Pyroptosis correlates with tumor immunity and prognosis

Tertiary amine modification enables triterpene nanoparticles to target the mitochondria and treat glioblastoma via pyroptosis induction

Glioblastoma (GBM), the most common primary brain tumor, lacks effective treatments. Emerging evidence suggests mitochondria as a promising therapeutic target, albeit successfully targeting represents a major challenge. Recently, we discovered a group of triterpenes that can self-assemble into nanoparticles (NPs) for cancer treatment. However, unmodified triterpene NPs lack affinity for mitochondria. In this study, using oleanolic acid (OA) as an example, we demonstrated that tertiary amine modification enabled triterpene NPs to selectively target the mitochondria through interaction with translocase of outer mitochondrial membrane 70 (TOM70) leading to effective killing of GBM cells via pyroptosis. We showed that the NPs could be engineered for preferentially penetrating brain tumors through surface conjugation of iRGD, and treatment with the resulting NPs significantly prolonged the survival of tumor-bearing mice. We found that the efficacy could be further improved by encapsulating lonidamine, a mitochondrial hexokinase inhibitor. Furthermore, the observed mitochondria targeting effect through tertiary amine modification could be extended to other triterpenes, including lupeol and glycyrrhetinic acid. Collectively, this study reveals a novel strategy for targeting the mitochondria through tertiary amine modification of triterpenes, offering a promising avenue for the effective treatment of GBM.

Targeting pyroptosis for cancer immunotherapy: mechanistic insights and clinical perspectives

Pyroptosis is a distinct form of programmed cell death characterized by the rupture of the cell membrane and robust inflammatory responses. Increasing evidence suggests that pyroptosis significantly affects the tumor microenvironment and antitumor immunity by releasing damage-associated molecular patterns (DAMPs) and pro-inflammatory mediators, thereby establishing it as a pivotal target in cancer immunotherapy. This review thoroughly explores the molecular mechanisms underlying pyroptosis, with a particular focus on inflammasome activation and the gasdermin family of proteins (GSDMs). It examines the role of pyroptotic cell death in reshaping the tumor immune microenvironment (TIME) involving both tumor and immune cells, and discusses recent advancements in targeting pyroptotic pathways through therapeutic strategies such as small molecule modulators, engineered nanocarriers, and combinatory treatments with immune checkpoint inhibitors. We also review recent advances and future directions in targeting pyroptosis to enhance tumor immunotherapy with immune checkpoint inhibitors, adoptive cell therapy, and tumor vaccines. This study suggested that targeting pyroptosis offers a promising avenue to amplify antitumor immune responses and surmount resistance to existing immunotherapies, potentially leading to more efficacious cancer treatments.

Metabolic Inhibition Induces Pyroptosis in Uveal Melanoma

Few treatment options are available for patients with metastatic uveal melanoma. Although the bispecific tebentafusp is FDA approved, immunotherapy has largely failed, likely given the poorly immunogenic nature of uveal melanoma. Treatment options that improve the recognition of uveal melanoma by the immune system may be key to reducing disease burden. We investigated whether uveal melanoma has the ability to undergo pyroptosis, a form of immunogenic cell death. Publicly available patient data and cell line analysis showed that uveal melanoma expressed the machinery needed for pyroptosis, including gasdermins D and E (GSDMD and E), caspases 1, 3, 4, and 8, and ninjurin-1. We induced cleavage of GSDMs in uveal melanoma cell lines treated with metabolic inhibitors. In particular, the carnitine palmitoyltransferase 1 (CPT1) inhibitor, etomoxir, induced propidium iodide uptake, caspase 3 cleavage, and the release of HMGB1 and IL-1β, indicating that the observed cleavage of GSDMs led to pyroptosis. Importantly, a gene signature reflecting CPT1A activity correlated with poor prognosis in patients with uveal melanoma and knockdown of CPT1A also induced pyroptosis. Etomoxir-induced pyroptosis was dependent on GSDME but not on GSDMD, and a pyroptosis gene signature correlated with immune infiltration and improved response to immune checkpoint blockade in a set of patients with uveal melanoma. Together, these data show that metabolic inhibitors can induce pyroptosis in uveal melanoma cell lines, potentially offering an approach to enhance inflammation-mediated immune targeting in patients with metastatic uveal melanoma. Implications: Induction of pyroptosis by metabolic inhibition may alter the tumor immune microenvironment and improve the efficacy of immunotherapy in uveal melanoma.

Nanoparticle-mediated efficient up-regulation of GSDMD-N to induce pyroptosis and enhance NK cell-based cancer immunotherapy

Natural killer (NK) cell-based immunotherapy has emerged as a safe and effective therapeutic modality for cancer treatment. However, therapeutic benefits can be only seen in hematological tumors (e.g., leukemia) and the treatment of solid tumors is still less effective due to the immunosuppressive tumor microenvironment (TME)-induced poor infiltration and dysfunction of NK cells in tumor tissues. We herein developed a robust nucleus-targeted nanoparticle (NP) platform for systemic delivery of plasmid expressing the N-terminal domain of GSDMD (i.e., pGSDMD-N) and augment of NK cell-based immunotherapy for oral squamous cell carcinoma (OSCC). This nanoplatform is made of a PEGylated poly(2-(diisopropylamino) ethyl methacrylate) (PDPA) polymer and a nucleus-targeting peptide amphiphile (NTPA) that can complex pGSDMD-N. After intravenous administration, this nanoplatform could specifically deliver pGSDMD-N into the nuclei of OSCC cells, leading to their pyroptosis via up-regulating GSDMD-N expression. More importantly, this pyroptosis could boost NK cell-based immunotherapy via promoting the recruitment of NK cells into tumor tissues and enhancing their activation to further enhance the anticancer effect of the pGSDMD-N delivery system. STATEMENT OF SIGNIFICANCE: : NK cell-based immunotherapy has made a significant breakthrough in the treatment of hematological tumors (e.g., leukemia), but it is still less effective for solid tumors due to immunosuppressive tumor microenvironment (TME)-induced dysfunction of NK cells. We herein developed a nucleus-targeted nanoplatform for systemic delivery of plasmid expressing the N-terminal domain of gasdermin D (denoted pGSDMD-N) and augment of NK cell-based immunotherapy for oral squamous cell carcinoma (OSCC). This delivery system could not only induce the pyroptosis of OSCC cells, but also promote the secretion of functional chemokines (e.g., CCL3) and cytokines (e.g., IL-18) to boost NK cell-based immunotherapy. The strategy demonstrated herein could be a promising strategy to enhance the NK cell-based immunotherapy for solid tumors.

Network-based analysis of heterogeneous patient-matched brain and extracranial melanoma metastasis pairs reveals three homogeneous subgroups

Melanoma, the deadliest form of skin cancer, can metastasize to different organs. Molecular differences between brain and extracranial melanoma metastases are poorly understood. Here, promoter methylation and gene expression of 11 heterogeneous patient-matched pairs of brain and extracranial metastases were analyzed using melanoma-specific gene regulatory networks learned from public transcriptome and methylome data followed by network-based impact propagation of patient-specific alterations. This innovative data analysis strategy allowed to predict potential impacts of patient-specific driver candidate genes on other genes and pathways. The patient-matched metastasis pairs clustered into three robust subgroups with specific downstream targets with known roles in cancer, including melanoma (SG1: RBM38, BCL11B, SG2: GATA3, FES, SG3: SLAMF6, PYCARD). Patient subgroups and ranking of target gene candidates were confirmed in a validation cohort. Summarizing, computational network-based impact analyses of heterogeneous metastasis pairs predicted individual regulatory differences in melanoma brain metastases, cumulating into three consistent subgroups with specific downstream target genes.

Local anesthetic tetracaine hydrochloride induces pyroptosis via caspase-3/gasdermin E in uveal melanoma

BACKGROUND

Evasion of pyroptosis is an effective survival strategy employed by cancer cells to evade immune cell attacks and drug-induced cytotoxicity. Exploring potent molecules capable of inducing pyroptosis in cancer cells has significant clinical implications for the control of cancer progression. Unexpectedly, we found that the local anesthetic tetracaine hydrochloride (TTC) induced pyroptosis, specifically in uveal melanoma but not in acral or cutaneous melanoma.

METHODS

We investigated the effects of TTC on various melanoma cell lines and performed transcriptome sequencing of TTC-treated uveal melanoma cells. The role of gasdermin E (GSDME), an executive protein responsible for pyroptosis, was explored using CRISPR-Cas13d knockdown, caspase-3 inhibitor treatment, and western blot analysis. Differential gene expression and pathway enrichment analyses were performed. Furthermore, we used tissue microarrays to assess GSDME expression levels in melanoma tissues from different anatomical sites.

RESULTS

TTC significantly induced pyroptosis specifically in uveal melanoma cells with high GSDME expression levels. TTC treatment could lead to GSDME cleavage by the caspase-3 in uveal melanoma C918 cells. GSDME knockdown or caspase-3 inhibition suppressed TTC-induced pyroptosis. Transcriptome analysis revealed differentially expressed genes enriched in signaling pathways related to pyroptosis, immunity, and cytokines.

CONCLUSIONS

This study showed that the local anesthetic TTC effectively induces pyroptosis in uveal melanoma through the caspase-3/GSDME pathway, highlighting its potential application in immunotherapy. Notably, the use of TTC has potential as an agent for inducing pyroptosis and as an adjuvant anticancer therapy in uveal melanoma.

In-depth study of pyroptosis-related genes and immune infiltration in colon cancer

Background

Pyroptosis is a form of regulated necrosis that occurs in many cell and tissue types and plays a critical role in tumor progression. The diagnostic value of pyroptosis-related genes (PRGs) in colon cancer has been widely investigated. In the present study, we explored the relationship between PRG expression and colon cancer.

Methods

We retrieved genomic and clinical data pertaining to The Cancer Genome Atlas-Colon Adenocarcinoma from the UCSC Xena database, along with the corresponding genome annotation information from the GENCODE data portal. Utilising these data and a list of 33 pyrogenic genes, we performed principal component analysis and unsupervised clustering analysis to assess the pyroptosis subtypes. We analysed the differential expression between these subtypes to obtain PRGs, ultimately selecting 10 PRGs. We conducted Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, gene set variation analysis, protein-protein interaction, and immune infiltration analyses of these PRGs. We validated the expression of TNNC1 via immunohistochemistry (IHC) and real-time quantitative PCR.

Results

After rigorous screening, excluding patients with incomplete survival data and unmatched transcriptomes, we refined our study cohort to 431 patients. We performed differential mRNA analysis and identified 445 PRGs, 10 of which were selected as hub genes. These genes were associated with various immune cell types. Specifically, TNNC1 expression was positively associated with immature dendritic cells and NK CD56+ cells. IHC staining indicated higher TNNC1 expression levels in tumor samples. Notably, TNNC1 expression levels were high in all the colon cancer cell lines, particularly in SW480 cells.

Conclusion

In this study, we explored the characteristics of PRGs in colon cancer and identified novel biological targets for early individualised treatment and accurate diagnosis of colon cancer, thus contributing to the advancement of clinical oncology.

The Role of Caspases in Melanoma Pathogenesis

Melanoma (malignant melanoma, MM) is an aggressive malignant skin cancer with an increasing incidence rate. The complete pathogenesis of MM in not clear. Due to DNA damage, mutations, dysregulation of growth factors, inactivation of tumor suppressor genes, and activation of oncogenes, excessive uncontrolled growth of abnormal melanocytes occurs in melanomas. Caspases are a group of proteolytic enzymes that participate in several processes important in regulating mechanisms at the cellular level. They play a role in cell homeostasis and programmed cell death (apoptosis) and in the regulation of non-apoptotic cell death processes. Dysregulation of caspase activation plays a role in the etiology of cancers, including melanoma. Caspases can initiate and execute apoptosis and are involved in regulating cell death and controlling tumor growth. These enzymes also inhibit tumor growth by cleaving and inactivating proteins that are involved in cell proliferation and angiogenesis. Moreover, caspases are involved in the activation of immune processes through the processing and presentation of tumor antigens, which facilitates recognition of the tumor by the immune system. The role of caspases in melanoma is complex, and they may inhibit melanoma growth and progression. This work aims to review the current knowledge of the role of individual caspases in melanoma pathogenesis.

Unlocking the potential of pyroptosis in tumor immunotherapy: a new horizon in cancer treatment

Background

The interaction between pyroptosis-a form of programmed cell death-and tumor immunity represents a burgeoning field of interest. Pyroptosis exhibits a dual role in cancer: it can both promote tumor development and counteract it by activating immune responses that inhibit tumor evasion and encourage cell death. Current tumor immunotherapy strategies, notably CAR-T cell therapy and immune checkpoint inhibitors (ICIs), alongside the potential of certain traditional Chinese medicinal compounds, highlight the intricate relationship between pyroptosis and cancer immunity. As research delves deeper into pyroptosis mechanisms within tumor therapy, its application in enhancing tumor immune responses emerges as a novel research avenue.

Purpose

This review aims to elucidate the mechanisms underlying pyroptosis, its impact on tumor biology, and the advancements in tumor immunotherapy research.

Methods

A comprehensive literature review was conducted across PubMed, Embase, CNKI, and Wanfang Database from the inception of the study until August 22, 2023. The search employed keywords such as "pyroptosis", "cancer", "tumor", "mechanism", "immunity", "gasdermin", "ICB", "CAR-T", "PD-1", "PD-L1", "herbal medicine", "botanical medicine", "Chinese medicine", "traditional Chinese medicine", "immunotherapy", linked by AND/OR, to capture the latest findings in pyroptosis and tumor immunotherapy.

Results

Pyroptosis is governed by a complex mechanism, with the Gasdermin family playing a pivotal role. While promising for tumor immunotherapy application, research into pyroptosis's effect on tumor immunity is still evolving. Notably, certain traditional Chinese medicine ingredients have been identified as potential pyroptosis inducers, meriting further exploration.

Conclusion

This review consolidates current knowledge on pyroptosis's role in tumor immunotherapy. It reveals pyroptosis as a beneficial factor in the immunotherapeutic landscape, suggesting that leveraging pyroptosis for developing novel cancer treatment strategies, including those involving traditional Chinese medicine, represents a forward-looking approach in oncology.

Prognostic and chemotherapeutic implications of a novel four-gene pyroptosis model in head and neck squamous cell carcinoma

Background

Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers. Chemotherapy remains one dominant therapeutic strategy, while a substantial proportion of patients may develop chemotherapeutic resistance; therefore, it is particularly significant to identify the patients who could achieve maximum benefits from chemotherapy. Presently, four pyroptosis genes are reported to correlate with the chemotherapeutic response or prognosis of HNSCC, while no study has assessed the combinatorial predicting efficacy of these four genes. Hence, this study aims to evaluate the predictive value of a multi-gene pyroptosis model regarding the prognosis and chemotherapeutic responsiveness in HNSCC.

Methods

By utilizing RNA-sequencing data from The Cancer Genome Atlas database and the Gene Expression Omnibus database, the pyroptosis-related gene score (PRGscore) was computed for each HNSCC sample by performing a Gene Set Variation Analysis (GSVA) based on four genes (Caspase-1, Caspase-3, Gasdermin D, Gasdermin E). The prognostic significance of the PRGscore was assessed through Cox regression and Kaplan-Meier survival analyses. Additionally, chemotherapy sensitivity stratified by high and low PRGscore was examined to determine the potential association between pyroptosis activity and chemosensitivity. Furthermore, chemotherapy sensitivity assays were conducted in HNSCC cell lines in vitro.

Results

As a result, our study successfully formulated a PRGscore reflective of pyroptotic activity in HNSCC. Higher PRGscore correlates with worse prognosis. However, patients with higher PRGscore were remarkably more responsive to chemotherapy. In agreement, chemotherapy sensitivity tests on HNSCC cell lines indicated a positive association between overall pyroptosis levels and chemosensitivity to cisplatin and 5-fluorouracil; in addition, patients with higher PRGscore may benefit from the immunotherapy. Overall, our study suggests that HNSCC patients with higher PRGscore, though may have a less favorable prognosis, chemotherapy and immunotherapy may exhibit better benefits in this population.

Development and validation of a pyroptosis-related prognostic signature associated with osteosarcoma metastasis and immune infiltration

Pyroptosis is a programmed cell death, which has garnered increasing attention because it relates to the immune and therapy response. However, few studies focus on the application of pyroptosis-related genes (PRGs) in predicting osteosarcoma (OS) patients' prognoses. In this study, the gene expression and clinical information of OS patients were downloaded from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. Based on these PRGs and unsupervised clustering analysis, all OS samples can be classified into 2 clusters. The 8 key differential expressions for PRGs (LAG3, ITGAM, CCL2, TLR4, IL2RA, PTPRC, FCGR2B, and CD5) were established through the univariate Cox regression and utilized to calculate the risk score of all samples. According to the 8-gene signature, OS samples can be divided into high and low-risk groups and correlation analysis can be performed using immune cell infiltration and immune checkpoints. Finally, we developed a nomogram to improve the PRG-predictive model in clinical application. We verified the predictive performance using receiver operating characteristic (ROC) and calibration curves. There were significant differences in survival, immune cell infiltration and immune checkpoints between the low and high-risk groups. A nomogram was developed with clinical indicators and the risk scores were effective in predicting the prognosis of patients with OS. In this study, a prognostic model was constructed based on 8 PRGs were proved to be independent prognostic factors of OS and associated with tumor immune microenvironment. These 8 prognostic genes were involved in OS development and may serve as new targets for developing therapeutic drugs.

Pyroptosis-Related Gene Signature Predicts Prognosis and Response to Immunotherapy and Medication in Pediatric and Young Adult Osteosarcoma Patients

Purpose

Pyroptosis, a new form of inflammatory programmed cell death, has recently gained attention. However, the impact of the expression levels of pyroptosis-related genes (PRGs) on the overall survival (OS) of osteosarcoma patients remains unclear. This study aims to investigate the impact of the expression levels of PRGs on the OS of pediatric and young adult patients with osteosarcoma.

Patients and Methods

Transcriptome matrix datasets of normal muscle or skeletal tissues from the Genotype-Tissue Expression (GTEx) project and osteosarcoma specimen the National Cancer Institute's (NCI) Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database were used to identify pyroptosis-related genes (PRGs) associated with prognosis. The National Center for Biotechnology Information's (NCBI) GSE21257 dataset was employed to validate the predictive value of the pyroptosis-related signature (PRS). Additionally, reverse transcription polymerase chain reaction (RT-qPCR) experiment was performed in normal and osteosarcoma cell lines.

Results

The study identified 18 differentially expressed PRGs (DEPRGs) between normal muscle or skeletal tissues and tumor samples. Multiple machine learning techniques were used to select PRGs, resulting in the identification of four hub PRGs. A PRS-score was calculated for each sample based on the expression of these four hub PRGs, and samples were categorized into low and high PRS-score level groups. It was confirmed that metastatic status and PRS-score level are independent prognostic predictors. A nomogram model for predicting OS of osteosarcoma patients was constructed. Single-cell RNA-sequencing data display the expression patterns of the hub PRGs. RT-qPCR data results were found to be consistent with the differential expression analysis performed on TARGET and GTEx samples.

Conclusion

The study developed a novel pyroptosis-related gene signature that can stratify pediatric and young adult osteosarcoma patients into different risk groups, thus predicting their response to immunotherapy and chemotherapy.

Multiomics characterization of pyroptosis in the tumor microenvironment and therapeutic relevance in metastatic melanoma

BACKGROUND

Pyroptosis, mediated by gasdermins with the release of multiple inflammatory cytokines, has emerged as playing an important role in targeted therapy and immunotherapy due to its effectiveness at inhibiting tumor growth. Melanoma is one of the most commonly used models for immunotherapy development, though an inadequate immune response can occur. Moreover, the development of pyroptosis-related therapy and combinations with other therapeutic strategies is limited due to insufficient understanding of the role of pyroptosis in the context of different tumor immune microenvironments (TMEs).

METHODS

Here, we present a computational model (pyroptosis-related gene score, PScore) to assess the pyroptosis status. We applied PScore to 1388 melanoma samples in our in-house cohort and eight other publicly available independent cohorts and then calculated its prognostic power of and potential as a predictive marker of immunotherapy efficacy. Furthermore, we performed association analysis for PScore and the characteristics of the TME by using bulk, single-cell, and spatial transcriptomics and assessed the association of PScore with mutation status, which contributes to targeted therapy.

RESULTS

Pyroptosis-related genes (PRGs) showed distinct expression patterns and prognostic predictive ability in melanoma. Most PRGs were associated with better survival in metastatic melanoma. Our PScore model based on genes associated with prognosis exhibits robust performance in survival prediction in multiple metastatic melanoma cohorts. We also found PScore to be associated with BRAF mutation and correlate positively with multiple molecular signatures, such as KRAS signaling and the IFN gamma response pathway. Based on our data, melanoma with an immune-enriched TME had a higher PScore than melanoma with an immune-depleted or fibrotic TME. Additionally, monocytes had the highest PScore and malignant cells and fibroblasts the lowest PScore based on single-cell and spatial transcriptome analyses. Finally, a higher PScore was associated with better therapeutic efficacy of immune checkpoint blockade, suggesting the potential of pyroptosis to serve as a marker of immunotherapy response.

CONCLUSIONS

Collectively, our findings indicate that pyroptosis is a prognostic factor and is associated with the immune response in metastatic melanoma, as based on multiomics data. Our results provide a theoretical basis for drug combination and reveal potential immunotherapy response markers.

Quercetin inhibits caspase-1-dependent macrophage pyroptosis in experimental folic acid nephropathy

BACKGROUND

The role of pyroptosis in kidney disease is limited and incomplete. Quercetin, a flavonoid compound present in a variety of fruits, vegetables, and plants, has shown antioxidant and anti-inflammatory properties. This study was designed to validate the importance of pyroptosis in an experimental model of folic acid nephropathy and to explore the effect of quercetin in protecting against pyroptosis.

METHODS

Gene set enrichment analysis (GSEA) and weighted gene co-expression network analysis (WGCNA) were used to establish the correlation between pyroptosis and folic acid nephropathy. Immune cell infiltration, network pharmacology and single-cell RNA sequencing analysis were utilized to ascertain the specific target of quercetin in relation to pyroptosis. Finally, quercetin's role was verified in vivo and in vitro.

RESULTS

The GSEA analysis revealed a significant correlation between pyroptosis and folic acid nephropathy (NES = 1.764, P = 0.004). The hub genes identified through WGCNA were closely associated with inflammation. Molecular docking demonstrated a strong binding affinity between quercetin and caspase-1, a protein known to be involved in macrophage function, as confirmed by immune cell infiltration and single-cell analysis. Quercetin demonstrated a significant amelioration of kidney injury and reduction in macrophage infiltration in the animal model. Furthermore, quercetin exhibited a significant inhibition of caspase-1 expression, subsequently leading to the inhibition of pro-inflammatory cytokines expression, such as IL-1β, IL-18, TNF-α, and IL-6. The inhibitory effect of quercetin on macrophage pyroptosis was also confirmed in RAW264.7 cells.

CONCLUSION

This study contributes substantial evidence to support the significant role of pyroptosis in the development of folic acid nephropathy, and highlights the ability of quercetin to downregulate caspase-1 in macrophages as a protective mechanism against pyroptosis.

Application of pyroptosis in tumor research (Review)

As a potent clinical strategy, cancer therapy has sparked an academic boom over the past few years. Immune checkpoint inhibitors (ICIs) have been demonstrated to be highly successful. These achievements have progressed cancer treatment and have made an indelible mark on cancer. However, the inherent complexity of cancer means that only part of the population can benefit from this treatment. Pyroptosis is a new suicidal cellular mechanism that induces inflammation by releasing immunogenic cellular components. Inflammatory signaling cascades mediated by pyroptosis commonly inspire numerous cell lysis in immune diseases. Contrariwise, this consequence may be a promising target in cancer research. Therefore, the present study briefly described programmed cell death processes and their potential roles in cancer. Because of the rapid development of bioengineering in cancer, the present study also examined the associated scaffolding available for cancer, highlighting advances in tumor engineering approaches. Ultimately, an improved understanding of pyroptosis and tumor scaffolding might shed light on a combination that can be manipulated for therapeutic purposes.

Harnessing the Potential of Non-Apoptotic Cell Death Processes in the Treatment of Drug-Resistant Melanoma

Melanoma is a highly malignant skin cancer that is known for its resistance to treatments. In recent years, there has been significant progress in the study of non-apoptotic cell death, such as pyroptosis, ferroptosis, necroptosis, and cuproptosis. This review provides an overview of the mechanisms and signaling pathways involved in non-apoptotic cell death in melanoma. This article explores the interplay between various forms of cell death, including pyroptosis, necroptosis, ferroptosis, and cuproptosis, as well as apoptosis and autophagy. Importantly, we discuss how these non-apoptotic cell deaths could be targeted as a promising therapeutic strategy for the treatment of drug-resistant melanoma. This review provides a comprehensive overview of non-apoptotic processes and gathers recent experimental evidence that will guide future research and eventually the creation of treatment strategies to combat drug resistance in melanoma.

An ICD-Associated DAMP Gene signature predicts survival and immunotherapy response of patients with lung adenocarcinoma

BACKGROUND

While some lung adenocarcinoma (LUAD) patients benefit long-term from treatment with immune checkpoint inhibitors, the sad reality is that a considerable proportion of patients do not. The classification of the LUAD tumor microenvironment (TME) can be used to conceptually comprehend primary resistance mechanisms. In addition, the most recent research demonstrates that the release of damage-associated molecular pattern (DAMP) in TME by immunogenic cell death (ICD) may contribute to the adaptive immune response. Currently, however, there is no such comprehensive research on this topic in LUAD patients. Therefore, we set out to investigate how to reverse the poor infiltration characteristics of immune cells and boost antitumor immunity by identifying DAMP model.

METHODS

In this study, ICD-related DAMP genes were selected to investigate their effects on the prognosis of LUAD. To create a risk signature using the TCGA-LUAD cohort, the univariate COX regression and the least absolute shrinkage and selection operator regression were carried out, and the results were verified in a GEO dataset. Subsequently, the multivariate COX regression was applied to establish a prognostic nomogram. And the ESTIMATE and ssGSEA algorithms were utilized to analyze immune activity and the TIDE algorithm was for responsiveness to immunotherapy. Moreover, clinical tissue samples were used to verify the differential expression of 9 DAMP genes in the signature.

RESULTS

We identified two distinct DAMP molecular subtypes, and there are remarkable differences in survival probability between the two subtypes, and patients with higher levels of DAMP-related genes are "hot tumors" with increased immune activity. In addition, 9 DAMP genes were selected as prognostic signature genes, and clinical outcomes and immunotherapy response were better for participants in the low-risk group. Importantly, according to the area under the curve (AUC) value in evaluating the efficacy of immunotherapy, this signature is superior to existing predictors, such as PD-L1 and TIDE.

CONCLUSIONS

Our study suggests ICD plays an important part in modeling the TME of LUAD patients. And this signature could be utilized as a reliable predictor to estimate clinical outcomes and predict immunotherapy efficacy among LUAD patients.

Comprehensive landscape of the IPAF inflammasomes in pan-cancer: A bulk omics research and single-cell sequencing validation

BACKGROUND

IPAF (ICE-protease Activating Factor) is a nucleotide-binding/leucine-rich repeat (NLR) protein known as the cysteine-associated recruitment domain 12 (CARD12). Previous studies only discuss the role of IPAF inflammasomes in specific tumors. The role of IPAF inflammasomes in pan-cancer is still unclear. Therefore, we performed a comprehensive analysis of IPAF inflammasome in 33 tumors.

METHODS

We used databases like The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) from the UCSC XENA (http://xena.ucsc.edu/) to retrieve and analyze gene expression. The influence of IPAF inflammasome on the prognosis of tumor patients was analyzed using univariate Cox regression analysis and Kaplan-Meier survival analysis. Furthermore, we conducted the following analysis: Single-sample gene set enrichment analysis, single-cell level functional state analysis, single-cell sequencing, immune cell infiltration analysis, and tumor immune dysfunction and exclusion (TIDE) score.

RESULTS

First, the differential expression of IPAF inflammasome-related genes (IPAF-RGs) in 33 tumors were analyzed. The results revealed that IPAF-RGs were significantly and differentially expressed in eight tumors. The prognostic significance of IPAF inflammasome scores was different in different tumors. A positive correlation was observed between IPAF inflammasomes scores and CD8+ T cells in most tumors. Further analysis revealed that IPAF inflammasome might affect tumor immunity mainly by mediating effector T cell recruitment via the expression of chemokines such as CXCL9, CXCL10, and CCL5. The analysis of TIDE and IPAF inflammasome scores revealed a significant negative correlation between IPAF inflammasome and TIDE scores in 11 tumors.

CONCLUSION

A pan-cancer analysis of IPAF inflammasome in various tumors was performed. The results highlight the potential value of IPAF inflammasome in response to immunotherapy in patients and provide a new direction for future immunotherapy.

The Therapeutic Potential of Pyroptosis in Melanoma

Pyroptosis is a programmed cell death characterized by the rupture of the plasma membranes and release of cellular content leading to inflammatory reaction. Four cellular mechanisms inducing pyroptosis have been reported thus far, including the (i) caspase 1-mediated canonical, (ii) caspase 4/5/11-mediated non-canonical, (iii) caspase 3/8-mediated and (iv) caspase-independent pathways. Although discovered as a defense mechanism protecting cells from infections of intracellular pathogens, pyroptosis plays roles in tumor initiation, progression and metastasis of tumors, as well as in treatment response to antitumor drugs and, consequently, patient outcome. Pyroptosis induction following antitumor therapies has been reported in several tumor types, including lung, colorectal and gastric cancer, hepatocellular carcinoma and melanoma. This review provides an overview of the cellular pathways of pyroptosis and discusses the therapeutic potential of pyroptosis induction in cancer, particularly in melanoma.