Mechanisms of Ferroptosis and Application to Head and Neck Squamous Cell Carcinoma Treatments

NAT10 inhibition promotes ac4C-dependent ferroptosis to counteract sorafenib resistance in nasopharyngeal carcinoma

Sorafenib, an anticancer drug, has been shown to induce ferroptosis in cancer cells. However, resistance to sorafenib greatly limits its therapeutic efficacy, and the exact mechanism of resistance is not fully understood. This study investigated the role of N-Acetyltransferase 10 (NAT10) in influencing the anticancer activity of sorafenib in nasopharyngeal carcinoma (NPC) and its molecular mechanism. NAT10 expression was significantly upregulated in NPC. Mechanistically, NAT10 promotes proteins of solute carrier family 7 member 11 (SLC7A11) expression through ac4C acetylation, inhibiting sorafenib-induced ferroptosis in NPC cells. The combined application of sorafenib and the NAT10 inhibitor remodelin significantly inhibits SLC7A11 expression and promotes ferroptosis in NPC cells. In vivo knockout of NAT10 inhibited the growth of sorafenib-resistant NPC. Our findings suggest that NAT10 inhibition might be a promising therapeutic approach to enhance the anticancer activity of sorafenib.

The Evaluation of Prognostic Value and Immune Characteristics of Ferroptosis-Related Genes in Lung Squamous Cell Carcinoma

Background  The purpose of our study was to construct a prognostic model based on ferroptosis-related gene signature to improve the prognosis prediction of lung squamous carcinoma (LUSC). Methods  The mRNA expression profiles and clinical data of LUSC patients were downloaded. LUSC-related essential differentially expressed genes were integrated for further analysis. Prognostic gene signatures were identified through random forest regression and univariate Cox regression analyses for constructing a prognostic model. Finally, in a preliminary experiment, we used the reverse transcription-quantitative polymerase chain reaction assay to verify the relationship between the expression of three prognostic gene features and ferroptosis. Results  Fifty-six ferroptosis-related essential genes were identified by using integrated analysis. Among these, three prognostic gene signatures (HELLS, POLR2H, and POLE2) were identified, which were positively affected by LUSC prognosis but negatively affected by immune cell infiltration. Significant overexpression of immune checkpoint genes occurred in the high-risk group. In preliminary experiments, we confirmed that the occurrence of ferroptosis can reduce three prognostic gene signature expression. Conclusions  The three ferroptosis-related genes could predict the LUSC prognostic risk of antitumor immunity.

Ferroptosis promotes anti-tumor immune response by inducing immunogenic exposure in HNSCC

Accumulated evidence indicates that immune cell populations play pivotal roles in the process of tumor initiation, progression, recurrence, metastasis, and immune escape. Ferroptosis is a form of regulating cell death in the nexus between metabolism, redox biology, and human health. Ferroptosis is considered as a vital important event in HNSCC, but the underling mechanism of regulating immune cell populations remains poorly understood. Our tissue microarray study showed that patients with high expression of GPX4 were related to poor survival. Moreover, the expression of GPX4 has been negatively associated with immunogenic cell death-related protein calreticulin in HNSCC tissue cohort. Further, RSL3 was used to induce ferroptosis in HNSCC xenograft of C3H/He mouse. We found that the occurrence of ferroptosis had significantly reduced the number of myeloid-derived suppressor cells (MDSCs) and tumor-associated M2-like macrophages (M2 TAMs) in tumor microenvironment. Meanwhile, the tumor-infiltrating CD4⁺ and CD8⁺ T cells were increased. And the calreticulin and HMGB1 may be potential candidate proteins improving the immunosuppressive tumor microenvironment. Taken together, our project suggests that ferroptosis can promote anti-tumor immune response by reversing immunosuppressive microenvironment, indicating that ferroptosis inducer is a promising therapeutic strategy in HNSCC.

Erk1/2-Dependent HNSCC Cell Susceptibility to Erastin-Induced Ferroptosis

Unfavorable clinical outcomes mean that cancer researchers must attempt to develop novel therapeutic strategies to overcome therapeutic resistance in patients with HNSCC. Recently, ferroptosis was shown to be a promising pathway possessing druggable targets, such as xCT (SLC7A11). Unfortunately, little is known about the molecular mechanisms underlying the susceptibility of HNSCC cells to ferroptosis. The goal of this study was to determine whether HNSCC cells with activated Erk1/2 are vulnerable to ferroptosis induction. Our results have shown that xCT (SLC7A11) was overexpressed in malignant tissues obtained from the patients with HNSCC, whereas normal mucosa demonstrated weak expression of the protein. In order to investigate the role of Erk1/2 in the decrease in cell viability caused by erastin, xCT-overexpressing FaDu and SCC25 HNSCC cells were used. The ravoxertinib-dependent inhibition of Erk1/2 signaling led to the decrease in erastin efficacy due to the effect on ROS production and the upregulation of ROS scavengers SOD1 and SOD2, resulting in repressed lipid peroxidation. Therefore, it was concluded that the erastin-dependent activation of ferroptosis seems to be a promising approach which can be further developed as an additional strategy for the treatment of HNSCC. As ferroptosis induction via erastin is strongly dependent on the expression of Erk1/2, this MAP kinase can be considered as a predictor for cancer cells' response to erastin.

Effect of regulatory cell death on the occurrence and development of head and neck squamous cell carcinoma

Head and neck cancer is a malignant tumour with a high mortality rate characterized by late diagnosis, high recurrence and metastasis rates, and poor prognosis. Head and neck squamous cell carcinoma (HNSCC) is the most common type of head and neck cancer. Various factors are involved in the occurrence and development of HNSCC, including external inflammatory stimuli and oncogenic viral infections. In recent years, studies on the regulation of cell death have provided new insights into the biology and therapeutic response of HNSCC, such as apoptosis, necroptosis, pyroptosis, autophagy, ferroptosis, and recently the newly discovered cuproptosis. We explored how various cell deaths act as a unique defence mechanism against cancer emergence and how they can be exploited to inhibit tumorigenesis and progression, thus introducing regulatory cell death (RCD) as a novel strategy for tumour therapy. In contrast to accidental cell death, RCD is controlled by specific signal transduction pathways, including TP53 signalling, KRAS signalling, NOTCH signalling, hypoxia signalling, and metabolic reprogramming. In this review, we describe the molecular mechanisms of nonapoptotic RCD and its relationship to HNSCC and discuss the crosstalk between relevant signalling pathways in HNSCC cells. We also highlight novel approaches to tumour elimination through RCD.

Overcoming cancer chemotherapy resistance by the induction of ferroptosis

Development of resistance to chemotherapy in cancer continues to be a major challenge in cancer management. Ferroptosis, a unique type of cell death, is mechanistically and morphologically different from other forms of cell death. Ferroptosis plays a pivotal role in inhibiting tumour growth and has presented new opportunities for treatment of chemotherapy-insensitive tumours in recent years. Emerging studies have suggested that ferroptosis can regulate the therapeutic responses of tumours. Accumulating evidence supports ferroptosis as a potential target for chemotherapy resistance. Pharmacological induction of ferroptosis could reverse drug resistance in tumours. In this review article, we first discuss the key principles of chemotherapeutic resistance in cancer. We then provide a brief overview of the core mechanisms of ferroptosis in cancer chemotherapeutic drug resistance. Finally, we summarise the emerging data that supports the fact that chemotherapy resistance in different types of cancers could be subdued by pharmacologically inducing ferroptosis. This review article suggests that pharmacological induction of ferroptosis by bioactive compounds (ferroptosis inducers) could overcome chemotherapeutic drug resistance. This article also highlights some promising therapeutic avenues that could be used to overcome chemotherapeutic drug resistance in cancer.

Identification of lysine acetylome of oral squamous cell carcinoma by label-free quantitative proteomics

Lysine acetylation (Kac) on histone promotes relaxation of the chromatin conformation and favors gene transcription to regulate oncogenesis, whereas the total acetylation profiling of oral squamous cell carcinoma (OSCC) is unknown. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was utilised to investigate lysine acetylation features of tumor tissues and adjacent normal tissues from 9 patients with OCSS. 282 upregulated Kac sites in 234 proteins and 235 downregulated Kac sites in 162 proteins between OSCC tissues and paired adjacent normal tissues were identified. Different acetylation proteins (DAPs) were analyzed through KEGG-based and MCODE. These DAPs are enriched in the ribosome biogenesis pathway. Survival Analysis of hub genes with TCGA database was performed. In addition, IPA software was used to explore the connection between 9 core DAPs (RPS3, RPL24, RPL19, EIF4A2, RPL12, MYBPC1, RPS6, ARCN1, and TMEM9) and the different expression of KATs and KDACs identified in our proteomic. The study is the first comparative study of Kac modification on oral squamous cell carcinoma. We propose to put forward the hypothesis that the dysfunction of ribosome biogenesis caused by the change of Lysine acetylation, especially downregulated acetylation on RPS6 and RPS3 may associated with the pathogenesis of OSCC. SIGNIFICANCE: The study is the first comparative study of Kac modification on oral squamous cell carcinoma through LC-MS/MS-based modified proteomic. These DAPs are high enriched in the ribosome biogenesis pathway. Used MCODE and survival analysis, 9 core DAPs (RPS3, RPL24, RPL19, EIF4A2, RPL12, MYBPC1, RPS6, ARCN1, and TMEM9) were screened. IPA software was used to explore the connection between 9 core DAPs and the different expression of KATs and KDACs identified in our proteomic. In addition, we propose to put forward the hypothesis that the dysfunction of ribosome biogenesis caused by the change of Lysine acetylation, especially downregulated acetylation on RPS6 and RPS3 may associated with the pathogenesis of OSCC.

Moving beyond the Tip of the Iceberg: DJ-1 Implications in Cancer Metabolism

DJ-1, also called Parkinson’s protein 7 (PARK7), is ubiquitously expressed and plays multiple actions in different physiological and, especially, pathophysiological processes, as evidenced by its identification in neurodegenerative diseases and its high expression in different types of cancer. To date, the exact activity of DJ-1 in carcinogenesis has not been fully elucidated, however several recent studies disclosed its involvement in regulating fundamental pathways involved in cancer onset, development, and metastatization. At this purpose, we have dissected the role of DJ-1 in maintaining the transformed phenotype, survival, drug resistance, metastasis formation, and differentiation in cancer cells. Moreover, we have discussed the role of DJ-1 in controlling the redox status in cancer cells, along with the ability to attenuate reactive oxygen species (ROS)-dependent cell death, as well as to mediate ferropotosis. Finally, a mention to the development of therapeutic strategies targeting DJ-1 has been done. We have reported the most recent studies, aiming to shed light on the role played by DJ-1 in different cancer aspects and create the foundation for moving beyond the tip of the iceberg.