Regulated Cell Death in Urinary Malignancies

NLRP3 inflammasome and pyroptosis in cardiovascular diseases and exercise intervention

NOD-like receptor protein 3 (NLRP3) inflammasome is an intracellular sensing protein complex that possesses NACHT, leucine-rich repeat, and pyrin domain, playing a crucial role in innate immunity. Activation of the NLRP3 inflammasome leads to the production of pro-inflammatory cellular contents, such as interleukin (IL)-1β and IL-18, and induction of inflammatory cell death known as pyroptosis, thereby amplifying or sustaining inflammation. While a balanced inflammatory response is beneficial for resolving damage and promoting tissue healing, excessive activation of the NLRP3 inflammasome and pyroptosis can have harmful effects. The involvement of the NLRP3 inflammasome has been observed in various cardiovascular diseases (CVD). Indeed, the NLRP3 inflammasome and its associated pyroptosis are closely linked to key cardiovascular risk factors including hyperlipidemia, diabetes, hypertension, obesity, and hyperhomocysteinemia. Exercise compared with medicine is a highly effective measure for both preventing and treating CVD. Interestingly, emerging evidence suggests that exercise improves CVD and inhibits the activity of NLRP3 inflammasome and pyroptosis. In this review, the activation mechanisms of the NLRP3 inflammasome and its pathogenic role in CVD are critically discussed. Importantly, the purpose is to emphasize the crucial role of exercise in managing CVD by suppressing NLRP3 inflammasome activity and proposes it as the foundation for developing novel treatment strategies.

Current and Potential Roles of Ferroptosis in Bladder Cancer

Ferroptosis, a type of regulated cell death driven by iron-dependent lipid peroxidation, is mainly initiated by extramitochondrial lipid peroxidation due to the accumulation of iron-dependent reactive oxygen species. Ferroptosis is a prevalent and primitive form of cell death. Numerous cellular metabolic processes regulate ferroptosis, including redox homeostasis, iron regulation, mitochondrial activity, amino acid metabolism, lipid metabolism, and various disease-related signaling pathways. Ferroptosis plays a pivotal role in cancer therapy, particularly in the eradication of aggressive malignancies resistant to conventional treatments. Multiple studies have explored the connection between ferroptosis and bladder cancer, focusing on its incidence and treatment outcomes. Several biomolecules and tumor-associated signaling pathways, such as p53, heat shock protein 1, nuclear receptor coactivator 4, RAS-RAF-MEK, phosphatidylinositol 3-kinase-AKT-mammalian target of rapamycin, and the Hippo-tafazzin signaling system, exert a moderating influence on ferroptosis in bladder cancer. Ferroptosis inducers, including erastin, artemisinin, conjugated polymer nanoparticles, and quinazolinyl-arylurea derivatives, hold promise for enhancing the effectiveness of conventional anticancer medications in bladder cancer treatment. Combining conventional therapeutic drugs and treatment methods related to ferroptosis offers a promising approach for the treatment of bladder cancer. In this review, we analyze the research on ferroptosis to augment the efficacy of bladder cancer treatment.

Nanocurcumin attenuates pyroptosis and inflammation through inhibiting NF-κB/GSDMD signal in high altitude-associated acute liver injury

Exposure to a hypobaric hypoxic environment at high altitudes can lead to liver injury, and mounting evidence indicates that pyroptosis and inflammation play important roles in liver injury. Curcumin (Cur) can inhibit pyroptosis and inflammation. Therefore, our purpose here was to clarify the mechanism underlying the protective effect of nanocurcumin (Ncur) and Cur in a rat model of high altitude-associated acute liver injury. Eighty healthy rats were selected and exposed to different altitudes (6000 or 7000 m) for 0, 24, 48, or 72 h. Fifty normal healthy rats were divided into normal control, high-altitude control, salidroside (40 mg/kg [Sal-40]), Cur (200 mg/kg [Cur-200]), and Ncur (25 mg/kg [Ncur-25]) groups and exposed to a high-altitude hypobaric hypoxic environment (48 h, 7000 m). Serum-liver enzyme activities (alanine transaminase, aspartate transaminase, and lactate dehydrogenase were detected and histopathology of liver injury was evaluated by hematoxylin and eosin staining, and inflammatory factors were detected in liver tissues by enzyme-linked immunosorbent assays. Pyroptosis-associated proteins (gasdermin D, gasdermin D N-terminal [GSDMD-N], pro-Caspase-1, and cleaved-Caspase-1 [cleaved-Casp1]) and inflammation-associated proteins (nuclear factor-κB [NF-κB], phospho-NF-κB [P-NF-κB], and high-mobility group protein B1 [HMGB1]) levels were analyzed by immunoblotting. Ncur and Cur inhibited increased serum-liver enzyme activities, alleviated liver injury in rats caused by high-altitude hypobaric hypoxic exposure, and downregulated inflammatory factors, including tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and IL-18, in rat liver tissues. The level of P-NF-κB, GSDMD-N, cleaved-Casp1, and HMGB1 in rat liver tissues increased significantly after high-altitude exposure. Ncur and Cur downregulated P-NF-κB, GSDMD-N, cleaved-Casp-1, and HMGB1. Ncur and Cur may inhibit inflammatory responses and pyroptosis in a rat model of high altitude-associated acute liver injury.

A review focusing on the role of pyroptosis in prostate cancer

As one of the types of programmed cell death, pyroptosis has become a focus of research in recent years. Numerous studies have shown that pyroptosis plays a regulatory role in tumor cell invasiveness, differentiation, proliferation, and metastasis. It has been demonstrated that pyroptosis is involved in the regulation of signaling pathways implicated in the pathogenesis of prostate cancer (PCa). Furthermore, the loss of expression of pyroptosis-related genes in PCa has been reported, and pyroptosis-related genes have demonstrated a considerable ability in predicting the prognosis of PCa. Therefore, the potential role of pyroptosis in regulating the development of PCa warrants further investigation and attention. In this review, we summarize the basics of the role of pyroptosis and also discuss research into the mechanisms of action associated with pyroptosis in PCa. It is hoped that by exploring the potential of the pyroptosis pathway in intervening in PCa, it will provide a viable direction for the diversification of PCa treatment.

An Fc Binding Peptide-Based Facile and Versatile Build Platform for Multispecific Antibodies

Multispecific antibodies (MsAbs) maintain the specificity of versatile antibodies while simultaneously addressing different epitopes for a cumulative, collaborative effect. They could be an alternative treatment to chimeric antigen receptor-T cell therapy by helping to redirect T cells to tumors in vivo. However, one major limitation of their development is their relatively complex production process, which involves performance of a massive screen with low yield, inconsistent quality, and nonnegligible impurities. Here, a poly(l-glutamic acid)-conjugated multiple Fc binding peptide-based synthesis nanoplatform was proposed, in which MsAbs were constructed by mixing the desired monoclonal antibodies (mAbs) with polymeric Fc binding peptides in aqueous solution without purification. To determine its efficacy, a dual immune checkpoint-based PD1/OX40 bispecific antibody and PDL1/CD3e/4-1BB trispecific antibody-based T cell engager were generated to trigger antitumor CD8⁺ T responses in mice, showing superior tumor suppression over free mixed mAbs. In this study, a facile, versatile build platform for MsAbs was established.

Genome-Wide Screening Identifies Gene AKR1C1 Critical for Resistance to Pirarubicin in Bladder Cancer

Non-muscle-invasive bladder cancer (NMIBC) is a common tumor of the urinary system. Given its high rates of recurrence, progression, and drug resistance, NMIBC seriously affects the quality of life and limits the survival time of patients. Pirarubicin (THP) is a bladder infusion chemotherapy drug recommended by the guidelines for NMIBC. Although the widespread use of THP reduces the recurrence rate of NMIBC, 10-50% of patients still suffer from tumor recurrence, which is closely related to tumor resistance to chemotherapy drugs. This study was performed to screen the critical genes causing THP resistance in bladder cancer cell lines by using the CRISPR/dCas9-SAM system. Thus, AKR1C1 was screened. Results showed that the high expression of AKR1C1 could enhance the drug resistance of bladder cancer to THP both in vivo and in vitro. This gene could reduce the levels of 4-hydroxynonenal and reactive oxygen species (ROS) and resist THP-induced apoptosis. However, AKR1C1 did not affect the proliferation, invasion, or migration of the bladder cancer cells. Aspirin, which is an AKR1C1 inhibitor, could help reduce the drug resistance caused by AKR1C1. After receiving THP treatment, the bladder cancer cell lines could upregulate the expression of the AKR1C1 gene through the ROS/KEAP1/NRF2 pathway, leading to resistance to THP treatment. Using tempol, which is an inhibitor of ROS, could prevent the upregulation of AKR1C1 expression.

Prognostic implications of necroptosis-related long noncoding RNA signatures in muscle-invasive bladder cancer

Background: Bladder cancer (BLCA) is the sixth most common cancer in men, with an increasing incidence of morbidity and mortality. Necroptosis is a type of programmed cell death and plays a critical role in the biological processes of bladder cancer (BLCA). However, current studies focusing on long noncoding RNA (lncRNA) and necroptosis in cancer are limited, and there is no research about necroptosis-related lncRNAs (NRLs) in BLCA. Methods: We obtained the RNA-seq data and corresponding clinical information of BLCA from The Cancer Genome Atlas (TCGA) database. The seven determined prognostic NLRs were analyzed by several methods and verified by RT-qPCR. Then, a risk signature was established based on the aforementioned prognostic NLRs. To identify it, we evaluated its prognostic value by Kaplan-Meier (K-M) survival curve and receiver operating characteristics (ROC) curve analysis. Moreover, the relationships between risk signature and clinical features, functional enrichment, immune landscape, and drug resistance were explored as well. Results: We constructed a signature based on seven defined NLRs (HMGA2-AS1, LINC02489, ETV7-AS1, EMSLR, AC005954.1, STAG3L5P-PVRIG2P-PILRB, and LINC02178). Patients in the low-risk cohort had longer survival times than those in the high-risk cohort, and the area under the ROC curve (AUC) value of risk signature was higher than other clinical variables. Functional analyses, the infiltrating level of immune cells and functions, ESTIMATE score, and immune checkpoint analysis all indicated that the high-risk group was in a relatively immune-activated state. In terms of treatments, patients in the high-risk group were more sensitive to immunotherapy, especially anti-PD1/PD-L1 immunotherapy and conventional chemotherapy. Conclusion: The novel NLR signature acts as an invaluable tool for predicting prognosis, immune microenvironment, and drug resistance in muscle-invasive bladder cancer (MIBC) patients.

Scabertopin Derived from Elephantopus scaber L. Mediates Necroptosis by Inducing Reactive Oxygen Species Production in Bladder Cancer In Vitro

Bladder cancer remains one of the most common malignant tumors that threatens human health worldwide. It imposes a heavy burden on patients and society due to the high medical costs associated with its easy metastasis and recurrence. Although several treatment options for bladder cancer are available, their clinical efficacy remains unsatisfactory. Therefore, actively exploring new drugs and their mechanisms of action for the clinical treatment of bladder cancer is very important. Scabertopin is one of the major sesquiterpene lactones found in Elephantopus scaber L. Sesquiterpene lactones are thought to have fairly strong anti-cancer efficacy. However, the anticancer effect of sesquiterpenoid scabertopin on bladder cancer and its mechanism are still unclear. The aim of this study is to evaluate the antitumor activity of scabertopin in bladder cancer and its potential molecular mechanism in vitro. Our results suggest that scabertopin can induce RIP1/RIP3-dependent necroptosis in bladder cancer cells by promoting the production of mitochondrial reactive oxygen species (ROS), inhibit the expression of MMP-9 by inhibiting the FAK/PI3K/Akt signaling pathway, and ultimately inhibit the migration and invasion ability of bladder cancer cells. At the same time, we also demonstrated that the half-inhibition concentration (IC50) of scabertopin on various bladder cancer cell lines (J82, T24, RT4 and 5637) is much lower than that on human ureteral epithelial immortalized cells (SV-HUC-1). The above observations indicate that scabertopin is a potential therapeutic agent for bladder cancer that acts by inducing necroptosis and inhibiting metastasis.

Integrated bioinformatic analysis identified a novel prognostic pan-programmed cell death signature for bladder cancer

Programmed cell death (PCD) refers to a molecularly regulated form of cell death that functions as an essential anticancer defense mechanism and serves as a target of anticancer therapies. Multiple types of PCD comprehensively regulate tumorigenesis and tumor progression and metastasis. However, a systemic exploration of the multiple types of PCD in cancers, especially bladder cancer, is lacking. In this study, we evaluated the expression pattern of genes associated with multiple types of PCD in bladder cancer using the "ssGSEA" method and conceptualized the multiple types of PCD as being collectively involved in "Pan-PCD". Based on the differentially expressed genes related to Pan-PCD, we developed a Pan-PCD-related prognostic signature (PPRPS) to predict patient prognosis via univariate and multivariate Cox regression analysis. The PPRPS is an independent prognostic factor, and the AUC (Area Under Curve) for 3-year overall survival was 0.748. Combined with age and stage, PPRPS displayed excellent predictive ability. Based on the PPRPS, higher levels of immune cell infiltration, tumor microenvironment, and immune checkpoint molecules were observed in the high-PPRPS group. Furthermore, PPRPS enabled accurate risk prediction for metastatic urothelial carcinoma after anti-PD-L1 monoclonal antibody treatment. Patients in the high-PPRPS group had poor prognoses. Docetaxel, staurosporine, and luminespib were identified as potentially effective drugs for high-PPRPS bladder cancer patients. In summary, we developed the Pan-PCD signature to improve the accuracy of bladder cancer prognostic predictions and to provide a novel classification method to guide treatment selection.

Necroptosis and Prostate Cancer: Molecular Mechanisms and Therapeutic Potential

Necroptosis is a programmed form of necrosis characterized by mitochondrial alterations and plasma membrane permeabilization resulting in the release of cytoplasmic content into extracellular space, and leading to inflammatory reactions. Besides its critical role in viral defense mechanisms and inflammatory diseases, necroptosis plays pivotal functions in the drug response of tumors, including prostate cancer. Necroptosis is mainly governed by kinase enzymes, including RIP1, RIP3, and MLKL, and conversely to apoptosis, is a caspase-independent mechanism of cell death. Numerous compounds induce necroptosis in prostate cancer models, including (i) compounds of natural origin, (ii) synthetic and semisynthetic small molecules, and (iii) selenium and selenium-based nanoparticles. Here, we overview the molecular mechanisms underlying necroptosis and discuss the possible implications of drugs inducing necroptosis for prostate cancer therapy.