Mutation of TP53 Confers Ferroptosis Resistance in Lung Cancer Through the FOXM1/MEF2C Axis

Bypassing the guardian: regulated cell death pathways in p53-mutant cancers

Approximately half of all cancers bear mutations in the tumor suppressor p53. Despite decades of research studying p53 function, treatment of p53-mutant cancers remains challenging owing to the effects of p53 mutations on many complex and interrelated signaling networks that promote tumor metastasis and chemoresistance. Mutations in p53 promote tumor survival by dysregulating cellular homeostasis and preventing activation of regulated cell death (RCD) pathways, which normally promote organismal health by eliminating dysregulated cells. Activation of RCD is a hallmark of effective cancer therapies, and p53-mutant cancers may be particularly susceptible to activation of certain RCD pathways. In this review, we discuss four RCD pathways that are the targets of emerging cancer therapeutics to treat p53-mutant cancers. These RCD pathways include E2F1-dependent apoptosis, necroptosis, mitochondrial permeability transition-driven necrosis, and ferroptosis. We discuss mechanisms of RCD activation, effects of p53 mutation on RCD activation, and current pharmaceutical strategies for RCD activation in p53-mutant cancers.

p53-regulated non-apoptotic cell death pathways and their relevance in cancer and other diseases

Programmed cell death is a mechanism that is crucial for numerous physiological and pathological processes. Whereas p53-mediated apoptosis is a major cell death pathway in cancer, accumulating evidence indicates that p53 also has crucial roles in controlling different non-apoptotic cell death (NACD) pathways, including ferroptosis, necroptosis, pyroptosis, autophagy-dependent cell death, entotic cell death, parthanatos and paraptosis, and may regulate PANoptosis, cuproptosis and disulfidptosis. Notably, the function of p53 in these NACDs substantially contributes to its biological effects, particularly in cancer development and other pathological processes. In this Review, we discuss recent advances in understanding the roles and underlying mechanisms of p53-mediated NACDs, focusing on ferroptosis, necroptosis and pyroptosis. We discuss the complex and distinct physiological settings in which NACDs are regulated by p53, and potential targeting of p53-regulated NACDs for the treatment of cancer and other human diseases. Finally, we highlight several important questions concerning p53-regulated NACDs that warrant further investigation.

The molecular and metabolic landscape of ferroptosis in respiratory diseases: Pharmacological aspects

Ferroptosis is a form of cell death that occurs when there is an excess of reactive oxygen species (ROS), lipid peroxidation, and iron accumulation. The precise regulation of metabolic pathways, including iron, lipid, and amino acid metabolism, is crucial for cell survival. This type of cell death, which is associated with oxidative stress, is controlled by a complex network of signaling molecules and pathways. It is also implicated in various respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), acute lung injury (ALI), lung cancer, pulmonary fibrosis (PF), and the coronavirus disease 2019 (COVID-19). To combat drug resistance, it is important to identify appropriate biological markers and treatment targets, as well as intervene in respiratory disorders to either induce or prevent ferroptosis. The focus is on the role of ferroptosis in the development of respiratory diseases and the potential of targeting ferroptosis for prevention and treatment. The review also explores the interaction between immune cell ferroptosis and inflammatory mediators in respiratory diseases, aiming to provide more effective strategies for managing cellular ferroptosis and respiratory disorders.

MEF2C Alleviates Postoperative Cognitive Dysfunction by Repressing Ferroptosis

BACKGROUND

Ferroptosis, a form of programmed cell death featured by lipid peroxidation, has been proposed as a potential etiology for postoperative cognitive dysfunction (POCD). Myocyte-specific enhancer factor 2C (MEF2C), a transcription factor expressed in various brain cell types, has been implicated in cognitive disorders. This study sought to ascertain whether MEF2C governs postoperative cognitive capacity by affecting ferroptosis.

METHODS

Transcriptomic analysis of public data was used to identify MEF2C as a candidate differentially expressed gene in the hippocampus of POCD mice. The POCD mouse model was established via aseptic laparotomy under isoflurane anesthesia after treatment with recombinant adeno-associated virus 9 (AAV9)-mediated overexpression of MEF2C and/or the glutathione peroxidase 4 (GPX4) inhibitor RSL3. Cognitive performance, Nissl staining, and ferroptosis-related parameters were assessed. Dual-luciferase reporter gene assays and chromatin immunoprecipitation assays were implemented to elucidate the mechanism by which MEF2C transcriptionally activates GPX4.

RESULTS

MEF2C mRNA and protein levels decreased in the mouse hippocampus following anesthesia and surgery. MEF2C overexpression ameliorated postoperative memory decline, hindered lipid peroxidation and iron accumulation, and enhanced antioxidant capacity, which were reversed by RSL3. Additionally, MEF2C was found to directly bind to the Gpx4 promoter and activate its transcription.

CONCLUSIONS

Our findings suggest that MEF2C may be a promising therapeutic target for POCD through its negative modulation of ferroptosis.

Heparanase accelerates the angiogenesis and inhibits the ferroptosis of p53-mutant non-small cell cancers in VEGF-dependent manner

The aim of this study is to explore the effects and specific mechanisms of heparanase on angiogenesis and iron deficiency anemia in TP53 mutant cancer. For this purpose, we conducted in vitro cell experiments and in vivo animal experiments respectively. In this study, we first analyzed the differential expression of heparanase in TP53 wild-type and mutant cells, and analyzed its effects on iron removal and angiogenesis in two types of CALU-1 and NCI-H358 cells. Secondly, we validated whether the mechanism of action of heparanase on TP53 mutant cells for iron removal and angiogenesis is related to VEGF. We applied the iron removal agonist erastin and VEGF inhibitor bevacizumab in both in vitro and in vivo experiments to validate the relationship between heparanase and VEGF in the mechanisms of iron removal and angiogenesis. The experimental results show that heparanase is highly expressed in TP53 mutated cancer cells, and has anti-ferroptosis and pro-angiogenic effects. Our experiment also confirmed that the effect of heparanase on TP53 mutant cancer's iron removal and angiogenesis is related to VEGF. In short, heparanase is highly expressed in p53 mutated lung cancer, and the mechanism of ferroptosis tolerance to TP53 mutated cancer is related to VEGF.

Ferroptosis in lung cancer: dual role, multi-level regulation, and new therapeutic strategies

Lung cancer is a highly prevalent malignant tumor worldwide, with high incidence and death rates. Recently, there has been increasing recognition of the role of ferroptosis, a unique cell death mechanism, in lung cancer. This review aims to summarize the current research progress on the relationship between ferroptosis and lung cancer. It also provides a comprehensive analysis of the regulatory processes of ferroptosis in various stages, including epigenetics, transcription, post-transcription, translation, and post-translation. Additionally, the review explores the dual nature of ferroptosis in lung cancer progression, which presents interesting therapeutic possibilities. On one hand, ferroptosis can promote the escape of immune surveillance and reduce the efficacy of treatment in the early stages of tumors. On the other hand, it can counter drug resistance, enhance radiosensitivity, and promote immunotherapy. The article also discusses various combination treatment strategies based on the mechanism of ferroptosis. Overall, this review offers a holistic perspective on the role of ferroptosis in the onset, progression, and treatment of lung cancer. It aims to contribute to future research and clinical interventions in this field.