Downregulation of HULC Induces Ferroptosis in Hepatocellular Carcinoma via Targeting of the miR-3200-5p/ATF4 Axis

Ferroptosis-Regulated Natural Products and miRNAs and Their Potential Targeting to Ferroptosis and Exosome Biogenesis

Ferroptosis, which comprises iron-dependent cell death, is crucial in cancer and non-cancer treatments. Exosomes, the extracellular vesicles, may deliver biomolecules to regulate disease progression. The interplay between ferroptosis and exosomes may modulate cancer development but is rarely investigated in natural product treatments and their modulating miRNAs. This review focuses on the ferroptosis-modulating effects of natural products and miRNAs concerning their participation in ferroptosis and exosome biogenesis (secretion and assembly)-related targets in cancer and non-cancer cells. Natural products and miRNAs with ferroptosis-modulating effects were retrieved and organized. Next, a literature search established the connection of a panel of ferroptosis-modulating genes to these ferroptosis-associated natural products. Moreover, ferroptosis-associated miRNAs were inputted into the miRNA database (miRDB) to bioinformatically search the potential targets for the modulation of ferroptosis and exosome biogenesis. Finally, the literature search provided a connection between ferroptosis-modulating miRNAs and natural products. Consequently, the connections from ferroptosis-miRNA-exosome biogenesis to natural product-based anticancer treatments are well-organized. This review sheds light on the research directions for integrating miRNAs and exosome biogenesis into the ferroptosis-modulating therapeutic effects of natural products on cancer and non-cancer diseases.

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.

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.

The role of competing endogenous RNA network in the development of hepatocellular carcinoma: potential therapeutic targets

The current situation of hepatocellular carcinoma (HCC) management is challenging due to its high incidence, mortality, recurrence and metastasis. Recent advances in gene genetic and expression regulation have unveiled the significant role of non-coding RNA (ncRNA) in various cancers. This led to the formulation of the competing endogenous RNA (ceRNA) hypothesis, which posits that both coding RNA and ncRNA, containing miRNA response elements (MRE), can share the same miRNA sequence. This results in a competitive network between ncRNAs, such as lncRNA and mRNA, allowing them to regulate each other. Extensive research has highlighted the crucial role of the ceRNA network in HCC development, impacting various cellular processes including proliferation, metastasis, cell death, angiogenesis, tumor microenvironment, organismal immunity, and chemotherapy resistance. Additionally, the ceRNA network, mediated by lncRNA or circRNA, offers potential in early diagnosis and prevention of HCC. Consequently, ceRNAs are emerging as therapeutic targets for HCC. The complexity of these gene networks aligns with the multi-target approach of traditional Chinese medicine (TCM), presenting a novel perspective for TCM in combating HCC. Research is beginning to show that TCM compounds and prescriptions can affect HCC progression through the ceRNA network, inhibiting proliferation and metastasis, and inducing apoptosis. Currently, the lncRNAs TUG1, NEAT1, and CCAT1, along with their associated ceRNA networks, are among the most promising ncRNAs for HCC research. However, this field is still in its infancy, necessitating advanced technology and extensive basic research to fully understand the ceRNA network mechanisms of TCM in HCC treatment.

Ferroptosis: a new promising target for hepatocellular carcinoma therapy

Hepatocellular carcinoma (HCC) is the sixed most common malignant tumor in the world. The study for HCC is mired in the predicament confronted with the difficulty of early diagnosis and high drug resistance, the survival rate of patients with HCC being low. Ferroptosis, an iron-dependent cell death, has been discovered in recent years as a cell death means with tremendous potential to fight against cancer. The in-depth researches for iron metabolism, lipid peroxidation and dysregulation of antioxidant defense have brought about tangible progress in the firmament of ferroptosis with more and more results showing close connections between ferroptosis and HCC. The potential role of ferroptosis has been widely used in chemotherapy, immunotherapy, radiotherapy, and nanotherapy, with the development of various new drugs significantly improving the prognosis of patients. Based on the characteristics and mechanisms of ferroptosis, this article further focuses on the main signaling pathways and promising treatments of HCC, envisioning that existing problems in regard with ferroptosis and HCC could be grappled with in the foreseeable future.

Epigenetic modulation of ferroptosis in cancer: Identifying epigenetic targets for novel anticancer therapy

Ferroptosis is a newly recognized form of oxidative-regulated cell death resulting from iron-mediated lipid peroxidation accumulation. Radical-trapping antioxidant systems can eliminate these oxidized lipids and prevent disrupting the integrity of cell membranes. Epigenetic modifications can regulate ferroptosis by altering gene expression or cell phenotype without permanent sequence changes. These mechanisms include DNA methylation, histone modifications, RNA modifications, and noncoding RNAs. Epigenetic alterations in cancer can control the expression of ferroptosis regulators or related pathways, leading to changes in cell sensitivity to ferroptosis inducers or cancer progression. Epigenetic alterations in cancer are influenced by a wide range of cancer hallmarks, contributing to therapeutic resistance. Targeting epigenetic alterations is a promising approach to overcoming cancer resilience. However, the exact mechanisms involved in different types of cancer remain unresolved. Discovering more ferroptosis-associated epigenetic targets and interventions can help overcome current barriers in anticancer therapy. Many papers on epigenetic modifications of ferroptosis have been continuously published, making it essential to summarize the current state-of-the-art in the epigenetic regulation of ferroptosis in human cancer.

miR-3200 accelerates the growth of liver cancer cells by enhancing Rab7A

Researches indicate miR-3200 is closely related to tumorigenesis, However, the role of miR-3200 in human hepatocarcinogenesis is still unclear. In this study, we clearly demonstrate that miR-3200 accelerates the growth of liver cancer cells in vivo and in vitro. Obviously, these findings are noteworthy that miR-3200 affects the transcriptional regulation for several genes, including DSP，BABAM2, Rab7A,SQSTM1,PRKAG2,CDK1,ABCE1,BECN1,PTEN,UPRT. And miR-3200 affects the transcriptional ability of several genes, such as, upregulating CADPS, DSP,FBXO32, PPCA,SGK1, PATXN7L1, PLK2,ITGB5,FZD3,HOXC8,HSPA1A,C-Myc,CyclnD1,CyclinE,PCNA and down -regulating SUV39H1, MYO1G, OLFML3, CBX5, PPDE2A, HOXA7, RAD54L, CDC45,SHMT7,MAD2L1,P27,IQGAP3,PTEN,P57,SCAMP3,etc...On the other hand, it is obvious that miR-3200 affects the translational ability of several genes, such as, upregulating GNS,UPRT,EIFAD,YOS1,SGK1,K-Ras,PKM2,C-myc,Pim1,CyclinD1,mTOR,erbB-2,CyclinE,PCNA,RRAS,ARAF,RAPH1,etc.. and down-regulating KDM2A, AATF, TMM17B, RAB8B, MYO1G,P21WAF1/Cip1,GADD45,PTEN,P27,P18,P57,SERBP1,RPL34,UFD1,Bax,ANXA6,GSK3β. Strikingly, miR-3200 affects some signaling pathway in liver cancer, including carbon metabolism signaling pathway, DNA replication pathway, FoxO signaling pathway, Hippo signaling pathway, serine and threonine metabolism signaling pathway, mTOR signaling pathway, Fatty acid biosynthesis signaling pathway, carcinogenesis-receptor activation signaling pathway, autophagy signaling pathway. Furthermore, our results suggest that miR-3200 enhances expression of RAB7A, and then Rab7A regulates the carcinogenic function of miR-3200 by increasing telomere remodeling in human liver cancer. These results are of great significance for the prevention and treatment of human liver cancer.

Combating drug resistance in hepatocellular carcinoma: No awareness today, no action tomorrow

Hepatocellular carcinoma (HCC), the sixth most common cancer worldwide, is associated with a high degree of malignancy and poor prognosis. Patients with early HCC may benefit from surgical resection to remove tumor tissue and a margin of healthy tissue surrounding it. Unfortunately, most patients with HCC are diagnosed at an advanced or distant stage, at which point resection is not feasible. Systemic therapy is now routinely prescribed to patients with advanced HCC; however, drug resistance has become a major obstacle to the treatment of HCC and exploring purported mechanisms promoting drug resistance remains a challenge. Here, we focus on the determinants of drug resistance from the perspective of non-coding RNAs (ncRNAs), liver cancer stem cells (LCSCs), autophagy, epithelial-mesenchymal transition (EMT), exosomes, ferroptosis, and the tumor microenvironment (TME), with the aim to provide new insights into HCC treatment.

Noncoding RNAs in cancer ferroptosis: From biology to clinical opportunity

Ferroptosis is a recently discovered pattern of programmed cell death that is nonapoptotic and irondependent. It is involved in lipid peroxidation dependent on reactive oxygen species. Ferroptosis has been verified to play a crucial regulatory role in a variety of pathological courses of disease, in particularly cancer. Emerging research has highlighted the potential of ferroptosis in tumorigenesis, cancer development and resistance to chemotherapy. However, the regulatory mechanism of ferroptosis remains unclear, which limits the application of ferroptosis in cancer treatment. Noncoding RNAs (ncRNAs) are noncoding transcripts that regulate gene expression in various ways to affect the malignant phenotypes of cancer cells. At present, the biological function and underlying regulatory mechanism of ncRNAs in cancer ferroptosis have been partially elucidated. Herein, we summarize the current knowledge of the central regulatory network of ferroptosis, with a focus on the regulatory functions of ncRNAs in cancer ferroptosis. The clinical application and prospects of ferroptosis-related ncRNAs in cancer diagnosis, prognosis and anticancer therapies are also discussed. Elucidating the function and mechanism of ncRNAs in ferroptosis, along with assessing the clinical significance of ferroptosis-related ncRNAs, provides new perspectives for understanding cancer biology and treatment approaches, which may benefit numerous cancer patients in the future.

The Regulation of Ferroptosis by Noncoding RNAs

As a novel form of regulated cell death, ferroptosis is characterized by intracellular iron and lipid peroxide accumulation, which is different from other regulated cell death forms morphologically, biochemically, and immunologically. Ferroptosis is regulated by iron metabolism, lipid metabolism, and antioxidant defense systems as well as various transcription factors and related signal pathways. Emerging evidence has highlighted that ferroptosis is associated with many physiological and pathological processes, including cancer, neurodegeneration diseases, cardiovascular diseases, and ischemia/reperfusion injury. Noncoding RNAs are a group of functional RNA molecules that are not translated into proteins, which can regulate gene expression in various manners. An increasing number of studies have shown that noncoding RNAs, especially miRNAs, lncRNAs, and circRNAs, can interfere with the progression of ferroptosis by modulating ferroptosis-related genes or proteins directly or indirectly. In this review, we summarize the basic mechanisms and regulations of ferroptosis and focus on the recent studies on the mechanism for different types of ncRNAs to regulate ferroptosis in different physiological and pathological conditions, which will deepen our understanding of ferroptosis regulation by noncoding RNAs and provide new insights into employing noncoding RNAs in ferroptosis-associated therapeutic strategies.

Metformin promotes ferroptosis and sensitivity to sorafenib in hepatocellular carcinoma cells via ATF4/STAT3

BACKGROUND

Hepatocellular carcinoma (HCC) is a common cancer worldwide, and sorafenib is a first-line drug for the treatment of advanced liver cancer. Resistance to sorafenib has become a major challenge in the treatment of hepatocellular carcinoma, however, studies have shown that metformin can promote ferroptosis and sorafenib sensitivity. Therefore, the aim of this study was to investigate the promotion of ferroptosis and sorafenib sensitivity by metformin via ATF4/STAT3 in hepatocellular carcinoma cells.

METHODS

Hepatocellular carcinoma cells Huh7 and Hep3B and induced sorafenib resistance (SR) Huh7/SR and Hep3B/SR cells were used as in vitro cell models. Cells were injected subcutaneously to establish a drug-resistant mouse model. CCK-8 was used to detect cell viability and sorafenib IC50. Western blotting was used to detect the expression of relevant proteins. BODIPY staining was used to analyze the lipid peroxidation level in cells. A scratch assay was used to detect cell migration. Transwell assays were used to detect cell invasion. Immunofluorescence was used to localize the expression of ATF4 and STAT3.

RESULTS

Metformin promoted ferroptosis in hepatocellular carcinoma cells through ATF4/STAT3, decreased sorafenib IC50, increased ROS and lipid peroxidation levels, decreased cell migration and invasion, inhibited the expression of the drug-resistant proteins ABCG2 and P-GP in hepatocellular carcinoma cells, and thus inhibited sorafenib resistance in hepatocellular carcinoma cells. Downregulating ATF4 inhibited the phosphorylated nuclear translocation of STAT3, promoted ferroptosis, and increased the sensitivity of Huh7 cells to sorafenib. Metformin was also shown in animal models to promote ferroptosis and sorafenib sensitivity in vivo via ATF4/STAT3.

CONCLUSION

Metformin promotes ferroptosis and sensitivity to sorafenib in hepatocellular carcinoma cells via ATF4/STAT3, and it inhibits HCC progression.

Ferroptosis in tumors and its relationship to other programmed cell death: role of non-coding RNAs

Programmed cell death (PCD) plays an important role in many aspects of individual development, maintenance of body homeostasis and pathological processes. Ferroptosis is a novel form of PCD characterized by the accumulation of iron-dependent lipid peroxides resulting in lethal cell damage. It contributes to tumor progression in an apoptosis-independent manner. In recent years, an increasing number of non-coding RNAs (ncRNAs) have been demonstrated to mediate the biological process of ferroptosis, hence impacting carcinogenesis, progression, drug resistance, and prognosis. However, the clear regulatory mechanism for this phenomenon remains poorly understood. Moreover, ferroptosis does not usually exist independently. Its interaction with PCD, like apoptosis, necroptosis, autophagy, pyroptosis, and cuproptosis, to destroy cells appears to exist. Furthermore, ncRNA seems to be involved. Here, we review the mechanisms by which ferroptosis occurs, dissect its relationship with other forms of death, summarize the key regulatory roles played by ncRNAs, raise relevant questions and predict possible barriers to its application in the clinic, offering new ideas for targeted tumour therapy.

Deciphering the mechanisms of action of progesterone in breast cancer

A practice-changing, randomized, controlled clinical study established that preoperative hydroxyprogesterone administration improves disease-free and overall survival in patients with node-positive breast cancer. This research perspective summarizes evidences from our studies that preoperative hydroxyprogesterone administration may improve disease-free and overall survival in patients with node-positive breast cancer by modulating cellular stress response and negative regulation of inflammation. Non-coding RNAs, particularly DSCAM-AS1, play a regulatory role in this process, along with the upregulation of the kinase gene SGK1 and activation of the SGK1/AP-1/NDRG1 axis. Progesterone-induced modification of the progesterone receptor and estrogen receptor genomic binding pattern is also involved in orchestrating estrogen signaling in breast cancer, preventing cell migration and invasion, and improving patient outcomes. We also highlight the role of progesterone in endocrine therapy resistance, which could lead to novel treatment options for patients with hormone receptor-positive breast cancer and for those who develop resistance to traditional endocrine therapies.

Activating transcription factor 4 drives the progression of diabetic cardiac fibrosis

AIMS

Diabetic cardiomyopathy (DC) is one of serious complications of diabetic patients. This study investigated the biological function of activating transcription factor 4 (ATF4) in DC.

METHODS AND RESULTS

Streptozotocin-treated mice and high glucose (HG)-exposed HL-1 cells were used as the in vivo and in vitro models of DC. Myocardial infarction (MI) was induced by left coronary artery ligation in mice. Cardiac functional parameters were detected by echocardiography. Target molecule expression was determined by real time quantitative PCR and western blotting. Cardiac fibrosis was observed by haematoxylin and eosin and Masson's staining. Cardiac apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labelling. Activities of superoxide dismutase, glutathione peroxidase, and levels of malonic dialdehyde and reactive oxygen species were used to assess oxidative stress damage. Molecular mechanisms were evaluated by chromatin immunoprecipitation, dual luciferase assay, and co-immunoprecipitation. ATF4 was up-regulated in the DC and MI mice (P < 0.01). Down-regulation of ATF4 improved cardiac function as evidenced by changes in cardiac functional parameters (P < 0.01), inhibited myocardial collagen I (P < 0.001) and collagen III (P < 0.001) expression, apoptosis (P < 0.001), and oxidative stress (P < 0.001) in diabetic mice. Collagen I (P < 0.01) and collagen III (P < 0.01) expression was increased in MI mice, which was reversed by ATF4 silencing (P < 0.05). ATF4 depletion enhanced viability (P < 0.01), repressed apoptosis (P < 0.001), oxidative damage (P < 0.001), and collagen I (P < 0.001), and collagen III (P < 0.001) expression of HG-stimulated HL-1 cells. ATF4 transcriptionally activated Smad ubiquitin regulatory factor 2 (Smurf2, P < 0.001) to promote ubiquitination and degradation of homeodomain interacting protein kinase-2 (P < 0.001) and subsequently caused inactivation of nuclear factor erythroid 2-related factor 2/heme oxygenase 1 pathway (P < 0.001). The inhibitory effects of ATF4 silencing on HG-induced apoptosis (P < 0.01), oxidative injury (P < 0.01), collagen I (P < 0.001), and collagen III (P < 0.001) expression were reversed by Smurf2 overexpression.

CONCLUSIONS

ATF4 facilitates diabetic cardiac fibrosis and oxidative stress by promoting Smurf2-mediated ubiquitination and degradation of homeodomain interacting protein kinase-2 and then inactivation of nuclear factor erythroid 2-related factor 2/heme oxygenase 1 pathway, suggesting ATF4 as a treatment target for DC.

Regulation of ncRNAs involved with ferroptosis in various cancers

As a special pattern of programmed cell death, ferroptosis is reported to participate in several processes of tumor progression, including regulating proliferation, suppressing apoptotic pathways, increasing metastasis, and acquiring drug resistance. The marked features of ferroptosis are an abnormal intracellular iron metabolism and lipid peroxidation that are pluralistically modulated by ferroptosis-related molecules and signals, such as iron metabolism, lipid peroxidation, system Xc−, GPX4, ROS production, and Nrf2 signals. Non-coding RNAs (ncRNAs) are a type of functional RNA molecules that are not translated into a protein. Increasing studies demonstrate that ncRNAs have a diversity of regulatory roles in ferroptosis, thus influencing the progression of cancers. In this study, we review the fundamental mechanisms and regulation network of ncRNAs on ferroptosis in various tumors, aiming to provide a systematic understanding of recently emerging non-coding RNAs and ferroptosis.

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.

miR-21-5p Inhibits Ferroptosis in Hepatocellular Carcinoma Cells by Regulating the AKT/mTOR Signaling Pathway through MELK

Background

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers, and its incidence rate is increasing worldwide. At present, there is no ideal treatment for HCC. In recent years, molecular-targeted therapy has shown significant therapeutic benefits for patients. Ferroptosis is a modality of regulated cell death, and previous studies have found that inducing ferroptosis in liver cancer cells can inhibit the progression of liver cancer. The aim of this study is to investigate the regulatory mechanism of miR-21-5p in regulating ferroptosis in HCC cells.

Methods

CCK-8 was used to measure cell viability, EdU and colony formation were used to measure cell proliferation, and Transwell assays were used to measure cell migration and invasion. RT-qPCR was used to detect the level of miR-21-5p, Western blotting was used to detect the protein expression level, a dual-luciferase reporter gene assay was used to determine the targeting relationship between miR-21-5p and MELK, and coimmunoprecipitation was used to determine the interaction between MELK and AKT.

Results

Overexpression of miR-21-5p and MELK facilitated the viability, proliferation, colony formation, invasion, and migration of HCC cells. Downregulation of miR-21-5p suppressed the level of MELK and the progression of HCC. MELK regulated the AKT/mTOR signaling pathway, causing changes in the levels of GPX4, GSH, FTH1, xCT, heme oxygenase 1(HO-1), reactive oxygen species, and Fe²⁺ to regulate the ferroptosis of hepatoma cells. Erastin, an inducer of ferroptosis, attenuated the repressive influence of miR-21-5p on ferroptosis in HCC cells.

Conclusion

In summary, this study demonstrates that miR-21-5p inhibits the ferroptosis of HCC cells by regulating the AKT/mTOR signaling pathway through MELK.

Identification of a Novel N7-Methylguanosine-Related LncRNA Signature Predicts the Prognosis of Hepatocellular Carcinoma and Experiment Verification

(1) Background: It is well-known that long non-coding RNAs (lncRNAs) and N7-methylguanosine (m7G) contribute to hepatocellular carcinoma (HCC) progression. However, it remains unclear whether lncRNAs regulating m7G modification could predict HCC prognosis. Thus, we sought to explore the prognostic implications of m7G-related lncRNAs in HCC patients. (2) Methods: Prognostic M7G-related lncRNAs obtained from The Cancer Genome Atlas (TCGA) database were screened by co-expression analysis and univariate Cox regression analysis. Next, the m7G-related lncRNA signature (m7GRLSig) was conducted by Least absolute shrinkage and selection operator (LASSO) Cox regression and multivariate Cox regression analysis. Kaplan-Meier analysis and time-dependent receiver operating characteristics (ROC) assessed the prognostic abilities of our signature. Univariate and multivariate Cox regression, nomogram, and principal component analysis (PCA) were conducted to evaluate our signature. Subsequently, we investigated the role of m7GRLSig on the immune landscape and sensitivity to drugs in HCC patients. The potential function of lncRNAs obtained from the prognostic signature was explored by in vitro experiments. (3) Results: A novel m7GRLSig was identified using seven meaningful lncRNA (ZFPM2-AS1, AC092171.2, PIK3CD-AS2, NRAV, CASC19, HPN-AS1, AC022613.1). The m7GLPSig exhibited worse survival in the high-risk group and served as an independent prognostic factor. The m7GRLSig stratification was sensitive in assessing the immune landscape and sensitivity to drugs between the high-risk and low-risk groups. Finally, in vitro experiments confirmed that the knockdown of NRAV was accompanied by the downregulation of METTL1 during HCC progression. (4) Conclusions: The m7G-related signature is a potential predictor of HCC prognosis and contributes to individualize the effective drug treatment of HCC.

Relationship between miRNA and ferroptosis in tumors

Malignant tumor is a major killer that seriously endangers human health. At present, the methods of treating tumors include surgical resection, chemotherapy, radiotherapy and immunotherapy. However, the survival rate of patients is still very low due to the complicated mechanism of tumor occurrence and development and high recurrence rate. Individualized treatment will be the main direction of tumor treatment in the future. Because only by understanding the molecular mechanism of tumor development and differentially expressed genes can we carry out accurate treatment and improve the therapeutic effect. MicroRNA (miRNA) is a kind of small non coding RNA, which regulates gene expression at mRNA level and plays a key role in tumor regulation. Ferroptosis is a kind of programmed death caused by iron dependent lipid peroxidation, which is different from apoptosis, necrosis and other cell death modes. Now it has been found that ferroptosis plays an important role in the occurrence and development of tumors and drug resistance. More and more studies have found that miRNAs can regulate tumor development and drug resistance through ferroptosis. Therefore, in this review, the mechanism of ferroptosis is briefly outlined, and the relationship between miRNAs and ferroptosis in tumors is reviewed.

Identification and Validation of Ferroptosis-Related Genes in Sevoflurane-Induced Hippocampal Neurotoxicity

Background

Sevoflurane is one of the most popular inhalational anesthetics during perioperative period but presenting neurotoxicity among pediatric and aged populations. Recent experiments in vivo and in vitro have indicated that ferroptosis may contribute to the neurotoxicity of sevoflurane anesthesia. However, the exact mechanism is still unclear.

Methods

In current study, we explored the differential expressed genes (DEGs) in HT-22 mouse hippocampal neuronal cells after sevoflurane anesthesia using RNA-seq. Differential expressed ferroptosis-related genes (DEFRGs) were screened and analyzed by Gene Ontology (GO) and pathway enrichment analysis. Protein-to-protein interaction (PPI) network was constructed by the Search Tool for the Retrieval of Interacting Genes (STRING). Significant modules and the hub genes were identified by using Cytoscape. The Connectivity Map (cMAP) was used for screening drug candidates targeting the identified DEFRGs. Potential TF-gene network and drug-gene pairs were established towards the hub genes. In final, we validated these results in experiments.

Results

A total of 37 ferroptosis-related genes (18 upregulated and 19 downregulated) after sevoflurane exposure in hippocampal neuronal cells were finally identified. These differentially expressed genes were mainly involved into the biological processes of cellular response to oxidative stress. Pathway analysis indicated that these genes were involved in ferroptosis, mTOR signaling pathway, and longevity-regulating pathway. PPI network was constructed. 10 hub genes including Prkaa2, Chac1, Arntl, Tfrc, Slc7a11, Atf4, Mgst1, Lpin1, Atf3, and Sesn2 were found. Top 10 drug candidates, gene-drug networks, and TFs targeting these genes were finally identified. These results were validated in experiments.

Conclusion

Our results suggested that ferroptosis-related genes play roles in sevoflurane anesthesia-related hippocampal neuron injury and offered the hub genes and potential therapeutic agents for investigating and treatment of this neurotoxicity after sevoflurane exposure. Finally, therapeutic effect of these drug candidates and function of potential ferroptosis targets should be further investigated for treatment and clarifying mechanisms of sevoflurane anesthesia-induced neuron injury in future research.

Integrative analyses of prognosis, tumor immunity, and ceRNA network of the ferroptosis-associated gene FANCD2 in hepatocellular carcinoma

Extensive evidence has revealed that ferroptosis plays a vital role in HCC development and progression. Fanconi anemia complementation group D2 (FANCD2) has been reported to serve as a ferroptosis-associated gene and has a close relationship with tumorigenesis and drug resistance. However, the impact of the FANCD2-related immune response and its mechanisms in HCC remains incompletely understood. In the current research, we evaluated the prognostic significance and immune-associated mechanism of FANCD2 based on multiple bioinformatics methods and databases. The results demonstrated that FANCD2 was commonly upregulated in 15/33 tumors, and only the high expression of FANCD2 in HCC was closely correlated with worse clinical outcomes by OS and DFS analyses. Moreover, ncRNAs, including two major types, miRNAs and lncRNAs, were closely involved in mediating FANCD2 upregulation in HCC and were established in a ceRNA network by performing various in silico analyses. The DUXAP8-miR-29c-FANCD2 and LINC00511-miR-29c-FANCD2 axes were identified as the most likely ncRNA-associated upstream regulatory axis of FANCD2 in HCC. Finally, FANCD2 expression was confirmed to be positively related to HCC immune cell infiltration, immune checkpoints, and IPS analysis, and GSEA results also revealed that this ferroptosis-associated gene was primarily involved in cancer-associated pathways in HCC. In conclusion, our investigations indicate that ncRNA-related modulatory overexpression of FANCD2 might act as a promising prognostic and immunotherapeutic target against HCC.

Ferroptosis interaction with inflammatory microenvironments: Mechanism, biology, and treatment

Ferroptosis is a newly discovered form of regulated cell death. Ferroptosis is an iron-dependent lipid peroxidation reaction of cell membrane lipids, and it is closely related to the occurrence and development of many inflammatory diseases, such as ischemia-reperfusion injury, nonalcoholic steatohepatitis, and tumors. Although the precise role of ferroptosis in these inflammatory diseases is still unclear, recent evidence indicates that the association between ferroptosis and inflammatory diseases is related to the interaction of ferroptosis and inflammatory microenvironments. In inflammatory microenvironments, ferroptosis can be regulated by metabolic changes or the secretion of related substances between microorganisms and host cells or between host cells. At the same time, ferroptotic cells can also recruit immune cells by releasing injury-related molecular patterns, which in turn induces the generation of inflammatory microenvironments. Molecular crosstalk between ferroptosis and other cell death types also exists in inflammatory microenvironments. In addition, the interaction of ferroptosis and the tumor microenvironment is also correlated with tumor growth. This article reviews the main metabolic processes of ferroptosis, describes the interaction mechanism between ferroptosis and inflammatory microenvironments, and summarizes the role of ferroptosis in the treatment of diseases.

Emerging roles and potential clinical applications of long non-coding RNAs in hepatocellular carcinoma

Hepatocellular carcinoma is one of the most common highly malignant tumors in humans, as well as the leading cause of cancer-related death worldwide. Growing evidence has indicated that lncRNAs are implicated in different molecular mechanisms, including interactions with DNA, RNA, or protein, so that to regulate the gene expression at epigenetic, transcriptional, or posttranscriptional level. Moreover, the mechanism of action of lncRNA is closely related to its subcellular localization. An increasing number of studies have certified that lncRNA plays a significant biological function in the occurrence and development of hepatocellular carcinoma, such as involving in cell proliferation, metastasis, apoptosis, ferroptosis, autophagy, and reprogramming of energy metabolism. As a result, lncRNA has great potential as a novel biomarker for diagnosis or therapeutics of hepatocellular carcinoma. In this review, we highlight the correlation between subcellular localization of lncRNA and its mechanism of action, discuss the biological roles of lncRNA and the latest research advances in hepatocellular carcinoma, and emphasize the potential of lncRNA as a therapeutic target for advanced patients of hepatocellular carcinoma.