The prognostic value of NLRP1/NLRP3 and its relationship with immune infiltration in human gastric cancer

Unraveling the NLRP family: Structure, function, activation, critical influence on tumor progression, and potential as targets for cancer therapy

The innate immune system serves as the body's initial defense, swiftly detecting danger via pattern recognition receptors (PRRs). Among these, nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing proteins (NLRPs) are pivotal in recognizing pathogen-associated and damage-associated molecular patterns, thereby triggering immune responses. NLRPs, the most extensively studied subset within the NLR family, form inflammasomes that regulate inflammation, essential for innate immunity activation. Recent research highlights NLRPs' significant impact on various human diseases, including cancer. With differential expression across organs, NLRPs influence cancer progression by modulating immune reactions, cell fate, and proliferation. Their clinical significance in cancer makes them promising therapeutic targets. This review provides a comprehensive overview of the structure, function, activation mechanism of the NLRPs family and its potential role in cancer progression. In addition, we particularly focused on the concept of NLRP as a therapeutic target and its potential value in combination with immune checkpoint inhibitors.

PLUNC inhibits invasion and metastasis in nasopharyngeal carcinoma by inhibiting NLRP3 inflammasome activation

Nasopharyngeal carcinoma (NPC) is a malignant tumor that occurs in the nasopharynx. Palate, lung, and nasal epithelium clone (PLUNC) has been identified as an early secreted protein that is specifically expressed in the nasopharynx. The aim of this study was to determine the role and mechanism of PLUNC in NPC. We used mRNA sequencing (seq) combined with ribosome-nascent chain complex (RNC)-seq to determine the biological role of PLUNC. The expression of epithelial-to-mesenchymal transition (EMT)-related molecules was detected by western blotting. Then, cell migration and invasion were detected by wound healing and Transwell chamber assays. NPC cells were injected into the tail vein of nude mice to explore the biological role of PLUNC in vivo. The sequencing results showed that PLUNC inhibited the progression of NPC and its expression was correlated with that of NOD-like receptors. Experiments confirmed that PLUNC inhibited the invasion and metastasis of NPC cells by promoting the ubiquitination degradation of NLRP3. PLUNC overexpression in combination with the treatment by MCC950, an inhibitor of NLRP3 inflammasome activation, was most effective in inhibiting NPC invasion and metastasis. In vivo experiments also confirmed that the combination of PLUNC overexpression and MCC950 treatment effectively inhibited the lung metastasis of NPC cells. In summary, our research suggested that PLUNC inhibited the invasion and metastasis of NPC by inhibiting NLRP3 inflammasome activation, and targeting the PLUNC-NLRP3 inflammasome axis could provide a new strategy for the diagnosis and treatment of NPC patients.

Clinical signature and associated immune metabolism of NLRP1 in pan-cancer

Inflammations have been linked to tumours, suggesting a potential association between NLRP1 and cancer. Nevertheless, a systematic assessment of NLRP1's role across various cancer types currently absent. A comprehensive bioinformatic analysis was conducted to determine whether NLRP1 exhibits prognostic relevance linked to immune metabolism across various cancers. The study leveraged data from the TCGA and GTEx databases to explore the clinical significance, metabolic features, and immunological characteristics of NLRP1, employing various tools such as R, GEPIA, STRING and TISIDB. NLRP1 exhibited differential expression patterns across various cancers, with elevated expression correlating with a more favourable prognosis in lung adenocarcinoma (LUAD) and pancreatic adenocarcinoma (PAAD). Downregulation of NLRP1 reduced tumour metabolic activity in LUAD. Moreover, the mutational signature of NLRP1 was linked to a favourable prognosis. Interestingly, high NLRP1 expression inversely correlated with tumour stemness while positively correlating with tumour immune infiltration in various cancers including LUAD and PAAD. Through extensive big data analysis, we delved into the role of NLRP1 across various tumour types, constructing a comprehensive role map of its involvement in pan-cancer scenarios. Our findings highlight the potential of NLRP1 as a promising therapeutic target specifically in LUAD and PAAD.

Mechanisms and effects of NLRP3 in digestive cancers

Inflammasomes are thought to be important mediators of host defense against microbial pathogens and maintenance of gastrointestinal tract homeostasis. They can modulate caspase-1 to promote IL-18 and IL-1β secretion and promote phagocytosis induced by bacterial pathogens. NLRP3 is an inflammasome comprising a multiprotein complex assembled by pattern recognition receptors in the cell cytoplasm. It is a crucial component of the innate immune system. Dysregulation of NLRP3 may contribute to inflammatory diseases and intestinal cancers. Recent research suggests that NLRP3 plays an essential role in tumor development; therefore, intensive study of its mechanism is warranted as it could play a key role in the treatment of digestive system tumors. In this review, we discuss the mechanism and role of NLRP3 in tumors of the digestive system and response strategies to modulate NLRP3 for potential use in tumor treatment.

Screening of novel tumor-associated antigens for lung adenocarcinoma mRNA vaccine development based on pyroptosis phenotype genes

This study aimed to identify new pyroptosis-associated tumor antigens for use in mRNA vaccines and the screening of sensitive LUAD populations suitable for vaccination. The association between tumor immune infiltrating cell abundance and potential tumor antigens was investigated and visualized using the analysis modules of gene expression, clinical outcomes, and somatic copy number variation. In addition, the pyroptosis-related genes (PRGs) were clustered, the relative pyroptosis subtypes (PSs) and gene modules were identified, and the prognostic value of the PSs was examined. The expression of key PRGs in two lung adenocarcinoma cell lines was verified by RT-qPCR. Four tumor pyroptosis-associated antigens, CARD8, NAIP, NLRP1, and NLRP3, were screened as potential candidates for LUAD mRNA vaccine development. In the construction of consensus clusters for PRGs, two PSs, PS1 and PS2, were classified, in which patients with PS1 LUAD had a better prognosis. In contrast, patients with PS2 LUAD may have better responsiveness to mRNA vaccine treatment. The key PRGs can be regarded as biomarkers to predict the LUAD prognosis and identify patients suitable for mRNA vaccines. The RT-qPCR results showed that the expression levels of CSMD3, LRP1B, MUC16 and TTN were significantly increased in the two lung adenocarcinoma cell lines, while the expression levels of CARD8, TP53 and ZFHX4 were significantly reduced. The antigens CARD8, NAIP, NLRP1, and NLRP3, which are associated with tumor pyroptosis, could be candidate molecules for LUAD mRNA vaccine development. Patients with PS2 LUAD may be suitable candidates for mRNA vaccine treatment.

Application of pyroptosis score in the treatment and prognosis evaluation of gastric cancer

Pyroptosis is a kind of proinflammatory programmed cell death mediated by inflammasome. It affects the occurrence and development of gastric cancer through different ways, showing dual effects. On the one hand, inflammasome-mediated inflammatory response is highly likely to participate in the formation and development of early tumors; on the other hand, drugs can inhibit the deterioration process of tumor proliferation, invasion and metastasis through activating the pathways of inflammasome and pyroptosis. Recently, many agents based on pyroptosis have been found to inhibit gastric cancer by promoting the secondary pyroptosis pathway, regulating NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and inhibiting caspase-1. The establishment of cell pyrodeath models can predict the prognosis of gastric cancer patients. Most of the models show that gastric cancer patients with high pyroptosis level have better prognosis and longer overall survival. Pyroptosis scores can also be used to predict the response of gastric cancer patients to immunotherapy and to screen potential anti-gastric cancer drugs. Therefore, in-depth understanding of the potential mechanism of pyroptosis affecting the progression of gastric cancer and the role of pyroptosis score in the treatment and prognosis assessment of gastric cancer will be helpful to find a new and effective method for the treatment of gastric cancer.