Construction and Validation of a Combined Ferroptosis and Hypoxia Prognostic Signature for Hepatocellular Carcinoma

Exploring the Metabolic Impact of FLASH Radiotherapy

FLASH radiotherapy (FLASH RT) is an innovative modality in cancer treatment that delivers ultrahigh dose rates (UHDRs), distinguishing it from conventional radiotherapy (CRT). FLASH RT has demonstrated the potential to enhance the therapeutic window by reducing radiation-induced damage to normal tissues while maintaining tumor control, a phenomenon termed the FLASH effect. Despite promising outcomes, the precise mechanisms underlying the FLASH effect remain elusive and are a focal point of current research. This review explores the metabolic and cellular responses to FLASH RT compared to CRT, with particular focus on the differential impacts on normal and tumor tissues. Key findings suggest that FLASH RT may mitigate damage in healthy tissues via altered reactive oxygen species (ROS) dynamics, which attenuate downstream oxidative damage. Studies indicate the FLASH RT influences iron metabolism and lipid peroxidation pathways differently than CRT. Additionally, various studies indicate that FLASH RT promotes the preservation of mitochondrial integrity and function, which helps maintain apoptotic pathways in normal tissues, attenuating damage. Current knowledge of the metabolic influences following FLASH RT highlights its potential to minimize toxicity in normal tissues, while also emphasizing the need for further studies in biologically relevant, complex systems to better understand its clinical potential. By targeting distinct metabolic pathways, FLASH RT could represent a transformative advance in RT, ultimately improving the therapeutic window for cancer treatment.

Construction of a ferroptosis and hypoxia-related gene signature in cervical cancer to assess tumour immune microenvironment and predict prognosis

BACKGROUND

This study aimed to investigate the potential role of ferroptosis/hypoxia-related genes in cervical cancer to improve early management and treatment of cervical cancer.

METHODS

All data were downloaded from public databases. Ferroptosis/hypoxia-related genes associated with cervical cancer prognosis were selected to construct a risk score model. The relationship between risk score and clinical features, immune microenvironment and prognosis were analysed.

RESULTS

Risk score model was constructed based on eight signature genes. Drug prediction analysis showed that bevacizumab and cisplatin were related to vascular endothelial growth factor A. Risk score, as an independent prognostic factor of cervical cancer, had a good survival prediction effect. The two groups differed significantly in degree of immune cell infiltration, gene expression, tumour mutation burden and somatic variation.

CONCLUSIONS

We developed a novel prognostic gene signature combining ferroptosis/hypoxia-related genes, which provides new ideas for individual treatment of cervical cancer.

[Research Advances in the Roles of High-Altitude Hypoxic Stress in Hepatocellular Carcinoma]

Hepatocellular carcinoma (HCC), one of the most prevalent malignant tumors causing the highest mortality globally, imposes an especially heavy burden of disease in China. Individuals living in high-altitude areas have a lower incidence of and mortality resulting from HCC compared with those in low-altitude regions do, potentially due to adaptive evolution in responses to hypoxic stress. Notably, high-altitude hypoxic stress is associated with the development and progression of HCC. Hypoxic stress may be involved in the development and progression of HCC by modulating the senescence, apoptosis, metabolism, tumor microenvironment, and tumor immunity of HCC cells. Additionally, the latest clinical findings indicate that high-altitude hypoxic environment has a significant impact on liver regeneration after HCC resection surgery. However, there is still a debate going on regarding whether high-altitude hypoxic stress promotes or inhibits the progression of HCC. This review covers three main aspects, the impact of adaptive evolution to high-altitude hypoxic stress on the development and progression of HCC in long-term residents of high-altitude areas, the effects of high-altitude hypoxic stress on the senescence, apoptosis, metabolism, tumor microenvironment, tumor metabolism, and tumor immunity of HCC cells, and the effect of high-altitude hypoxic stress on liver regeneration after HCC resection. We discussed the effect of changes in oxygen concentrations, cellular context, and tissue microenvironment on HCC development and progression. Moreover, we highlighted the potential for using research findings on mechanisms underlying high-altitude hypoxic stress to optimize HCC treatment strategies.

Ferroptosis: Frenemy of Radiotherapy

Recently, it was established that ferroptosis, a type of iron-dependent regulated cell death, plays a prominent role in radiotherapy-triggered cell death. Accordingly, ferroptosis inducers attracted a lot of interest as potential radio-synergizing drugs, ultimately enhancing radioresponses and patient outcomes. Nevertheless, the tumor microenvironment seems to have a major impact on ferroptosis induction. The influence of hypoxic conditions is an area of interest, as it remains the principal hurdle in the field of radiotherapy. In this review, we focus on the implications of hypoxic conditions on ferroptosis, contemplating the plausibility of using ferroptosis inducers as clinical radiosensitizers. Furthermore, we dive into the prospects of drug repurposing in the domain of ferroptosis inducers and radiosensitizers. Lastly, the potential adverse effects of ferroptosis inducers on normal tissue were discussed in detail. This review will provide an important framework for subsequent ferroptosis research, ascertaining the feasibility of ferroptosis inducers as clinical radiosensitizers.

Identification and validation of stemness-based and ferroptosis-related molecular clusters in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with an extremely poor prognosis. Cancer stem cells (CSCs) are considered to be responsible for the poor survival, recurrence and therapy resistance of PDAC. Ferroptosis plays a crucial role in the sustain and survival of CSCs. Here, we employed a rigorous evaluation of multiple datasets to identify a novel stemness-based and ferroptosis-related genes (SFRGs) signature to access the potential prognostic application. This work we retrieved RNA-sequencing and clinical annotation data from the TCGA, ICGC, GTEx and GEO database, and acquired 26 stem cell gene sets and 259 ferroptosis genes from StemChecker database and FerrDb database, respectively. Based on consensus clustering and ssGSEA analysis, we identified two expression patterns of CSCs traits (C1 and C2). Then, WGCNA analysis was implemented to screen out hub module genes correlated with stemness. Furthermore, differential expression analysis, Pearson correlation analysis, and the Least absolute shrinkage and selection operator (LASSO) and Cox regression were performed to identify the SFRGs and to construct model. In addition, the differences in prognosis, tumor microenvironment (TME) components and therapy responses were evaluated between two risk groups. Finally, we verified the most influential marker ARNTL2 experimentally by western blot, qRT-PCR, sphere formation assay, mitoscreen assay, intracellular iron concentration determination and MDA determination assays. In conclusion, we developed a stemness-based and ferroptosis-related prognostic model, which could help predict overall survival for PDAC patients. Targeting ferroptosis may be a promising therapeutic strategy to inhibit PDAC progression by suppressing CSCs.

A novel hypoxia-associated gene signature for prognosis prediction in head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is the most common malignant tumor of head and neck, which seriously threatens human life and health. However, the mechanism of hypoxia-associated genes (HAGs) in HNSCC remains unelucidated. This study aims to establish a hypoxia-associated gene signature and the nomogram for predicting the prognosis of patients with HNSCC.

METHODS

Previous literature reports provided a list of HAGs. The TCGA database provided genetic and clinical information on HNSCC patients. First, a hypoxia-associated gene risk model was constructed for predicting overall survival (OS) in HNSCC patients and externally validated in four GEO datasets (GSE27020, GSE41613, GSE42743, and GSE117973). Then, immune status and metabolic pathways were analyzed. A nomogram was constructed and assessed the predictive value. Finally, experimental validation of the core genes was performed by qRT-PCR.

RESULTS

A HNSCC prognostic model was constructed based on 8 HAGs. This risk model was validated in four external datasets and exhibited high predictive value in various clinical subgroups. Significant differences in immune cell infiltration levels and metabolic pathways were found between high and low risk subgroups. The nomogram was highly accurate for predicting OS in HNSCC patients.

CONCLUSIONS

The 8 hypoxia-associated gene signature can serve as novel independent prognostic indicators in HNSCC patients. The nomogram combining the risk score and clinical stage enhanced predictive performance in predicting OS compared to the risk model and clinical characteristics alone.

Ferroptosis: From Basic Research to Clinical Therapeutics in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common and highly heterogeneous malignancies worldwide. Despite the rapid development of multidisciplinary treatment and personalized precision medicine strategies, the overall survival of HCC patients remains poor. The limited survival benefit may be attributed to difficulty in early diagnosis, the high recurrence rate and high tumor heterogeneity. Ferroptosis, a novel mode of cell death driven by iron-dependent lipid peroxidation, has been implicated in the development and therapeutic response of various tumors, including HCC. In this review, we discuss the regulatory network of ferroptosis, describe the crosstalk between ferroptosis and HCC-related signaling pathways, and elucidate the potential role of ferroptosis in various treatment modalities for HCC, such as systemic therapy, radiotherapy, immunotherapy, interventional therapy and nanotherapy, and applications in the diagnosis and prognosis of HCC, to provide a theoretical basis for the diagnosis and treatment of HCC to effectively improve the survival of HCC patients.

Uncover diagnostic immunity/hypoxia/ferroptosis/epithelial mesenchymal transformation-related CCR5, CD86, CD8A, ITGAM, and PTPRC in kidney transplantation patients with allograft rejection

The aim of this study was to identify predictive immunity/hypoxia/ferroptosis/epithelial mesenchymal transformation (EMT)-related biomarkers, pathways and new drugs in allograft rejection in kidney transplant patients. First, gene expression data were downloaded followed by identification of differentially expressed genes (DEGs), weighted gene co-expression network analysis (WGCNA) and protein–protein interaction (PPI) analysis. Second, diagnostic model was construction based on key genes, followed by correlation analysis between immune/hypoxia/ferroptosis/EMT and key diagnostic genes. Finally, drug prediction of diagnostic key genes was carried out. Five diagnostic genes were further identified, including CCR5, CD86, CD8A, ITGAM, and PTPRC, which were positively correlated with allograft rejection after the kidney transplant. Highly infiltrated immune cells, highly expression of hypoxia-related genes and activated status of EMT were significantly positively correlated with five diagnostic genes. Interestingly, suppressors of ferroptosis (SOFs) and drivers of ferroptosis (DOFs) showed a complex regulatory relationship between ferroptosis and five diagnostic genes. CD86, CCR5, and ITGAM were respectively drug target of ABATACEPT, MARAVIROC, and CLARITHROMYCIN. PTPRC was drug target of both PREDNISONE and EPOETIN BETA. In conclusion, the study could be useful in understanding changes in the microenvironment within transplantation, which may promote or sustain the development of allograft rejection after kidney transplantation.

Prognostic prediction and immune infiltration analysis based on ferroptosis and EMT state in hepatocellular carcinoma

Background

Ferroptosis is one of the main mechanisms of sorafenib against hepatocellular carcinoma (HCC). Epithelial-mesenchymal transition (EMT) plays an important role in the heterogeneity, tumor metastasis, immunosuppressive microenvironment, and drug resistance of HCC. However, there are few studies looking into the relationship between ferroptosis and EMT and how they may affect the prognosis of HCC collectively.

Methods

We downloaded gene expression and clinical data of HCC patients from the Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) databases for prognostic model construction and validation respectively. The Least absolute shrinkage and selection operator (LASSO) Cox regression was used for model construction. The predictive ability of the model was assessed by Kaplan-Meier survival analysis and receiver operating characteristic (ROC) curve. We performed the expression profiles analysis to evaluate the ferroptosis and EMT state. CIBERSORT and single-sample Gene Set Enrichment Analysis (ssGSEA) methods were used for immune infiltration analysis.

Results

A total of thirteen crucial genes were identified for ferroptosis-related and EMT-related prognostic model (FEPM) stratifying patients into two risk groups. The high-FEPM group had shorter overall survivals than the low-FEPM group (p<0.0001 in the TCGA cohort and p<0.05 in the ICGC cohort). The FEPM score was proved to be an independent prognostic risk factor (HR>1, p<0.01). Furthermore, the expression profiles analysis suggested that the high-FEPM group appeared to have a more suppressive ferroptosis status and a more active EMT status than the low- FEPM group. Immune infiltration analysis showed that the myeloid-derived suppressor cells (MDSCs), and regulatory T cells (Tregs) were highly enriched in the high-FEPM group. Finally, a nomogram enrolling FEPM score and TNM stage was constructed showing outstanding predictive capacity for the prognosis of patients in the two cohorts.

Conclusion

In conclusion, we developed a ferroptosis-related and EMT-related prognostic model, which could help predict overall survival for HCC patients. It might provide a new idea for predicting the response to targeted therapies and immunotherapies in HCC patients.

Integrative analysis identifies potential ferroptosis-related genes of hypoxia adaptation in yak

There are studies on the hypoxia adaptation in yak, but there are few studies on the regulation of ferroptosis by hypoxia. This study was the first time to explore ferroptosis-related genes about hypoxia in yak. In this study, the oviduct epithelial cells between yak and bovine are performed by integrative analysis for functions, regulating network and hub genes. The results showed 29 up-regulated ferroptosis genes and 67 down-regulated ferroptosis genes, and GO-KEGG analysis showed that up-regulated differentially expressed genes (DEGs) were significantly enriched in ribosome pathway and oxidative phosphorylation pathway. Down-regulated DEGs were significantly enriched in longevity regulating pathway-mammal pathway. Mitophagy-Animal Pathway was a significant enrichment pathway for the up-regulated differentially expressed ferroptosis genes (DE-FRGs). HIF-1 signaling pathway is a significant pathway for the down-regulated DE-FRGs. By constructing DE-FRGs protein-protein interaction (PPI) network, 10 hub DE-FRGs (Jun, STAT3, SP1, HIF1A, Mapk1, Mapk3, Rela, Ulk1, CDKN1A, EPAS1) were obtained. The bta-mir-21-5p, bta-mir-10a and bta-mir-17-5p related to STAT3 were predicted. The results of this study indicated the important genes and pathways of the hypoxia in yak, and it was the first time to study ferroptosis genes and pathways related to the hypoxia adaptation by bulk-seq in yak. This study provided sufficient transcriptome datas for hypoxia adaptation.

Prospective Application of Ferroptosis in Hypoxic Cells for Tumor Radiotherapy

Radiation therapy plays an increasingly important role in cancer treatment. It can inhibit the progression of various cancers through radiation-induced DNA breakage and reactive oxygen species (ROS) overload. Unfortunately, solid tumors, such as breast and lung cancer, often develop a hypoxic microenvironment due to insufficient blood supply and rapid tumor proliferation, thereby affecting the effectiveness of radiation therapy. Restraining hypoxia and improving the curative effect of radiotherapy have become difficult problems. Ferroptosis is a new type of cell death caused by lipid peroxidation due to iron metabolism disorders and ROS accumulation. It plays an important role in both hypoxia and radiotherapy and can enhance the radiosensitivity of hypoxic tumor cells by amplifying oxidative stress or inhibiting antioxidant regulation. In this review, we summarize the internal relationship and related mechanisms between ferroptosis and hypoxia, thus exploring the possibility of inducing ferroptosis to improve the prognosis of hypoxic tumors.

The Prognostic Significance and Potential Mechanism of Ferroptosis-Related Genes in Hepatocellular Carcinoma

Ferroptosis exerts a pivotal role in the formation and dissemination processes of hepatocellular carcinoma (HCC). The heterogeneity of ferroptosis and the link between ferroptosis and immune responses have remained elusive. Based on ferroptosis-related genes (FRGs) and HCC patients from The Cancer Genome Atlas (TCGA), International Cancer Genome Consortium (ICGC), and Gene Expression Omnibus (GEO) cohorts, we comprehensively explored the heterogeneous ferroptosis subtypes. The genetic alterations, consensus clustering and survival analysis, immune infiltration, pathway enrichment analysis, integrated signature development, and nomogram building were further investigated. Kaplan-Meier plotter confirmed statistically differential probabilities of survival among the three subclusters. Immune infiltration analysis showed there were clear differences among the types of immune cell infiltration, the expression of PD-L1, and the distribution of TP53 mutations among the three clusters. Univariate Cox regression analysis, random survival forest, and multivariate Cox analysis were used to identify the prognostic integrated signature, including MED8, PIGU, PPM1G, RAN, and SNRPB. Kaplan-Meier analysis and time-dependent receiver operating characteristic (ROC) curves revealed the satisfactory predictive potential of the five-gene model. Subsequently, a nomogram was established, which combined the signature with clinical factors. The nomogram including the ferroptosis-based signature was conducted and showed some clinical net benefits. These results facilitated an understanding of ferroptosis and immune responses for HCC.