Wild-type and mutant p53 in cancer-related ferroptosis. A matter of stress management?

Prognostic significance and therapeutic potential of guanosine triphosphate cyclohydrolase 1 in esophageal squamous cell carcinoma: clinical implications of ferroptosis and lipid peroxidation regulation

Background

Esophageal cancer, particularly esophageal squamous cell carcinoma (ESCC), is a leading cause of cancer-related death and has a poor prognosis. Despite the advancements in multidisciplinary therapies, resistance to conventional treatments warrants the development of novel therapeutic strategies. Ferroptosis, a form of cell death dependent on intracellular iron, has emerged as a potential mechanism for targeting cancer cells resistant to apoptosis. Guanosine triphosphate cyclohydrolase 1 (GCH1) has been identified as a novel antagonist of ferroptosis; however, its role in ESCC remains unclear. This study aimed to investigate the correlation between the expression and accumulation of the lipid peroxidation markers and regulators, including GCH1, in patients with ESCC and examined their prognostic significance. Furthermore, we investigated the relationship between lipid peroxidation regulators and cell death using an in vitro system to establish the basis for new therapeutic strategies.

Methods

We retrospectively analyzed 312 patients with ESCC who underwent radical esophagectomy at the Tokyo Medical and Dental University. Immunohistochemistry was performed to evaluate the expression of lipid peroxidation markers (4-hydroxy-2-nonenal) and regulators (glutathione peroxidase 4 [GPX4], ferroptosis suppressor protein 1 [FSP1], and GCH1). The correlation between these markers, clinicopathological features, and overall survival was assessed. In vitro experiments were performed using KYSE-150 cells to investigate the effects of GCH1 knockdown and overexpression on cell proliferation, cisplatin-induced cell death, and ferroptosis.

Results

Low GCH1 expression was significantly associated with a poor prognosis in patients with ESCC. GCH1 expression correlated with lymph node metastases, vessel invasion, and the pathological tumor stage. In vitro, GCH1-knockdown cells exhibited increased proliferation and resistance to cisplatin-induced cell death, whereas GCH1 overexpression reduced cell proliferation. Simultaneous inhibition of GPX4 and FSP1 induced mild cell death; however, GCH1 knockdown dramatically enhanced ferroptosis, suggesting a synergistic effect.

Conclusion

GCH1 is a critical prognostic factor for ESCC and plays a significant role in the regulation of cell proliferation and ferroptosis. Targeting GCH1 in combination with GPX4 and FSP1 inhibitors may offer a novel therapeutic strategy for overcoming resistance in ESCC. Further studies are warranted to elucidate the involved molecular mechanisms and validate these findings in vivo.

AKRs confer oligodendrocytes resistance to differentiation-stimulated ferroptosis

Ferroptosis is a recently characterized form of cell death that has gained attention for its roles in both pathological and physiological contexts. The existence of multiple anti-ferroptotic pathways in both neoplastic and healthy cells, along with the critical regulation of iron metabolism involved in lipid peroxides (lipid-ROS) production-the primary mediators of this cell death process-underscores the necessity of precisely controlling or preventing accidental/unwanted ferroptosis. Conversely, dysregulated iron metabolism and alterations in the expression or activity of key anti-ferroptotic components are linked to the development and progression of various human diseases, including multiple sclerosis (MS). In MS, the improper activation of ferroptosis has been associated with the progressive loss of myelinating oligodendrocytes (myOLs). Our study demonstrates that the physiological and maturation-dependent increase in iron accumulation within oligodendrocytes acts as a pro-ferroptotic signal, countered by the concurrent expression of AKR1C1. Importantly, MS-related neuroinflammation contributes to the down-regulation of AKR1C1 through miRNA-mediated mechanisms, rendering mature oligodendrocytes more vulnerable to ferroptosis. Together, these findings highlight the role of ferroptosis in MS-associated oligodendrocyte loss and position AKR1C1 as a potential therapeutic target for preserving oligodendrocyte integrity and supporting neuronal function in MS patients.

Calcium signals as regulators of ferroptosis in cancer

The field of ferroptosis research has grown exponentially since this form of cell death was first identified over a decade ago. Ferroptosis, an iron- and ROS-dependent type of cell death, is controlled by various metabolic pathways, including but not limited to redox and calcium (Ca2+) homeostasis, iron fluxes, mitochondrial function and lipid metabolism. Importantly, therapy-resistant tumors are particularly susceptible to ferroptotic cell death, rendering ferroptosis a promising therapeutic strategy against numerous malignancies. Calcium signals are important regulators of both cancer progression and cell death, with recent studies indicating their involvement in ferroptosis. Cells undergoing ferroptosis are characterized by plasma membrane rupture and the formation of nanopores, which facilitate influx of ions such as Ca2+ into the affected cells. Furthermore, mitochondrial Ca²⁺ levels have been implicated in directly influencing the cellular response to ferroptosis. Despite the remarkable progress made in the field, our understanding of the contribution of Ca2+ signals to ferroptosis remains limited. Here, we summarize key connections between Ca²⁺ signaling and ferroptosis in cancer pathobiology and discuss their potential therapeutic significance.

Tellurium-Doped Bioactive Glass Induces Ferroptosis in Osteosarcoma Cells Regardless of FSP1

Human osteosarcoma (OS) is a rare tumor predominantly affecting long bones and characterized by a poor prognosis. Currently, the first line of intervention consists of the surgical resection of primary tumors combined with radiotherapy and chemotherapy, with a profound impact on the patient's life. Since the surgical removal of OS frequently results in a large resection of bones, the use of biomaterials to sustain the stability of the remaining tissue and to stimulate bone regeneration is challenging. Moreover, residual neoplastic cells might be responsible for tumor recurrence. Here, we explored the potential of tellurium-ion-doped bioactive glass as a novel therapeutic intervention to both eradicate residual malignant cells and promote bone regeneration. Bioactive glass (BAG) has been extensively studied and employed in the field of regenerative medicine due to its osseointegration properties and ability to improve bone tissue regeneration. We found that the incorporation of tellurium (Te) in BAG selectively kills OS cells through ferroptosis while preserving the viability of hBMSCs and stimulating their osteodifferentiation. However, the mechanism of Te toxicity is still unclear: (i) Te-BAG generates lipid-ROS through LOXs activity but not iron overload; (ii) Te-dependent ferroptosis is mediated by GPX4 down-regulation; and (iii) the anti-ferroptotic activity of FSP1 is abrogated, whose expression confers the resistance of OS to the canonical induction of ferroptosis. Overall, our data show that Te-doped bioglass could represent an interesting biomaterial with both pro-ferroptotic activity towards residual cancer cells and pro-osteoregenerative activity.

Multiple roles of p53 in cancer development: Regulation of tumor microenvironment, m6A modification and diverse cell death mechanisms

BACKGROUND

The protein p53, encoded by the most frequently mutated gene TP53 in human cancers, has diverse functions in tumor suppression. As a best known transcription factor, p53 can regulate various fundamental cellular responses, ranging from the cell-cycle arrest, DNA repair, senescence to the programmed cell death (PCD), which includes autophagy, apoptosis, ferroptosis, cuproptosis, pyroptosis and disulfidoptosis. Accumulating evidence has indicated that the tumor microenvironment (TME), N6-methyladenosine (m6A) modification and diverse PCD are important for the progression, proliferation and metastases of cancers.

AIM OF REVIEW

This paper aims to systematically and comprehensively summarize the multiple roles of p53 in the development of cancers from the regulation of TME, m6A Modification and diverse PCD.

KEY SCIENTIFIC CONCEPTS OF REVIEW

TME, a crucial local homeostasis environment, influences every step of tumorigenesis and metastasis. m6A, the most prevalent and abundant endogenous modification in eukaryotic RNAs, plays an essential role in various biological processes, containing the progression of cancers. Additionally, PCD is an evolutionarily conserved mechanism of cell suicide and a common process in living organisms. Some forms of PCD contribute to the occurrence and development of cancer. However, the complex roles of p53 within the TME, m6A modification and diverse PCD mechanisms are still not completely understood. Presently, the function roles of p53 including the wild-type and mutant p53 in different context are summarized. Additionally, the interaction between the cancer immunity, cancer cell death and RNA m6A methylation and the p53 regulation during the development and progress of cancers were discussed. Moreover, the key molecular mechanisms by which p53 participates in the regulation of TME, m6A and diverse PCD are also explored. All the findings will facilitate the development of novel therapeutic approaches.

p53 Genetics and Biology in Lung Carcinomas: Insights, Implications and Clinical Applications

The TP53 gene is renowned as a tumor suppressor, playing a pivotal role in overseeing the cell cycle, apoptosis, and maintaining genomic stability. Dysregulation of p53 often contributes to the initiation and progression of various cancers, including lung cancer (LC) subtypes. The review explores the intricate relationship between p53 and its role in the development and progression of LC. p53, a crucial tumor suppressor protein, exists in various isoforms, and understanding their distinct functions in LC is essential for advancing our knowledge of this deadly disease. This review aims to provide a comprehensive literature overview of p53, its relevance to LC, and potential clinical applications.

Ferroptosis is an effective strategy for cancer therapy

Ferroptosis is a form of intracellular iron-dependent cell death that differs from necrosis, autophagy and apoptosis. Intracellular iron mediates Fenton reaction resulting in lipid peroxidation production, which in turn promotes cell death. Although cancer cell exhibit's ability to escape ferroptosis by multiple pathways such as SLC7A11, GPX4, induction of ferroptosis could inhibit cancer cell proliferation, migration and invasion. In tumor microenvironment, ferroptosis could affect immune cell (T cells, macrophages etc.) activity, which in turn regulates tumor immune escape. In addition, ferroptosis in cancer cells could activate immune cell activity by antigen processing and presentation. Therefore, ferroptosis could be an effective strategy for cancer therapy such as chemotherapy, radiotherapy, and immunotherapy. In this paper, we reviewed the role of ferroptosis on tumor progression and therapy, which may provide a strategy for cancer treatment.

FSP1 is a predictive biomarker of osteosarcoma cells' susceptibility to ferroptotic cell death and a potential therapeutic target

Human osteosarcoma (OS) is a relatively rare malignancy preferentially affecting long body bones which prognosis is often poor also due to the lack of effective therapies. Clinical management of this cancer basically relies on surgical removal of primary tumor coupled with radio/chemotherapy. Unfortunately, most osteosarcoma cells are resistant to conventional therapy, with the undergoing epithelial-mesenchymal transition (EMT) giving rise to gene expression reprogramming, thus increasing cancer cell invasiveness and metastatic potential. Alternative clinical approaches are thus urgently needed. In this context, the recently described ferroptotic cell death represents an attractive new strategy to efficiently kill cancer cells, since most chemoresistant and mesenchymal-shaped tumors display high susceptibility to pro-ferroptotic compounds. However, cancer cells have also evolved anti-ferroptotic strategies, which somehow sustain their survival upon ferroptosis induction. Indeed, here we show that osteosarcoma cell lines display heterogeneous sensitivity to ferroptosis execution, correlating with the mesenchymal phenotype, which is consistently affected by the expression of the well-known anti-ferroptotic factor ferroptosis suppressor protein 1 (FSP1). Interestingly, inhibiting the activity or expression of FSP1 restores cancer cell sensitivity to ferroptosis. Moreover, we also found that: i) AKRs might also contribute to resistance; ii) NRF2 enhances FSP1 expression upon ferroptosis induction; while iii) p53 contributes to the regulation of FSP1 basal expression in OS cells.In conclusion, FSP1 expression can potentially be used as a valuable predictive marker of OS sensitivity to ferroptosis and as a new potential therapeutic target.