G6PD inhibits ferroptosis in hepatocellular carcinoma by targeting cytochrome P450 oxidoreductase

CETZOLE Analogs as Potent Ferroptosis Inducers and Their Target Identification Using Covalent/Affinity Probes

Ferroptosis is a recently discovered cell death mechanism triggered by iron-dependent elevation of reactive oxygen species leading to lipid membrane peroxidation. We previously reported the development of a new class of ferroptosis inducers referred to as CETZOLEs with CC50 values in the low micromolar range. Structure-activity relationship study of these compounds led to the development of more potent analogs with CC50 values in the nanomolar range. Cells exposed to these compounds displayed the hallmarks of ferroptosis including cell death through ROS accumulation. Cancer cells were found to be more sensitive to these compounds than normal cells. Proteomic studies using covalent and affinity probes led to the identification of cystathionine β-synthase, peroxiredoxins, ADP/ATP carriers, and glucose dehydrogenase as enriched proteins. The binding of CETZOLEs to these proteins as well as GPX4 was validated by Western blotting. This group of proteins is known to be associated with cellular antioxidant pathways.

Ferroptosis in hepatocellular carcinoma: from bench to bedside

The most widespread type of liver cancer, HCC, is associated with disabled cellular death pathways. Despite therapeutic advancements, resistance to current systemic treatments (including sorafenib) compromises the prognosis of patients with HCC, driving the search for agents that might target novel cell death pathways. Ferroptosis, a form of iron-mediated nonapoptotic cell death, has gained considerable attention as a potential target for cancer therapy, especially in HCC. The role of ferroptosis in HCC is complex and diverse. On one hand, ferroptosis can contribute to the progression of HCC through its involvement in both acute and chronic liver conditions. In contrast, having ferroptosis affect HCC cells might be desirable. This review examines the role of ferroptosis in HCC from cellular, animal, and human perspectives while examining its mechanisms, regulation, biomarkers, and clinical implications.

Methanolic extracts of litchi (Litchi chinensis Sonn.): A novel approach of targeting glucose-6-phosphate dehydrogenase for liver cancer therapy

Cancer metabolism has emerged as a potential target for innovative therapeutic approaches in the treatment of cancer. Cancer metabolism has received much attention, particularly in relation to glucose metabolism. It has been observed that human malignancies have high levels of glucose-6-phosphate dehydrogenase (G6PD) activity which is an important enzyme of glucose metabolism. This overactivity is associated with the cell death and angiogenesis, highlighting its potential as a viable target for cancer treatment. This study was conducted to examine the methanolic extracts from the seeds, bark and leaves of litchi (Litchi chinensis Sonn.) in order to discover effective compounds targeting G6PD and potentially active entities against liver cancer. Plant extract screening for the target protein was carried out through enzymatic activity assay. The recombinant plasmid pET-24a-HmG6PD was expressed in E. coli (BL21-DE3) strain, then purified and assessed using metal affinity chromatography with Ni-NTA columns and SDS-PAGE. The cytotoxicity of plant extracts against liver cancer HepG2 cells was assessed using the MTT assay. All three extracts demonstrated significant inhibitory effects (>80% inhibition) against G6PD. They were then subjected to testing at various concentrations, and their IC50 values were subsequently determined. The extracts of litchi (leaf, IC50: 1.199 μg/mL; bark, IC50: 2.350 μg/mL; seeds, IC50: 1.238 μg/mL) displayed significant inhibition of G6PD activity at lower concentrations. Subsequently, the leaf extract of litchi was further assessed for its impact on HepG2 cell lines in a dose-dependent manner and exhibited strong potential as an inhibitor of cancer cell progression. Moreover, the results of acute toxicity study in mice revealed nontoxic effects of litchi leaf extract on hepatocytes. The results imply that Litchi chinensis leaf extract could be considered as a promising candidate for safer drug development in the treatment of liver cancer.

Deficiency of betaine-homocysteine methyltransferase activates glucose-6-phosphate dehydrogenase (G6PD) by decreasing arginine methylation of G6PD in hepatocellular carcinogenesis

Betaine-homocysteine methyltransferase (BHMT) regulates protein methylation and is correlated with tumorigenesis; however, the effects and regulation of BHMT in hepatocarcinogenesis remain largely unexplored. Here, we determined the clinical significance of BHMT in the occurrence and progression of hepatocellular carcinoma (HCC) using tissue samples from 198 patients. BHMT was to be frequently found (86.6%) expressed at relatively low levels in HCC tissues and was positively correlated with the overall survival of patients with HCC. Bhmt overexpression effectively suppressed several malignant phenotypes in hepatoma cells in vitro and in vivo, whereas complete knockout of Bhmt (Bhmt-/-) produced the opposite effect. We combined proteomics, metabolomics, and molecular biological strategies and detected that Bhmt-/- promoted hepatocarcinogenesis and tumor progression by enhancing the activity of glucose-6-phosphate dehydrogenase (G6PD) and PPP metabolism in DEN-induced HCC mouse and subcutaneous tumor-bearing models. In contrast, restoration of Bhmt with an AAV8-Bhmt injection or pharmacological inhibition of G6PD attenuated hepatocarcinogenesis. Additionally, coimmunoprecipitation identified monomethylated modifications of the G6PD, and BHMT regulated the methylation of G6PD. Protein sequence analysis, generation and application of specific antibodies, and site-directed mutagenesis indicated G6PD methylation at the arginine residue 246. Furthermore, we established bidirectionally regulated BHMT cellular models combined with methylation-deficient G6PD mutants to demonstrate that BHMT potentiated arginine methylation of G6PD, thereby inhibiting G6PD activity, which in turn suppressed hepatocarcinogenesis. Taken together, this study reveals a new methylation-regulatory mechanism in hepatocarcinogenesis owing to BHMT deficiency, suggesting a potential therapeutic strategy for HCC treatment.

Development and Validation of a Carbohydrate Metabolism-Related Model for Predicting Prognosis and Immune Landscape in Hepatocellular Carcinoma Patients

OBJECTIVE

The activities and products of carbohydrate metabolism are involved in key processes of cancer. However, its relationship with hepatocellular carcinoma (HCC) is unclear.

METHODS

The cancer genome atlas (TCGA)-HCC and ICGC-LIRI-JP datasets were acquired via public databases. Differentially expressed genes (DEGs) between HCC and control samples in the TCGA-HCC dataset were identified and overlapped with 355 carbohydrate metabolism-related genes (CRGs) to obtain differentially expressed CRGs (DE-CRGs). Then, univariate Cox and least absolute shrinkage and selection operator (LASSO) analyses were applied to identify risk model genes, and HCC samples were divided into high/low-risk groups according to the median risk score. Next, gene set enrichment analysis (GSEA) was performed on the risk model genes. The sensitivity of the risk model to immunotherapy and chemotherapy was also explored.

RESULTS

A total of 8 risk model genes, namely, G6PD, PFKFB4, ACAT1, ALDH2, ACYP1, OGDHL, ACADS, and TKTL1, were identified. Moreover, the risk score, cancer status, age, and pathologic T stage were strongly associated with the prognosis of HCC patients. Both the stromal score and immune score had significant negative/positive correlations with the risk score, reflecting the important role of the risk model in immunotherapy sensitivity. Furthermore, the stromal and immune scores had significant negative/positive correlations with risk scores, reflecting the important role of the risk model in immunotherapy sensitivity. Eventually, we found that high-/low-risk patients were more sensitive to 102 drugs, suggesting that the risk model exhibited sensitivity to chemotherapy drugs. The results of the experiments in HCC tissue samples validated the expression of the risk model genes.

CONCLUSION

Through bioinformatic analysis, we constructed a carbohydrate metabolism-related risk model for HCC, contributing to the prognosis prediction and treatment of HCC patients.

The regulation and function of Nrf2 signaling in ferroptosis-activated cancer therapy

Ferroptosis is an iron-dependent programmed cell death process that involves lipid oxidation via the Fenton reaction to produce lipid peroxides, causing disruption of the lipid bilayer, which is essential for cellular survival. Ferroptosis has been implicated in the occurrence and treatment response of various types of cancer, and targeting ferroptosis has emerged as a promising strategy for cancer therapy. However, cancer cells can escape cellular ferroptosis by activating or remodeling various signaling pathways, including oxidative stress pathways, thereby limiting the efficacy of ferroptosis-activating targeted therapy. The key anti-oxidative transcription factor, nuclear factor E2 related factor 2 (Nrf2 or NFE2L2), plays a dominant role in defense machinery by reprogramming the iron, intermediate, and glutathione peroxidase 4 (GPX4)-related network and the antioxidant system to attenuate ferroptosis. In this review, we summarize the recent advances in the regulation and function of Nrf2 signaling in ferroptosis-activated cancer therapy and explore the prospect of combining Nrf2 inhibitors and ferroptosis inducers as a promising cancer treatment strategy.

A Novel Amino Acid-Related Gene Signature Predicts Overall Survival in Patients With Hepatocellular Carcinoma

BACKGROUND AND AIMS

Hepatocellular carcinoma (HCC) is an extremely harmful malignant tumor in the world. Since the energy metabolism and biosynthesis of HCC cells are closely related to amino acids, it is necessary to further explore the relationship between amino acid-related genes and the prognosis of HCC to achieve individualized treatment. We herein aimed to develop a prognostic model for HCC based on amino acid genes.

METHODS

In this study, RNA-sequencing data of HCC patients were downloaded from the TCGA-LIHC cohort as the training cohort and the GSE14520 cohort as the validation cohort. Amino acid-related genes were derived from the Molecular Signatures Database. Univariate Cox and Lasso regression analysis were used to construct an amino acid-related signature (AARS). The predictive value of this risk score was evaluated by Kaplan-Meier (K-M) curve, receiver operating characteristic (ROC) curve, univariate and multivariate Cox regression analysis. Gene set variation analysis (GSVA) and immune characteristics evaluation were used to explore the underlying mechanisms. Finally, a nomogram was established to help the personalized prognosis assessment of patients with HCC.

RESULTS

The AARS comprises 14 amino acid-related genes to predict overall survival (OS) in HCC patients. HCC patients were divided into AARS-high group and AARS-low group according to the AARS scores. The K-M curve, ROC curve, and univariate and multivariate Cox regression analysis verified the good prediction efficiency of the risk score. Using GSVA, we found that AARS variants were concentrated in four pathways, including cholesterol metabolism, delayed estrogen response, fatty acid metabolism, and myogenesis metabolism.

CONCLUSION

Our results suggest that the AARS as a prognostic model based on amino acid-related genes is of great value in the prediction of survival of HCC, and can help improve the individualized treatment of patients with HCC.

Crosstalk of non-apoptotic RCD panel in hepatocellular carcinoma reveals the prognostic and therapeutic optimization

Non-apoptotic regulated cell death (RCD) of tumor cells profoundly affects tumor progression and plays critical roles in determining response to immune checkpoint inhibitors (ICIs). Prognosis-distinctive HCC subtypes were identified by consensus cluster analysis based on the expressions of 507 non-apoptotic RCD genes obtained from databases and literature. Meanwhile, a set of bioinformatic tools was integrated to analyze the differences of the tumor immune microenvironment infiltration, genetic mutation, copy number variation, and epigenetics alternations within two subtypes. Finally, a non-apoptotic RCDRS signature was constructed and its reliability was evaluated in HCC patients' tissues. The high-RCDRS HCC subgroup showed a significantly lower overall survival and less sensitivity to ICIs compared to low-RCDRS subgroup, but higher sensitivity to cisplatin, paclitaxel, and sorafenib. Overall, we established an RCDRS panel consisting of four non-apoptotic RCD genes, which might be a promising predictor for evaluating HCC prognosis, guiding therapeutic decision-making, and ultimately improving patient outcomes.

Ferroptosis regulates hemolysis in stored murine and human red blood cells

Red blood cell (RBC) metabolism regulates hemolysis during aging in vivo and in the blood bank. Here, we leveraged a diversity outbred mouse population to map the genetic drivers of fresh/stored RBC metabolism and extravascular hemolysis upon storage and transfusion in 350 mice. We identify the ferrireductase Steap3 as a critical regulator of a ferroptosis-like process of lipid peroxidation. Steap3 polymorphisms were associated with RBC iron content, in vitro hemolysis, and in vivo extravascular hemolysis both in mice and 13,091 blood donors from the Recipient Epidemiology and Donor evaluation Study. Using metabolite Quantitative Trait Loci analyses, we identified a network of gene products (FADS1/2, EPHX2 and LPCAT3) - enriched in donors of African descent - associated with oxylipin metabolism in stored human RBCs and related to Steap3 or its transcriptional regulator, the tumor protein TP53. Genetic variants were associated with lower in vivo hemolysis in thousands of single-unit transfusion recipients.

Highlights

Steap3 regulates lipid peroxidation and extravascular hemolysis in 350 diversity outbred miceSteap3 SNPs are linked to RBC iron, hemolysis, vesiculation in 13,091 blood donorsmQTL analyses of oxylipins identified ferroptosis-related gene products FADS1/2, EPHX2, LPCAT3Ferroptosis markers are linked to hemoglobin increments in transfusion recipients.

Graphical abstract

E3 ubiquitin ligase CHIP interacts with transferrin receptor 1 for degradation and promotes cell proliferation through inhibiting ferroptosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the major form of liver malignancy with high incidence and mortality. Identifying novel biomarkers and understanding regulatory mechanisms underlying the development and progression of HCC are critical for improving diagnosis, treatment and patient outcomes. Carboxyl terminus of Hsc-70-interacting protein (CHIP) is a well-described U-box-type E3 ubiquitin ligase which promotes the ubiquitination and degradation of numerous tumor-associated proteins. Recent studies have shown that CHIP can play as a tumor-suppressor gene or an oncogene in different kinds of malignancies. To date, the function and mechanism of CHIP in hepatocellular carcinoma remains largely unknown. Based on TCGA data, we found that compared with high CHIP expression, the overall survival of HCC patients with low expression of CHIP was better. In addition, CHIP overexpression markedly enhanced HCC cell proliferation and colony formation. Conversely, knockdown of CHIP restrained the proliferation and colony formation of HCC cells. Meanwhile, knockdown of CHIP decreased mitochondrial cristae or ruptured outer mitochondrial membrane, promoted the accumulation of Fe2+ and ferroptosis of HCC cells. Further research for the first time confirmed that CHIP interacts and degrades transferrin receptor 1 (TfR1) by ubiquitin-proteasome pathway, which leads to the inhibition of ferroptosis and promotes the proliferation of HCC cells. The analysis of proteomics data from CPTAC revealed a negative correlation between CHIP and TfR1 protein expression levels in HCC. These findings indicate that CHIP acts as a negative modulator of ferroptosis and functions as an oncogene in HCC.

Ferroptosis and hepatocellular carcinoma: the emerging role of lncRNAs

Hepatocellular carcinoma is the most common form of primary liver cancer and poses a significant challenge to the medical community because of its high mortality rate. In recent years, ferroptosis, a unique form of cell death, has garnered widespread attention. Ferroptosis, which is characterized by iron-dependent lipid peroxidation and mitochondrial alterations, is closely associated with the pathological processes of various diseases, including hepatocellular carcinoma. Long non-coding RNAs (lncRNAs), are a type of functional RNA, and play crucial regulatory roles in a variety of biological processes. In this manuscript, we review the regulatory roles of lncRNAs in the key aspects of ferroptosis, and summarize the research progress on ferroptosis-related lncRNAs in hepatocellular carcinoma.

Melatonin alleviates ischemic stroke by inhibiting ferroptosis through the CYP1B1/ACSL4 pathway

This study utilized middle cerebral artery occlusion (MCAO) mouse models and HT-22 cell oxygen and glucose deprivation/reoxygenation (OGD/R) models to investigate the therapeutic effects of melatonin on ischemic brain injury. In the experiments, MCAO mice were treated with 5 and 10 mg/kg doses of melatonin, and H-T22 cells underwent OGD/R treatment and were administered different concentrations of melatonin. The results showed that melatonin significantly reduced ischemic brain area, neural damage, cerebral edema, and neuronal apoptosis in MCAO mice. In the HT-22 cell model, melatonin also improved cell proliferation ability, reduced apoptosis, and ROS production. Further mechanistic studies found that melatonin exerts protective effects by inhibiting ferroptosis, an iron-dependent form of regulated cell death, through regulation of the ACSL4/CYP1B1 pathway. In MCAO mice, melatonin decreased lipid peroxidation, ROS production, and ACSL4 protein expression. Overexpression of CYP1B1 increased ACSL4 ubiquitination and degradation, thereby increasing cell tolerance to ferroptosis, reducing ACSL4 protein levels, and decreasing ROS production. CYP1B1 knockdown obtained opposite results. The CYP1B1 metabolite 20-HETE induces expression of the E3 ubiquitin ligase FBXO10 by activating PKC signaling, which promotes ACSL4 degradation. In the OGD/R cell model, inhibition of CYP1B1 expression reversed the therapeutic effects of melatonin. In summary, this study demonstrates that melatonin protects the brain from ischemic injury by inhibiting ferroptosis through regulation of the ACSL4/CYP1B1 pathway, providing evidence for new therapeutic targets for ischemic brain injury.

Prognostic value and potential mechanism of cellular senescence and tumor microenvironment in hepatocellular carcinoma: Insights from bulk transcriptomics and single-cell sequencing analysis

The high mortality rate and postoperative recurrence of hepatocellular carcinoma (HCC) contribute to the burden on society and healthcare. The prognostic value and underlying mechanisms of cellular senescence and tumor microenvironment (TME) in HCC remain unclear. Bulk transcriptomic data were obtained from 368 HCC samples in The Cancer Genome Atlas-liver hepatocellular carcinoma cohort and 64 samples from the GSE116174 dataset. Single-cell RNA sequencing (scRNA-seq) data of HCC were obtained from the GSE149614 dataset, including 18 tumor samples from 10 patients. Prognosis-related cellular senescence genes and immune cells were identified through univariate analysis. Least absolute shrinkage and selection operator regression analysis was performed to construct the CellAge score and TME score, both of which were identified as independent prognostic factors for HCC based on multivariate Cox analysis. The combined CellAge and TME scores showed improved prognostic stratification for HCC patients, as confirmed by multivariate Cox analysis (p < .001). The gene set enrichment analysis (GSEA) revealed enrichment of the extracellular matrix receptor interaction signaling pathway in the group with high CellAge scores and low TME scores, which exhibited a worse prognosis. Single-cell sequencing results revealed higher expression activity of the cAMP response element modulator (CREM) extended transcription factor in HCC cells and most immune cells, indicating its involvement in TME remodeling. Finally, the tumor immune dysfunction and exclusion (TIDE) analysis demonstrated that the combined scores could predict the outcomes of immune therapy in patients with HCC. In conclusion, cellular senescence contributes to TME remodeling in HCC, and the developed CellAge and TME scores serve as independent prognostic factors and predictors of immune therapy in HCC.

Identification of PANoptosis-related subtypes, construction of a prognosis signature, and tumor microenvironment landscape of hepatocellular carcinoma using bioinformatic analysis and experimental verification

Background

Hepatocellular carcinoma (HCC) is one of the most lethal malignancies worldwide. PANoptosis is a recently unveiled programmed cell death pathway, Nonetheless, the precise implications of PANoptosis within the context of HCC remain incompletely elucidated.

Methods

We conducted a comprehensive bioinformatics analysis to evaluate both the expression and mutation patterns of PANoptosis-related genes (PRGs). We categorized HCC into two clusters and identified differentially expressed PANoptosis-related genes (DEPRGs). Next, a PANoptosis risk model was constructed using LASSO and multivariate Cox regression analyses. The relationship between PRGs, risk genes, the risk model, and the immune microenvironment was studies. In addition, drug sensitivity between high- and low-risk groups was examined. The expression profiles of these four risk genes were elucidate by qRT-PCR or immunohistochemical (IHC). Furthermore, the effect of CTSC knock down on HCC cell behavior was verified using in vitro experiments.

Results

We constructed a prognostic signature of four DEPRGs (CTSC, CDCA8, G6PD, and CXCL9). Receiver operating characteristic curve analyses underscored the superior prognostic capacity of this signature in assessing the outcomes of HCC patients. Subsequently, patients were stratified based on their risk scores, which revealed that the low-risk group had better prognosis than those in the high-risk group. High-risk group displayed a lower Stromal Score, Immune Score, ESTIMATE score, and higher cancer stem cell content, tumor mutation burden (TMB) values. Furthermore, a correlation was noted between the risk model and the sensitivity to 56 chemotherapeutic agents, as well as immunotherapy efficacy, in patient with. These findings provide valuable guidance for personalized clinical treatment strategies. The qRT-PCR analysis revealed that upregulated expression of CTSC, CDCA8, and G6PD, whereas downregulated expression of CXCL9 in HCC compared with adjacent tumor tissue and normal liver cell lines. The knockdown of CTSC significantly reduced both HCC cell proliferation and migration.

Conclusion

Our study underscores the promise of PANoptosis-based molecular clustering and prognostic signatures in predicting patient survival and discerning the intricacies of the tumor microenvironment within the context of HCC. These insights hold the potential to advance our comprehension of the therapeutic contribution of PANoptosis plays in HCC and pave the way for generating more efficacious treatment strategies.

Metabolism-regulated ferroptosis in cancer progression and therapy

Cancer metabolism mainly includes carbohydrate, amino acid and lipid metabolism, each of which can be reprogrammed. These processes interact with each other to adapt to the complicated microenvironment. Ferroptosis is a regulated cell death induced by iron-dependent lipid peroxidation, which is morphologically different from apoptosis, necrosis, necroptosis, pyroptosis, autophagy-dependent cell death and cuprotosis. Cancer metabolism plays opposite roles in ferroptosis. On the one hand, carbohydrate metabolism can produce NADPH to maintain GPX4 and FSP1 function, and amino acid metabolism can provide substrates for synthesizing GPX4; on the other hand, lipid metabolism might synthesize PUFAs to trigger ferroptosis. The mechanisms through which cancer metabolism affects ferroptosis have been investigated extensively for a long time; however, some mechanisms have not yet been elucidated. In this review, we summarize the interaction between cancer metabolism and ferroptosis. Importantly, we were most concerned with how these targets can be utilized in cancer therapy.

The molecular mechanisms and potential drug targets of ferroptosis in myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI), caused by the initial interruption and subsequent restoration of coronary artery blood, results in further damage to cardiac function, affecting the prognosis of patients with acute myocardial infarction. Ferroptosis is an iron-dependent, superoxide-driven, non-apoptotic form of regulated cell death that is involved in the pathogenesis of MIRI. Ferroptosis is characterized by the accumulation of lipid peroxides (LOOH) and redox disequilibrium. Free iron ions can induce lipid oxidative stress as a substrate of the Fenton reaction and lipoxygenase (LOX) and participate in the inactivation of a variety of lipid antioxidants including CoQ10 and GPX4, destroying the redox balance and causing cell death. The metabolism of amino acid, iron, and lipids, including associated pathways, is considered as a specific hallmark of ferroptosis. This review systematically summarizes the latest research progress on the mechanisms of ferroptosis and discusses and analyzes the therapeutic approaches targeting ferroptosis to alleviate MIRI.

Cellular metabolism: A key player in cancer ferroptosis

Cellular metabolism is the fundamental process by which cells maintain growth and self-renewal. It produces energy, furnishes raw materials, and intermediates for biomolecule synthesis, and modulates enzyme activity to sustain normal cellular functions. Cellular metabolism is the foundation of cellular life processes and plays a regulatory role in various biological functions, including programmed cell death. Ferroptosis is a recently discovered form of iron-dependent programmed cell death. The inhibition of ferroptosis plays a crucial role in tumorigenesis and tumor progression. However, the role of cellular metabolism, particularly glucose and amino acid metabolism, in cancer ferroptosis is not well understood. Here, we reviewed glucose, lipid, amino acid, iron and selenium metabolism involvement in cancer cell ferroptosis to elucidate the impact of different metabolic pathways on this process. Additionally, we provided a detailed overview of agents used to induce cancer ferroptosis. We explained that the metabolism of tumor cells plays a crucial role in maintaining intracellular redox homeostasis and that disrupting the normal metabolic processes in these cells renders them more susceptible to iron-induced cell death, resulting in enhanced tumor cell killing. The combination of ferroptosis inducers and cellular metabolism inhibitors may be a novel approach to future cancer therapy and an important strategy to advance the development of treatments.

G6PD and machine learning algorithms as prognostic and diagnostic indicators of liver hepatocellular carcinoma

BACKGROUND

Liver Hepatocellular carcinoma (LIHC) exhibits a high incidence of liver cancer with escalating mortality rates over time. Despite this, the underlying pathogenic mechanism of LIHC remains poorly understood.

MATERIALS & METHODS

To address this gap, we conducted a comprehensive investigation into the role of G6PD in LIHC using a combination of bioinformatics analysis with database data and rigorous cell experiments. LIHC samples were obtained from TCGA, ICGC and GEO databases, and the differences in G6PD expression in different tissues were investigated by differential expression analysis, followed by the establishment of Nomogram to determine the percentage of G6PD in causing LIHC by examining the relationship between G6PD and clinical features, and the subsequent validation of the effect of G6PD on the activity, migration, and invasive ability of hepatocellular carcinoma cells by using the low expression of LI-7 and SNU-449. Additionally, we employed machine learning to validate and compare the predictive capacity of four algorithms for LIHC patient prognosis.

RESULTS

Our findings revealed significantly elevated G6PD expression levels in liver cancer tissues as compared to normal tissues. Meanwhile, Nomogram and Adaboost, Catboost, and Gbdt Regression analyses showed that G6PD accounted for 46%, 31%, and 49% of the multiple factors leading to LIHC. Furthermore, we observed that G6PD knockdown in hepatocellular carcinoma cells led to reduced proliferation, migration, and invasion abilities. Remarkably, the Decision Tree C5.0 decision tree algorithm demonstrated superior discriminatory performance among the machine learning methods assessed.

CONCLUSION

The potential diagnostic utility of G6PD and Decision Tree C5.0 for LIHC opens up a novel avenue for early detection and improved treatment strategies for hepatocellular carcinoma.

Identifying the programmed cell death index of hepatocellular carcinoma for prognosis and therapy response improvement by machine learning: a bioinformatics analysis and experimental validation

Background

Despite advancements in hepatocellular carcinoma (HCC) treatments, the prognosis for patients remains suboptimal. Cumulative evidence suggests that programmed cell death (PCD) exerts crucial functions in HCC. PCD-related genes are potential predictors for prognosis and therapeutic responses.

Methods

A systematic analysis of 14 PCD modes was conducted to determine the correlation between PCD and HCC. A novel machine learning-based integrative framework was utilized to construct the PCD Index (PCDI) for prognosis and therapeutic response prediction. A comprehensive analysis of PCDI genes was performed, leveraging data including single-cell sequencing and proteomics. GBA was selected, and its functions were investigated in HCC cell lines by in vitro experiments.

Results

Two PCD clusters with different clinical and biological characteristics were identified in HCC. With the computational framework, the PCDI was constructed, demonstrating superior prognostic predictive efficacy and surpassing previously published prognostic models. An efficient clinical nomogram based on PCDI and clinicopathological factors was then developed. PCDI was intimately associated with immunological attributes, and PCDI could efficaciously predict immunotherapy response. Additionally, the PCDI could predict the chemotherapy sensitivity of HCC patients. A multilevel panorama of PCDI genes confirmed its stability and credibility. Finally, the knockdown of GBA could suppress both the proliferative and invasive capacities of HCC cells.

Conclusion

This study systematically elucidated the association between PCD and HCC. A robust PCDI was constructed for prognosis and therapy response prediction, which would facilitate clinical management and personalized therapy for HCC.

An integrative view on glucagon function and putative role in the progression of pancreatic neuroendocrine tumours (pNETs) and hepatocellular carcinomas (HCC)

Cancer metabolism research area evolved greatly, however, is still unknown the impact of systemic metabolism control and diet on cancer. It makes sense that systemic regulators of metabolism can act directly on cancer cells and activate signalling, prompting metabolic remodelling needed to sustain cancer cell survival, tumour growth and disease progression. In the present review, we describe the main glucagon functions in the control of glycaemia and of metabolic pathways overall. Furthermore, an integrative view on how glucagon and related signalling pathways can contribute for pancreatic neuroendocrine tumours (pNETs) and hepatocellular carcinomas (HCC) progression, since pancreas and liver are the major organs exposed to higher levels of glucagon, pancreas as a producer and liver as a scavenger. The main objective is to bring to discussion some glucagon-dependent mechanisms by presenting an integrative view on microenvironmental and systemic aspects in pNETs and HCC biology.

The ubiquitin-proteasome system links NADPH metabolism to ferroptosis

Ferroptosis is the type of cell death arising from uncontrolled and excessive lipid peroxidation. NADPH is essential for ferroptosis regulation because it supplies reducing equivalents for antioxidant defense systems and contributes to the generation of reactive oxygen species. Moreover, NADPH level serves as a biomarker for predicting the sensitivity of cells to ferroptosis. The ubiquitin-proteasome system governs the stability of many ferroptosis effectors. Recent research has revealed MARCHF6, the endoplasmic reticulum ubiquitin ligase, as an unprecedented NADPH sensor in the ubiquitin system and a critical regulator of ferroptosis involved in tumorigenesis and fetal development. This review summarizes the current understanding of NADPH metabolism and the ubiquitin-proteasome system in regulating ferroptosis and highlights the emerging importance of MARCHF6 as a vital connector between NADPH metabolism and ferroptosis.

Development and Validation of a Propionate Metabolism-Related Gene Signature for Prognostic Prediction of Hepatocellular Carcinoma

Background

Studies have demonstrated that propionate metabolism-related genes (PMRGs) are associated with cancer progression. PMRGs are not known to be involved in Hepatocellular carcinoma (HCC).

Methods

In this study, The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were accessed for HCC-related transcriptome data and clinical information. First, DE-PMRGs were derived by intersecting PMRGs and DEGs between HCC tissues and normal controls. The clusterProfiler R package was then used to enrich DE-PMRGs. In addition, biomarkers of HCC were identified, and a prognostic model was developed. Using functional analysis and tumor microenvironment analysis, new insights were obtained into HCC. The expression of biomarkers was validated using quantitative real-time polymerase chain reaction (qRT-PCR).

Results

132 DE-PMRGs were obtained by intersecting 3690 DEGs and 291 PMRGs. Steroid and organic acid metabolism were associated with these genes. For the construction of the risk model for HCC samples, five biomarkers were identified, including Acyl-CoA dehydrogenase short chain (ACADS), CYP19A1, formiminotransferase cyclodeaminase (FTCD), glucose-6-phosphate dehydrogenase (G6PD), and glutamic-oxaloacetic transaminase (GOT2). ACADS, FTCD, and GOT2 were positive factors, whereas CYP19A1 and G6PD were negative. HCC patients with AUC greater than 0.6 were predicted to survive 1/2/3/4/5 years, indicating decent efficiency of the model. The probability of 1/3/5-survival for HCC was also predicted by the nomogram using the risk score, pathologic T stage, and cancer status. Moreover, functional enrichment analysis revealed the high-risk genes were associated with invasion and epithelial-mesenchymal transition. Significantly, immune cell infiltration and immune checkpoint expression were linked to HCC development.

Conclusion

This study identified five biomarkers of propionate metabolism that can predict HCC prognosis. This finding may provide a deeper understanding of PMRG function in HCC.

LncRNA SNHG1 upregulates FANCD2 and G6PD to suppress ferroptosis by sponging miR-199a-5p/3p in hepatocellular carcinoma

Ferroptosis is a form of regulated cell death (RCD) triggered by iron-dependent lipid peroxidation and is closely associated with the occurrence and progression of hepatocellular carcinoma (HCC). The lncRNA SNHG1 (small nucleolar RNA host gene 1) has been shown to play an oncogenic role in HCC, but its function in RCD other than autophagy and apoptosis is still unknown. Here, we investigated the correlation between SNHG1 and 156 typical markers of five RCD types based on RNA sequencing data from The Cancer Genome Atlas database and showed the negative regulators of ferroptosis FANCD2 (Fanconi anemia complementation group D2) and G6PD (glucose-6-phosphate dehydrogenase) to be the most highly and fifth most highly correlating factors with SNHG1, respectively. A competitive endogenous RNA network of SNHG1 - miR-199a-5p/3p - FANCD2/G6PD was constructed bioinformatically. In vitro experiments showed that overexpression of the miR-199a precursor led to a decrease in expression of SNHG1, FANCD2, and G6PD, whereas knockdown of SNHG1 decreased expression of FANCD2 and G6PD but increased levels of miR-199a-5p and miR-199a-3p in HCC cells (Huh7 and HepG2). In addition, knockdown of SNHG1 increased erastin-mediated ferroptosis, iron accumulation, and lipid peroxidation. These results suggest that SNHG1 upregulates FANCD2 and G6PD by sponging miR-199a, thereby inhibiting ferroptosis in HCC. Moreover, a signature based on expression of SNHG1, FANCD2, and G6PD was identified as being associated with overall survival and the immunological microenvironment in HCC. Collectively, this study identified the SNHG1-miR-199a-FANCD2/G6PD axis in HCC, which is a potential marker for the prognosis and therapy of this tumor.

Cellular senescence throws new insights into patient classification and pharmacological interventions for clinical management of hepatocellular carcinoma

BACKGROUND

Cellular senescence, a state of stable growth arrest, is intertwined with human cancers. However, characterization of cellular senescence-associated phenotypes in hepatocellular carcinoma (HCC) remains unexplored.

AIM

To address this issue, we delineated cellular senescence landscape across HCC.

METHODS

We enrolled two HCC datasets, TCGA-LIHC and International Cancer Genome Consortium (ICGC). Unsupervised clustering was executed to probe tumor heterogeneity based upon cellular senescence genes. Least absolute shrinkage and selection operator algorithm were utilized to define a cellular senescence-relevant scoring system. TRNP1 expression was measured in HCCs and normal tissues through immunohistochemistry, immunoblotting and quantitative real-time polymerase chain reaction. The influence of TMF-regulated nuclear protein (TRNP)1 on HCC senescence and growth was proven via a series of experiments.

RESULTS

TCGA-LIHC patients were classified as three cellular senescence subtypes, named C1-3. The robustness and reproducibility of these subtypes were proven in the ICGC cohort. C2 had the worst overall survival, C1 the next, and C3 the best. C2 presented the highest levels of immune checkpoints, abundance of immune cells, and immunogenetic indicators. Thus, C2 might possibly respond to immunotherapy. C2 had the lowest somatic mutation rate, while C1 presented the highest copy number variations. A cellular senescence-relevant gene signature was generated, which can predict patient survival, and chemo- or immunotherapeutic response. Experimentally, it was proven that TRNP1 presented the remarkable upregulation in HCCs. TRNP1 knockdown induced apoptosis and senescence of HCC cells and attenuated tumor growth.

CONCLUSION

These findings provide a systematic framework for assessing cellular senescence in HCC, which decode the tumor heterogeneity and tailor the pharmacological interventions to improve clinical management.

Ferroptosis, Necroptosis, and Pyroptosis in Gastrointestinal Cancers: The Chief Culprits of Tumor Progression and Drug Resistance

In recent years, the incidence of gastrointestinal cancers is increasing, particularly in the younger population. Effective treatment is crucial for improving patients' survival outcomes. Programmed cell death, regulated by various genes, plays a fundamental role in the growth and development of organisms. It is also critical for maintaining tissue and organ homeostasis and takes part in multiple pathological processes. In addition to apoptosis, there are other types of programmed cell death, such as ferroptosis, necroptosis, and pyroptosis, which can induce severe inflammatory responses. Notably, besides apoptosis, ferroptosis, necroptosis, and pyroptosis also contribute to the occurrence and development of gastrointestinal cancers. This review aims to provide a comprehensive summary on the biological roles and molecular mechanisms of ferroptosis, necroptosis, and pyroptosis, as well as their regulators in gastrointestinal cancers and hope to open up new paths for tumor targeted therapy in the near future.

Ferroptosis in Cancer Progression

Ferroptosis is a newly discovered iron-dependent form of regulated cell death driven by phospholipid peroxidation and associated with processes including iron overload, lipid peroxidation, and dysfunction of cellular antioxidant systems. Ferroptosis is found to be closely related to many diseases, including cancer at every stage. Epithelial-mesenchymal transition (EMT) in malignant tumors that originate from epithelia promotes cancer-cell migration, invasion, and metastasis by disrupting cell-cell and cell-cell matrix junctions, cell polarity, etc. Recent studies have shown that ferroptosis appears to share multiple initiators and overlapping pathways with EMT in cancers and identify ferroptosis as a potential predictor of various cancer grades and prognoses. Cancer metastasis involves multiple steps, including local invasion of cancer cells, intravasation, survival in circulation, arrest at a distant organ site, extravasation and adaptation to foreign tissue microenvironments, angiogenesis, and the formation of "premetastatic niche". Numerous studies have revealed that ferroptosis is closely associated with cancer metastasis. From the cellular perspective, ferroptosis has been implicated in the regulation of cancer metastasis. From the molecular perspective, the signaling pathways activated during the two events interweave. This review briefly introduces the mechanisms of ferroptosis and discusses how ferroptosis is involved in cancer progression, including EMT, cancer angiogenesis, invasion, and metastasis.

The role of molecular subtypes and immune infiltration characteristics based on disulfidptosis-associated genes in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is the most common type of lung cancer which accounts for about 40% of all lung cancers. Early detection, risk stratification and treatment are important for improving outcomes for LUAD. Recent studies have found that abnormal accumulation of cystine and other disulfide occurs in the cell under glucose starvation, which induces disulfide stress and increases the content of disulfide bond in actin cytoskeleton, resulting in cell death, which is defined as disulfidptosis. Because the study of disulfidptosis is in its infancy, its role in disease progression is still unclear. In this study, we detected the expression and mutation of disulfidptosis genes in LUAD using a public database. Clustering analysis based on disulfidptosis gene was performed and differential genes of disulfidptosis subtype were analyzed. 7 differential genes of disulfidptosis subtype were used to construct a prognostic risk model, and the causes of prognostic differences were investigated by immune-infiltration analysis, immune checkpoint analysis, and drug sensitivity analysis. qPCR was used to verify the expression of 7 key genes in lung cancer cell line (A549) and normal bronchial epithelial cell line (BEAS-2B). Since G6PD had the highest risk factor of lung cancer, we further verified the protein expression of G6PD in lung cancer cells by western blot, and confirmed through colony formation experiment that interference with G6PD was able to significantly inhibit the proliferation ability of lung cancer cells. Our results provide evidence for the role of disulfidptosis in LUAD and provide new ideas for individualized precision therapy of LUAD.

Role of Escin in breast cancer therapy: potential mechanism for inducing ferroptosis and synergistic antitumor activity with cisplatin

Breast cancer (BC) has threatened women worldwide for a long time, and novel treatments are needed. Ferroptosis is a new form of regulated cell death that is a potential therapeutic target for BC. In this study, we identified Escin, a traditional Chinese medicine, as a possible supplement for existing chemotherapy strategies. Escin inhibited BC cell growth in vitro and in vivo, and ferroptosis is probable to be the main cause for Escin-induced cell death. Mechanistically, Escin significantly downregulated the protein level of GPX4, while overexpression of GPX4 could reverse the ferroptosis triggered by Escin. Further study revealed that Escin could promote G6PD ubiquitination and degradation, thus inhibiting the expression of GPX4 and contributing to the ferroptosis. Moreover, proteasome inhibitor MG132 or G6PD overexpression could partially reverse Escin-induced ferroptosis, when G6PD knockdown aggravated that. In vivo study also supported that downregulation of G6PD exacerbated tumor growth inhibition by Escin. Finally, our data showed that cell apoptosis was dramatically elevated by Escin combined with cisplatin in BC cells. Taken together, these results suggest that Escin inhibits tumor growth in vivo and in vitro via regulating the ferroptosis mediated by G6PD/GPX4 axis. Our findings provide a promising therapeutic strategy for BC.

Malic Enzyme 1 as a Novel Anti-Ferroptotic Regulator in Hepatic Ischemia/Reperfusion Injury

Ferroptosis has been linked to the pathogenesis of hepatic injury induced by ischemia/reperfusion (I/R). However, the mechanistic basis remains unclear. In this study, by using a mouse model of hepatic I/R injury, it is observed that glutathione (GSH) and cysteine depletion are associated with deficiency of the reducing power of nicotinamide adenine dinucleotide phosphate (NADPH). Genes involved in maintaining NADPH homeostasis are screened, and it is identified that I/R-induced hepatic ferroptosis is significantly associated with reduced expression and activity of NADP⁺ -dependent malic enzyme 1 (Me1). Mice with hepatocyte-specific Me1 gene deletion exhibit aggravated ferroptosis and liver injury under I/R treatment; while supplementation with L-malate, the substrate of ME1, restores NADPH and GSH levels and eventually inhibits I/R-induced hepatic ferroptosis and injury. A mechanistic study further reveals that downregulation of hepatic Me1 expression is largely mediated by the phosphatase and tensin homologue (PTEN)-dependent suppression of the mechanistic target of rapamycin/sterol regulatory element-binding protein 1 (mTOR/SREBP1) signaling pathway in hepatic I/R model. Finally, PTEN inhibitor, mTOR activator, or SREBP1 over-expression all increase hepatic NADPH, block ferroptosis, and protect liver against I/R injury. Taken together, the findings suggest that targeting ME1 may provide new therapeutic opportunities for I/R injury and other ferroptosis-related hepatic conditions.

A pyroptosis-related gene signature for prognosis prediction in hepatocellular carcinoma

Introduction

Hepatocellular carcinoma (HCC) is one of the most invasive cancers with a low 5-year survival rate. Pyroptosis, a specialized form of cell death, has shown its association with cancer progression. However, its role in the prognosis of HCC has not been fully understood.

Methods

In our study, clinical information and mRNA expression for 1076 patients with HCC were obtained from the five public cohorts. Pyroptotic clusters were generated by unsupervised clustering based on 40 pyroptosis-related genes (PRGs) in the TCGA and ICGC cohort. A pyroptosis-related signature was constructed using least absolute shrinkage and selection operator (LASSO) regression according to differentially expressed genes (DEGs) of pyroptotic clusters. The signature was then tested in the validation cohorts (GES10142 and GSE14520) and subsequently validated in the CPTAC cohort (n=159) at both mRNA and protein levels. Response to sorafenib was explored in GSE109211.

Results

Three clusters were identified based on the 40 PRGs in the TCGA cohort. A total of 24 genes were selected based on DEGs of the above three pyroptotic clusters to construct the pyroptotic risk score. Patients with the high-risk score showed shorter overall survival (OS) compared to those with the low-risk score in the training set (P&lt;0.001; HR, 3.06; 95% CI, 2.22-4.24) and the test set (P=0.008; HR, 1.61; 95% CI, 1.13-2.28). The predictive ability of the risk score was further confirmed in the CPTAC cohort at both mRNAs (P&lt;0.001; HR, 2.99; 95% CI, 1.67-5.36) and protein levels (P&lt;0.001; HR, 2.97; 95% CI 1.66-5.31). The expression of the model genes was correlated with immune cell infiltration, angiogenesis-related genes, and sensitivity to antiangiogenic therapy (P&lt;0.05).

Discussion

In conclusion, we established a prognostic signature of 24 genes based on pyroptosis clusters for HCC patients, providing insight into the risk stratification of HCC.

Ferroptosis in gastrointestinal cancer: From mechanisms to implications

Ferroptosis is a form of regulated cell death that is initiated by excessive lipid peroxidation that results in plasma membrane damage and the release of damage-associated molecular patterns. In recent years, ferroptosis has gained significant attention in cancer research due to its unique mechanism compared to other forms of regulated cell death, especially caspase-dependent apoptotic cell death. Gastrointestinal (GI) cancer encompasses malignancies that arise in the digestive tract, including the stomach, intestines, pancreas, colon, liver, rectum, anus, and biliary system. These cancers are a global health concern, with high incidence and mortality rates. Despite advances in medical treatments, drug resistance caused by defects in apoptotic pathways remains a persistent challenge in the management of GI cancer. Hence, exploring the role of ferroptosis in GI cancers may lead to more efficacious treatment strategies. In this review, we provide a comprehensive overview of the core mechanism of ferroptosis and discuss its function, regulation, and implications in the context of GI cancers.

The advancements in targets for ferroptosis in liver diseases

Ferroptosis is a type of regulated cell death caused by iron overload and lipid peroxidation, and its core is an imbalance of redox reactions. Recent studies showed that ferroptosis played a dual role in liver diseases, that was, as a therapeutic target and a pathogenic factor. Therefore, herein, we summarized the role of ferroptosis in liver diseases, reviewed the part of available targets, such as drugs, small molecules, and nanomaterials, that acted on ferroptosis in liver diseases, and discussed the current challenges and prospects.

NRF2 signaling pathway: A comprehensive prognostic and gene expression profile analysis in breast cancer

Breast cancer is the most frequently diagnosed malignant tumor in women and a major public health concern. NRF2 axis is a cellular protector signaling pathway protecting both normal and cancer cells from oxidative damage. NRF2 is a transcription factor that binds to the gene promoters containing antioxidant response element-like sequences. In this report, differential expression of NRF2 signaling pathway elements, as well as the correlation of NRF2 pathway mRNAs with various clinicopathologic characteristics, including molecular subtypes, tumor grade, tumor stage, and methylation status, has been investigated in breast cancer using METABRIC and TCGA datasets. In the current report, our findings revealed the deregulation of several NRF2 signaling elements in breast cancer patients. Moreover, there were negative correlations between the methylation of NRF2 genes and mRNA expression. The expression of NRF2 genes significantly varied between different breast cancer subtypes. In conclusion, substantial deregulation of NRF2 signaling components suggests an important role of these genes in breast cancer. Because of the clear associations between mRNA expression and methylation status, DNA methylation could be one of the mechanisms that regulate the NRF2 pathway in breast cancer. Differential expression of Hippo genes among various breast cancer molecular subtypes suggests that NRF2 signaling may function differently in different subtypes of breast cancer. Our data also highlights an interesting link between NRF2 components' transcription and tumor grade/stage in breast cancer.

Integrated analysis of ferroptosis-related gene signature for overall survival prediction in Asian patients with hepatocellular carcinoma

PURPOSE

Hepatocellular carcinoma (HCC) is one of the most prevalent types of cancers in Asia. Accumulating evidence suggests that ferroptosis is a non-apoptotic form of cell death, and has played an important role in cancer biology.

METHODS

Based on the manually curated ferroptosis-related gene set and TCGA-LIHC dataset of Asian patients, we used DESeq2, Kaplan-Meier analysis, and univariate Cox regression to identify differentially expressed ferroptosis-related genes with significantly prognostic capacity. A risk signature was constructed based on the selected genes for predicting the survival of HCC patients in Asia. The survival prediction accuracy was confirmed by the time-dependent receiver operating characteristic (ROC) curve analysis. Gene set variation analysis (GSVA) was used to explore the functional associations of the signature. Ferroptosis potential index (FPI) and xCell algorithm was applied to quantify ferroptosis and immune cell infiltration, respectively. Two independent datasets from the GEO and the ICGC database were used for external validation.

RESULTS

The ferroptosis-related signature could accurately predict the survival outcomes of HCC patients in Asian (p value < 0.0001). We showed that the signature was an independent factor and was beneficial in elevating risk stratification of current clinicopathologic features, such as the amount of alpha-fetoprotein (AFP) and residual tumor classification. Functional characterization showed that critical processes in tumorigenesis belonged to the high-risk groups, for example inflammatory response, which may be the main driver of HCC. The high-risk group had higher FPIs and infiltrations of macrophages and T-helper cells than the low-risk group. Furthermore, two independent cohorts confirmed the prognostic value of our signature.

CONCLUSION

Overall, our results demonstrated potential application of ferroptosis-related genes as independent biomarkers in Asian HCC patients. Targeting ferroptosis may be clinically useful beyond known clinicopathological factors and provide benefit in immunotherapy.

Tiliroside targets TBK1 to induce ferroptosis and sensitize hepatocellular carcinoma to sorafenib

BACKGROUND

Combination therapy with other antineoplastic agent is a favorable approach for targeting the molecules involved in sorafenib resistance.

PURPOSE

In the present study, we determined whether tiliroside, a natural flavonoid glycoside isolated from oriental paperbush flower, could improve the sensitivity of hepatocellular carcinoma (HCC) cells to sorafenib. Furthermore, we investigated the mechanisms and identified the potential drug targets of tiliroside.

METHODS

Synergy was performed using CalcuSyn. Transcriptomic studies were adopted to investigate whether tiliroside could induce ferroptosis and inhibit the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway in HCC cells. Ferroptosis was analyzed using western blotting, flow cytometry, and transmission electron microscopy. Immunofluorescence, co-immunoprecipitation, and Nrf2 knockdown or overexpression were performed to confirm the involvement of Nrf2 in tiliroside-induced ferroptosis. Additionally, molecular docking and biolayer interferometry-based measurements were used to confirm the direct target of tiliroside. Finally, subcutaneous xenograft and orthotopic xenograft tumors in nude mice were used to assess the effects of tiliroside in vivo.

RESULTS

Tiliroside significantly enhanced the anti-HCC activity of sorafenib without any discernible side effects. Moreover, the combination of tiliroside and sorafenib induced synergistic effects against HCC in vitro. The inhibitory effects of tiliroside on HCC were antagonized by N-acetylcysteine and the ferroptosis inhibitor liproxstatin-1. Studies on the mechanism of action revealed that tiliroside could directly bind to TANK-binding kinase 1 (TBK1) and inhibit its enzymatic activity. Inhibition of TBK1 by tiliroside decreased the phosphorylation of serine 349 on sequestosome-1 (p62) and the affinity of p62 for kelch like ECH-associated protein 1 (Keap1) and promoted Keap1-mediated Nrf2 ubiquitination and degradation. The downstream target proteins of Nrf2, including glutathione peroxidase 4, ferritin heavy chain 1, and glucose-6-phosphate dehydrogenase, demonstrated similar results to that of Nrf2 protein, inducing ferroptosis in tiliroside-treated HCC cells. We extended these findings in vivo and found that tiliroside inhibited the growth of HepG2 tumors in both subcutaneous xenograft and orthotopic xenograft tumor models of HCC.

CONCLUSION

Our findings imply that tiliroside is a potent TBK1 inhibitor and a candidate natural anti-cancer product that could function as a sensitizer of sorafenib in HCC treatment by targeting TBK1 to induce ferroptosis.

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.

A cellular senescence-related genes model allows for prognosis and treatment stratification of hepatocellular carcinoma: A bioinformatics analysis and experimental verification

Introduction: Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer with low 5-year survival rate. Cellular senescence, characterized by permanent and irreversible cell proliferation arrest, plays an important role in tumorigenesis and development. This study aims to develop a cellular senescence-based stratified model, and a multivariable-based nomogram for guiding clinical therapy for HCC. Materials and methods: The mRNAs expression data of HCC patients and cellular senescence-related genes were obtained from TCGA and CellAge database, respectively. Through multiple analysis, a four cellular senescence-related genes-based prognostic stratified model was constructed and its predictive performance was validated through various methods. Then, a nomogram based on the model was constructed and HCC patients stratified by the model were analyzed for tumor mutation burden, tumor microenvironment, immune infiltration, drug sensitivity and immune checkpoint. Functional enrichment analysis was performed to explore potential biological pathways. Finally, we verified this model by siRNA transfection, scratch assay and Transwell Assay. Results: We established an cellular senescence-related genes-based stratified model, and a multivariable-based nomogram, which could accurately predict the prognosis of HCC patients in the ICGC database. The low and high risk score HCC patients stratified by the model showed different tumor mutation burden, tumor microenvironment, immune infiltration, drug sensitivity and immune checkpoint expressions. Functional enrichment analysis suggested several biological pathways related to the process and prognosis of HCC. Scratch assay and transwell assay indicated the promotion effects of the four cellular senescence-related genes (EZH2, G6PD, CBX8, and NDRG1) on the migraiton and invasion of HCC. Conclusion: We established a cellular senescence-based stratified model, and a multivariable-based nomogram, which could predict the survival of HCC patients and guide clinical treatment.

Role of ferroptosis and its non-coding RNA regulation in hepatocellular carcinoma

Ferroptosis is a newly discovered form of programmed cell death that involves the accumulation of iron-dependent lipid peroxides and plays a vital role in the tumorigenesis, development, and drug resistance of various tumors such as hepatocellular carcinoma (HCC). As a hotspot in molecular biology, non-coding RNAs (ncRNAs) participate in the initiation and progression of HCC, either act as oncogenes or tumor suppressors. Recent studies have shown that ncRNAs can regulate ferroptosis in HCC cells, which would affect the tumor progression and drug resistance. Therefore, clarifying the underlying role of ferroptosis and the regulatory role of ncRNA on ferroptosis in HCC could develop new treatment interventions for this disease. This review briefly summarizes the role of ferroptosis and ferroptosis-related ncRNAs in HCC tumorigenesis, progression, treatment, drug resistance and prognosis, for the development of potential therapeutic strategies and prognostic markers in HCC patients.

Ferroptosis in hepatocellular carcinoma: mechanisms and targeted therapy

Hepatocellular carcinoma is the most prevalent form of primary liver cancer with a multifactorial aetiology comprising genetic, environmental, and behavioural factors. Evading cell death is a defining hallmark of hepatocellular carcinoma, underpinning tumour growth, progression, and therapy resistance. Ferroptosis is a form of nonapoptotic cell death driven by an array of cellular events, including intracellular iron overload, free radical production, lipid peroxidation and activation of various cell death effectors, ultimately leading to rupture of the plasma membrane. Although induction of ferroptosis is an emerging strategy to suppress hepatocellular carcinoma, malignant cells manage to develop adaptive mechanisms, conferring resistance to ferroptosis and ferroptosis-inducing drugs. Herein, we aim at elucidating molecular mechanisms and signalling pathways involved in ferroptosis and offer our opinions on druggable targets and new therapeutic strategy in an attempt to restrain the growth and progression of hepatocellular carcinoma through induction of ferroptotic cell death.

Genes Modulating Butyrate Metabolism for Assessing Clinical Prognosis and Responses to Systematic Therapies in Hepatocellular Carcinoma

Butyrate, one of the major products of the gut microbiota, has played notable roles in diverse therapies for multiple tumors. Our study aimed to determine the roles of genes that modulate butyrate metabolism (BM) in predicting the clinical prognosis and responses to systemic therapies in hepatocellular carcinoma (HCC). The genes modulating BM were available from the GeneCard database, and gene expression and clinical information were obtained from TCGA-LIHC, GEO, ICGC-JP, and CCLE databases. Candidate genes from these genes that regulate BM were then identified by univariate Cox analysis. According to candidate genes, the patients in TCGA were grouped into distinct subtypes. Moreover, BM- related gene signature (BMGs) was created via the LASSO Cox algorithm. The roles of BMGs in identifying high-risk patients of HCC, assessing the prognoses, and predicting systematic therapies were determined in various datasets. The statistical analyses were fulfilled with R 4.1.3, GraphPad Prism 8.0 and Perl 5.30.0.1 software. In the TCGA cohort, most butyrate-related genes were over-expressed in the B cluster, and patients in the B cluster showed worse prognoses. BMGs constructed by LASSO were composed of eight genes. BMGs exhibited a strong performance in evaluating the prognoses of HCC patients in various datasets, which may be superior to 33 published biomarkers. Furthermore, BMGs may contribute to the early surveillance of HCC, and BMGs could play active roles in assessing the effectiveness of immunotherapy, TACE, ablation therapy, and chemotherapeutic drugs for HCC. BMGs may be served as novel promising biomarkers for early identifying high-risk groups of HCC, as well as assessing prognoses, drug sensitivity, and the responses to immunotherapy, TACE, and ablation therapy in patients with HCC.

Cuproptosis regulator-mediated patterns associated with immune infiltration features and construction of cuproptosis-related signatures to guide immunotherapy

Background

Liver hepatocellular carcinoma (HCC) is a prevalent cancer that lacks a sufficiently efficient approach to guide immunotherapy. Additionally, cuproptosis is a recently identified regulated cell death program that is triggered by copper ionophores. However, its possible significance in tumor immune cell infiltration is still unclear.

Methods

Cuproptosis subtypes in HCC were identified using unsupervised consensus cluster analysis based on 10 cuproptosis regulators expressions, and a cuproptosis-related risk signature was generated using univariate and LASSO Cox regression and validated using the ICGC data. Moreover, the relationship between signature and tumor immune microenvironment (TME) was studied through tumor immunotherapy responsiveness, immune cell infiltration, and tumor stem cell analysis. Finally, clinical specimens were analyzed using immunohistochemistry to verify the expression of the three genes in the signature.

Results

Two subtypes of cuproptosis regulation were observed in HCC, with different immune cell infiltration features. Genes expressed differentially between the two cuproptosis clusters in the TCGA were determined and used to construct a risk signature that was validated using the ICGC cohort. Greater immune and stromal cell infiltration were observed in the high-risk group and were associated with unfavorable prognosis. Elevated risk scores were linked with higher RNA stemness scores (RNAss) and tumor mutational burden (TMB), together with a greater likelihood of benefitting from immunotherapy.

Conclusion

It was found that cuproptosis regulatory patterns may play important roles in the heterogeneity of immune cell infiltration. The risk signature associated with cuproptosis can assess each patient's risk score, leading to more individualized and effective immunotherapy.

A Novel Ferroptosis-Related Signature for Prediction of Prognosis, Immune Profiles and Drug Sensitivity in Hepatocellular Carcinoma Patients

Hepatocellular carcinoma (HCC) is a malignant disease with an increasing incidence and a high mortality rate. Ferroptosis, a novel type of cell death, has been reported to be closely associated with the progression of HCC. The aim of our study was to construct a novel ferroptosis-related signature (nFRGs) for prediction of prognosis, immune features and drug sensitivity of HCC patients. Data were obtained from the TCGA, ICGC, GSE104580, CCLE and IMvigor210 datasets, and the least absolute shrinkage and selection operator (LASSO) was used to construct nFRGs. In addition, the analyses involved in prognoses, molecular function, stemness indices, somatic mutation, responses to immunologic therapy, efficacy of transcatheter arterial chemoembolization (TACE) therapy and drug sensitivity were performed using diverse packages of R 4.1.3 between the low- and high-risk groups. The nFRGs included seven ferroptosis-related genes. Our results showed that nFRGs was an independent risk factor for prognoses of HCC patients, and HCC patients in the high-risk group presented with worse prognosis. Compared with the results of other studies, nFRGs was superior to other promising signatures in predicting prognoses of patients with HCC. In addition, most of the enriched pathways of differentially expressed genes (DEGs) between these subgroups were related to immune features. The molecular functions, genetic mutation and mRNAsi were varied between the high- and low-risk groups. Moreover, we observed significant immunosuppression state in the high-risk group. Patients in the high-risk group might benefit from immunotherapy, whereas patients in the low-risk group may be susceptible to TACE therapy. Finally, five sensitive drugs and four sensitive drugs were screened for patients in the high- and low-risk groups, respectively. nFRGs may served as a novel biomarker of prognosis and aid in personalized therapeutic strategies for patients with HCC.

A novel signature of combing cuproptosis- with ferroptosis-related genes for prediction of prognosis, immunologic therapy responses and drug sensitivity in hepatocellular carcinoma

Background

Our study aimed to construct a novel signature (CRFs) of combing cuproptosis-related genes with ferroptosis-related genes for the prediction of the prognosis, responses of immunological therapy, and drug sensitivity of hepatocellular carcinoma (HCC) patients.

Methods

The RNA sequencing and corresponding clinical data of patients with HCC were downloaded from The Cancer Genome Atlas (TCGA), International Cancer Genome Consortium (ICGC), GSE76427, GSE144269, GSE140580, Cancer Cell Line Encyclopedia (CCLE), and IMvigor210 cohorts. CRFs was constructed using the least absolute shrinkage and selection operator (LASSO) algorithm. The analyses involved in the prognosis, response to immunologic therapy, efficacy of transcatheter arterial chemoembolization (TACE) therapy, and drug sensitivity were performed. Furthermore, the molecular function, somatic mutation, and stemness analyses were further performed between the low- and high-risk groups, respectively. In this study, the statistical analyses were performed by using the diverse packages of R 4.1.3 software and Cytoscape 3.8.0.

Results

CRFs included seven genes (G6PD, NRAS, RRM2, SQSTM1, SRXN1, TXNRD1, and ZFP69B). Multivariate Cox regression analyses demonstrated that CRFs were an independent risk factor for prognosis. In addition, these patients in the high-risk group presented with worse prognoses and a significant state of immunosuppression. Moreover, patients in the high-risk group might achieve greater outcomes after receiving immunologic therapy, while patients in the low-risk group are sensitive to TACE. Furthermore, we discovered that patients in the high-risk group may benefit from the administration of sunitinib. In addition, enhanced mRANsi and tumor mutation burden (TMB) yielded in the high-risk group. Additionally, the functions enriched in the low-risk group differed from those in the other group.

Conclusion

In summary, CRFs may be regarded not only as a novel biomarker of worse prognosis, but also as an excellent predictor of immunotherapy response, efficacy of TACE and drug sensitivity in HCC, which is worthy of clinical promotion.

Recent findings in the regulation of G6PD and its role in diseases

Glucose-6-phosphate dehydrogenase (G6PD) is the only rate-limiting enzyme in the pentose phosphate pathway (PPP). Rapidly proliferating cells require metabolites from PPP to synthesize ribonucleotides and maintain intracellular redox homeostasis. G6PD expression can be abnormally elevated in a variety of cancers. In addition, G6PD may act as a regulator of viral replication and vascular smooth muscle function. Therefore, G6PD-mediated activation of PPP may promote tumor and non-neoplastic disease progression. Recently, studies have identified post-translational modifications (PTMs) as an important mechanism for regulating G6PD function. Here, we provide a comprehensive review of various PTMs (e.g., phosphorylation, acetylation, glycosylation, ubiquitination, and glutarylation), which are identified in the regulation of G6PD structure, expression and enzymatic activity. In addition, we review signaling pathways that regulate G6PD and evaluate the role of oncogenic signals that lead to the reprogramming of PPP in tumor and non-neoplastic diseases as well as summarize the inhibitors that target G6PD.

Perspectives and mechanisms for targeting ferroptosis in the treatment of hepatocellular carcinoma

Ferroptosis is a novel process of regulated cell death discovered in recent years, mainly caused by intracellular lipid peroxidation. It is morphologically manifested as shrinking of mitochondria, swelling of cytoplasm and organelles, rupture of plasma membrane, and formation of double-membrane vesicles. Work done in the past 5 years indicates that induction of ferroptosis is a promising strategy in the treatment of hepatocellular carcinoma (HCC). System xc^-/GSH/GPX4, iron metabolism, p53 and lipid peroxidation pathways are the main focus areas in ferroptosis research. In this paper, we analyze the ferroptosis-inducing drugs and experimental agents that have been used in the last 5 years in the treatment of HCC. We summarize four different key molecular mechanisms that induce ferroptosis, i.e., system xc^-/GSH/GPX4, iron metabolism, p53 and lipid peroxidation. Finally, we outline the prognostic analysis associated with ferroptosis in HCC. The findings summarized suggest that ferroptosis induction can serve as a promising new therapeutic approach for HCC and can provide a basis for clinical diagnosis and prevention of this disease.

Understanding the mechanistic regulation of ferroptosis in cancer: gene matters

Ferroptosis has emerged as a crucial regulated cell death involved in a variety of physiological processes or pathological diseases, such as tumor suppression. Though initially being found from anti-cancer drug screening and considered not essential as apoptosis for growth and development, numerous studies have demonstrated that ferroptosis is tightly regulated by key genetic pathways and/or genes, including several tumor suppressors and oncogenes. In this review, we will first introduce the basic concepts of ferroptosis, characterized by the features of non-apoptotic, iron-dependent and overwhelmed accumulation of lipid peroxides, and the underlying regulated circuits are considered to be pro-ferroptotic pathways. Then we discuss several established lipid peroxidation defending systems within cells, including SLC7A11/GPX4, FSP1/CoQ, GCH1/BH4, and mitochondria DHODH/CoQ, all of which serve as anti-ferroptoic pathways to prevent ferroptosis. Moreover, we provide a comprehensive summary of the genetic regulation of ferroptosis via targeting the above-mentioned pro-ferroptotic or anti-ferroptotic pathways. The regulation of pro- and anti-ferroptotic pathways gives rise to more specific responses to the tumor cells in a context-dependent manner, highlighting the unceasing study and deeper understanding of mechanistic regulation of ferroptosis for the purpose of applying ferroptosis induction in cancer therapy.

The Role of Ferroptosis in the Treatment and Drug Resistance of Hepatocellular Carcinoma

Cell death is a fundamental feature of multicellular organisms’ development and a key driver of degenerative diseases. Ferroptosis is a new regulatory cell death mediated by iron-dependent lipid peroxidation, which is different from apoptosis and necrosis in morphology, pathophysiology and mechanism. Recent studies have found that ferroptosis is involved in the development of many diseases including hepatocellular carcinoma (HCC). As further research progresses, specific mechanisms of ferroptosis in HCC are being revealed. In this review, we summarize these recent advances about the treatment of drug-resistance in HCC and the latest ferroptosis-related treatment for HCC.

Bioinformatics analysis of genes related to iron death in diabetic nephropathy through network and pathway levels based approaches

Diabetic nephropathy is one of the common microvascular complications of diabetes. Iron death is a recently reported way of cell death. To explore the effects of iron death on diabetic nephropathy, iron death score of diabetic nephropathy was analyzed based on the network and pathway levels. Furthermore, markers related to iron death were screened. Using RNA-seq data of diabetic nephropathy, samples were clustered uniformly and the disease was classified. Differentially expressed gene analysis was conducted on the typed disease samples, and the WGCNA algorithm was used to obtain key modules. String database was used to perform protein interaction analysis on key module genes for the selection of Hub genes. Moreover, principal component analysis method was applied to get transcription factors and non-coding genes, which interact with the Hub gene. All samples can be divided into two categories and principal component analysis shows that the two categories are significantly different. Hub genes (FPR3, C3AR1, CD14, ITGB2, RAC2 and ITGAM) related to iron death in diabetic nephropathy were obtained through gene expression differential analysis between different subtypes. Non-coding genes that interact with Hub genes, including hsa-miR-572, hsa-miR-29a-3p, hsa-miR-29b-3p, hsa-miR-208a-3p, hsa-miR-153-3p and hsa-miR-29c-3p, may be related to diabetic nephropathy. Transcription factors HIF1α, KLF4, KLF5, RUNX1, SP1, VDR and WT1 may be related to diabetic nephropathy. The above factors and Hub genes are collectively involved in the occurrence and development of diabetic nephropathy, which can be further studied in the future. Moreover, these factors and genes may be potential target for therapeutic drugs.

A Cell Cycle Progression-Derived Gene Signature to Predict Prognosis and Therapeutic Response in Hepatocellular Carcinoma

Objective

Dysregulation of cell cycle progression (CCP) is one of the hallmarks of cancer. Here, our study is aimed at developing a CCP-derived gene signature for predicting high-risk population of hepatocellular carcinoma (HCC).

Methods

Our study retrospectively analyzed the transcriptome profiling and clinical information of HCC patients from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) projects. Uni- and multivariate cox regression models were conducted for identifying which hallmarks of cancer were risk factors of HCC. CCP-derived gene signature was developed with LASSO method. The predictive efficacy was verified by ROC curves and subgroup analyses. A nomogram was then generated and validated by ROC, calibration, and decisive curves. Immune cell infiltration was estimated with ssGSEA method. Potential small molecular compounds were predicted via CTRP and CMap analyses. The response to chemotherapeutic agents was evaluated based on the GDSC project.

Results

Among hallmarks of cancer, CCP was identified as a dominant risk factor for HCC prognosis. CCP-derived gene signature displayed the favorable predictive efficacy in HCC prognosis independent of other clinicopathological parameters. A nomogram was generated for optimizing risk stratification and quantifying risk evaluation. CCP-derived signature was in relation to immune cell infiltration, HLA, and immune checkpoint expression. Combining CTRP and CMap analyses, fluvastatin was identified as a promising therapeutic agent against HCC. Furthermore, CCP-derived signature might be applied for predicting the response to doxorubicin and gemcitabine.

Conclusion

Collectively, CCP-derived gene signature was a promising marker in prediction of survival outcomes and therapeutic responses for HCC patients.