Prognostic role of DFNA5 in head and neck squamous cell carcinoma revealed by systematic expression analysis

Comprehensive analysis, diagnosis, prognosis, and cordycepin (CD) regulations for GSDME expressions in pan-cancers

The Gasdermin E gene (GSDME) plays roles in deafness and cancers. However, the roles and mechanisms in cancers are complex, and the same gene exhibits different mechanisms and actions in different types of cancers. Online databases, such as GEPIA2, cBioPortal, and DNMIVD, were used to comprehensively analyze GSDME profiles, DNA methylations, mutations, diagnosis, and prognosis in patients with tumor tissues and matched healthy tissues. Western blotting and RT-PCR were used to monitor the regulation of GSDME by Cordycepin (CD) in cancer cell lines. We revealed that GSDME expression is significantly upregulated in eight cancers (ACC, DLBC, GBM, HNSC, LGG, PAAD, SKCM, and THYM) and significantly downregulated in seven cancers (COAD, KICH, LAML, OV, READ, UCES, and UCS). The overall survival was longer only in ACC, but shorter in four cancers, including COAD, KIRC, LIHC, and STAD, when GSDME was highly expressed in cancers compared with the corresponding normal tissues. Moreover, the high expression of GSDME was negatively correlated with the poor prognosis of ACC, while the low expression of GSDME was negatively correlated with the poor prognosis of COAD, suggesting that GSDME might serve as a good prognostic factor in these two cancer types. Accordingly, results indicated that the DNA methylations of those 7 CpG sites constitute a potentially effective signature to distinguish different tumors from adjacent healthy tissues. Gene mutations for GSDME were frequently observed in a variety of tumors, with UCES having the highest frequency. Moreover, CD treatment inhibited GSDME expression in different cancer cell lines, while overexpression of GSDME promoted cell migration and invasion. Thus, we have systematically and successfully clarified the GSDME expression profiles, diagnostic values, and prognostic values in pan-cancers. Targeting GSDME with CD implies therapeutic significance and a mechanism for antitumor roles in some types of cancers via increasing the sensitivity of chemotherapy. Altogether, our study may provide a strategy and biomarker for clinical diagnosis, prognostics, and treatment of cancers by targeting GSDME.

Insight into the structure, function and the tumor suppression effect of gasdermin E

Gasdermin E (GSDME), which is also known as DFNA5, was first identified as a deafness-related gene that is expressed in cochlear hair cells, and mutation of this gene causes autosomal dominant neurogenic hearing loss. Later studies revealed that GSDME is mostly expressed in the kidney, placenta, muscle and brain cells, but it is expressed at low levels in tumor cells. The GSDME gene encodes the GSDME protein, which is a member of the gasdermin (GSDM) family and has been shown to participate in the induction of apoptosis and pyroptosis. The current literature suggests that Caspase-3 and Granzyme B (Gzm B) can cleave GSDME to generate the active N-terminal fragment (GSDME-NT), which integrates with the cell membrane and forms pores in this membrane to induce pyroptosis. Furthermore, GSDME also forms pores in mitochondrial membranes to release apoptosis factors, such as cytochrome c (Cyt c) and high-temperature requirement protein A2 (HtrA2/Omi), and subsequently activates the intrinsic apoptosis pathway. In recent years, GSDME has been shown to exert tumor-suppressive effects, suggesting that it has potential therapeutic effects on tumors. In this review, we introduce the structure and function of GSDME and the mechanism by which it induces cell death, and we discuss its tumor suppressive effect.

Expression of CD44 in Head and Neck Squamous Cell Carcinoma-An In-Silico Study

Introduction  CD44, a multistructural and multifunctional transmembrane glycoprotein, is a promising cancer stem cell (CSC) marker that regulates the properties of CSCs, including self-renewal, tumor initiation, and metastasis, and confers resistance to chemotherapy and radiotherapy. The aim of the present study was to evaluate the gene and protein expression of CD44 and explore its prognostic value in head and neck squamous cell carcinoma (HNSCC). Methodology  The present observational study employs computational tools for analysis. The Cancer Genome Atlas Head-Neck Squamous Cell Carcinoma dataset (520 primary HNSCC and 44 normal tissues) from the University of Alabama at Birmingham Cancer platform was used to study the association of CD44 mRNA transcript levels with various clinicopathological characteristics of HNSCC including age, gender, tumor grade, tumor stage, human papillomavirus (HPV) status, p53 mutation status, and overall survival. The CD44 protein expression in HNSCC and normal tissues was ascertained using the National Cancer Institute's Clinical Proteomic Tumor Analysis Consortium Head-and-Neck cancer dataset (108 primary HNSCC and 71 normal tissues). Results  CD44 mRNA transcript and protein expression levels were significantly higher in HNSCC tissues than in normal tissues, and high CD44 expression was correlated with poor survival. CD44 was upregulated in Stage 1 and Grade 2 HNSCC compared with other stages and grades. Overexpression of CD44 was observed in HPV-negative and TP53-positive mutant status in HNSCC. Conclusion  The pleiotropic roles of CD44 in tumorigenesis urge the need to explore its differential expression in HNSCC. The study concludes that CD44 can be a potential diagnostic and prognostic biomarker for HNSCC and offer new molecular targets for CD44-targeted therapy for cancer management.

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.

CTLA-4 blockade induces tumor pyroptosis via CD8+ T cells in head and neck squamous cell carcinoma

Immune checkpoint blockade (ICB) treatment has demonstrated excellent medical effects in oncology, and it is one of the most sought after immunotherapies for tumors. However, there are several issues with ICB therapy, including low response rates and a lack of effective efficacy predictors. Gasdermin-mediated pyroptosis is a typical inflammatory death mode. We discovered that increased expression of gasdermin protein was linked to a favorable tumor immune microenvironment and prognosis in head and neck squamous cell carcinoma (HNSCC). We used the mouse HNSCC cell lines 4MOSC1 (responsive to CTLA-4 blockade) and 4MOSC2 (resistant to CTLA-4 blockade) orthotopic models and demonstrated that CTLA-4 blockade treatment induced gasdermin-mediated pyroptosis of tumor cells, and gasdermin expression positively correlated to the effectiveness of CTLA-4 blockade treatment. We found that CTLA-4 blockade activated CD8+ T cells and increased the levels of interferon γ (IFN-γ) and tumor necrosis factor α (TNF-α) cytokines in the tumor microenvironment. These cytokines synergistically activated the STAT1/IRF1 axis to trigger tumor cell pyroptosis and the release of large amounts of inflammatory substances and chemokines. Collectively, our findings revealed that CTLA-4 blockade triggered tumor cells pyroptosis via the release of IFN-γ and TNF-α from activated CD8+ T cells, providing a new perspective of ICB.

Chemotherapeutic drugs-induced pyroptosis mediated by gasdermin E promotes the progression and chemoresistance of pancreatic cancer

Pyroptosis is closely associated with cancer development; however, the role of pyroptosis in pancreatic ductal adenocarcinoma (PDAC), a fatal malignant tumour with a poor overall survival rate, remains elusive. Here, we explored the mechanism of chemotherapy-induced pyroptosis and elucidated the role of pyroptosis in mediating PDAC progression and chemoresistance. The results demonstrated first- and second-line chemotherapeutic drugs against PDAC, including gemcitabine, irinotecan, 5-fluorouracil, paclitaxel, and cisplatin, induced concurrent pyroptosis and apoptosis. During this process, gasdermin E (GSDME) was cleaved by activated caspase-3, which was accompanied by pro-apoptotic caspase-7/8 activation. GSDME knockdown switched pyroptosis to apoptosis, decreased invasion and migration, and enhanced the sensitivity of PDAC cells to chemotherapy in vitro and in vivo. GSDME was highly expressed in PDAC tissues and positively correlated with histological differentiation and vascular invasion. Furthermore, cells that survived pyroptosis promoted proliferation and invasion and impaired the chemosensitivity of PDAC cells, which was attenuated by the GSDME knockdown. Our findings demonstrated that chemotherapeutics against PDAC induce GSDME-dependent pyroptosis, and GSDME expression positively correlated with PDAC progression and chemoresistance. Targeting GSDME may be a novel approach to overcoming chemoresistance in PDAC.

A comprehensive analysis of gasdermin family gene as therapeutic targets in pan-cancer

Six members of the gasdermin family are involved in various biological functions in malignant tumors. The present study aimed to perform a comprehensive analysis of gasdermin family genes in pan-cancer. Raw data was acquired from the genotype-tissue expression (GTEx) and the Cancer Genome Atlas. High inter-tumor heterogeneity in the expression between paracancerous and tumor tissues was observed across cancers. Survival analysis confirmed that the risk or protective effects of gasdermin family members on prognosis depended on the cancer types. The mutation frequency appeared to be high, and the mutation group had a worse prognosis. Besides, gasdermin family genes were associated with immune infiltrate subtypes, stromal and immune cell infiltration levels, TMB, MSI, immune checkpoint gene expression, and tumor stemness scores. Moreover, gasdermin family gene expressions affected the expressions of MMR genes and methyltransferases and could predict cancer cells sensitivity to chemotherapeutic drugs. Subsequently, the findings were double-checked in LIHC and PAAD. GSEA results indicated the gasdermin family genes mainly involved in tumor metabolism and immune microenvironment remodeling related signaling pathways. In conclusion, our findings confirmed that gasdermin family genes were potential therapeutic cancer targets in pan-cancer.

Identification of a novel DFNA5 mutation, IVS7-2 a > G, in a Chinese family with non-syndromic sensorineural hearing loss

BACKGROUND

To date, seven DFNA5 mutations have been reported in families with autosomal dominant non-syndromic hearing loss worldwide. All the mutations cause exon 8 skipping at the mRNA level, that led to the protein truncated and the protein could exert a gain of ototoxic function.

OBJECTIVE

In this study, we found an autosomal-dominant non-syndromic hearing loss Chinese pedigree which spanned four generations and comprised 43 members. We want to identify the causative gene and mutation.

METHODS

Application of microsatellite markers on DFNA 23 loci preliminary screening of 25 genes, data were analyzed by linkage analysis.

RESULTS

We mapped the locus to the region between D7S629 and D7S516 (two-point lod-score of 5.39) with the application of 8 microsatellite markers. By direct sequencing of candidate genes in mapping region, we identified a novel missense mutation ivs7-2 A > G in DFNA5 gene, which was faithfully cosegregated with hearing loss in the family.

CONCLUSION AND SIGNIFICANCE

The missense mutation in intron 7 of DFNA5 causes skipping of exon 8, resulting in premature termination of the open reading frame. This type of mutation has repeatedly confirmed that it provides more evidence for the previous view and provides a more solid foundation for future research.

Gasdermin E: A Prospective Target for Therapy of Diseases

Gasdermin E (GSDME) is a member of the gasdermin protein family, which mediates programmed cell death including apoptosis and pyroptosis. Recently, it was suggested that GSDME is activated by chemotherapeutic drugs to stimulate pyroptosis of cancer cells and trigger anti-tumor immunity, which is identified as a tumor suppressor. However, GSDME-mediated pyroptosis contributes to normal tissue damage, leading to pathological inflammations. Inhibiting GSDME-mediated pyroptosis might be a potential target in ameliorating inflammatory diseases. Therefore, targeting GSDME is a promising option for the treatment of diseases in the future. In this review, we introduce the roles of GSDME-driven programmed cell death in different diseases and the potential targeted therapies of GSDME, so as to provide a foundation for future research.

Identification of a Pyroptosis-Related Gene Signature for Predicting Overall Survival and Response to Immunotherapy in Hepatocellular Carcinoma

Pyroptosis is a novel kind of cellular necrosis and shown to be involved in cancer progression. However, the diverse expression, prognosis and associations with immune status of pyroptosis-related genes in Hepatocellular carcinoma (HCC) have yet to be analyzed. Herein, the expression profiles and corresponding clinical characteristics of HCC samples were collected from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Then a pyroptosis-related gene signature was built by applying the least absolute shrinkage and selection operator (LASSO) Cox regression model from the TCGA cohort, while the GEO datasets were applied for verification. Twenty-four pyroptosis-related genes were found to be differentially expressed between HCC and normal samples. A five pyroptosis-related gene signature (GSDME, CASP8, SCAF11, NOD2, CASP6) was constructed according to LASSO Cox regression model. Patients in the low-risk group had better survival rates than those in the high-risk group. The risk score was proved to be an independent prognostic factor for overall survival (OS). The risk score correlated with immune infiltrations and immunotherapy responses. GSEA indicated that endocytosis, ubiquitin mediated proteolysis and regulation of autophagy were enriched in the high-risk group, while drug metabolism cytochrome P450 and tryptophan metabolism were enriched in the low-risk group. In conclusion, our pyroptosis-related gene signature can be used for survival prediction and may also predict the response of immunotherapy.