CD147 Expression Is Associated with Tumor Proliferation in Bladder Cancer via GSDMD

GSDMD is associated with survival in human breast cancer but does not impact anti-tumor immunity in a mouse breast cancer model

Inflammation plays a pivotal role in cancer development, with chronic inflammation promoting tumor progression and treatment resistance, whereas acute inflammatory responses contribute to protective anti-tumor immunity. Gasdermin D (GSDMD) mediates the release of pro-inflammatory cytokines such as IL-1β. While the release of IL-1β is directly linked to the progression of several types of cancers, the role of GSDMD in cancer is less clear. In this study, we show that GSDMD expression is upregulated in human breast, kidney, liver, and prostate cancer. Higher GSDMD expression correlated with increased survival in primary breast invasive carcinoma (BRCA), but not in liver hepatocellular carcinoma (LIHC). In BRCA, but not in LIHC, high GSDMD expression correlated with a myeloid cell signature associated with improved prognosis. To further investigate the role of GSDMD in anticancer immunity, we induced breast cancer and hepatoma tumors in GSDMD-deficient mice. Contrary to our expectations, GSDMD deficiency had no effect on tumor growth, immune cell infiltration, or cytokine expression in the tumor microenvironment, except for Cxcl10 upregulation in hepatoma tumors. In vitro and in vivo innate immune activation with TLR ligands, that prime inflammatory responses, revealed no significant difference between GSDMD-deficient and wild-type mice. These results suggest that the impact of GSDMD on anticancer immunity is dependent on the tumor type. They underscore the complex role of inflammatory pathways in cancer, emphasizing the need for further exploration into the multifaceted effects of GSDMD in various tumor microenvironments. As several pharmacological modulators of GSDMD are available, this may lead to novel strategies for combination therapy in cancer.

The roles of pyroptosis in genitourinary diseases

Pyroptosis, a form of programmed cell death distinct from apoptosis and necrosis, is thought to be closely associated with the pathogenesis of diseases. Recently, the association between pyroptosis and urinary diseases has attracted considerable attention, and a comprehensive review focusing on this issue is not available. In this study, we reviewed the role of pyroptosis in the development and progression of benign urinary diseases and urinary malignancies. Based on this, pyroptosis has been implicated in the development of urinary diseases. In summary, this review sheds light on future research directions and provides novel ideas for using pyroptosis as a powerful tool to fight urinary diseases.

EMMPRIN promotes spheroid organization and metastatic formation: comparison between monolayers and spheroids of CT26 colon carcinoma cells

Background

In vitro studies often use two-dimensional (2D) monolayers, but 3D cell organization, such as in spheroids, better mimics the complexity of solid tumors. To metastasize, cancer cells undergo the process of epithelial-to-mesenchymal transition (EMT) to become more invasive and pro-angiogenic, with expression of both epithelial and mesenchymal markers.

Aims

We asked whether EMMPRIN/CD147 contributes to the formation of the 3D spheroid structure, and whether spheroids, which are often used to study proliferation and drug resistance, could better model the EMT process and the metastatic properties of cells, and improve our understanding of the role of EMMPRIN in them.

Methods

We used the parental mouse CT26 colon carcinoma (CT26-WT) cells, and infected them with a lentivirus vector to knock down EMMPRIN expression (CT26-KD cells), or with an empty lentivirus vector (CT26-NC) that served as a negative control. In some cases, we repeated the experiments with the 4T1 or LLC cell lines. We compared the magnitude of change between CT26-KD and CT26-WT/NC cells in different metastatic properties in cells seeded as monolayers or as spheroids formed by the scaffold-free liquid overlay method.

Results

We show that reduced EMMPRIN expression changed the morphology of cells and their spatial organization in both 2D and 3D models. The 3D models more clearly demonstrated how reduced EMMPRIN expression inhibited proliferation and the angiogenic potential, while it enhanced drug resistance, invasiveness, and EMT status, and moreover it enhanced cell dormancy and prevented CT26-KD cells from forming metastatic-like lesions when seeded on basement membrane extract (BME). Most interestingly, this approach enabled us to identify that EMMPRIN and miR-146a-5p form a negative feedback loop, thus identifying a key mechanism for EMMPRIN activities. These results underline EMMPRIN role as a gatekeeper that prevents dormancy, and suggest that EMMPRIN links EMT characteristics to the process of spheroid formation.

Conclusions

Thus, 3D models can help identify mechanisms by which EMMPRIN facilitates tumor and metastasis progression, which might render EMMPRIN as a promising target for anti-metastatic tumor therapy.

Cluster of differentiation 147 (CD147) as potential membrane protein biomarker for bladder cancer cells

Studies reveal that alterations in membrane protein (MP) patterns are associated with underlying drug resistance to chemotherapy. Therefore, the tryptic-digested MPs from the bladder cancer cell line were subjected to global proteomics using LC-MS/MS to identify the highly expressed potential MPs in bladder cancer cells. Our findings revealed the identification of MP biomarkers, CD147, and caveolin-1. Immunocytochemistry analysis confirmed the presence of CD147 on the cell membrane, while caveolin-1 showed positive signals without apparent staining on the membrane, suggesting its existence in multiple locations. Western blot analysis confirmed the higher expression of CD147 in non-invasive (RT 112) and metastatic (UM-UC-13) bladder cancer cells compared to invasive bladder cancer cells (5637 and J82), suggesting its potential as an MP biomarker for both of the former subtypes. The identified MPs could be used as drug therapy targets aimed at improving drug sensitivity and enhancing treatment outcomes in bladder cancer patients. SIGNIFICANCE: Identification of the membrane proteins associated with bladder cancer recurrence is crucial to understanding the mechanisms underlying the drug resistance to chemotherapy.

Role of gasdermin family proteins in cancers (Review)

The gasdermin (GSDM) family comprises six proteins, including GSDMA‑GSDME and Pejvakin. Most of these proteins have a crucial role in inducing pyroptosis; in particular, GSDMD and GSDME are the most extensively studied proteins as the executioners of the pyroptosis process. Pyroptosis is a highly pro‑inflammatory form of programmed cell death and is closely associated with the incidence, development and prognosis of multiple cancer types. The present review focused on the current knowledge of the molecular mechanism of GSDM‑mediated pyroptosis, its intricate role in cancer and the potential therapeutic value of its anti‑tumor effects.

Pyroptosis: a new therapeutic strategy in cancer

Programmed cell death pathways play important roles in a wide variety of physiological processes. Although it has similarities with apoptosis pyroptosis is a different type of programmed cell death. Pyroptosis can be triggered by different molecules originating from the cells or their environment. Once a pyroptotic pathway is started, it is followed by different molecular steps, and, it ends with the disruption of cell membrane integrity and the onset of inflammatory processes. In addition to the role of pyroptosis in the host's innate immunity against pathogens, uncontrolled pyroptosis can lead to increased inflammation and lead various diseases. The contradictory role of pyroptosis-related molecular changes in the pathogenesis of cancer has attracted attention lately. Excessive or decreased expression of molecules involved in pyroptotic pathways is associated with various cancers. There are ongoing studies on the use of different treatment methods for cancer in combination with new therapies targeting pyroptosis. The potential beneficial effects or side-effect profiles of these protocols targeting pyroptosis still need to be investigated. This will provide us with more efficient and safer options to treat cancer. This review aims to overview the main pathways and mechanisms of pyroptosis and to discuss its role in cancer.

Gasdermin D-mediated pyroptosis: mechanisms, diseases, and inhibitors

Gasdermin D (GSDMD)-mediated pyroptosis and downstream inflammation are important self-protection mechanisms against stimuli and infections. Hosts can defend against intracellular bacterial infections by inducing cell pyroptosis, which triggers the clearance of pathogens. However, pyroptosis is a double-edged sword. Numerous studies have revealed the relationship between abnormal GSDMD activation and various inflammatory diseases, including sepsis, coronavirus disease 2019 (COVID-19), neurodegenerative diseases, nonalcoholic steatohepatitis (NASH), inflammatory bowel disease (IBD), and malignant tumors. GSDMD, a key pyroptosis-executing protein, is linked to inflammatory signal transduction, activation of various inflammasomes, and the release of downstream inflammatory cytokines. Thus, inhibiting GSDMD activation is considered an effective strategy for treating related inflammatory diseases. The study of the mechanism of GSDMD activation, the formation of GSDMD membrane pores, and the regulatory strategy of GSDMD-mediated pyroptosis is currently a hot topic. Moreover, studies of the structure of caspase-GSDMD complexes and more in-depth molecular mechanisms provide multiple strategies for the development of GSDMD inhibitors. This review will mainly discuss the structures of GSDMD and GSDMD pores, activation pathways, GSDMD-mediated diseases, and the development of GSDMD inhibitors.

Preliminary Study of the Cancer Stem Cells' Biomarker CD147 in Leukoplakia: Dysplasia and Squamous Cell Carcinoma of Oral Epithelial Origin

Objectives Cancer stem cells (CSCs) are responsible for initiating the process of carcinogenesis de novo, as well as through the transformation of oral potential malignant disorders (OPMDs) to oral squamous cell carcinoma (OSCC). The aim of our study was to detect the expression of stemness-type CSC marker CD147 in oral leukoplakias (OLs), the most common OPMD, and OSCCs as well. Materials and methods This study focuses on the semiquantitative immunohistochemical pattern of the expression of the CSC protein biomarker CD147 in paraffin-embedded samples of 20 OSCCs of different grades of differentiation and 30 cases of OLs without or with different grades of dysplasia, compared to the normal oral epithelium in terms of cells' stain positivity. Statistical analysis was performed through Statistical Package for Social Sciences (SPSS) version 25.0 (IBM SPSS Statistics, Armonk, NY) with Pearson chi-square test, and the significance level was set at 0.05 (p=0.05). In addition, the study clarified the expression of the respective gene of CD147 through quantitative polymerase chain (qPCR), in paraffin-embedded samples of the two extreme graduations: OLs of mildly dysplastic or non-dysplastic cases (n=10 cases) and OSCCs of moderately/poorly differentiated cases (n=17). Statistical analysis was then performed through SPSS version 25.0 with an independent paired t-test, and the significance level was set at 0.05 (p=0.05). Results The gene CD147 was expressed in all cases, although no statistically significant correlations were established. Regarding its protein products, the characteristic membranous staining of CD147 was noticed in the majority of the samples, mostly in the basal and parabasal layers of the epithelium. CD147 was upregulated significantly in the moderately and severely dysplastic OLs than in the mildly dysplastic and non-dysplastic OLs (p=0.008). Also, CD147 was upregulated significantly in the mildly dysplastic and non-dysplastic OLs than in the normal oral epithelium (p=0.012). Discussion The characteristic expression of CD147 in OLs and OSCCs' lesions suggests the presence of stemlike cancer cells, illustrating an underlying effect on the early stages of oral dysplasia, in the OL stage. The clinical application of CD147 as prognostic factor requires the experimental evaluation in larger number of samples. Conclusion Stem cells play an important role in the process of carcinogenesis. A major goal in cancer research is the identification of specific biomarkers for the detection of cancer stem cells. CD147 is considered as an innovative stem cell marker. Our findings in oral mucosal potentially malignant disorders showed that CD147 is expressed more intensely in parallel with the progression of the grade of dysplasia in OL. On the other hand, in oral squamous cell carcinoma, CD147 expression remains stable regardless of the degree of differentiation.

Expression of a Siglec-Fc Protein and Its Characterization

The emerging importance of the Siglec-sialic acid axis in human disease, especially cancer, has necessitated the identification of ligands for Siglecs. Recombinant Siglec-Fc fusion proteins have been widely used as ligand detectors, and also as sialic acid-targeted antibody-like proteins for cancer treatment. However, the heterogenetic properties of the Siglec-Fc fusion proteins prepared from various expression systems have not been fully elucidated. In this study, we selected HEK293 and CHO cells for producing Siglec9-Fc and further evaluated the properties of the products. The protein yield in CHO (8.23 mg/L) was slightly higher than that in HEK293 (7.46 mg/L). The Siglec9-Fc possesses five N-glycosylation sites and one of them is located in its Fc domain, which is important for the quality control of protein production and also the immunogenicity of Siglec-Fc. Our glycol-analysis confirmed that the recombinant protein from HEK293 received more fucosylation, while CHO showed more sialylation. Both products revealed a high dimerization ratio and sialic acid binding activity, which was confirmed by the staining of cancer cell lines and bladder cancer tissue. Finally, our Siglec9-Fc product was used to analyze the potential ligands on cancer cell lines.

Pyroptosis in urinary malignancies: a literature review

Urinary neoplasms refer to malignant tumours occurring in any part of the urinary system, including the kidney, renal pelvis, ureter, bladder, prostate, etc. The worldwide incidence of urinary system tumours has been increasing yearly. Available methods include surgical treatment, radiotherapy, chemotherapy, endocrine therapy, molecular targeted therapy, and immune therapy. In recent years, emerging evidence has demonstrated that cell pyroptosis plays an important role in the occurrence and progression of malignant urinary tumours. Pyroptosis is a new type of cell death that involves inflammatory processes regulated by gasdermins (GSDMs) and is characterized by membrane perforation, cell swelling and cell rupture. Recent studies have shown that pyroptosis can inhibit and promote the development of tumours. This manuscript reviews the role of pyroptosis in the development and progression of prostate cancer, kidney cancer and bladder cancer and introduces the latest research results in these fields to discuss the therapeutic potential of the pyroptosis pathway in urinary malignancies.

Research advances and challenges in tissue-derived extracellular vesicles

Extracellular vesicles (EV) are vesicular vesicles with phospholipid bilayer, which are present in biological fluids and extracellular microenvironment. Extracellular vesicles serve as pivotal mediators in intercellular communication by delivering lipids, proteins, and RNAs to the recipient cells. Different from extracellular vesicles derived from biofluids and that originate from cell culture, the tissue derived extracellular vesicles (Ti-EVs) send us more enriched and accurate information of tissue microenvironment. Notably, tissue derived extracellular vesicles directly participate in the crosstalk between numerous cell types within microenvironment. Current research mainly focused on the extracellular vesicles present in biological fluids and cell culture supernatant, yet the studies on tissue derived extracellular vesicles are increasing due to the tissue derived extracellular vesicles are promising agents to reflect the occurrence and development of human diseases more accurately. In this review, we aimed to clarify the characteristics of tissue derived extracellular vesicles, specify the isolation methods and the roles of tissue derived extracellular vesicles in various diseases, including tumors. Moreover, we summarized the advances and challenges of tissue derived extracellular vesicles research.

The emerging role of pyroptosis in pediatric cancers: from mechanism to therapy

Pediatric cancers are the driving cause of death for children and adolescents. Due to safety requirements and considerations, treatment strategies and drugs for pediatric cancers have been so far scarcely studied. It is well known that tumor cells tend to progressively evade cell death pathways, which is known as apoptosis resistance, one of the hallmarks of cancer, dominating tumor drug resistance. Recently, treatments targeting nonapoptotic cell death have drawn great attention. Pyroptosis, a newly specialized form of cell death, acts as a critical physiological regulator in inflammatory reaction, cell development, tissue homeostasis and stress response. The action in different forms of pyroptosis is of great significance in the therapy of pediatric cancers. Pyroptosis could be induced and consequently modulate tumorigenesis, progression, and metastasis if treated with local or systemic therapies. However, excessive or uncontrolled cell death might lead to tissue damage, acute inflammation, or even cytokine release syndrome, which facilitates tumor progression or recurrence. Herein, we aimed to describe the molecular mechanisms of pyroptosis, to highlight and discuss the challenges and opportunities for activating pyroptosis pathways through various oncologic therapies in multiple pediatric neoplasms, including osteosarcoma, neuroblastoma, leukemia, lymphoma, and brain tumors.

Gasdermin D: A potential mediator and prognostic marker of bladder cancer

Background: Bladder cancer is considered one of the commonest widespread cancers, its presentation ranges from non-muscle invasive form to being muscle-invasive. The gasdermin family of proteins consists of six proteins. Members of gasdermin family are involved in pyroptosis; which is considered as type of inflammatory apoptosis via participation of gasdermin D and inflammatory caspases.

Purpose: The goal of this research was to look into the potential involvement of gasdermin D in pathogenesis of bladder cancer, In addition, to investigate its potential role as a prognostic marker of bladder cancer.

Methods: Gasdermin D gene and protein expression was examined in fresh frozen 80 bladder cancer specimens (30 NMIBC, and 50 MIBC) and the matching 80 control tissue samples utilizing real-time polymerase chain reaction and western blotting. Furthermore, the immunoreactivity of gasdermin D protein was also detected by immunohistochemistry.

Results: Gasdermin D gene and protein expression showed a highly significant difference between the control and the two bladder cancer groups (p < 0.001), as demonstrated by real-time PCR, western blotting and immunohistochemistry. Cox proportional hazards regression models showed that lower gasdermin D gene expression in cancer patients (≤1.58-fold), and younger age (≤53 years) were linked with a higher risk of local tumor recurrence. Moreover, higher gasdermin D gene expression (>2.18-fold), and lymph nodes’ involvement were associated with an increased mortality.

Conclusion: Gasdermin D is involved in the pathogenesis of bladder cancer and muscle invasion, in addition, tissue gasdermin D expression may be used as useful tool to predict local tumor recurrence.

Cyclophilin A/CD147 Interaction: A Promising Target for Anticancer Therapy

Cyclophilin A (CypA), which has peptidyl-prolyl cis-trans isomerase (PPIase) activity, regulates multiple functions of cells by binding to its extracellular receptor CD147. The CypA/CD147 interaction plays a crucial role in the progression of several diseases, including inflammatory diseases, coronavirus infection, and cancer, by activating CD147-mediated intracellular downstream signaling pathways. Many studies have identified CypA and CD147 as potential therapeutic targets for cancer. Their overexpression promotes growth, metastasis, therapeutic resistance, and the stem-like properties of cancer cells and is related to the poor prognosis of patients with cancer. This review aims to understand the biology and interaction of CypA and CD147 and to review the roles of the CypA/CD147 interaction in cancer pathology and the therapeutic potential of targeting the CypA/CD147 axis. To validate the clinical significance of the CypA/CD147 interaction, we analyzed the expression levels of PPIA and BSG genes encoding CypA and CD147, respectively, in a wide range of tumor types using The Cancer Genome Atlas (TCGA) database. We observed a significant association between PPIA/BSG overexpression and poor prognosis, such as a low survival rate and high cancer stage, in several tumor types. Furthermore, the expression of PPIA and BSG was positively correlated in many cancers. Therefore, this review supports the hypothesis that targeting the CypA/CD147 interaction may improve treatment outcomes for patients with cancer.

CD147 Promotes Tumorigenesis via Exosome-Mediated Signaling in Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is an aggressive childhood soft-tissue tumor, with propensity for local invasion and distant metastasis. Exosomes are secreted vesicles that mediate paracrine signaling by delivering functional proteins and miRNA to recipient cells. The transmembrane protein CD147, also known as Basigin or EMMPRIN, is enriched in various tumor cells, as well as in tumor-derived exosomes, and has been correlated with poor prognosis in several types of cancer, but has not been previously investigated in RMS. We investigated the effects of CD147 on RMS cell biology and paracrine signaling, specifically its contribution to invasion and metastatic phenotype. CD147 downregulation diminishes RMS cell invasion and inhibits anchorage-independent growth in vitro. While treatment of normal fibroblasts with RMS-derived exosomes results in a significant increase in proliferation, migration, and invasion, these effects are reversed when using exosomes from CD147-downregulated RMS cells. In human RMS tissue, CD147 was expressed exclusively in metastatic tumors. Altogether, our results demonstrate that CD147 contributes to RMS tumor cell aggressiveness, and is involved in modulating the microenvironment through RMS-secreted exosomes. Targeted inhibition of CD147 reduces its expression levels within the isolated exosomes and reduces the capacity of these exosomes to enhance cellular invasive properties.

Mini-Review: Can the Metastatic Cascade Be Inhibited by Targeting CD147/EMMPRIN to Prevent Tumor Recurrence?

Solid tumors metastasize very early in their development, and once the metastatic cell is lodged in a remote organ, it can proliferate to generate a metastatic lesion or remain dormant for long periods. Dormant cells represent a real risk for future tumor recurrence, but because they are typically undetectable and insensitive to current modalities of treatment, it is difficult to treat them in time. We describe the metastatic cascade, which is the process that allows tumor cells to detach from the primary tumor, migrate in the tissue, intravasate and extravasate the lymphatics or a blood vessel, adhere to a remote tissue and eventually outgrow. We focus on the critical enabling role of the interactions between tumor cells and immune cells, especially macrophages, in driving the metastatic cascade, and on those stages that can potentially be targeted. In order to prevent the metastatic cascade and tumor recurrence, we would need to target a molecule that is involved in all of the steps of the process, and evidence is brought to suggest that CD147/EMMPRIN is such a protein and that targeting it blocks metastasis and prevents tumor recurrence.

Identification of a Pyroptosis-Related Gene Signature and Effect of Silencing the CHMP4C and CASP4 in Pancreatic Adenocarcinoma

Background

Pancreatic adenocarcinoma (PAAD) is a highly malignant tumor with an extremely poor prognosis. Pyroptosis has been demonstrated to play an important role in tumor prognosis. However, the expression of pyroptosis-related genes in PAAD and their correlations with prognosis remains unclear.

Methods

In this study, the 36 pyroptosis-related genes that were differentially expressed between normal pancreatic tissues and PAAD tissues were identified via the “limma” R package. Based on these differentially expressed genes (DEGs), a five-gene signature was established by applying the least absolute shrinkage and selection operator Cox regression in the TCGA cohort and was validated in the GEO cohort. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses of DEGs based on the risk model indicated that immune-associated biological processes and pathways were enriched. In vivo, we detected the expressions of CASP4 and CHMP4C by immunohistochemistry in tumor tissues and adjacent normal tissues. In vitro, we silenced CASP4 and CHMP4C to explore their effects on pancreatic cancer cells.

Results

PAAD patients in the low-risk group showed significantly higher survival possibilities than those in the high-risk group. The expressions of CASP4 and CHMP4C in tumor tissue were higher than those in the adjacent normal tissues in vivo. The knockdown of CASP4 significantly inhibited the invasion and migration but not the proliferation of PANC-1 cells. The knockdown of CHMP4C obviously inhibited the proliferation, migration, and invasion of PANC-1 cells.

Conclusion

Pyroptosis-related genes play important roles in predicting the prognosis of PAAD, and CASP4 and CHMP4C affect the metastasis of PAAD.

Biomarkers expression among paired serous ovarian cancer primary lesions and their peritoneal cavity metastases in treatment-naïve patients: A single-center study

Background

High‐grade serous ovarian carcinoma (HGSOC), the most common histologic subtype of ovarian epithelial cancer, is associated with treatment resistance, enhanced recurrence rates, and poor prognosis. HGSOCs often metastasize to the peritoneal cavity, while fluid cytology examination could identify such metastases. This retrospective study aimed to identify potential biomarker discrepancies between paired HGSOC primary tissues and metastatic peritoneal fluid cytology samples, processed as cell blocks (CBs).

Methods

Twenty‐four pairs of formalin‐fixed, paraffin‐embedded primary tissues and metastatic CBs from an equal number of treatment‐naïve patients were used, and immunohistochemistry (IHC) for epidermal growth factor receptor (EGFR), human epidermal growth factor receptor, programmed cell death‐1 ligand 1 (PD‐L1), and CD147 was applied.

Results

13/24 pairs showed discordant EGFR IHC results; in all these 13 patients, EGFR was positive (≥1+ membranous staining intensity found in at least 10% of the cancer cells) in the peritoneal, yet negative in the primary tissue samples. Notably, EGFR IHC was positive in 15/24 of the metastatic, whereas in just 2/24 of the primary HGSOC samples (p < 0.001). Although most PD‐L1 results were concordant, 5/24 and 6/24 pairs exhibited discordant results when stained with the E1L3N and 22C3 clones, respectively. Lastly, CD147 overexpression was found more often in the metastatic rather than the matched primary HGSOCs stained with CD147, though the difference was not significant.

Conclusions

Cytology from effusions could be considered for biomarker testing when present, even when tissue from the primary cancer is also available and adequately cellular, as it could provide additional information of potential clinical significance.

Regulated Cell Death in Urinary Malignancies

Urinary malignancies refer to a series of malignant tumors that occur in the urinary system and mainly include kidney, bladder, and prostate cancers. Although local or systemic radiotherapy and chemotherapy, immunotherapy, castration therapy and other methods have been applied to treat these diseases, their high recurrence and metastasis rate remain problems for patients. With in-depth research on the pathogenesis of urinary malignant tumors, this work suggests that regulatory cell death (RCD) plays an important role in their occurrence and development. These RCD pathways are stimulated by various internal and external environmental factors and can induce cell death or permit cell survival under the control of various signal molecules, thereby affecting tumor progression or therapeutic efficacy. Among the previously reported RCD methods, necroptosis, pyroptosis, ferroptosis, and neutrophil extracellular traps (NETs) have attracted research attention. These modes transmit death signals through signal molecules, such as cysteine-aspartic proteases (caspase) family and tumor necrosis factor-α (TNF-α) that have a wide and profound influence on tumor proliferation or death and even change the sensitivity of tumor cells to therapy. This review discussed the effects of necroptosis, pyroptosis, ferroptosis, and NETs on kidney, bladder and prostate cancer and summarized the latest research and achievements in these fields. Future directions and possibility of improving the denouement of urinary system tumors treatment by targeting RCD therapy were also explored.

Pan-cancer analysis reveals the expression, genetic alteration and prognosis of pyroptosis key gene GSDMD

BACKGROUND

Gasdermins (GSDMs)-mediated pyroptosis is widely involved in activating anti-tumor immunity and suppressing tumor growth. However, whether gasdermin D (GSDMD)-mediated pyroptosis affects patient prognosis in pan-cancer remains unknown.

METHODS

We performed analyses of the RNA expression, genetic alteration, prognosis and immune infiltration of GSDMD in pan-cancer. In order to explore the relationship between pyroptosis and tumors, we calculated the correlation between GSDMD and pyroptosis key genes in pan-cancer. We also investigated the enrichment pathway of GSDMD-related genes.

RESULTS

GSDMD was differentially expressed in the vast majority of cancer, and could be used as a prognostic marker in adrenocortical carcinoma (ACC), kidney renal clear cell carcinoma (KIRC), brain lower grade glioma (LGG), liver hepatocellular carcinoma (LIHC), skin cutaneous melanoma (SKCM) and rectum adenocarcinoma (READ). Strong evidence indicated the significant correlation of GSDMD with almost all immune checkpoints and immune cells. Pyroptosis-related genes strongly associated with GSDMD in ACC, KIRC, LGG, LIHC and SKCM, suggesting that GSDMD-mediated pyroptosis might play a critical role in the five cancers.

CONCLUSION

All the evidence supported the potential role of GSDMD-mediated pyroptosis in cancer. Our results provided new insights into GSDMD as a prognostic marker and potential therapeutic target for cancer.

Gasdermin D in pyroptosis

Pyroptosis is the process of inflammatory cell death. The primary function of pyroptosis is to induce strong inflammatory responses that defend the host against microbe infection. Excessive pyroptosis, however, leads to several inflammatory diseases, including sepsis and autoimmune disorders. Pyroptosis can be canonical or noncanonical. Upon microbe infection, the canonical pathway responds to pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs), while the noncanonical pathway responds to intracellular lipopolysaccharides (LPS) of Gram-negative bacteria. The last step of pyroptosis requires the cleavage of gasdermin D (GsdmD) at D275 (numbering after human GSDMD) into N- and C-termini by caspase 1 in the canonical pathway and caspase 4/5/11 (caspase 4/5 in humans, caspase 11 in mice) in the noncanonical pathway. Upon cleavage, the N-terminus of GsdmD (GsdmD-N) forms a transmembrane pore that releases cytokines such as IL-1β and IL-18 and disturbs the regulation of ions and water, eventually resulting in strong inflammation and cell death. Since GsdmD is the effector of pyroptosis, promising inhibitors of GsdmD have been developed for inflammatory diseases. This review will focus on the roles of GsdmD during pyroptosis and in diseases.

Inflammation-related pyroptosis, a novel programmed cell death pathway, and its crosstalk with immune therapy in cancer treatment

In recent decades, chemotherapies targeting apoptosis have emerged and demonstrated remarkable achievements. However, emerging evidence has shown that chemoresistance is mediated by impairing or bypassing apoptotic cell death. Several novel types of programmed cell death, such as ferroptosis, necroptosis, and pyroptosis, have recently been reported to play significant roles in the modulation of cancer progression and are considered a promising strategy for cancer treatment. Thus, the switch between apoptosis and pyroptosis is also discussed. Cancer immunotherapy has gained increasing attention due to breakthroughs in immune checkpoint inhibitors; moreover, ferroptosis, necroptosis, and pyroptosis are highly correlated with the modulation of immunity in the tumor microenvironment. Compared with necroptosis and ferroptosis, pyroptosis is the primary mechanism for host defense and is crucial for bridging innate and adaptive immunity. Furthermore, recent evidence has demonstrated that pyroptosis exerts benefits on cancer immunotherapies, including immune checkpoint inhibitors (ICIs) and chimeric antigen receptor T-cell therapy (CAR-T). Hence, in this review, we elucidate the role of pyroptosis in cancer progression and the modulation of immunity. We also summarize the potential small molecules and nanomaterials that target pyroptotic cell death mechanisms and their therapeutic effects on cancer.

lncRNA BSG-AS1 is hypoxia-responsive and promotes hepatocellular carcinoma by enhancing BSG mRNA stability

Emerging evidence indicates that aberrant changes of lncRNAs expression induced by hypoxia participate in the development of HCC. The present study aimed to identify novel hypoxia-responsive lncRNAs and reveal its role and mechanism in HCC. Hypoxia exposure in HCC tissues was comprehensively estimated based on public data using multiple hypoxia gene signatures. Huh7 cells were treated with hypoxia and RNA-seq was performed. Then we analyzed the changes of lncRNAs in HCC tissues and cells exposed to hypoxia. We found that lncRNA BSG-AS1 was highly expressed in tissues with high hypoxia score. Then we verified the response of lncRNA BSG-AS1 to hypoxia in the cell hypoxia model in vitro. Through functional phenotypic analysis, we found that lncRNA BSG-AS1 can mediate the promoting effect of hypoxia on the proliferation and migration in HCC cells. RNA-seq was used to find the downstream target genes of lncRNA BSG-AS1. Sequencing data and wet experiments showed that mRNA of BSG decreased after knockout of lncRNA BSG-AS1, and mediated the promotive effect of lncRNA BSG-AS1 on proliferation and migration in HCC cells. The mechanism is that lncRNA BSG-AS1 can enhance the stability of BSG mRNA as antisense lncRNA. Finally, the data based on the public cohort and the cohort we collected suggested that the overexpression of lncRNA BSG-AS1 and BSG are related to the poor prognosis. In conclusion, lncRNA BSG-AS1 is a novel hypoxia-responsive lncRNA. LncRNA BSG-AS1 can positively regulate BSG, by maintaining the mRNA stability of BSG, thus promoting the proliferation and migration of HCC. High expression of lncRNA BSG-AS1 and BSG are risk factors for prognosis.

Gasdermin D expression and clinicopathologic outcome in primary osteosarcoma patients

Gasdermin D (GSDMD), a recently discovered pyroptosis-related protein, has been extensively studied in inflammatory diseases. Research has indicated that inflammation is a causative factor of malignant tumors, including osteosarcoma. Nevertheless, the specific functions of GSDMD in osteosarcoma have not well been studied. This study aimed to explore the clinicopathologic values of GSDMD in osteosarcoma. The expression of GSDMD protein in 41 samples of primary osteosarcoma and 20 normal bone tissues were evaluated by immunohistochemistry and western blot. The χ² test and Student's t test were applied to analyze the differences of GSDMD expression between osteosarcoma and normal bone tissues. The χ² test and Fisher's exact test were used to assess the associations of GSDMD expression with clinicopathologic characteristics of osteosarcoma patients. Moreover, the Kaplan-Meier and Cox regression model methods were used to analyze the relations between GSDMD expression and disease-free survival (DFS) and overall survival (OS) of osteosarcoma patients. The GSDMD protein was significantly overexpressed in osteosarcoma compared to non-neoplastic bone samples. Additionally, GSDMD overexpression was related to poor chemotherapy response (P = 0.031), distant metastasis (P < 0.001), as well as worse prognosis of osteosarcoma patients. Furthermore, GSDMD protein overexpression was an independent predictor of poor survival time in primary osteosarcoma patients. In conclusion, GSDMD overexpression was related to adverse clinical outcome of osteosarcoma, and could be a therapy target in osteosarcoma. Further study should focus on the related mechanism of GSDMD in osteosarcoma.