Sorafenib induces mitochondrial dysfunction and exhibits synergistic effect with cysteine depletion by promoting HCC cells ferroptosis

Targeting hyperactive mitochondria in activated HSCs and inhibition of liver fibrogenesis in mice using sorafenib complex micelles

Liver fibrosis is a pathological condition marked by the excessive buildup of extracellular matrix primarily resulting from the transformation of quiescent hepatic stellate cells (HSCs) to myofibroblastic (MF) phenotype and their resultant over-expansion. Activated HSCs completely rely on their hyperactive mitochondria to supply the energy and biomass for their rapid proliferation and collagen secretion, so an intervention targeting their mitochondria can effectively restrict their pathological amplification and contribution to liver fibrosis. Here we tried sorafenib, a drug that plays anticancer roles by inducing the disruption and loss of mitochondrial functions, to reach an antifibrotic goal. And a complex micellar system, VA-PEG-PCL/TPGS (VPP/TPGS), was specifically designed and fabricated to encapsulate and deliver sorafenib selectively to activated HSCs to overcome its application limitations in bioavailability, toxicity and intracellular stay, and eventually maximize its induction of mitochondrial dysfunction and therapeutically antifibrotic efficacy. The prepared sorafenib complex micelles not only exhibited a suitable particle size, uniform morphology, and nice stability, but also performed excellently in the biosafety and HSCs-targetability in vitro and in vivo. In human active HSC cell lines, they markedly attenuated mitochondrial hyperactivity, induced apoptosis, and downregulated fibrosis markers as expected; while in a CCl4-induced murine model of hepatic fibrosis, they effectively restricted the expansion of MF-HSCs, reduced collagen deposition, and promoted the healing of liver damage, showing a good potential in fibrosis curation. Collectively, our VPP/TPGS complex micelles provide an ideal drug delivery platform that has the potential to revolutionize the treatment of liver fibrosis via addressing its cellular and metabolic underpinnings and thus improve patient outcomes.

Natural product mitigation of ferroptosis in platinum-based chemotherapy toxicity: targeting the underpinning oxidative signaling pathways

OBJECTIVES

Platinum-based anticancer chemotherapy (PAC) represents a cornerstone in cancer treatment, retaining its status as the gold standard therapy. However, PAC's efficacy is countered by significant toxicities, such as nephrotoxicity, ototoxicity, and neurotoxicity. Recent studies have linked these toxicities to ferroptosis, characterized by iron accumulation, reactive oxygen species generation, and lipid peroxidation. This review explores the mechanisms underlying PAC-induced toxicities, focusing on the involvement of ferroptosis with three major PAC drugs-cisplatin, carboplatin, and oxaliplatin. Further, we provide a comprehensive analysis of the natural product mitigation of PAC-induced ferroptotic toxicity.

KEY FINDINGS

The mechanistic role of ferroptosis in cisplatin- and oxaliplatin-induced toxicities has been investigated, while studies on carboplatin-induced ferroptotic toxicities are lacking. Natural compounds targeting molecular pathways of ferroptosis have been explored to mitigate PAC-induced ferroptotic toxicity.

CONCLUSION

While ferroptosis in cisplatin- and oxaliplatin-induced toxicities has been investigated, there remains a notable dearth of studies examining its involvement in carboplatin-induced toxicities. Hence, further exploration is warranted to define the role of ferroptosis in carboplatin-induced toxicities, and its further mitigation. Moreover, in-depth mechanistic evaluation is necessary to establish natural products evaluated against PAC-induced ferroptosis, as PAC adjuvants.

Progress in research of ferroptosis in gastrointestinal tumors

Ferroptosis is a non-apoptotic and oxidation-damaged regulated cell death caused by iron accumulation, lipid peroxidation, and subsequent plasma membrane rupture. Ferroptosis is the main cause of tissue damage caused by iron overload and lipid peroxidation. With the deepening of the research in recent years, the understanding of the occurrence and treatment of tumors has made a major breakthrough, which brings new strategies for anti-cancer treatment. This paper reviews the relationship between ferroptosis and gastrointestinal tumors, the research of ferroptosis in cancer prevention and treatment, and the role of ferroptosis in the prevention and treatment of gastrointestinal tumors.

CuO Nanozymes Catalyze Cysteine and Glutathione Depletion Induced Ferroptosis and Cuproptosis for Synergistic Tumor Therapy

The latest research identifies that cysteine (Cys) is one of the key factors in tumor proliferation, metastasis, and recurrence. The direct depletion of intracellular Cys shows a profound antitumor effect. However, using nanozymes to efficiently deplete Cys for tumor therapy has not yet attracted widespread attention. Here, a (3-carboxypropyl) triphenylphosphonium bromide-derived hyaluronic acid-modified copper oxide nanorods (denoted as MitCuOHA) are designed with cysteine oxidase-like, glutathione oxidase-like and peroxidase-like activities to realize Cys depletion and further induce cellular ferroptosis and cuproptosis for synergistic tumor therapy. MitCuOHA nanozymes can efficiently catalyze the depletion of Cys and glutathione (GSH), accompanied by the generation of H2O2 and the subsequent conversion into highly active hydroxyl radicals, thereby successfully inducing ferroptosis in cancer cells. Meanwhile, copper ions released by MitCuOHA under tumor microenvironment stimulation directly bind to lipoylated proteins of the tricarboxylic acid cycle, leading to the abnormal aggregation of lipoylated proteins and subsequent loss of iron-sulfur cluster proteins, which ultimately triggers proteotoxic stress and cell cuproptosis. Both in vitro and in vivo results show the drastically enhanced anticancer efficacy of Cys oxidation catalyzed by the MitCuOHA nanozymes, demonstrating the high feasibility of such catalytic Cys depletion-induced synergistic ferroptosis and cuproptosis therapeutic concept.

GSH exhaustion via inhibition of xCT-GSH-GPX4 pathway synergistically enhanced DSF/Cu-induced cuproptosis in myelodysplastic syndromes

The clinical application of the therapeutic approach in myelodysplastic syndromes (MDS) remains an insurmountable challenge for the high propensity for progressing to acute myeloid leukemia and predominantly affecting elderly individuals. Thus, the discovery of molecular mechanisms underlying the regulatory network of different programmed cell death holds great promise for the identification of therapeutic targets and provides insights into new therapeutic avenues. Herein, we found that disulfiram/copper (DSF/Cu) significantly repressed the cell viability, increased reactive oxygen species (ROS) accumulation, destroyed mitochondrial morphology, and altered oxygen consumption rate. Further studies verified that DSF/Cu induces cuproptosis, as evidenced by the depletion of glutathione (GSH), aggregation of lipoylated DLAT, and induced loss of Fe-S cluster-containing proteins, which could be rescued by tetrathiomolybdate and knockdown of ferredoxin 1 (FDX1). Additionally, GSH contributed to the tolerance of DSF/Cu-mediated cuproptosis, while pharmacological chelation of GSH triggered ROS accumulation and sensitized cell death. The xCT-GSH-GPX4 axis is the ideal downstream component of ferroptosis that exerts a powerful protective mechanism. Notably, classical xCT inhibitors were capable of leading to the catastrophic accumulation of ROS and exerting synergistic cell death, while xCT overexpression restored these phenomena. Simvastatin, an inhibitor of HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase, has beneficial effects in repurposing for inhibiting GPX4. Similarly, the combination treatment of DSF/Cu and simvastatin dramatically decreased the expression of GPX4 and Fe-S proteins, ultimately accelerating cell death. Moreover, we identified that the combination treatment of DSF/Cu and simvastatin also had a synergistic antitumor effect in the MDS mouse model, with the reduced GPX4, increased COX-2 and accumulated lipid peroxides. Overall, our study provided insight into developing a novel synergistic strategy to sensitize MDS therapy by targeting ferroptosis and cuproptosis.

Phosphorylated FOXQ1, a novel substrate of JNK1, inhibits sorafenib-induced ferroptosis by activating ETHE1 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly heterogeneous and malignant cancer with poor overall survival. The application of sorafenib is a major breakthrough in the treatment of HCC. In our study, FOXQ1 was significantly overexpressed in sorafenib-resistant HCC cells and suppressed sorafenib-induced ferroptosis. We found that phosphorylation of FOXQ1 at serine 248 is critical for the suppression of sorafenib-induced ferroptosis. Furthermore, as the upstream phosphorylation kinase of FOXQ1, JNK1, which is activated by sorafenib, can directly phosphorylate the serine 248 site of FOXQ1. Then, the phosphorylated FOXQ1 got a high affinity for the promoter of ETHE1 and activates its transcription. Further flow cytometry results showed that ETHE1 reduced intracellular lipid peroxidation and iron levels. Collectively, our study implicated the JNK1-FOXQ1-ETHE1 axis in HCC ferroptosis induced by sorafenib, providing mechanistic insight into sensitivity to sorafenib therapy of HCC.

Elesclomol-copper synergizes with imidazole ketone erastin by promoting cuproptosis and ferroptosis in myelodysplastic syndromes

Myelodysplastic syndromes (MDS) encompass a collection of clonal hematopoietic malignancies distinguished by the depletion of peripheral blood cells. The treatment of MDS is hindered by the advanced age of patients, with a restricted repertoire of drugs currently accessible for therapeutic intervention. In this study, we found that ES-Cu strongly inhibited the viability of MDS cell lines and activated cuproptosis in a copper-dependent manner. Importantly, ferroptosis inducer IKE synergistically enhanced ES-Cu-mediated cytotoxicity both in vitro and in vivo. Of note, the combination of IKE and ES-Cu intensively impaired mitochondrial homeostasis with increased mitochondrial ROS, MMP hyperpolarized, down-regulated iron-sulfur proteins and declined oxygen consumption rate. Additionally, ES-Cu/IKE treatment could enhance the lipoylation-dependent oligomerization of the DLAT. To elucidate the specific order of events in the synergistic cell death, inhibitors of ferroptosis and cuproptosis were utilized to further characterize the basis of cell death. Cell viability assays showed that the glutathione and its precursor N-acetylcysteine could significantly rescue the cell death under either mono or combination treatment, demonstrating that GSH acts at the crossing point in the regulation network of cuproptosis and ferroptosis. Significantly, the reconstitution of xCT expression and knockdown of FDX1 cells have been found to contribute to the tolerance of mono treatment but have little recovery impact on the combined treatment. Collectively, these findings suggest that a synergistic interaction leading to the induction of multiple programmed cell death pathways could be a promising approach to enhance the effectiveness of therapy for MDS.

Cadmium exposure induced neuronal ferroptosis and cognitive deficits via the mtROS-ferritinophagy pathway

Exposure to environmental cadmium (Cd) is known to cause neuronal death and cognitive decline in humans. Ferroptosis, a novel iron-dependent type of regulated cell death, is involved in various neurological disorders. In the present study, Cd exposure triggered ferroptosis in the mouse hippocampus and in the HT22 murine hippocampal neuronal cell line, as indicated by significant increases in ferroptotic marker expression, intracellular iron levels, and lipid peroxidation. Interestingly, ferroptosis of hippocampal neurons in response to Cd exposure relied on the induction of autophagy since the suppression of autophagy by 3-methyladenine (3-MA) and chloroquine (CQ) substantially ameliorated Cd-induced ferroptosis. Furthermore, nuclear receptor coactivator 4 (NCOA4)-mediated degradation of ferritin was required for the Cd-induced ferroptosis of hippocampal neurons, demonstrating that NCOA4 knockdown decreased intracellular iron levels and lipid peroxidation and increased cell survival, following Cd exposure. Moreover, Cd-induced mitochondrial reactive oxygen species (mtROS) generation was essential for the ferritinophagy-mediated ferroptosis of hippocampal neurons. Importantly, pretreatment with the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively attenuated Cd-induced hippocampal neuronal death and cognitive impairment in mice. Taken together, these findings indicate that ferroptosis is a novel mechanism underlying Cd-induced neurotoxicity and cognitive impairment and that the mtROS-ferritinophagy axis modulates Cd-induced neuronal ferroptosis.

The involvement of ROS-regulated programmed cell death in hepatocellular carcinoma

Reactive oxidative species (ROS) is a crucial factor in the regulation of cellular biological activity and function, and aberrant levels of ROS can contribute to the development of a variety of diseases, particularly cancer. Numerous discoveries have affirmed that this process is strongly associated with "programmed cell death (PCD)," which refers to the suicide protection mechanism initiated by cells in response to external stimuli, such as apoptosis, autophagy, ferroptosis, etc. Research has demonstrated that ROS-induced PCD is crucial for the development of hepatocellular carcinoma (HCC). These activities serve a dual function in both facilitating and inhibiting cancer, suggesting the existence of a delicate balance within healthy cells that can be disrupted by the abnormal generation of reactive oxygen species (ROS), thereby influencing the eventual advancement or regression of a tumor. In this review, we summarize how ROS regulates PCD to influence the tumorigenesis and progression of HCC. Studying how ROS-induced PCD affects the progression of HCC at a molecular level can help develop better prevention and treatment methods and facilitate the design of more effective preventative and therapeutic strategies.

Aldehyde Dehydrogenase 2 (ALDH2): A novel sorafenib target in hepatocellular carcinoma unraveled by the proteome-wide cellular thermal shift assay

Sorafenib is a multikinase inhibitor indicated for first-line treatment of unresectable hepatocellular carcinoma. Despite its widespread use in the clinic, the existing knowledge of sorafenib mode-of-action remains incomplete. To build upon the current understanding, we used the Cellular Thermal Shift Assay (CETSA) coupled to Mass Spectrometry (CETSA-MS) to monitor compound binding to its target proteins in the cellular context on a proteome-wide scale. Among the potential sorafenib targets, we identified aldehyde dehydrogenase 2 (ALDH2), an enzyme that plays a major role in alcohol metabolism. We validated the interaction of sorafenib with ALDH2 by orthogonal methods using pure recombinant protein, proving that this interaction is not mediated by other cellular components. Moreover, we showed that sorafenib inhibits ALDH2 activity, supporting a functional role for this interaction. Finally, we were able to demonstrate that both ALDH2 protein expression and activity were reduced in sorafenib-resistant cells compared to the parental cell line. Overall, our study allowed the identification of ALDH2 as a novel sorafenib target and sheds light on its potential role in both hepatocellular carcinoma and sorafenib resistance condition.

Ferroptosis mechanisms and its novel potential therapeutic targets for DLBCL

Diffuse large B-cell lymphoma (DLBCL), a heterogeneous lymphoid malignancy, poses a significant threat to human health. The standard therapeutic regimen for patients with DLBCL is rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), with a typical cure rate of 50-70%. However, some patients either relapse after complete remission (CR) or exhibit resistance to R-CHOP treatment. Therefore, novel therapeutic approaches are imperative for managing high-risk or refractory DLBCL. Ferroptosis is driven by iron-dependent phospholipid peroxidation, a process that relies on the transition metal iron, reactive oxygen species (ROS), and phospholipids containing polyunsaturated fatty acids-containing phospholipids (PUFA-PLs). Research indicates that ferroptosis is implicated in various carcinogenic and anticancer pathways. Several hematological disorders exhibit heightened sensitivity to cell death induced by ferroptosis. DLBCL cells, in particular, demonstrate an increased demand for iron and an upregulation in the expression of fatty acid synthase. Additionally, there exists a correlation between ferroptosis-associated genes and the prognosis of DLBCL. Therefore, ferroptosis may be a promising novel target for DLBCL therapy. In this review, we elucidate ferroptosis mechanisms, its role in DLBCL, and the potential therapeutic targets in DLBCL. This review offers novel insights into the application of ferroptosis in treatment strategies for DLBCL.

New daphnane diterpenoidal 1,3,4-oxdiazole derivatives as potential anti-hepatoma agents: Synthesis, biological evaluation and molecular modeling studies

Hepatocellular carcinoma (HCC) is a major challenge for human healthy. Daphnane-type diterpenes have attracted increasingly attention due to remarkable pharmaceutical potential including anti-HCC activity. To further develop this class of compounds as inhibitors of HCC, the daphnane diterpenoids 12-O-debenzoyl-Yuanhuacine (YHC) and 12-hydroxydaphnetoxin (YHE) were prepared by a standard chemical transformation from dried flower buds of the Daphne genkwa plant. Subsequently, 22 daphnane diterpenoidal 1,3,4-oxdiazole derivatives were rationally designed and synthesized based on YHC and YHE. The assessment of the target compound's anti-hepatocellular carcinoma activity revealed that YHC1 exhibited comparable activity to sorafenib in the Hep3B cell line, while demonstrating higher selectivity. The mechanistic investigation demonstrates that compound YHC1 induces cell cycle arrest at the G0/G1 phase, cellular senescence, apoptosis, and elevates cellular reactive oxygen species levels. Moreover, molecular docking and CETSA results confirm the interaction between YHC1 and YAP1 as well as TEAD1. Co-IP experiments further validated that YHC1 can effectively inhibit the binding of YAP1 and TEAD1. In conclusion, YHC1 selectively targets YAP1 and TEAD1, exhibiting its anti-hepatocellular carcinoma effects through the inhibition of their interaction.

Understanding Sorafenib-Induced Cardiovascular Toxicity: Mechanisms and Treatment Implications

Tyrosine kinase inhibitors (TKIs) have been recognized as crucial agents for treating various tumors, and one of their key targets is the intracellular site of the vascular endothelial growth factor receptor (VEGFR). While TKIs have demonstrated their effectiveness in solid tumor patients and increased life expectancy, they can also lead to adverse cardiovascular effects including hypertension, thromboembolism, cardiac ischemia, and left ventricular dysfunction. Among the TKIs, sorafenib was the first approved agent and it exerts anti-tumor effects on hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC) by inhibiting angiogenesis and tumor cell proliferation through targeting VEGFR and RAF. Unfortunately, the adverse cardiovascular effects caused by sorafenib not only affect solid tumor patients but also limit its application in curing other diseases. This review explores the mechanisms underlying sorafenib-induced cardiovascular adverse effects, including endothelial dysfunction, mitochondrial dysfunction, endoplasmic reticulum stress, dysregulated autophagy, and ferroptosis. It also discusses potential treatment strategies, such as antioxidants and renin-angiotensin system inhibitors, and highlights the association between sorafenib-induced hypertension and treatment efficacy in cancer patients. Furthermore, emerging research suggests a link between sorafenib-induced glycolysis, drug resistance, and cardiovascular toxicity, necessitating further investigation. Overall, understanding these mechanisms is crucial for optimizing sorafenib therapy and minimizing cardiovascular risks in cancer patients.

Phospholipids with two polyunsaturated fatty acyl tails promote ferroptosis

Phospholipids containing a single polyunsaturated fatty acyl tail (PL-PUFA1s) are considered the driving force behind ferroptosis, whereas phospholipids with diacyl-PUFA tails (PL-PUFA2s) have been rarely characterized. Dietary lipids modulate ferroptosis, but the mechanisms governing lipid metabolism and ferroptosis sensitivity are not well understood. Our research revealed a significant accumulation of diacyl-PUFA phosphatidylcholines (PC-PUFA2s) following fatty acid or phospholipid treatments, correlating with cancer cell sensitivity to ferroptosis. Depletion of PC-PUFA2s occurred in aging and Huntington's disease brain tissue, linking it to ferroptosis. Notably, PC-PUFA2s interacted with the mitochondrial electron transport chain, generating reactive oxygen species (ROS) for initiating lipid peroxidation. Mitochondria-targeted antioxidants protected cells from PC-PUFA2-induced mitochondrial ROS (mtROS), lipid peroxidation, and cell death. These findings reveal a critical role for PC-PUFA2s in controlling mitochondria homeostasis and ferroptosis in various contexts and explain the ferroptosis-modulating mechanisms of free fatty acids. PC-PUFA2s may serve as diagnostic and therapeutic targets for modulating ferroptosis.

Regulation of NCOA4-mediated iron recycling ameliorates paraquat-induced lung injury by inhibiting ferroptosis

Paraquat (PQ) is an irreplaceable insecticide in many countries for the advantage of fast-acting and broad-spectrum. However, PQ was classified as the most prevailing poisoning substance for suicide with no specific antidote. Therefore, it is imperative to develop more effective therapeutic agents for the treatment of PQ poisoning. In the present study, both the RNA-Seq and the application of various cell death inhibitors reflected that ferroptosis exerts a crucial regulatory role in PQ poisoning. Moreover, we found PQ strengthens lipid peroxidation as evidenced by different experimental approaches. Of note, pretreatment of iron chelation agent DFO could ameliorate the ferroptotic cell death and alleviate the ferroptosis-related events. Mechanistically, PQ treatment intensively impaired mitochondrial homeostasis, enhanced phosphorylation of AMPK, accelerated the autophagy flux and triggered the activation of Nuclear receptor coactivator 4-ferritin heavy chain (NCOA4-FTH) axis. Importantly, the activation of autophagy was observed prior to the degradation of ferritin, and inhibition of autophagy could inhibit the accumulation of iron caused by the ferritinophagy process. Genetic and pharmacological inhibition of ferritinophagy could alleviate the lethal oxidative events, and rescue the ferroptotic cell death. Excitingly, in the mouse models of PQ poisoning, both the administration of DFO and adeno-associated virus-mediated FTH overexpression significantly reduced PQ-induced ferroptosis and improved the pathological characteristics of pulmonary fibrosis. In summary, the current work provides an in-depth study on the mechanism of PQ intoxication, describes a framework for the further understanding of ferroptosis in PQ-associated biological processes, and demonstrates modulation of iron metabolism may act as a promising therapeutic agent for the management of PQ toxicity.

Inhibiting the compensatory elevation of xCT collaborates with disulfiram/copper-induced GSH consumption for cascade ferroptosis and cuproptosis

Hepatocellular carcinoma (HCC) is one of the most prevalent malignant tumors and the fourth leading cause of cancer-related death globally, which is characterized by complicated pathophysiology, high recurrence rate, and poor prognosis. Our previous study has demonstrated that disulfiram (DSF)/Cu could be repurposed for the treatment of HCC by inducing ferroptosis. However, the effectiveness of DSF/Cu may be compromised by compensatory mechanisms that weaken its sensitivity. The mechanisms underlying these compensatory responses are currently unknown. Herein, we found DSF/Cu induces endoplasmic reticulum stress with disrupted ER structures, increased Ca2+ level and activated expression of ATF4. Further studies verified that DSF/Cu induces both ferroptosis and cuproptosis, accompanied by the depletion of GSH, elevation of lipid peroxides, and compensatory increase of xCT. Comparing ferroptosis and cuproptosis, it is interesting to note that GSH acts at the crossing point of the regulation network and therefore, we hypothesized that compensatory elevation of xCT may be a key aspect of the therapeutic target. Mechanically, knockdown of ATF4 facilitated the DSF/Cu-induced cell death and exacerbated the generation of lipid peroxides under the challenge of DSF/Cu. However, ATF4 knockdown was unable to block the compensatory elevation of xCT and the GSH reduction. Notably, we found that DSF/Cu induced the accumulation of ubiquitinated proteins, promoted the half-life of xCT protein, and dramatically dampened the ubiquitination-proteasome mediated degradation of xCT. Moreover, both pharmacologically and genetically suppressing xCT exacerbated DSF/Cu-induced cell death. In conclusion, the current work provides an in-depth study of the mechanism of DSF/Cu-induced cell death and describes a framework for the further understanding of the crosstalk between ferroptosis and cuproptosis. Inhibiting the compensatory increase of xCT renders HCC cells more susceptible to DSF/Cu, which may provide a promising synergistic strategy to sensitize tumor therapy and overcome drug resistance, as it activates different programmed cell death.

Lipid peroxidation of immune cells in cancer

Growing evidence indicates that cellular metabolism is a critical determinant of immune cell viability and function in antitumor immunity and lipid metabolism is important for immune cell activation and adaptation to the tumor microenvironment (TME). Lipid peroxidation is a process in which oxidants attack lipid-containing carbon-carbon double bonds and is an important part of lipid metabolism. In the past decades, studies have shown that lipid peroxidation participates in signal transduction to control cell proliferation, differentiation, and cell death, which is essential for cell function execution and human health. More importantly, recent studies have shown that lipid peroxidation affects immune cell function to modulate tumor immunity and antitumor ability. In this review, we briefly overview the effect of lipid peroxidation on the adaptive and innate immune cell activation and function in TME and discuss the effectiveness and sensitivity of the antitumor ability of immune cells by regulating lipid peroxidation.

Enhancing anti-cancer potential by delivering synergistic drug combinations via phenylboronic acid modified PLGA nanoparticles through ferroptosis-based therapy

In this study, we investigated the potential of the sorafenib (SOR) and simvastatin (SIM) combination to induce ferroptosis-mediated cancer therapy. To enhance targeted drug delivery, we encapsulated the SOR + SIM combination within 4-carboxy phenylboronic acid (CPBA) modified PLGA nanoparticles (CPBA-PLGA(SOR + SIM)-NPs). The developed CPBA-PLGA(SOR + SIM)-NPs exhibited a spherical shape with a size of 213.1 ± 10.9 nm, a PDI of 0.22 ± 0.03, and a Z-potential of -22.9 ± 3.2 mV. Notably, these nanoparticles displayed faster drug release at acidic pH compared to physiological pH. In cellular experiments, CPBA-PLGA(SOR + SIM)-NPs demonstrated remarkable improvements, leading to a 2.51, 2.69, and 2.61-fold decrease in IC50 compared to SOR alone, and a 7.50, 16.71, and 5.11-fold decrease in IC50 compared to SIM alone in MDA-MB-231, A549, and HeLa cells, respectively. Furthermore, CPBA-PLGA(SOR + SIM)-NPs triggered a reduction in glutathione (GSH) levels, an increase in malondialdehyde (MDA) levels, and mitochondrial membrane depolarization in all three cell lines. Pharmacokinetic evaluation revealed a 2.50- and 2.63-fold increase in AUC0-∞, as well as a 1.53- and 2.46-fold increase in mean residence time (MRT) for SOR and SIM, respectively, compared to the free drug groups. Notably, the CPBA-PLGA(SOR + SIM)-NPs group exhibited significant reduction in tumor volume, approximately 9.17, 2.45, and 1.63-fold lower than the control, SOR + SIM, and PLGA(SOR + SIM)-NPs groups, respectively. Histological examination and biomarker analysis showed no significant differences compared to the control group, suggesting the biocompatibility of the developed particles for in-vivo applications. Altogether, our findings demonstrate that CPBA-PLGA(SOR + SIM)-NPs hold tremendous potential as an efficient drug delivery system for inducing ferroptosis, providing a promising therapeutic option for cancer treatment.

Ferroptosis Inducers as Promising Radiosensitizer Agents in Cancer Radiotherapy

Radiotherapy (RT) failure has historically been mostly attributed to radioresistance. Ferroptosis is a type of controlled cell death that depends on iron and is caused by polyunsaturated fatty acid peroxidative damage. Utilizing a ferroptosis inducer may be a successful tactic for preventing tumor growth and radiotherapy-induced cell death. A regulated form of cell death known as ferroptosis is caused by the peroxidation of phospholipids containing polyunsaturated fatty acids in an iron-dependent manner (PUFA-PLs). The ferroptosis pathway has a number of important regulators. By regulating the formation of PUFA-PLs, the important lipid metabolism enzyme ACSL4 promotes ferroptosis, whereas SLC7A11 and (glutathione peroxidase 4) GPX4 prevent ferroptosis. In addition to introducing the ferroptosis inducer chemicals that have recently been demonstrated to have a radiosensitizer effect, this review highlights the function and methods by which ferroptosis contributes to RT-induced cell death and tumor suppression in vitro and in vivo.

Protective role of hesperetin in sorafenib-induced hepato- and neurotoxicity in mice via modulating apoptotic pathways and mitochondrial reprogramming

INTRODUCTION

Sorafenib, an FDA-approved standard chemotherapy for advanced hepatocellular carcinoma, is associated with numerous adverse effects that significantly impact patients' physiological well-being. Consequently, identifying agents that mitigate these side effects while enhancing efficacy is crucial. Hesperetin, a flavone present in fruits and vegetables, possesses antioxidant, anti-inflammatory, and anti-cancer properties. This study aimed to investigate the hepatotoxic and neurotoxic effects of sorafenib and the potential protective role of hesperetin.

MATERIALS AND METHODS

Swiss albino mice were orally administered sorafenib (100 mg/kg) alone or in combination with hesperetin (50 mg/kg) over 21 days. Behavioral assessments for anxiety and depressive-like behaviors were conducted. Additionally, evaluations encompassed apoptotic activity, mitochondrial integrity, liver enzyme levels, proliferation rates, and histopathological changes.

RESULTS

Combining hesperetin with sorafenib showed improvements in behavioral alterations, liver damage, brain mitochondrial dysfunction, and liver apoptosis compared to the sorafenib-only group in mice.

CONCLUSION

Hesperetin exhibits potential as an adjunct to sorafenib, mitigating its side effects by attenuating its toxicity, enhancing efficacy, and potentially reducing the occurrence of sorafenib-induced resistance through the downregulation of hepatocyte growth factor levels.

From synergy to resistance: Navigating the complex relationship between sorafenib and ferroptosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains a major global health burden, and sorafenib, a multi-kinase inhibitor, has shown effectiveness in the treatment of HCC and is considered as the first-line therapy for advanced HCC. However, the response to sorafenib varies among patients, and the development of drug resistance poses a prevalent obstacle. Ferroptosis, a newly characterized form of cell death featured by iron-dependent lipid peroxidation, has emerged as a critical player in the reaction to sorafenib therapy in HCC. The induction of ferroptosis has been shown to augment the anticancer benefits of sorafenib. However, it has also been observed to contribute to sorafenib resistance. This review presents a comprehensive and thorough analysis that elucidates the intricate relationship between ferroptosis and sorafenib over recent years, aiming to formulate effective therapeutic approaches for liver cancer. Based on this exploration, we propose innovative strategies intended to overcome sorafenib resistance via targeted modulation of ferroptosis.

Synergistic anticancer therapy via ferroptosis using modified bovine serum albumin nanoparticles loaded with sorafenib and simvastatin

Ferroptosis is a non-apoptotic cell death pathway characterized by the accumulation of lipid-peroxy radicals within the affected cells. Here, we investigate the synergistic capacity of sorafenib (SOR) and simvastatin (SIM) to trigger ferroptosis for cancer therapy. For precise in-vivo delivery, SOR + SIM was ratiometrically loaded in bovine serum albumin nanoparticles (BSA-NPs) modified with 4-carboxy phenylboronic acid (CPBA). The developed CPBA-BSA(SOR + SIM)-NPs revealed size of 175.2 ± 12.8 nm, with PDI of 0.22 ± 0.03 and Z-potential of -29.6 ± 4.8 mV. Significantly, CPBA-BSA(SOR + SIM)-NPs exhibited > 2 and > 5-fold reduction in IC50 values compared to individual SOR and SIM treatments respectively, in all tested cell lines. Moreover, CPBA-BSA(SOR + SIM)-NPs treated cells exhibited decrease in glutathione levels, increase in malonaldehyde levels and depolarization of mitochondrial membrane potential (JC-1 assay). Pharmacokinetic analysis revealed enhanced AUC0-∞ and MRT levels for SOR and SIM when administered as CPBA-BSA(SOR + SIM)-NPs compared to free drugs. Crucially, in in-vivo experiments, CPBA-BSA(SOR + SIM)-NPs led to a significant reduction in tumor volume compared to various control groups. Histological and biomarker analyses underscore their biocompatibility for clinical applications. In conclusion, this study highlights the potential of CPBA-BSA(SOR + SIM)-NPs as a promising strategy for inducing ferroptosis in cancer cells, concurrently improving drug delivery and therapeutic efficacy. This approach opens new avenues in cancer treatment.

Molecular Mechanisms of Ferroptosis and Its Role in Viral Pathogenesis

Ferroptosis is a novelty form of regulated cell death, and it is mainly characterized by iron accumulation and lipid peroxidation in the cells. Its underlying mechanism is related to the amino acid, iron, and lipid metabolisms. During viral infection, pathogenic microorganisms have evolved to interfere with ferroptosis, and ferroptosis is often manipulated by viruses to regulate host cell servicing for viral reproduction. Therefore, this review provides a comprehensive overview of the mechanisms underlying ferroptosis, elucidates the intricate signaling pathways involved, and explores the pivotal role of ferroptosis in the pathogenesis of viral infections. By enhancing our understanding of ferroptosis, novel therapeutic strategies can be devised to effectively prevent and treat diseases associated with this process. Furthermore, unraveling the developmental mechanisms through which viral infections exploit ferroptosis will facilitate development of innovative antiviral agents.

The potential role of ferroptosis in COVID-19-related cardiovascular injury

COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged as a global health threat in 2019. An important feature of the disease is that multiorgan symptoms of SARS-CoV-2 infection persist after recovery. Evidence indicates that people who recovered from COVID-19, even those under the age of 65 years without cardiovascular risk factors such as smoking, obesity, hypertension, and diabetes, had a significantly increased risk of cardiovascular disease for up to one year after diagnosis. Therefore, it is important to closely monitor individuals who have recovered from COVID-19 for potential cardiovascular damage that may manifest at a later stage. Ferroptosis is an iron-dependent form of non-apoptotic cell death characterized by the production of reactive oxygen species (ROS) and increased lipid peroxide levels. Several studies have demonstrated that ferroptosis plays an important role in cancer, ischemia/reperfusion injury (I/RI), and other cardiovascular diseases. Altered iron metabolism, upregulation of reactive oxygen species, and glutathione peroxidase 4 inactivation are striking features of COVID-19-related cardiovascular injury. SARS-CoV-2 can cause cardiovascular ferroptosis, leading to cardiovascular damage. Understanding the mechanism of ferroptosis in COVID-19-related cardiovascular injuries will contribute to the development of treatment regimens for preventing or reducing COVID-19-related cardiovascular complications. In this article, we go over the pathophysiological underpinnings of SARS-CoV-2-induced acute and chronic cardiovascular injury, the function of ferroptosis, and prospective treatment approaches.

Scutellarein alleviates chronic obstructive pulmonary disease through inhibition of ferroptosis by chelating iron and interacting with arachidonate 15-lipoxygenase

Ferroptosis, an iron-dependent cell death characterized by lethal lipid peroxidation, is involved in chronic obstructive pulmonary disease (COPD) pathogenesis. Therefore, ferroptosis inhibition represents an attractive strategy for COPD therapy. Herein, we identified natural flavonoid scutellarein as a potent ferroptosis inhibitor for the first time, and characterized its underlying mechanisms for inhibition of ferroptosis and COPD. In vitro, the anti-ferroptotic activity of scutellarein was investigated through CCK8, real-time quantitative polymerase chain reaction (RT-qPCR), Western blotting, flow cytometry, and transmission electron microscope (TEM). In vivo, COPD was induced by lipopolysaccharide (LPS)/cigarette smoke (CS) and assessed by changes in histopathological, inflammatory, and ferroptotic markers. The mechanisms were investigated by RNA-sequencing (RNA-seq), electrospray ionization mass spectra (ESI-MS), local surface plasmon resonance (LSPR), drug affinity responsive target stability (DARTS), cellular thermal shift assay (CETSA), and molecular dynamics. Our results showed that scutellarein significantly inhibited Ras-selective lethal small molecule (RSL)-3-induced ferroptosis and mitochondria injury in BEAS-2B cells, and ameliorated LPS/CS-induced COPD in mice. Furthermore, scutellarein also repressed RSL-3- or LPS/CS-induced lipid peroxidation, GPX4 down-regulation, and overactivation of Nrf2/HO-1 and JNK/p38 pathways. Mechanistically, scutellarein inhibited RSL-3- or LPS/CS-induced Fe2+ elevation through directly chelating Fe2+ . Moreover, scutellarein bound to the lipid peroxidizing enzyme arachidonate 15-lipoxygenase (ALOX15), which resulted in an unstable state of the catalysis-related Fe2+ chelating cluster. Additionally, ALOX15 overexpression partially abolished scutellarein-mediated anti-ferroptotic activity. Our findings revealed that scutellarein alleviated COPD by inhibiting ferroptosis via directly chelating Fe2+ and interacting with ALOX15, and also highlighted scutellarein as a candidate for the treatment of COPD and other ferroptosis-related diseases.

Targeting ferroptosis opens new avenues for the development of novel therapeutics

Ferroptosis is an iron-dependent form of regulated cell death with distinct characteristics, including altered iron homeostasis, reduced defense against oxidative stress, and abnormal lipid peroxidation. Recent studies have provided compelling evidence supporting the notion that ferroptosis plays a key pathogenic role in many diseases such as various cancer types, neurodegenerative disease, diseases involving tissue and/or organ injury, and inflammatory and infectious diseases. Although the precise regulatory networks that underlie ferroptosis are largely unknown, particularly with respect to the initiation and progression of various diseases, ferroptosis is recognized as a bona fide target for the further development of treatment and prevention strategies. Over the past decade, considerable progress has been made in developing pharmacological agonists and antagonists for the treatment of these ferroptosis-related conditions. Here, we provide a detailed overview of our current knowledge regarding ferroptosis, its pathological roles, and its regulation during disease progression. Focusing on the use of chemical tools that target ferroptosis in preclinical studies, we also summarize recent advances in targeting ferroptosis across the growing spectrum of ferroptosis-associated pathogenic conditions. Finally, we discuss new challenges and opportunities for targeting ferroptosis as a potential strategy for treating ferroptosis-related diseases.

Understanding sorafenib-induced ferroptosis and resistance mechanisms: Implications for cancer therapy

Sorafenib is an important first-line treatment option for liver cancer due to its well-characterized safety profile. While novel first-line drugs may have better efficacy than Sorafenib, they also have limitations such as worse safety and cost-effectiveness. In addition to inducing apoptosis, Sorafenib can also trigger ferroptosis, which has recently been recognized as an immunogenic cell death, unleashing new possibilities for cancer treatment. However, resistance to Sorafenib-induced ferroptosis remains a major challenge. To overcome this resistance and augment the efficacy of Sorafenib, a wide range of nanomedicines has been developed to amplify its pro-ferroptotic effects. This review highlights the mechanisms underlying Sorafenib-triggered ferroptosis and its resistance, and outlines innovative strategies, particularly nanomedicines, to overcome ferroptosis resistance. Moreover, we summarize molecular biomarkers that signify resistance to Sorafenib-mediated ferroptosis, which can assist in predicting therapeutic outcomes.

Exploring Sorafenib and Simvastatin Combination for Ferroptosis-Induced Cancer Treatment: Cytotoxicity Screening, In Vivo Efficacy, and Safety Assessment

Ferroptosis, a pathway dependent on oxygen and iron catalysts, holds promise as a therapeutic approach for cancer treatment due to its manageable regulation, direct control, and immunogenic properties. The sensitivity of cancer cells to ferroptosis induction varies based on their metabolic, genetic, and signalling pathways, prompting the use of combination therapy. In this study, we conducted a screening of drug combinations, including sorafenib (SOR) with simvastatin (SIM), phenethyl isothiocyanate, and trigonelline, in MDA-MB-231, A549, and HeLa cells to assess their cytotoxicity. The SOR-SIM combination exhibited a synergistic effect in MDA-MB-231, A549, and HeLa cells, with calculated CI values of ~ 0.66, 0.53, and 0.59, respectively. Furthermore, co-treatment with ferrostatin-1 resulted in a concentration-dependent increase in the IC50 values. Additionally, SOR + SIM demonstrated a significant reduction in GSH levels, an increase in MDA levels, and mitochondrial membrane depolarization across all three cell lines, indicating their ferroptosis inducing potential. In-vivo studies showed a significant reduction in tumor volume by 3.53-, 2.55-, and 1.47-fold compared to control, SIM, and SOR, respectively. Toxicity assessments revealed insignificant changes in biomarker levels and no observable deformations in isolated organs, except for erythrocyte shrinkage and membrane scrambling effects caused by the SOR + SIM combination. Overall, our findings highlight the potential of the SOR + SIM combination as an effective strategy for cancer treatment, emphasizing the importance of further research in targeted drug delivery systems to ensure its safety.

Copper metabolism and hepatocellular carcinoma: current insights

Copper is an essential trace element that acts as a cofactor in various enzyme active sites in the human body. It participates in numerous life activities, including lipid metabolism, energy metabolism, and neurotransmitter synthesis. The proposal of "Cuproptosis" has made copper metabolism-related pathways a research hotspot in the field of tumor therapy, which has attracted great attention. This review discusses the biological processes of copper uptake, transport, and storage in human cells. It highlights the mechanisms by which copper metabolism affects hepatocellular carcinogenesis and metastasis, including autophagy, apoptosis, vascular invasion, cuproptosis, and ferroptosis. Additionally, it summarizes the current clinical applications of copper metabolism-related drugs in antitumor therapy.

Copper exerts cytotoxicity through inhibition of iron-sulfur cluster biogenesis on ISCA1/ISCA2/ISCU assembly proteins

Copper is an essential mineral nutrient that provides the cofactors for some key enzymes. However, excess copper is paradoxically cytotoxic. Wilson's disease is an autosomal recessive hereditary disease characterized by pathological copper accumulation in many organs, with high mortality and disability. Nevertheless, many questions about the molecular mechanism in Wilson's disease remain unknown and there is an imperative need to address these questions to better exploit therapeutic strategy. In this study, we constructed the mouse model of Wilson's disease, ATP7A^-/- immortalized lymphocyte cell line and ATP7B knockdown cells to explore whether copper could impair iron-sulfur cluster biogenesis in eukaryotic mitochondria. Through a series of cellular, molecular, and pharmacological analyses, we demonstrated that copper could suppress the assembly of Fe-S cluster, decrease the activity of the Fe-S enzyme and disorder the mitochondrial function both in vivo and in vitro. Mechanistically, we found that human ISCA1, ISCA2 and ISCU proteins have a strong copper-binding activity, which would hinder the process of iron-sulfur assembly. Of note, we proposed a novel mechanism of action to explain the toxicity of copper by providing evidence that iron-sulfur cluster biogenesis may be a primary target of copper toxicity both in cells and mouse models. In summary, the current work provides an in-depth study on the mechanism of copper intoxication and describes a framework for the further understanding of impaired Fe-S assembly in the pathological processes of Wilson's diseases, which helps to develop latent therapeutic strategies for the management of copper toxicity.

Identification of mitochondrial respiratory chain signature for predicting prognosis and immunotherapy response in stomach adenocarcinoma

Stomach adenocarcinoma (STAD) is the third leading cause of cancer-related deaths and the fifth most prevalent malignancy worldwide. Mitochondrial respiratory chain complexes play a crucial role in STAD pathogenesis. However, how mitochondrial respiratory chain complex genes (MRCCGs) affect the prognosis and tumor microenvironment in STAD remains unclear. In this study, we systematically analyzed genetic alterations and copy number variations of different expression densities of MRCCGs, based on 806 samples from two independent STAD cohorts. Then we employed the unsupervised clustering method to classify the samples into three expression patterns based on the prognostic MRCCG expressions, and found that they were involved in different biological pathways and correlated with the clinicopathological characteristics, immune cell infiltration, and prognosis of STAD. Subsequently, we conducted a univariate Cox regression analysis to identify the prognostic value of 1175 subtype-related differentially expressed genes (DEGs) and screened out 555 prognostic-related genes. Principal component analysis was performed and developed the MG score system to quantify MRCCG patterns of STAD. The prognostic significance of MG Score was validated in three cohorts. The low MG score group, characterized by increased microsatellite instability-high (MSI-H), tumor mutation burden (TMB), PD-L1 expression, had a better prognosis. Interestingly, we demonstrated MRCCG patterns score could predict the sensitivity to ferroptosis inducing therapy. Our comprehensive analysis of MRCCGs in STAD demonstrated their potential roles in the tumor-immune-stromal microenvironment, clinicopathological features, and prognosis. Our findings highlight that MRCCGs may provide a new understanding of immunotherapy strategies for gastric cancer and provide a new perspective on the development of personalized immune therapeutic strategies for patients with STAD.

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.

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.

Comprehensive Analysis of the Sorafenib-Associated Druggable Targets on Differential Gene Expression and ceRNA Network in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the predominant pathological type of liver cancer. Several therapeutic treatments, including sorafenib and regorafenib, have only modestly improved survival in patients with HCC. The aim of this study was to investigate the expression profiles and the regulation of competitive endogenous RNAs (ceRNAs) of the sorafenib-related target genes in HCC. Based on clinical information and expression profiles of HCC clinical samples from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, shared differentially expressed genes (DEGs) were analyzed and identified. Sorafenib-associated DEGs (SADs) were obtained by intersecting the DEGs with the sorafenib target genes from SuperTarget database. The expression patterns of SADs were verified in the Oncomine database. The biological functions of the SADs were annotated by gene set enrichment analysis (GSEA). In addition, a ceRNA network associated with SADs was constructed. Long non-coding RNAs (lncRNAs) in network that were significantly associated with overall survival were identified as prognosis of patients by Cox regression analysis. Finally, the expression levels of prognostic genes in HCC tissues and cell lines were verified using qRT-PCR. Gene expression differential analysis yielded a total of 146 common DEGs were obtained, including 21 upregulated and 125 downregulated DEGs. Among them, ten SADs were detected to be differentially expressed between tumor and normal tissues, including AXL, CYP2C19, CYP2C8, CYP2C9, CYP3A4, FGFR2, GMNN, PDGFRA, and TTK. GSEA analysis grouped them into three categories by function. The first category (CYP2C19, CYP2C8, CYP2C9 and CYP3A4) and second category (GMNN, TTK and EGER2) had the opposite roles in the enriched terms and pathways, while the third class (AXL and PDGFRA) has enrichment terms and pathways that intersect with those of the first and second categories. A ceRNA network associated with SADs was also constructed including 49 lncRNAs, 14 miRNAs, and 8 mRNAs. Three of these lncRNAs, SNHG7, GAS5 and HCP5, were found upregulated in HCC tissues and to be independent predictors in HCC patients. Significant correlations were found in expression between the prognostic lncRNAs and SADs. Ten SADs were systematically identified using expression data from HCC and normal tissues from TCGA and GEO datasets. GSEA analysis provided us with insight into the function of SADs. In the future, we will continue to explore the mechanisms of coordinated regulation of SADs-related prognostic lncRNAs and SADs at the ceRNA axis level and their potential functions in the development of HCC.

A comprehensive review of the relationship between autophagy and sorafenib-resistance in hepatocellular carcinoma: ferroptosis is noteworthy

Patients with hepatocellular carcinoma (HCC) bear a heavy burden of disease and economic burden but have fewer treatment options. Sorafenib, a multi-kinase inhibitor, is the only approved drug that can be used to limit the progression of inoperable or distant metastatic HCC. However, enhanced autophagy and other molecular mechanisms after sorafenib exposure further induce drug resistance in HCC patients. Sorafenib-associated autophagy also generates a series of biomarkers, which may represent that autophagy is a critical section of sorafenib-resistance in HCC. Furthermore, many classic signaling pathways have been found to be involved in sorafenib-associated autophagy, including the HIF/mTOR signaling pathway, endoplasmic reticulum stress, and sphingolipid signaling, among others. In turn, autophagy also provokes autophagic activity in components of the tumor microenvironment, including tumor cells and stem cells, further impacting sorafenib-resistance in HCC through a special autophagic cell death process called ferroptosis. In this review, we summarized the latest research progress and molecular mechanisms of sorafenib-resistance-associated autophagy in detail, providing new insights and ideas for unraveling the dilemma of sorafenib-resistance in HCC.

Zinc supplementation ameliorates sorafenib-induced cognitive impairment through ROS/JNK signaling pathway

Sorafenib, a multiple kinase inhibitor, is widely used in cancer patients. Recently, clinical studies highlighted the relationship between cognitive deficits and sorafenib exposure. Zinc abundant in the body has been reported to exert neuroprotective activities. However, the effects of zinc supplementation on sorafenib-induced cognitive impairment are still unknown. In the current study, we verified that mice challenged with sorafenib displayed characteristic features of cognitive impairment. However, zinc treatment effectively improved these changes. Histopathological staining also showed that zinc significantly alleviated hippocampal microstructural and ultrastructural damages induced by sorafenib. Meanwhile, zinc significantly reduced sorafenib-induced ROS production and neuronal cells apoptosis in vivo and vitro. Additionally, we also investigated whether zinc protected against sorafenib-induced neuronal cells apoptosis via ROS/JNK pathway through treating SH-SY5Y cells with the NAC or the specific JNK activator anisomycin. The results indicated that NAC performed the same protective effects as zinc in sorafenib-challenged SH-SY5Y cells and activation of JNK by anisomycin partly abolished the protective effects of zinc. Collectively, the present study suggested that inhibition of oxidative stress and the JNK pathway might contribute to the protective effects of zinc against sorafenib-caused cognitive impairment in vivo and vitro.

The leaves of Scutellaria baicalensis Georgi attenuate brain aging in D-galactose-induced rats via regulating glutamate metabolism and Nrf2 signaling pathway

The present study aimed to evaluate the anti-aging effect of the leaves of Scutellaria baicalensis Georgi (LSBG) and investigate its mechanisms. For this purpose, SD rats were received D-galactose (D-gal) subcutaneously (0.3 g/kg) and LSBG intragastrically (0.4 g/kg or 0.8 g/kg) for 7 weeks. Behavior tests were conducted to evaluate the cognitive function of all rats. Results showed that memory impairment was reversed by LSBG. Then, metabolomics of the cortex and hippocampus were used to investigate the potential mechanisms. 21 metabolites in the cortex and 22 metabolites in the hippocampus of aging rats were altered, respectively. Additionally, results showed that the content of key metabolites and activities of enzymes in glutamate metabolism and its downstream metabolism (glutathione metabolism) could be regulated by the LSBG. Additionally, proteins in the Nrf2 signaling pathway were analyzed by western blot. And the protein expression levels of Nrf2, GCLC, HO-1, NQO-1 were significantly regulated by the LSBG in the cortex and hippocampus. Above all, the anti-aging effects of the LSBG were involved in regulating the glutamate metabolism and Nrf2 signaling pathway.

Canonical WNT Signaling Activated by WNT7B Contributes to L-HBs-Mediated Sorafenib Resistance in Hepatocellular Carcinoma by Inhibiting Mitophagy

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death globally, with hepatitis B virus (HBV) infection accounting for over half of all cases. HBV leads to the development of HCC according to a body of literature. Our previous research and other studies also suggest that HBV causes chemotherapeutic treatment resistance, however, the mechanism is uncertain. The WNT family, which encodes secreted signaling molecules, has been linked to carcinogenesis in a variety of malignancies, including HCC. However, little is known regarding WNT7B, a WNT ligand, in the development of HCC and HBV-induced chemoresistance. In this study, the bioinformatics analysis and immunohistochemistry (IHC) staining of clinical samples revealed that WNT7B was overexpressed in HBV-associated HCC tissues versus nontumor liver tissues, which was related to HCC patient survival. Further study in vitro showed that WNT7B and its receptor frizzled-4 (FZD4) were upregulated in response to large hepatitis B surface antigens (L-HBs). L-HBs increased canonical WNT signaling in HCC cells through WNT7B/FZD4. According to functional experiments, WNT7B enhanced the cell proliferation and metastasis in HCC. In vivo and in vitro studies investigated whether L-HBs induced sorafenib resistance by WNT7B in HCC. Interestingly, L-HBs suppressed sorafenib-induced mitophagy by increasing WNT7B/CTNNB1 signaling, resulting in chemoresistance. The findings revealed that WNT7B could be a promising molecular therapeutic target as well as a predictor of sorafenib resistance in HBV-related HCC. The suppression of HBV structural proteins such as L-HBs may play a crucial role in systemic chemotherapy resistance in HBV-associated HCC.

Characterization of pyruvate metabolism and citric acid cycle patterns predicts response to immunotherapeutic and ferroptosis in gastric cancer

Background

Gastric cancer is one of the most common malignancies of the digestive system with a high lethal rate. Studies have shown that inherited and acquired mutations in pyruvate metabolism and citric acid cycle (P-CA) enzymes are involved in tumorigenesis and tumor development. However, it is unclear how different P-CA patterns affect the tumor microenvironment (TME), which is critical for cancer progression.

Methods

This study mainly concentrated on investigating the role of the P-CA patterns in multicellular immune cell infiltration of GC TME. First, the expression levels of P-CA regulators were profiled in GC samples from The Cancer Genome Atlas and Gene Expression Omnibus cohorts to construct a consensus clustering analysis and identify three distinct P-CA clusters. GSVA was conducted to reveal the different biological processes in three P-CA clusters. Subsequently, 1127 cluster-related differentially expressed genes were identified, and prognostic-related genes were screened using univariate Cox regression analysis. A scoring system was then set up to quantify the P-CA gene signature and further evaluate the response of the patients to the immunotherapy.

Results

We found that GC patients in the high P-CA score group had a higher tumor mutational burden, higher microsatellite instability, and better prognosis. The opposite was observed in the low P-CA score group. Interestingly, we demonstrated P-CA gene cluster could predict the sensitivity to immunotherapy and ferroptosis-induced therapy.

Conclusion

Collectively, the P-CA gene signature in this study exhibits potential roles in the tumor microenvironment and predicts the response to immunotherapeutic. The identification of these P-CA patterns may significantly accelerate the strategic development of immunotherapy for GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02739-z.

Development of a novel autophagy-related gene model for gastric cancer prognostic prediction

Gastric cancer (GC) is a major global health issue and one of the leading causes of tumor-associated mortality worldwide. Autophagy is thought to play a critical role in the development and progression of GC, and this process is controlled by a set of conserved regulators termed autophagy-related genes (ATGs). However, the complex contribution of autophagy to cancers is not completely understood. Accordingly, we aimed to develop a prognostic model based on the specific role of ATGs in GC to improve the prediction of GC outcomes. First, we screened 148 differentially expressed ATGs between GC and normal tissues in The Cancer Genome Atlas (TCGA) cohort. Consensus clustering in these ATGs was performed, and based on that, 343 patients were grouped into two clusters. According to Kaplan–Meier survival analysis, cluster C2 had a worse prognosis than cluster C1. Then, a disease risk model incorporating nine differentially expressed ATGs was constructed based on the least absolute shrinkage and selection operator (LASSO) regression analysis, and the ability of this model to stratify patients into high- and low-risk groups was verified. The predictive value of the model was confirmed using both training and validation cohorts. In addition, the results of functional enrichment analysis suggested that GC risk is correlated with immune status. Moreover, autophagy inhibition increased sensitivity to cisplatin and exacerbated reactive oxygen species accumulation in GC cell lines. Collectively, the results indicated that this novel constructed risk model is an effective and reliable tool for predicting GC outcomes and could help with individual treatment through ATG targeting.

Inhibition of CISD2 promotes ferroptosis through ferritinophagy-mediated ferritin turnover and regulation of p62-Keap1-NRF2 pathway

BACKGROUND

CDGSH iron sulfur domain 2 (CISD2) is an iron-sulfur protein with a [2Fe-2S] cluster, which is critical for cell proliferation and iron homeostasis. It has been demonstrated that aberrant expression of CISD2 is associated with the progression of multiple cancers. However, the underlying mechanism of CISD2 in regulating tumorigenesis remains obscure.

METHODS

Bioinformatics strategies were used to investigate the protein interaction network and functional annotation of CISD2. In the functional experiment, cell viability was measured by CCK-8 kit. The levels of cellular reactive oxygen species (ROS), intracellular free iron, lipid peroxides, and lysosomal activity were determined by DCF-DA, RPA, C11-BODIPY, and cathepsin B staining, respectively. The glutathione (GSH) content was determined using a GSH assay kit.

RESULTS

We showed that knockdown of CISD2 significantly accelerated the Erastin-induced ferroptotic cell death with excess lipid peroxidation, GSH exhaustion, and iron accumulation, while overexpression of CISD2 hindered the sensitivity to Erastin. Further assays via confocal microscopy and western blot exhibited that CISD2 knockdown markedly enhanced the lysosomal activity, and activated ferritinophagy under the exposure of Erastin. Pharmacological inhibition of lysosomal function could inhibit the degradation of ferritin heavy chain (FTH), and attenuate the phenotypes of ferroptosis, such as accelerated iron accumulation and lipid peroxidation. Notably, we found that Erastin-induced compensatory elevation of nuclear factor erythroid 2-related factor 2 (NRF2) could be eliminated in CISD2 depletion cells. Mechanically, CISD2 knockdown promoted the degradation of autophagy adaptor p62 and resulted in an increased binding affinity of Keap1 with NRF2, thus leading to the increased ubiquitination and subsequent degradation of NRF2. Enforced expression of NRF2 reversed the sensitivity of shCISD2 cells to ferroptosis both in vitro and in vivo. Conversely, enforced expression of Keap1 exacerbated the degradation of NRF2, reduced the transcriptional expression of FTH and heme oxygenase 1 (HO-1), increased the oxidative damage, and thus further facilitated ferroptosis.

CONCLUSION

Taken together, our current results illustrated two parallel mechanisms involved in the shCISD2-mediated ferroptosis. One was that shCISD2 enhanced the accumulation of free iron via ferritinophagy-dependent ferritin turnover; the other was that CISD2 depletion induced the inhibition of the p62-Keap1-NRF2 pathway, which resulted in oxidative stress and ferroptosis.

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.

New perspectives on ferroptosis and its role in hepatocellular carcinoma

ABSTRACT

For a long time, the morbidity and mortality rates of hepatocellular carcinoma (HCC) have remained high. Since the concept of ferroptosis was introduced in 2012, researchers' perspectives have shifted toward finding novel ferroptosis-related treatment strategies, especially for tumors that are resistant to apoptosis. In recent years, there have been an increasing number of studies on ferroptosis, and these studies have found that ferroptosis has great potential and promise for cancer treatment. Ferroptosis is a kind of regulated cell death (RCD); unlike apoptosis, ferroptosis is an iron-dependent type of RCD driven by lipid peroxidation. The whole process of ferroptosis mainly revolves around three pathways (system xc-/ glutathione peroxidase 4 [GPX4]), lipid peroxidation, and iron metabolism), which are also regulated by various metabolic factors. This review will attempt to analyze the relationship between the system xc-/GPX4 pathway, lipid peroxidation, iron metabolism, and ferroptosis from three aspects (triggering, execution, and regulation), and the regulatory factors for ferroptosis will be summarized. In this review, we will also illustrate the relationship between ferroptosis and tumors as well as its application in tumors from the perspective of HCC. Finally, we will summarize the current limitations and needs and provide perspectives related to the focus of development in the future.

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.

Autophagy-related prognostic signature characterizes tumor microenvironment and predicts response to ferroptosis in gastric cancer

Background

Gastric cancer (GC) is an important disease and the fifth most common malignancy worldwide. Autophagy is an important process for the turnover of intracellular substances. Autophagy-related genes (ARGs) are crucial in cancer. Accumulating evidence indicates the clinicopathological significance of the tumor microenvironment (TME) in predicting prognosis and treatment efficacy.

Methods

Clinical and gene expression data of GC were obtained from The Cancer Genome Atlas and Gene Expression Omnibus databases. A total of 22 genes with differences in expression and prognosis were screened from 232 ARGs. Three autophagy patterns were identified using an unsupervised clustering algorithm and scored using principal component analysis to predict the value of autophagy in the prognosis of GC patients. Finally, the relationship between autophagy and ferroptosis was validated in gastric cancer cells.

Results

The expression of ARGs showed obvious heterogeneity in GC patients. Three autophagy patterns were identified and used to predict the overall survival of GC patients. These three patterns were well-matched with the immunophenotype. Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment analyses showed that the biological functions of the three autophagy patterns were different. A scoring system was then set up to quantify the autophagy model and further evaluate the response of the patients to the immunotherapy. Patients with high autophagy scores had a more severe tumor mutation burden and better prognosis. High autophagy scores were accompanied by high microsatellite instability. Patients with high autophagy scores had significantly higher PD-L1 expression and increased survival. The experimental results confirmed that the expression of ferroptosis genes was positively correlated with the expression of autophagy genes in different autophagy clusters, and inhibition of autophagy dramatically reversed the decrease in ferroptotic cell death and lipid accumulation.

Conclusions

Autophagy patterns are involved in TME diversity and complexity. Autophagy score can be used as an independent prognostic biomarker in GC patients and to predict the effect of immunotherapy and ferroptosis-based therapy. This might benefit individualized treatment for GC.

Hypersensitivity to ferroptosis in chromophobe RCC is mediated by a glutathione metabolic dependency and cystine import via solute carrier family 7 member 11

Chromophobe (Ch) renal cell carcinoma (RCC) arises from the intercalated cell in the distal nephron. There are no proven treatments for metastatic ChRCC. A distinguishing characteristic of ChRCC is strikingly high levels of reduced (GSH) and oxidized (GSSG) glutathione. Here, we demonstrate that ChRCC-derived cells exhibit higher sensitivity to ferroptotic inducers compared with clear-cell RCC. ChRCC-derived cells are critically dependent on cystine via the cystine/glutamate antiporter xCT to maintain high levels of glutathione, making them sensitive to inhibitors of cystine uptake and cyst(e)inase. Gamma-glutamyl transferase 1 (GGT1), a key enzyme in glutathione homeostasis, is markedly suppressed in ChRCC relative to normal kidney. Importantly, GGT1 overexpression inhibits the proliferation of ChRCC cells in vitro and in vivo, suppresses cystine uptake, and decreases levels of GSH and GSSG. Collectively, these data identify ferroptosis as a metabolic vulnerability in ChRCC, providing a potential avenue for targeted therapy for these distinctive tumors.

Cuproptosis-Related Risk Score Predicts Prognosis and Characterizes the Tumor Microenvironment in Hepatocellular Carcinoma

Aims

Cuproptosis is a recently identified form of programmed cell death; however, its role in hepatocellular carcinoma (HCC) remains unclear.

Methods

A set of bioinformatic tools was integrated to analyze the expression and prognostic significance of ferredoxin 1 (FDX1), the key regulator of cuproptosis. A cuproptosis-related risk score (CRRS) was developed via correlation analyses, least absolute shrinkage and selection operator (LASSO) Cox regression, and multivariate Cox regression. The metabolic features, mutation signatures, and immune profile of CRRS-classified HCC patients were investigated, and the role of CRRS in therapy guidance was analyzed.

Results

FDX1 was significantly downregulated in HCC, and its high expression was associated with longer survival time. HCC patients in the high-CRRS group showed a significantly lower overall survival (OS) and enriched in cancer-related pathways. Mutation analyses revealed that the high-CRRS HCC patients had a high mutational frequency of some tumor suppressors such as tumor protein P53 (TP53) and Breast-cancer susceptibility gene 1 (BRCA1)-associated protein 1 (BAP1) and a low frequency of catenin beta 1 (CTNNB1). Besides, HCC patients with high CRRS showed an increase of protumor immune infiltrates and a high expression of immune checkpoints. Moreover, the area under the curve (AUC) values of CRRS in predicting the efficiency of sorafenib and the non-responsiveness to transcatheter arterial chemoembolization (TACE) in HCC patients reached 0.877 and 0.764, respectively.

Significance

The cuproptosis-related signature is helpful in prognostic prediction and in guiding treatment for HCC patients.