation of inflammasome‐mediated pyroptosis and the release of pyroptosis‐produced cytokines alter the immune microenvironment and promote the development of tumors by evading immune surveillance. On the other hand, pyroptosis‐produced cytokines can also collect immune cells and ignite the immune system to improve the efficiency of tumor immunotherapies. Pyroptosis is also related to some immune checkpoints, especially programmed death‐1 (PD‐1) or programmed death‐ ligand 1 (PD‐L1). In this review, we mainly focus on our current understanding of the interplay between the immune system and tumors that process through pyroptosis, and debate their use as potential therapeutic targets.

Identification of TLR2 Signalling Mechanisms Which Contribute to Barrett's and Oesophageal Adenocarcinoma Disease Progression

Simple Summary

Oesophageal adenocarcinoma (EAC) is a common type of oesophageal cancer with a rapidly rising incidence. Risk factors such as reflux, smoking, obesity and Barrett’s oesophagus cause chronic irritation and inflammation in the oesophagus. A receptor that causes inflammation, called Toll-like receptor 2 (TLR2), is expressed at higher levels in oesophageal cells from patients with Barrett’s and EAC, compared to disease-free patients. This study aimed to identify mechanisms involved in TLR2-mediated inflammation in oesophageal cells; and to assess whether TLR2 represents a therapeutic target to limit EAC development. Findings reveal that TLR2 activation in Barrett’s organoids and oesophageal cancer cells amplifies inflammation and promotes cancer development by causing the secretion of several inflammatory factors, most notably the nuclear protein, HMGB1. We demonstrate that TLR2 neutralisation efficiently blocks the inflammatory effects of TLR2 in these systems, revealing the therapeutic potential of TLR2 targeting to limit oesophageal disease and cancer progression.

Abstract

Chronic inflammation plays an important role in the pathogenesis of oesophageal adenocarcinoma (EAC) and its only known precursor, Barrett’s oesophagus (BE). Recent studies have shown that oesophageal TLR2 levels increase from normal epithelium towards EAC. TLR2 signalling is therefore likely to be important during EAC development and progression, which requires an inflammatory microenvironment. Here, we show that, in response to TLR2 stimulation, BE organoids and early-stage EAC cells secrete pro-inflammatory cytokines and chemokines which recruit macrophages to the tumour site. Factors secreted from TLR2-stimulated EAC cells are shown to subsequently activate TLR2 on naïve macrophages, priming them for inflammasome activation and inducing their differentiation to an M2/TAM-like phenotype. We identify the endogenous TLR2 ligand, HMGB1, as the factor secreted from EAC cells responsible for the observed TLR2-mediated effects on macrophages. Our results indicate that HMGB1 signalling between EAC cells and macrophages creates an inflammatory tumour microenvironment to facilitate EAC progression. In addition to identifying HMGB1 as a potential target for early-stage EAC treatment, our data suggest that blocking TLR2 signalling represents a mechanism to limit HMGB1 release, inflammatory cell infiltration and inflammation during EAC progression.

Systematic analysis of immune-related genes based on a combination of multiple databases to build a diagnostic and a prognostic risk model for hepatocellular carcinoma

The immune microenvironment plays a vital role in the progression of hepatocellular carcinoma (HCC). Thousands of immune-related genes (IRGs) have been identified, but their effects on HCC are not fully understood. In this study, we identified the differentially expressed IRGs and analyzed their functions in HCC in a systematic way. Furthermore, we constructed a diagnostic and a prognostic model using multiple statistical methods, and both models had good distinguishing performance, which we verified in several independent datasets. This diagnostic model was also adaptable to proteomic data. The combination of a prognostic risk model and classic clinical staging can effectively distinguish patients in high- and low-risk groups. Furthermore, we systematically explore the differences in the immune microenvironment between the high-risk group and the low-risk group to help clinical decision-making. In summary, we systematically analyzed immune-related genes in HCC, explored their functions, constructed a diagnostic and a prognostic model and investigated potential therapeutic schedules in high-risk patients. The model performance was verified in multiple databases. Our findings can provide directions for future research.