Lipid Metabolism Regulates Oxidative Stress and Ferroptosis in RAS-Driven Cancers: A Perspective on Cancer Progression and Therapy

Fatty acid synthase (FASN) signalome: A molecular guide for precision oncology

The initial excitement generated more than two decades ago by the discovery of drugs targeting fatty acid synthase (FASN)-catalyzed de novo lipogenesis for cancer therapy was short-lived. However, the advent of the first clinical-grade FASN inhibitor (TVB-2640; denifanstat), which is currently being studied in various phase II trials, and the exciting advances in understanding the FASN signalome are fueling a renewed interest in FASN-targeted strategies for the treatment and prevention of cancer. Here, we provide a detailed overview of how FASN can drive phenotypic plasticity and cell fate decisions, mitochondrial regulation of cell death, immune escape and organ-specific metastatic potential. We then present a variety of FASN-targeted therapeutic approaches that address the major challenges facing FASN therapy. These include limitations of current FASN inhibitors and the lack of precision tools to maximize the therapeutic potential of FASN inhibitors in the clinic. Rethinking the role of FASN as a signal transducer in cancer pathogenesis may provide molecularly driven strategies to optimize FASN as a long-awaited target for cancer therapeutics.

Exploring beyond Common Cell Death Pathways in Oral Cancer: A Systematic Review

Oral squamous cell carcinoma (OSCC) is the most common and lethal type of head and neck cancer in the world. Variable response and acquisition of resistance to traditional therapies show that it is essential to develop novel strategies that can provide better outcomes for the patient. Understanding of cellular and molecular mechanisms of cell death control has increased rapidly in recent years. Activation of cell death pathways, such as the emerging forms of non-apoptotic programmed cell death, including ferroptosis, pyroptosis, necroptosis, NETosis, parthanatos, mitoptosis and paraptosis, may represent clinically relevant novel therapeutic opportunities. This systematic review summarizes the recently described forms of cell death in OSCC, highlighting their potential for informing diagnosis, prognosis and treatment. Original studies that explored any of the selected cell deaths in OSCC were included. Electronic search, study selection, data collection and risk of bias assessment tools were realized. The literature search was carried out in four databases, and the extracted data from 79 articles were categorized and grouped by type of cell death. Ferroptosis, pyroptosis, and necroptosis represented the main forms of cell death in the selected studies, with links to cancer immunity and inflammatory responses, progression and prognosis of OSCC. Harnessing the potential of these pathways may be useful in patient-specific prognosis and individualized therapy. We provide perspectives on how these different cell death types can be integrated to develop decision tools for diagnosis, prognosis, and treatment of OSCC.

Unraveling the Role of Ras Homolog Enriched in Brain (Rheb1 and Rheb2): Bridging Neuronal Dynamics and Cancer Pathogenesis through Mechanistic Target of Rapamycin Signaling

Ras homolog enriched in brain (Rheb1 and Rheb2), small GTPases, play a crucial role in regulating neuronal activity and have gained attention for their implications in cancer development, particularly in breast cancer. This study delves into the intricate connection between the multifaceted functions of Rheb1 in neurons and cancer, with a specific focus on the mTOR pathway. It aims to elucidate Rheb1's involvement in pivotal cellular processes such as proliferation, apoptosis resistance, migration, invasion, metastasis, and inflammatory responses while acknowledging that Rheb2 has not been extensively studied. Despite the recognized associations, a comprehensive understanding of the intricate interplay between Rheb1 and Rheb2 and their roles in both nerve and cancer remains elusive. This review consolidates current knowledge regarding the impact of Rheb1 on cancer hallmarks and explores the potential of Rheb1 as a therapeutic target in cancer treatment. It emphasizes the necessity for a deeper comprehension of the molecular mechanisms underlying Rheb1-mediated oncogenic processes, underscoring the existing gaps in our understanding. Additionally, the review highlights the exploration of Rheb1 inhibitors as a promising avenue for cancer therapy. By shedding light on the complicated roles between Rheb1/Rheb2 and cancer, this study provides valuable insights to the scientific community. These insights are instrumental in guiding the identification of novel targets and advancing the development of effective therapeutic strategies for treating cancer.

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.

Replacing dietary sodium selenite with biogenic selenium nanoparticles improves the growth performance and gut health of early-weaned piglets

Selenium nanoparticles (SeNPs) are proposed as a safer and more effective selenium delivery system than sodium selenite (Na2SeO3). Here, we investigated the effects of replacing dietary Na2SeO3 with SeNPs synthesized by Lactobacillus casei ATCC 393 on the growth performance and gut health of early-weaned piglets. Seventy-two piglets (Duroc × Landrace × Large Yorkshire) weaned at 21 d of age were divided into the control group (basal diet containing 0.3 mg Se/kg from Na2SeO3) and SeNPs group (basal diet containing 0.3 mg Se/kg from SeNPs) during a 14-d feeding period. The results revealed that SeNPs supplementation increased the average daily gain (P = 0.022) and average daily feed intake (P = 0.033), reduced (P = 0.056) the diarrhea incidence, and improved (P = 0.013) the feed conversion ratio compared with Na2SeO3. Additionally, SeNPs increased jejunal microvilli height (P = 0.006) and alleviated the intestinal barrier dysfunction by upregulating (P < 0.05) the expression levels of mucin 2 and tight junction proteins, increasing (P < 0.05) Se availability, and maintaining mitochondrial structure and function, thereby improving antioxidant capacity and immunity. Furthermore, metabolomics showed that SeNPs can regulate lipid metabolism and participate in the synthesis, secretion and action of parathyroid hormone, proximal tubule bicarbonate reclamation and tricarboxylic acid cycle. Moreover, SeNPs increased (P < 0.05) the abundance of Holdemanella and the levels of acetate and propionate. Correlation analysis suggested that Holdemanella was closely associated with the regulatory effects of SeNPs on early-weaned piglets through participating in lipid metabolism. Overall, replacing dietary Na2SeO3 with biogenic SeNPs could be a potential nutritional intervention strategy to prevent early-weaning syndrome in piglets.

Oxidative stress induction by narasin augments doxorubicin's efficacy in osteosarcoma

Complications and fata toxicity induced by chemotherapy are the main challenge for clinical management of osteosarcoma. The identification of agents that can augment the efficacy of chemotherapy at lower doses may represent an alternative therapeutic strategy. Narasin is a polyether antibiotic widely used in veterinary medicine. In this study, we show that narasin is active against osteosarcoma cells at the same concentrations that are less toxic to normal cells. This effect is achieved by growth inhibition and apoptosis induction, which is mediated by oxidative stress and damage, and mitochondrial dysfunction. The antioxidant N-acetyl-l-cysteine (NAC) abolishes the anti-osteosarcoma activity. Importantly, narasin significantly augments doxorubicin's efficacy in both osteosarcoma cell culturing system and subcutaneous implantation mouse model. The combination of narasin and doxorubicin at non-toxic doses completely arrests osteosarcoma growth in mice. Our results suggest that the concurrent administration of doxorubicin and narasin could present a viable alternative therapeutic approach for osteosarcoma.

Arginine Expedites Erastin-Induced Ferroptosis through Fumarate

Ferroptosis is a newly characterized form of programmed cell death. The fundamental biochemical feature of ferroptosis is the lethal accumulation of iron-catalyzed lipid peroxidation. It has gradually been recognized that ferroptosis is implicated in the pathogenesis of a variety of human diseases. Increasing evidence has shed light on ferroptosis regulation by amino acid metabolism. Herein, we report that arginine deprivation potently inhibits erastin-induced ferroptosis, but not RSL3-induced ferroptosis, in several types of mammalian cells. Arginine presence reduces the intracellular glutathione (GSH) level by sustaining the biosynthesis of fumarate, which functions as a reactive α,β-unsaturated electrophilic metabolite and covalently binds to GSH to generate succinicGSH. siRNA-mediated knockdown of argininosuccinate lyase, the critical urea cycle enzyme directly catalyzing the biosynthesis of fumarate, significantly decreases cellular fumarate and thus relieves erastin-induced ferroptosis in the presence of arginine. Furthermore, fumarate is decreased during erastin exposure, suggesting that a protective mechanism exists to decelerate GSH depletion in response to pro-ferroptotic insult. Collectively, this study reveals the ferroptosis regulation by the arginine metabolism and expands the biochemical functionalities of arginine.

Hydrazide/Metal/Indocyanine Green Coordinated Nanoplatform for Potentiating Reciprocal Ferroptosis and Immunity against Melanoma

Ferroptosis holds great potential in cancer treatment, but its efficacy is severely limited by a low Fenton reaction efficacy. Meanwhile, the interactive relationship between Ferroptosis and the PD-1 blockade is still vague. Herein, a hydrazide/Cu/Fe/indocyanine green coordinated nanoplatform (TCFI) is constructed by a hydrazide-metal-sulfonate coordination process. The TCFI nanoplatform exhibits Fenton-/catalase-/glutathione oxidase-like triple activities and accordingly can trigger lipid peroxidation, relieve hypoxia, and downregulate the glutathione/glutathione peroxidase 4 axis, thus achieving positively and negatively dually enhanced Ferroptosis in B16F10 cancer cells. Under near-infrared laser irradiation, the TCFI nanoplatform induces robust immunogenic cancer cell death by elevating the intracellular reactive oxygen species level through synergistic photodynamic therapy/Ferroptosis, which significantly potentiates CD8+ T cell infiltration into tumors and interferon-γ secretion. Moreover, upregulated interferon-γ efficiently inhibits system xc- activity and sensitizes cancer cells to Ferroptosis. Interestingly, the PD-1 blockade may strengthen the reciprocal process. The combination of the TCFI nanoplatform and αPD-1 can eliminate primary tumors and inhibit distant tumor growth, lung metastasis, and tumor recurrence. This study presents a simple and novel coordination strategy to fabricate tumor microenvironment-responsive nanodrugs and highlights the enhancement effect of photodynamic therapy on reciprocal Ferroptosis and antitumor immunity.

Cell-free circulating RAS mutation concentrations significantly impact the survival of metastatic colorectal cancer patients

PURPOSE

RAS mutations are predictors of an adverse outcome in EGFR-targeted therapies and have been proposed as prognostic biomarkers of survival in metastatic colorectal cancer (mCRC). The analysis of circulating tumor DNA from plasma samples, known as liquid biopsies, has indicated that the RAS mutation status may change over time, potentially affecting patients' prognosis. To further evaluate the clinical validity of RAS mutation retesting using liquid biopsies, we prospectively investigated the impact of the circulating quantitative RAS mutation status on the course of mCRC.

METHODS

The present study included 81 consecutively recruited patients with mCRC. We used targeted next-generation sequencing of circulating cell-free DNA to determine and quantify plasma RAS mutation status.

RESULTS

Patients with a RAS mutation detected by liquid biopsy (37%; n = 30) were at increased risk of death during the follow-up period compared to RAS wild-type patients. Patients with evidence of a RAS mutation in the primary tumor but a putative RAS mutation loss in plasma (28%; n = 11) showed a prolonged survival compared to patients with a preserved RAS mutation status. Also, circulating RAS mutation concentrations significantly affected the outcome: The mortality risk of patients with a high RAS mutation concentration increased fivefold compared to subjects with a putative RAS mutation loss or low RAS mutation concentration.

CONCLUSION

Our results emphasize the clinical value of circulating RAS mutations in managing mCRC.

Osthole inhibits malignant phenotypes and induces ferroptosis in KRAS-mutant colorectal cancer cells via suppressing AMPK/Akt signaling

PURPOSE

Ferroptosis is a form of cell death driven by iron-dependent lipid peroxidation. Intriguingly, KRAS-mutant cancers are particularly vulnerable to ferroptosis. Osthole is a natural coumarin extracted from Cnidium spp. and other Apiaceous plants. In the present study, we explored the antitumor potential of osthole in KRAS-mutant colorectal cancer (CRC) cells.

METHODS

Cell viability assay, EdU incorporation assay, flow cytometry, tumor xenograft model, western blot, immunochemistry staining, immunofluorescence, transcriptome RNA sequencing and quantitative reverse transcription-PCR were performed to evaluate the influence of osthole treatment on KRAS-mutant CRC cells.

RESULTS

We found that osthole treatment suppressed proliferation and tumor growth of KRAS-mutant CRC cell lines HCT116 and SW480. Moreover, osthole treatment increased ROS production and induced ferroptosis. Osthole treatment also promoted autophagy, but inhibition of autophagy by ATG7 knockdown or 3-MA showed no influence on osthole-induced ferroptosis. In comparison, osthole increased lysosomal activation, and co-treatment with lysosome inhibitor Baf-A1 attenuated osthole-induced ferroptosis. Besides, osthole treatment reduced the phosphorylation of AMPK, Akt and mTOR in HCT116 and SW480 cells, while restored AMPK signaling by AMPK agonist AICAR partially abrogated ferroptosis induced by osthole treatment. Finally, co-treatment with osthole increased the cytotoxicity of cetuximab in KRAS-mutant CRC cells in vitro and in vivo.

CONCLUSION

Our results suggested that the natural product osthole exerted its anticancer effects in KRAS-mutant CRC cells via inducing ferroptosis, and this was partially through inhibiting AMPK/Akt/mTOR signaling. Our results may expand our current knowledge for the use of osthole as an anticancer agent.

Apoe-knockout induces strong vascular oxidative stress and significant changes in the gene expression profile related to the pathways implicated in redox, inflammation, and endothelial function

Apolipoprotein E (APOE) was recognized as a key regulator of lipid metabolism, which prompted the Apoe-knockout (Apoe^-/-) mouse to be the most widely used atherosclerotic model. However, with more and more important physiological roles of APOE being revealed, it is necessary to reacquaint its comprehensive function in the aorta. In this study, we aimed to reveal how Apoe-knockout impacts the gene pathways and phenotypes in the aorta of mice. We performed transcriptome sequencing to acquire the gene expression profile (GEP) for C57BL/6J and Apoe^-/- mouse aorta, and used enrichment analysis to reveal the signal pathways enriched for differentially expressed genes (DEGs). In addition, we used immunofluorescence and ELISA to detect the phenotypic differences of vascular tissues and plasma in the two-group mice. Apoe-knockout resulted in significant changes in the expression of 538 genes, among which about 75% were up-regulated and 134 genes were altered more than twice. In addition to the lipid metabolism pathways, DEGs were also mainly enriched in the pathways implicated in endothelial cell proliferation, migration of epithelial cells, immune regulatory, and redox. GSEA shows that the up-regulated genes are mainly enriched in 'immune regulation pathways' and 'signal regulation' pathways, while the down-regulated genes are enriched in lipid metabolism pathways, 'regulation_of_nitric_oxide_synthase_activity' and the pathways involved in redox homeostasis, including 'monooxygenase regulation', 'peroxisomes' and 'oxygen binding'. A significant increase of reactive oxygen species and a remarkable reduction of GSH/GSSG ratio were respectively observed in the vascular tissues and plasma of Apoe^-/- mice. In addition, endothelin-1 significantly increased in the vascular tissue and the plasma of Apoe^-/- mice. Taken together, our results suggest that besides functioning in lipid metabolism, APOE may be an important signal regulator that mediates the expression of the genes related to the pathways involved in redox, inflammation, and endothelial function. Apoe-knockout-induced strong vascular oxidative stress is also the key factor contributing to atherosclerosis.

Geometrical isomerization of arachidonic acid during lipid peroxidation interferes with ferroptosis

Geometrical mono-trans isomers of arachidonic acid (mtAA) are endogenous products of free radical-induced cis-trans double bond isomerization occurring to natural fatty acids during cell metabolism, including lipid peroxidation (LPO). Very little is known about the functional roles of mtAA and in general on the effects of mono-trans isomers of polyunsaturated fatty acids (mtPUFA) in various types of programmed cell death, including ferroptosis. Using HT1080 and MEF cell cultures, supplemented with 20 μM PUFA (i.e., AA, EPA or DHA) and their mtPUFA congeners, ferroptosis occurred in the presence of RSL3 (a direct inhibitor of glutathione peroxidase 4) only with the PUFA in their natural cis configuration, whereas mtPUFA showed an anti-ferroptotic effect. By performing the fatty acid-based membrane lipidome analyses, substantial differences emerged in the membrane fatty acid remodeling of the two different cell fates. In particular, during ferroptosis mtPUFA formation and their incorporation, together with the enrichment of SFA, occurred. This opens new perspectives in the role of the membrane composition for a ferroptotic outcome. While pre-treatment with AA promoted cell death for treatment with H₂O₂ and RSL3, mtAA did not. Cell death by AA supplementation was suppressed also in the presence of either ferroptosis inhibitors, such as the lipophilic antioxidant ferrostatin-1, or NADPH oxidase (NOX) inhibitors, including diphenyleneiodonium chloride and apocynin. Our results confirm a more complex scenario for ferroptosis than actually believed. While LPO processes are active, the importance of environmental lipid levels, balance among SFA, MUFA and PUFA in lipid pools and formation of mtPUFA influence the membrane phospholipid turnover, with crucial effects in the occurrence of cell death by ferroptosis.

Exploring a ferroptosis and oxidative stress-based prognostic model for clear cell renal cell carcinoma

Background

Ferroptosis is a newly defined cell death process triggered by increased iron load and tremendous lipid reactive oxygen species (ROS). Oxidative stress-related ferroptosis is of great important to the occurrence and progression of clear cell renal cell carcinoma (ccRCC), which is particularly susceptibility to ferroptosis agonist. Therefore, exploring the molecular features of ferroptosis and oxidative stress might guide the clinical treatment and prognosis prediction for ccRCC patients.

Methods

The differentially expressed ferroptosis and oxidative stress-associated genes (FPTOSs) between normal renal and ccRCC tissues were identified based on The Cancer Genome Atlas (TCGA) database, and those with prognostic significances were applied to develop a prognostic model and a risk scoring system (FPTOS_score). The clinical parameter, miRNA regulation, tumor mutation burden (TMB), immune cell infiltration, immunotherapy response, and drug susceptibility between two FPTOS-based risk stratifications were determined.

Results

We have identified 5 prognosis-associated FPTOSs (ACADSB, CDCA3, CHAC1, MYCN, and TFAP2A), and developed a reliable FPTOS_socre system to distinguish patients into low- and high-risk groups. The findings implied that patients from the high-risk group performed poor prognoses, even after stratified analysis of various clinical parameters. A total of 30 miRNA-FPTOS regulatory pairs were recognized to identify the possible molecular mechanisms. Meanwhile, patients from the high-risk group exhibited higher TMB levels than those from the low-risk groups, and the predominant mutated driver genes were VHL, PBRM1 and TTN in both groups. The main infiltrating immune cells of high- and low-risk groups were CD8+ T cells and resting mast cells, respectively, and patients from the high-risk groups showed preferable drug responsiveness to anti-PD-1 immunotherapy. Eventually, potential sensitive drugs (cisplatin, BI-D1870, and docetaxel) and their enrichment pathways were identified to guide the treatment of ccRCC patients with high-risk.

Conclusion

Our study comprehensively analyzed the expression profiles of FPTOSs and constructed a scoring system with considerable prognostic value, which would supply novel insights into the personalized treatment strategies and prognostic evaluation of ccRCC patient.

Identification of potential ferroptosis hub genes in acute-on-chronic liver failure based on bioinformatics analysis and experimental verification

BACKGROUND

Ferroptosis plays an important role in the development of acute-on-chronic liver failure (ACLF). The present project aimed to identify and validate the potential ferroptosis-related genes in ACLF by bioinformatics analysis and experimental verification.

MATERIALS AND METHODS

The GSE139602 dataset was obtained from the Gene Expression Omnibus database and intersected with ferroptosis genes. Ferroptosis-related differentially expressed genes (DEGs) between the ACLF tissue and healthy group were analyzed using bioinformatics methods. Analysis of enrichment, protein‒protein interactions, and hub genes was conducted. Potential drugs targeting these hub genes were retrieved from the DrugBank database. Finally, we performed real-time quantitative PCR (RT-qPCR) to validate the expression of the hub genes.

RESULTS

A total of 35 ferroptosis-related DEGs were screened, which were enriched in the biosynthesis of amino acids, peroxisomes, fluid shear stress and atherosclerosis. PPI network analysis indicated five ferroptosis-related hub genes, namely, HRAS, TXNRD1, NQO1, PSAT1, and SQSTM1. The experimental validation indicated that the expression levels of HRAS, TXNRD1, NQO1, and SQSTM1 were lower, while the expression level of PSAT1 was higher in ACLF model rats than in healthy rats.

CONCLUSIONS

Our findings reveal that PSAT1, TXNRD1, HRAS, SQSTM1 and NQO1 may affect the development of ACLF by regulating ferroptotic events. These results provide a valid reference for potential mechanisms and identification in ACLF.

Immunohistochemical expression of apolipoprotein B and 4-hydroxynonenal proteins in colorectal carcinoma patients: a retrospective study

AIM

To assess the association of the expression of apolipoprotein B (apoB) and 4-hydroxynonenal (4HNE) with the clinicopathological data of patients with colorectal cancer (CRC).

METHODS

We obtained 80 CRC histopathological specimens sent to the Pathology Laboratory of Hospital Universiti Sains Malaysia from 2015 to 2019. Data on demographic factors, body mass index (BMI), and clinicopathological characteristics were also collected. Formalin-fixed paraffin-embedded tissues were stained by using an optimized immunohistochemical protocol.

RESULTS

Patients were mostly older than 50 years, male, Malay, and overweight or obese. A high apoB expression was observed in 87.5% CRC samples (70/80), while a high 4HNE expression was observed in only 17.5% (14/80) of CRCs. The expression of apoB was significantly associated with the sigmoid and rectosigmoid tumor sites (p =0.001) and tumor size 3-5 cm (p =0.005). 4HNE expression was significantly associated with tumor size 3-5 cm (p =0.045). Other variables were not significantly associated with the expression of either marker.

CONCLUSION

ApoB and 4HNE proteins may play a role in promoting CRC carcinogenesis.

Immunohistochemical expression of apolipoprotein B and 4-hydroxynonenal proteins in colorectal carcinoma patients: a retrospective study

AIM

To assess the association of the expression of apolipoprotein B (apoB) and 4-hydroxynonenal (4HNE) with the clinicopathological data of patients with colorectal cancer (CRC).

METHODS

We obtained 80 CRC histopathological specimens sent to the Pathology Laboratory of Hospital Universiti Sains Malaysia from 2015 to 2019. Data on demographic factors, body mass index (BMI), and clinicopathological characteristics were also collected. Formalin-fixed paraffin-embedded tissues were stained by using an optimized immunohistochemical protocol.

RESULTS

Patients were mostly older than 50 years, male, Malay, and overweight or obese. A high apoB expression was observed in 87.5% CRC samples (70/80), while a high 4HNE expression was observed in only 17.5% (14/80) of CRCs. The expression of apoB was significantly associated with the sigmoid and rectosigmoid tumor sites (p =0.001) and tumor size 3-5 cm (p =0.005). 4HNE expression was significantly associated with tumor size 3-5 cm (p =0.045). Other variables were not significantly associated with the expression of either marker.

CONCLUSION

ApoB and 4HNE proteins may play a role in promoting CRC carcinogenesis.

Lipoxin and glycation in SREBP signaling: Insight into diabetic cardiomyopathy and associated lipotoxicity

Diabetes and cardiovascular diseases are the leading cause of morbidity and mortality worldwide. Diabetes increases cardiovascular risk through hyperglycemia and atherosclerosis. Chronic hyperglycemia accelerates glycation reaction, which forms advanced glycation end products (AGEs). Additionally, hyperglycemia with enhanced levels of cholesterol, native and oxidized low-density lipoproteins, free fatty acids, and oxidative stress induces lipotoxicity. Accelerated glycation and disturbed lipid metabolism are characteristic features of diabetic heart failure. SREBP signaling plays a significant role in lipid and glucose homeostasis. AGEs increase lipotoxicity in diabetic cardiomyopathy by inhibiting SREBP signaling. While anti-inflammatory lipid mediators, lipoxins resolve inflammation caused by lipotoxicity by upregulating the PPARγ expression and regulating CD36. PPARγ connects the bridge between glycation and lipoxin in SREBP signaling. A summary of treatment modalities against diabetic cardiomyopathy is given in brief. This review indicates the novel therapeutic approach in the crosstalk between glycation and lipoxin in SREBP signaling.

Cutaneous manifestations in Costello syndrome: HRAS p.Gly12Ser affects RIN1-mediated integrin trafficking in immortalized epidermal keratinocytes

Heterozygous germline missense variants in the HRAS gene underlie Costello syndrome (CS). The molecular basis for cutaneous manifestations in CS is largely unknown. We used an immortalized human cell line, HaCaT keratinocytes, stably expressing wild-type or CS-associated (p.Gly12Ser) HRAS and defined RIN1 as quantitatively most prominent, high-affinity effector of active HRAS in these cells. As an exchange factor for RAB5 GTPases, RIN1 is involved in endosomal sorting of cell-adhesion integrins. RIN1-dependent RAB5A activation was strongly increased by HRASGly12Ser, and HRAS-RIN1-ABL1/2 signaling was induced in HRASWT- and HRASGly12Ser-expressing cells. Along with that, HRASGly12Ser expression decreased total integrin levels and enriched β1 integrin in RAB5- and EEA1-positive early endosomes. The intracellular level of active β1 integrin was increased in HRASGly12Ser HaCaT keratinocytes due to impaired recycling, whereas RIN1 disruption raised β1 integrin cell surface distribution. HRASGly12Ser induced co-localization of β1 integrin with SNX17 and RAB7 in early/sorting and late endosomes, respectively. Thus, by retaining β1 integrin in intracellular endosomal compartments, HRAS-RIN1 signaling affects the subcellular availability of β1 integrin. This may interfere with integrin-dependent processes as we detected for HRASGly12Ser cells spreading on fibronectin. We conclude that dysregulation of receptor trafficking and integrin-dependent processes such as cell adhesion are relevant in the pathobiology of CS.

Targeting critical pathways in ferroptosis and enhancing antitumor therapy of Platinum drugs for colorectal cancer

Colorectal cancer (CRC) can be resistant to platinum drugs, possibly through ferroptosis suppression, albeit the need for further work to completely understand this mechanism. This work aimed to sum up current findings pertaining to oxaliplatin resistance (OR) or resistance to ascertain the potential of ferroptosis to regulate oxaliplatin effects. In this review, tumor development relating to iron homeostasis, which includes levels of iron that ascertain cells' sensitivity to ferroptosis, oxidative stress, or lipid peroxidation in colorectal tumor cells that are connected with ferroptosis initiation, especially the role of c-Myc/NRF2 signaling in regulating iron homeostasis, coupled with NRF2/GPX4-mediated ferroptosis are discussed. Importantly, ferroptosis plays a key role in OR and ferroptotic induction may substantially reverse OR in CRC cells, which in turn could inhibit the imbalance of intracellular redox induced by oxaliplatin and ferroptosis, as well as cause chemotherapeutic resistance in CRC. Furthermore, fundamental research of small molecules, ferroptosis inducers, GPX4 inhibitors, or natural products for OR coupled with their clinical applications in CRC have also been summarized. Also, potential molecular targets and mechanisms of small molecules or drugs are discussed as well. Suggestively, OR of CRC cells could significantly be reversed by ferroptosis induction, wherein this result is discussed in the current review. Prospectively, the existing literature discussed in this review will provide a solid foundation for scientists to research the potential use of combined anticancer drugs which can overcome OR via targeting various mechanisms of ferroptosis. Especially, promising therapeutic strategies, challenges ,and opportunities for CRC therapy will be discussed.

Diagnostic significance and utility of circulating redox biomarkers in patients with gastric cancer - preliminary study

BACKGROUND

This study aimed to evaluate the redox status, antioxidant barrier, and oxidative damage to proteins, lipids, and DNA in patients with gastric cancer (GC). We are also the first to assess the diagnostic utility of redox parameters in patients with GC with respect to histopathological parameters.

METHODS

Fifty patients with gastric cancer and 50 healthy controls matched for sex and age were included in the study. The antioxidant barrier, redox status, and oxidative damage products were measured in serum/plasma samples using colorimetric or spectrophotometric methods.

RESULTS

The activity of superoxide dismutase - SOD (p < 0.05) was significantly higher, whereas the activities of catalase - CAT (p < 0.0001), glutathione peroxidase - GPx (p < 0.0001), glutathione reductase - GR (p < 0.0001), and reduced glutathione - GSH (p < 0.05) were considerably lower in GC patients than in the control group. The levels of total oxidant status - TOS (p < 0.0001), oxidative stress index - OSI (p < 0.0001), advanced oxidation protein products - AOPP (p < 0.0001), ischaemia modified albumin - IMA (p < 0.01), lipid hydroperoxides - LOOH (p < 0.0001), 8-IsoProstane - 8-Iso-P (p < 0.0001), and DNA/RNA (p < 0.0001) were significantly higher, and the levels of total antioxidant capacity - TAC (p < 0.0001) and total thiols (p < 0.0001) were considerably lower in patients compared to the healthy controls. Some redox parameters are characterized by high AUC values in patients with differentiated GC according to histopathological parameters.

CONCLUSIONS

Gastric cancer is strongly linked to a systemic redox imbalance and increased oxidative damage to proteins, lipids, and DNA. Redox biomarkers are potential diagnostic indicators of gastric cancer advancement.

Lipid Metabolism Heterogeneity and Crosstalk with Mitochondria Functions Drive Breast Cancer Progression and Drug Resistance

Breast cancer (BC) is a heterogeneous disease that can be triggered by genetic alterations in mammary epithelial cells, leading to diverse disease outcomes in individual patients. The metabolic heterogeneity of BC enhances its ability to adapt to changes in the tumor microenvironment and metabolic stress, but unfavorably affects the patient's therapy response, prognosis and clinical effect. Extrinsic factors from the tumor microenvironment and the intrinsic parameters of cancer cells influence their mitochondrial functions, which consequently alter their lipid metabolism and their ability to proliferate, migrate and survive in a harsh environment. The balanced interplay between mitochondria and fatty acid synthesis or fatty acid oxidation has been attributed to a combination of environmental factors and to the genetic makeup, oncogenic signaling and activities of different transcription factors. Hence, understanding the mechanisms underlying lipid metabolic heterogeneity and alterations in BC is gaining interest as a major target for drug resistance. Here we review the major recent reports on lipid metabolism heterogeneity and bring to light knowledge on the functional contribution of diverse lipid metabolic pathways to breast tumorigenesis and therapy resistance.

Metabolic Regulation Effect and Potential Metabolic Biomarkers of Pre-Treated Delphinidin on Oxidative Damage Induced by Paraquat in A549 Cells

Delphinidin (Del) is an anthocyanin component with high in vitro antioxidant capacity. In this study, based on the screening of a cell model, gas chromatography-time of flight mass spectrometry (GC-TOF/MS) was used to evaluate the effect of Del pre-protection on the metabolite levels of intracellular oxidative stress induced by paraquat (PQ). According to the cytotoxicity and reactive oxygen species (ROS) responses of four lung cell lines to PQ induction, A549 cell was selected and treated with 100 μM PQ for 12 h to develop a cellular oxidative stress model. Compared with the PQ-induced group, the principal components of the Del pretreatment group had significant differences, but not significant with the control group, indicating that the antioxidant activity of Del can be correlated to the maintenance of metabolite levels. Del preconditioning protects lipid-related metabolic pathways from the disturbance induced by PQ. In addition, the levels of amino acid- and energy-related metabolites were significantly recovered. Del may also exert an antioxidant effect by regulating glucose metabolism. The optimal combinations of biomarkers in the PQ-treatment group and Del-pretreatment group were alanine-valine-urea and alanine-galactose-glucose. Cell metabolome data provided characteristic fingerprints associated with the antioxidant activity of Del.

Novel prognostic signature based on HRAS, MAPK3 and TFRC identified to be associated with ferroptosis and the immune microenvironment in hepatocellular carcinoma

OBJECTIVES

Ferroptosis, a programmed cell death, has been recognized recently. Several studies have shown the connection between ferroptosis and biological processes in cancer. However, the potential role and mechanism of ferroptosis-related genes in hepatocellular carcinoma (HCC) remain unclear, and understanding the crosstalk between the tumor immune microenvironment and ferroptosis is still a great challenge.

METHOD

We retrospectively analyzed the transcriptomic and clinical data of HCC from TCGA database. 74 ferroptosis-related genes (FRGs), including 14 immune-ferroptosis-related genes (IFRGs), were identified with differential expression in tumor and normal tissues. Then, we screened and constructed a prognostic signature using survival analysis and the least absolute shrinkage and selection operator. Furthermore, we validated the performance of the signature for assessing survival prognosis and clinicopathological staging. In addition, we investigated the link between the prognostic features and tumor-infiltrating immune cells using CIBERSORT.

RESULT

The results identified HRAS, MAPK3 and TFRC as prognostic IFRGs. The risk score was elevated when IFRGs were upregulated and patient outcomes worsened. In addition, the results show significant differences in tumor-infiltrating immune cells, especially immunosuppressive cells, including tumor-infiltrating macrophages cells and regulatory cells, implying that the expression of these three IFRGs may be an intrinsic barrier to strong ferritin-induced immune responses. Enrichment analysis revealed crosstalk between ferroptosis and tumor immunity. The effect of the risk score was validated in the ICGC cohort and the Human Protein Atlas database confirmed the high expression of IFRGs in tumor tissue.

CONCLUSIONS

In our study, these IFRGs may provide some new ideas for the study of ferroptosis and the tumor immunity. These findings may also provide new strategies for treatment of HCC.

Targeting de novo lipogenesis and the Lands cycle induces ferroptosis in KRAS-mutant lung cancer

Mutant KRAS (KM), the most common oncogene in lung cancer (LC), regulates fatty acid (FA) metabolism. However, the role of FA in LC tumorigenesis is still not sufficiently characterized. Here, we show that KMLC has a specific lipid profile, with high triacylglycerides and phosphatidylcholines (PC). We demonstrate that FASN, the rate-limiting enzyme in FA synthesis, while being dispensable in EGFR-mutant or wild-type KRAS LC, is required for the viability of KMLC cells. Integrating lipidomic, transcriptomic and functional analyses, we demonstrate that FASN provides saturated and monounsaturated FA to the Lands cycle, the process remodeling oxidized phospholipids, such as PC. Accordingly, blocking either FASN or the Lands cycle in KMLC, promotes ferroptosis, a reactive oxygen species (ROS)- and iron-dependent cell death, characterized by the intracellular accumulation of oxidation-prone PC. Our work indicates that KM dictates a dependency on newly synthesized FA to escape ferroptosis, establishing a targetable vulnerability in KMLC.

Ferroptosis: A Specific Vulnerability of RAS-Driven Cancers?

Ferroptosis has emerged as a new type of programmed cell death that can be harnessed for cancer therapy. The concept of ferroptosis was for the first time proposed in in the early 2000s, as an iron-dependent mode of regulated cell death caused by unrestricted lipid peroxidation (LPO) and subsequent plasma membrane rupture. Since the discovery and characterization of ferroptosis, a wealth of research has improved our understanding of the main pathways regulating this process, leading to both the repurposing and the development of small molecules.

However, ferroptosis is still little understood and several aspects remain to be investigated. For instance, it is unclear whether specific oncogenes, cells of origin or tumor niches impose specific susceptibility/resistance to ferroptosis or if there are some ferroptosis-related genes that may be used as bona fide pan-cancer targetable dependencies. In this context, even though RAS-driven cancer cell lines seemed to be selectively sensitive to ferroptosis inducers, subsequent studies have questioned these results, indicating that in some cases mutant RAS is necessary, but not sufficient to induce ferroptosis. In this perspective, based on publicly available genomic screening data and the literature, we discuss the relationship between RAS-mutation and ferroptosis susceptibility in cancer.

Metabolic Reprogramming in Cancer Cells: Emerging Molecular Mechanisms and Novel Therapeutic Approaches

The constant changes in cancer cell bioenergetics are widely known as metabolic reprogramming. Reprogramming is a process mediated by multiple factors, including oncogenes, growth factors, hypoxia-induced factors, and the loss of suppressor gene function, which support malignant transformation and tumor development in addition to cell heterogeneity. Consequently, this hallmark promotes resistance to conventional anti-tumor therapies by adapting to the drastic changes in the nutrient microenvironment that these therapies entail. Therefore, it represents a revolutionary landscape during cancer progression that could be useful for developing new and improved therapeutic strategies targeting alterations in cancer cell metabolism, such as the deregulated mTOR and PI3K pathways. Understanding the complex interactions of the underlying mechanisms of metabolic reprogramming during cancer initiation and progression is an active study field. Recently, novel approaches are being used to effectively battle and eliminate malignant cells. These include biguanides, mTOR inhibitors, glutaminase inhibition, and ion channels as drug targets. This review aims to provide a general overview of metabolic reprogramming, summarise recent progress in this field, and emphasize its use as an effective therapeutic target against cancer.

Ferroptosis: A New Road towards Cancer Management

Ferroptosis is a recently described programmed cell death mechanism that is characterized by the buildup of iron (Fe)-dependent lipid peroxides in cells and is morphologically, biochemically, and genetically distinct from other forms of cell death, having emerged to play an important role in cancer biology. Ferroptosis has significant importance during cancer treatment because of the combination of factors, including suppression of the glutathione peroxidase 4 (Gpx4), cysteine deficiency, and arachidonoyl (AA) peroxidation, which cause cells to undergo ferroptosis. However, the physiological significance of ferroptosis throughout development is still not fully understood. This current review is focused on the factors and molecular mechanisms with the diagrammatic illustrations of ferroptosis that have a role in the initiation and sensitivity of ferroptosis in various malignancies. This knowledge will open a new road for research in oncology and cancer management.

Emerging Roles of Aldehyde Dehydrogenase Isoforms in Anti-cancer Therapy Resistance

Aldehyde dehydrogenases (ALDHs) are a family of detoxifying enzymes often upregulated in cancer cells and associated with therapeutic resistance. In humans, the ALDH family comprises 19 isoenzymes active in the majority of mammalian tissues. Each ALDH isoform has a specific differential expression pattern and most of them have individual functional roles in cancer. ALDHs are overexpressed in subpopulations of cancer cells with stem-like features, where they are involved in several processes including cellular proliferation, differentiation, detoxification and survival, participating in lipids and amino acid metabolism and retinoic acid synthesis. In particular, ALDH enzymes protect cancer cells by metabolizing toxic aldehydes in less reactive and more soluble carboxylic acids. High metabolic activity as well as conventional anticancer therapies contribute to aldehyde accumulation, leading to DNA double strand breaks (DSB) through the generation of reactive oxygen species (ROS) and lipid peroxidation. ALDH overexpression is crucial not only for the survival of cancer stem cells but can also affect immune cells of the tumour microenvironment (TME). The reduction of ROS amount and the increase in retinoic acid signaling impairs immunogenic cell death (ICD) inducing the activation and stability of immunosuppressive regulatory T cells (Tregs). Dissecting the role of ALDH specific isoforms in the TME can open new scenarios in the cancer treatment. In this review, we summarize the current knowledge about the role of ALDH isoforms in solid tumors, in particular in association with therapy-resistance.

Disulfiram/Copper induces antitumor activity against gastric cancer via the ROS/MAPK and NPL4 pathways

Disulfiram (DSF) is an anti-alcoholism medication with superior antitumor activity and clinical safety; its antitumor mechanisms in gastric cancer (GC) have not been fully explored. In the present work, low nontoxic concentrations of copper (Cu) ions substantially enhanced DSF’s antitumor activity, inhibiting the proliferation and growth of GC cell lines. DSF/Cu elevated the generation of reactive oxygen species (ROS), and apoptosis was induced in an ROS-dependent manner. This process might involve primary inhibition GC by DSF/Cu through induction of apoptosis via the ROS/mitogen-activated protein kinase pathway. Disordering transportation of ubiquitinated protein may also fuel the process. In summary, we found that DSF exerts antitumor effects on GC. DSF/Cu should be considered as adjunctive therapy for GC.

Establishment and Validation of a Ferroptosis-Related Long Non-Coding RNA Signature for Predicting the Prognosis of Stomach Adenocarcinoma

Background: Ferroptosis is a form of regulated cell death that follows cell membrane damage and mostly depends on iron-mediated oxidative. Long non-coding RNAs (LncRNAs) are associated with the development of a variety of tumors. Till date, LncRNAs have been reported to intervene in ferroptosis. Therefore, we intended to provide a prognostic ferroptosis-related-lncRNA signature in stomach adenocarcinoma (STAD).

Methods: We downloaded ferroptosis-related genes from the FerrDb database and RNA sequencing data and clinicopathological characteristics from The Cancer Genome Atlas. Gene differential expression analysis was performed using the “limma” package. We used Cox regression analysis to determine the ferroptosis-related lncRNAs signature with the lowest AIC value. The Kaplan–Meier curve, ROC curve, and nomogram were used to evaluate the prognostic value of the risk score. Gene set enrichment analysis (GSEA) was used to explore the biologic functions of the three ferroptosis-related lncRNAs. LINC01615 expression in gastric cancer cell lines and tissues was measured by real-time PCR. A nuclear-cytoplasmic fractionation assay was used to analyze the subcellular localization for LINC01615. Furthermore, we used bioinformatics to predict potential target microRNAs (miRNAs) of LINC01615 and their target ferroptosis-related mRNAs.

Results: Three ferroptosis-related-lncRNA signatures (AP000695.2, AL365181.3, and LINC01615) were identified, and then Kaplan–Meier, Cox regression analyses, and ROC curve confirmed that the ferroptosis-related-lncRNA model could predict the prognosis of STAD. The GSEA indicated that the three ferroptosis-related lncRNAs might be related to the extracellular matrix and cellular activities. LINC01615 is highly expressed in gastric cancer cell lines and tissues. A nuclear-cytoplasmic fractionation assay confirmed that in gastric cancer cell lines, most LINC01615 was enriched in the cytoplasm. Bioinformatics further predicts four potential target miRNAs of LINC01615 and then figured out 26 target ferroptosis-related mRNAs.

Conclusion: We established a three-ferroptosis-related-lncRNA model (AP000695.2, AL365181.3, and LINC01615) that can predict the prognosis of STAD patients. We also expected to provide a promising target for LINC01615 for research in the future, which was highly expressed in gastric cancer and cell lines and acted as a ceRNA to get involved in ferroptosis.

RAS Mutation Conversion in Bevacizumab-Treated Metastatic Colorectal Cancer Patients: A Liquid Biopsy Based Study

Simple Summary

Recent evidence has been provided that the clonal evolution of mutant RAS colorectal tumors may lead to the negative selection of mutant RAS clones, with the appearance of a time window characterized by the disappearance of RAS mutant clones in plasma. We demonstrate here for the first time that the use of bevacizumab in the first-line treatment is the most significant factor for RAS conversion from mutant to wild type in plasma. The frequent appearance of this “RAS wild-type * window” in patients treated with a first line treatment containing bevacizumab could possibly present them as candidates for second line treatment with anti-EGFR monoclonal antibodies, which are otherwise precluded.

Abstract

Liquid biopsies have shown that, in RAS mutant colorectal cancer, the conversion to RAS wild-type * status during the course of the disease is a frequent event, supporting the concept that the evolutionary landscape of colorectal cancer can lead to an unexpected negative selection of RAS mutant clones. The aim of the present study was to clarify whether the negative selection of RAS mutation in plasma might be drug-dependent. For this purpose, we used liquid biopsy to compare the rate of conversion from RAS mutant to RAS wild-type * in two groups of originally RAS mutant mCRC patients: the first treated with chemotherapy alone, while the second was treated with chemotherapy combined with bevacizumab. Serial liquid biopsies were performed at 3 months (T1), 6 months (T2), 9 months (T3), and 12 months (T4) after starting first line treatments. We found that the only independent variable significantly associated to RAS status conversion was the use of bevacizumab. RAS conversion was not found associated to tumor burden reduction, although bevacizumab-treated patients who converted to RAS wild-type * had a significantly longer PFS compared to patients who remained RAS mutant. The appearance of a “RAS wild-type * window”, mainly in bevacizumab-treated patients, might present them as candidates for second line treatment with anti-EGFR, which was otherwise precluded.

Identification of ferroptosis-related genes as potential biomarkers of tongue squamous cell carcinoma using an integrated bioinformatics approach

Tongue squamous cell carcinoma (TSCC) is one of the deadliest cancers of the head and neck, but the role of the ferroptosis pathway in its development is still unknown. In this study we explored the pathogenetic mechanisms associated with ferroptosis in TSCC. We identified differentially expressed genes (DEGs) of TSCC patients and used gene ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA) to annotate, visualize, and integrate these DEGs. Receiver operating characteristic curve (ROC) analysis was performed, and the STRING database was used to construct a protein–protein interaction network to evaluate the predictive value of ferroptosis‐related DEGs. A total of 219 DEGs were identified and GO, KEGG, and GSEA showed that extracellular matrix (ECM)‐receptor interaction and interleukin (IL)‐17 signaling pathways were substantially upregulated in TSCC. Univariate Cox analysis revealed that high expression of CA9, TNFAIP3, and NRAS were predictive of a worse outcome. We then constructed a prognostic model that predicted survival in the validation cohort at 1 year and 32 months. Finally, 60 cases of tongue carcinoma and normal tissues were collected, and immunohistochemistry was used to detect the expression of CA9. We found that CA9 was strongly expressed in tongue carcinoma tissues and absent in adjacent tissues. Overall, we found that ferroptosis‐related genes may affect TSCC prognosis through the ECM‐receptor interaction and IL‐17 signaling pathways. Additionally, immunohistochemistry confirmed that CA9 was highly expressed in tongue carcinoma tissues, and a model based on ferroptosis‐related genes showed a good ability to predict overall survival in TSCC.