Expression Of SLC7A11 Research Articles

OTUB1 regulation of ferroptosis and the protective role of ferrostatin-1 in lupus nephritis

Lupus nephritis (LN) is a prevalent and severe manifestation of systemic lupus erythematosus (SLE), leading to significant morbidity and mortality. OTUB1, a deubiquitinating enzyme, has emerged as a potential therapeutic target due to its role in cellular protection and regulation of ferroptosis, a form of cell death linked to LN. Our study revealed significantly reduced OTUB1 expression in the glomeruli of LN patients and podocytes, correlated with disease severity. CRISPR/Cas9-mediated OTUB1 knockout in podocytes resulted in pronounced injury, indicated by decreased levels of nephrin and podocin. Ferrostatin-1 treatment effectively mitigated this injury, restoring SLC7A11 expression and significantly reducing MDA levels, Fe2+ levels, BODIPY C11 expression, and normalized cysteine and glutathione expression. In the MRL/lpr mouse model, Ferrostatin-1 significantly improved renal function decreased proteinuria, and ameliorated renal histopathological changes, including reduced glomerular endothelial swelling, mesangial cell proliferation, and leukocyte infiltration. These results underscore the protective role of Ferrostatin-1 in modulating the pathogenesis of LN. OTUB1 plays a crucial protective role against podocyte injury in LN by regulating ferroptosis. Ferrostatin-1 effectively mitigates podocyte damage induced by OTUB1 deficiency, suggesting that targeting ferroptosis could be a promising therapeutic strategy for LN.

Activation of autophagy, paraptosis, and ferroptosis by micheliolide through modulation of the MAPK signaling pathway in pancreatic and colon tumor cells

Micheliolide (MCL), a naturally occurring sesquiterpene lactone, has demonstrated significant anticancer properties through the induction of various programmed cell death mechanisms. This study aimed to explore MCL's effects on autophagy, paraptosis, and ferroptosis in pancreatic and colon cancer cells, along with its modulation of the MAPK signaling pathway. MCL was found to substantially suppress cell viability in these cancer cells, particularly in MIA PaCa-2 and HT-29 cell lines. The study identified that MCL induced autophagy by enhancing the levels of autophagy markers such as Atg7, p-Beclin-1, and Beclin-1, which was attenuated by the autophagy inhibitor 3-MA. Furthermore, MCL was found to facilitate paraptosis, indicated by decreased Alix and in-creased ATF4 and CHOP levels. It also promoted ferroptosis, as demonstrated by the reduced expression of SLC7A11, elevated TFRC levels, and increased intracellular iron. Additionally, MCL activated the MAPK signaling pathway, marked by the phosphorylation of JNK, p38, and ERK, linked with an increase in ROS production that is vital in regulating these cell death mechanisms. These findings propose that MCL is a versatile anticancer agent, capable of activating various cell death pathways by modulating MAPK signaling and ROS levels. These results emphasize the therapeutic promise of MCL in treating cancer, pointing to the necessity of further in vivo investigations to confirm these effects and determine its potential clinical uses.

Enhancer of Zeste Homolog 2 Protects Mucosal Melanoma from Ferroptosis via the KLF14-SLC7A11 Signaling Pathway

Background: Mucosal melanoma (MM) is epidemiologically, biologically, and molecularly distinct from cutaneous melanoma. Current treatment strategies have failed to significantly improve the prognosis for MM patients. This study aims to identify therapeutic targets and develop combination strategies by investigating the mechanisms underlying the tumorigenesis and progression of MM. Methods: We analyzed the copy number amplification of enhancer of zeste homolog 2 (EZH2) in 547 melanoma patients and investigated its correlation with clinical prognosis. Utilizing cell lines, organoids, and patient-derived xenograft models, we assessed the impact of EZH2 on cell proliferation and sensitivity to ferroptosis. Further, we explored the mechanisms of ferroptosis resistance associated with EZH2 by conducting RNA sequencing and chromatin immunoprecipitation sequencing. Results: EZH2 copy number amplification was closely associated with malignant phenotype and poor prognosis in MM patients. EZH2 was essential for MM cell proliferation in vitro and in vivo. Moreover, genetic perturbation of EZH2 rendered MM cells sensitized to ferroptosis. Combination treatment of EZH2 inhibitor with ferroptosis inducer significantly inhibited the growth of MM. Mechanistically, EZH2 inhibited the expression of Krüpple-Like factor 14 (KLF14), which binds to the promoter of solute carrier family 7 member 11 (SLC7A11) to repress its transcription. Loss of EZH2 therefore reduced the expression of SLC7A11, leading to reduced intracellular SLC7A11-dependent glutathione synthesis to promote ferroptosis. Conclusion: Our findings not only establish EZH2 as a biomarker for MM prognosis but also highlight the EZH2-KLF14-SLC7A11 axis as a potential target for MM treatment.

Puerarin Ameliorates Ferroptosis in Neuronal Injury Through the PI3K/AKT Signaling Pathway

Ferroptosis plays an important role in the pathogenesis of neuronal damage, generally mediated by iron and lipid peroxidation. In the present study, we measured the protective effects of puerarin against corticosterone-induced neuronal injury via PI3K/AKT-mediated activation of nuclear factor erythroid 2-related factor 2 (Nrf2). After exposing corticosterone-treated PC12 cells to indicated compounds, we measured the key regulators of ferroptosis (ferritin, SLC7A11, and Ptgs2), ferroptosis events (levels of iron, ROS, MDA, and GSH), and the PI3K/AKT/Nrf2 axis. Corticosterone induced ferroptosis in PC12 cells, evidenced by reduced levels of ferritin, SLC7A11, and GSH and increased levels of iron, ROS, and MDA. These effects were reversed by inhibiting ferroptosis with ferrostatin-1. Puerarin-mediated activation of Nrf2 repressed ferroptosis in corticosterone-treated PC12 cells by upregulating ferritin and SLC7A11 expression. Moreover, the protective effects of puerarin on ferroptosis in corticosterone-treated cells relied on the activation of the PI3K/AKT pathway though the upregulation of nuclear Nrf2. These findings indicate that ferroptosis plays an essential role in corticosterone-induced neuronal damage, and puerarin protects against ferroptosis in corticosterone-treated cells via PI3K/AKT-mediated activation of Nrf2.

Unraveling the Ferroptosis-inducing Potential of Methanol Leaves Extract of Prosopis Juliflora Via Downregulation of SLC7A11 and GPX4 mRNA Expression in A549 Lung Cancer Cells.

Prosopis juliflora has been employed in many traditional treatments. As evidenced by our earlier research, Prosopis juliflora leaf methanol extract (PJME) has a promising future in the fight against lung cancer. It may also be used in conjunction with other treatments to effectively manage lung cancer. The main objective of this study was to explore the potential of PJME to inhibit lung cancer in A549 cells, along with its underlying mechanisms of action. The antiproliferative effects were determined using MTT and LDH tests. Apoptosis- inducing capacity was evaluated using the DAPI staining, caspase-3 test, cytochrome C assay, PARP cleavage, and qRT-PCR. To investigate the mechanism of action of PJME in lung cancer, the levels of ROS, MMP, GSH, MDA, and specific ferroptosis indicators were measured. The experimental data of the current study indicated that exposure of A549 cells to PJME reduced cell viability and increased cellular cytotoxicity. The apoptosis-inducing ability of PJME in A549 cells was validated by enhanced nuclear condensation, level of the caspase- 3, cytochrome C, and PARP release. In addition, qRT-PCR investigations verified that the administration of PJME led to a decrease in the expression of anti-apoptotic gene Bcl2 while enhancing the mRNA level of pro-apoptotic genes, such as Bax and caspase-3, in A549 cells. The study also found that PJME has the ability to activate ferroptosis pathways, as evidenced by elevated reactive oxygen species (ROS) generation, changes in the levels of antioxidant markers (MDA and GSH), and decreased expression of SLC7A11 and GPX4. The results of the present study clearly showed that PJME inhibited the proliferation of A549 cells and induced ferroptosis by reducing the expression of the important targets SLC7A11 and GPX4. Further research is necessary to fully understand the clinical efficacy of PJME before it can be investigated as supplemental or adjuvant therapy for lung cancer.

Disulfidptosis-related subtype and prognostic signature in prostate cancer

BackgroundDisulfidptosis refers to cell death caused by the accumulation and bonding of disulfide in the cytoskeleton protein of SLC7A11-high level cells under glucose deprivation. However, the role of disulfidptosis-related genes (DRGs) in prostate cancer (PCa) classification and regulation of the tumor microenvironment remains unclear.MethodsFirstly, we analyzed the expression and mutation landscape of DRGs in PCa. We observed the expression levels of SLC7A11 in PCa cells through in vitro experiments and assessed the inhibitory effect of the glucose transporter inhibitor BAY-876 on SLC7A11-high cells using CCK-8 assay. Subsequently, we performed unsupervised clustering of the PCa population and analyzed the differentially expressed genes (DEGs) between clusters. Using machine learning techniques to select a minimal gene set and developed disulfidoptosis-related risk signatures for PCa. We analyzed the tumor immune microenvironment and the sensitivity to immunotherapy in different risk groups. Finally, we validated the accuracy of the prognostic signatures genes using single-cell sequencing, qPCR, and western blot.ResultsAlthough SLC7A11 can increase the migration ability of tumor cells, BAY-876 effectively suppressed the viability of prostate cancer cells, particularly those with high SLC7A11 expression. Based on the DRGs, PCa patients were categorized into two clusters (A and B). The risk label, consisting of a minimal gene set derived from DEGs, included four genes. The expression levels of these genes in PCa were initially validated through in vitro experiments, and the accuracy of the risk label was confirmed in an external dataset. Cluster-B exhibited higher expression levels of DRG, representing lower risk, better prognosis, higher immune cell infiltration, and greater sensitivity to immune checkpoint blockade, whereas Cluster A showed the opposite results. These findings suggest that DRGs may serve as targets for PCa classification and treatment. Additionally, we constructed a nomogram that incorporates DRGs and clinical pathological features, providing clinicians with a quantitative method to assess the prognosis of PCa patients.ConclusionThis study analyzed the potential connection between disulfidptosis and PCa, and established a prognostic model related to disulfidptosis, which holds promise as a valuable tool for the management and treatment of PCa patients.

Dexmedetomidine preconditioning attenuates ferroptosis in myocardial ischemia-reperfusion injury via α2 adrenergic receptor activation

ObjectiveDexmedetomidine (Dex) is a potent agonist of the α2 adrenergic receptor that has been shown to possess sedative and hypnotic properties. Dex can protect against myocardial ischemia-reperfusion injury (MIRI) by inhibiting ferroptosis. However, these studies were based on Dex post-conditioning, and the role of α2 adrenergic receptors in this process is unclear. In this study, we investigated whether Dex preconditioning can prevent MIRI by attenuating ferroptosis and whether this effect depends on α2 adrenergic receptors in rats. MethodsMale Sprague–Dawley rats were randomly assigned to five groups: sham (saline-treated), I/R (ischemia-exposed), Dex + I/R (Dex pre-treatment), Dex + Yoh + I/R (Dex and yohimbine pre-treatment), and Yoh + I/R (yohimbine pre-treatment). Cardiac function, myocardial infarction, and morphological changes were assessed. Transmission electron microscopy was used to analyze mitochondrial morphology. Ferroptosis-related indicators and lipid peroxidation were measured using western blotting and qRT-PCR. ResultsOur findings indicated that Dex preconditioning improved cardiac function, reduced infarct size and apoptosis, and inhibited ferroptosis in the rat myocardium after MIRI. These effects were associated with the upregulation of Nrf2, SLC7A11, and GPX4 expression, as well as the downregulation of Ferritin, TFR1, ACSL4, COX2, IL-1β, IL-6, and TNF-α expression. Importantly, yohimbine, an α2 adrenergic receptor antagonist, abolished these protective effects. ConclusionThese results suggest that Dex preconditioning can prevent MIRI by attenuating ferroptosis via α2 adrenergic receptor activation and by modulating the Nrf2/SLC7A11/GPX4 pathway.

ACSS2 regulates ferroptosis in an E2F1-dependent manner in breast cancer brain metastatic cells.

Brain metastasis diagnosis in breast cancer patients is considered an end-stage event. The median survival after diagnosis is measured in months, thus there is an urgent need to develop novel treatment strategies. Breast cancers that metastasize to the brain must adapt to the unique brain environment and are highly dependent on acetate metabolism for growth and survival. However, the signaling pathways that regulate survival in breast cancer brain metastatic (BCBM) tumors are not known. Primary brain tumor cells can convert acetate to acetyl-CoA via phosphorylation of acetyl-CoA synthetase 2 (ACSS2) by the cyclin-dependent kinase-5 (CDK5) regulated by the nutrient sensor O-GlcNAc transferase (OGT). Here, we show that breast cancer cells selected to metastasize to the brain contain increased levels of O-GlcNAc, OGT and ACSS2-Ser267 phosphorylation compared to parental breast cancer cells. Moreover, OGT and CDK5 are required for breast cancer cell growth in the brain parenchyma in vivo. Importantly, ACSS2 and ACSS2-S267D phospho-mimetic mutant are critical for in vivo breast cancer growth in the brain but not in the mammary fat pad. Mechanistically, we show that ACSS2 regulates BCBM cell survival by suppressing ferroptosis via regulation of E2F1-mediated expression of anti-ferroptotic proteins SLC7A11 and GPX4. Lastly, we show treatment with a novel brain-permeable small molecule ACSS2 inhibitor induced ferroptosis and reduced BCBM growth ex vivo and in vivo . These results suggest a crucial role for ACSS2 in protecting from ferroptosis in breast cancer brain metastatic cells and suggests that breast cancer brain metastatic cells may be susceptible to ferroptotic inducers.

α4 Nicotinic Acetylcholine Receptors in Lipopolysaccharide-Related Lung Inflammation

Sepsis remains an important healthcare challenge. The lungs are often affected in sepsis, resulting in acute lung injury characterized by inflammation. Mechanisms involving lipopolysaccharide (LPS) stimulation of toll-like receptor (TLR) signaling with induction of proinflammatory pathways have been implicated in this process. To date, however, studies targeting these pathways have failed to improve outcomes. We have found that LPS may also promote lung injury through the activation of α4 nicotinic acetylcholine receptors (α4 nAChRs) in immune cells. We observed increased expression of α4 nAChRs in human THP-1 monocytic cells exposed to LPS (100 ng/mL, 24 h). We also observed that LPS stimulated the expression of other relevant genes, including tumor necrosis factor-α, interleukin-1β, plasminogen activator inhibitor-1, the solute carrier family 7 member 11, extracellular superoxide dismutase, and transforming growth factor-β1. Of interest, dihydro-β-erythroidine hydrobromide (DHβE), a specific chemical inhibitor of α4 nAChRs, inhibited the LPS-induced expression of these genes. We generated mice with a global knockout mutation of the α4 nAChR subunit in the C57BL/6 background using CRISPR/Cas9 technology. The lungs of these LPS-treated animals demonstrated a reduction in the expression of the above-mentioned genes when compared with the lungs of wild-type animals. In support of the role of oxidative stress, we observed that LPS induced expression of the cystine transporter Slc7a11 in both THP-1 cells and in wild-type mouse lungs. The effects of LPS on THP-1 cells were blocked by the thiol antioxidant N-acetylcysteine and mimicked by redox stress. Importantly, the induction of IL-1β by redox stress was inhibited by the α4 nAChR inhibitor DHβE. Finally, we showed that LPS stimulated calcium influx in THP-1 cells, which was blocked by the α4 nAChR inhibitor. Our observations suggest that LPS promotes lung injury by stimulating redox stress, which activates α4 nAChR signaling and drives proinflammatory cytokine expression.

H19 lncRNA triggers ferroptosis, exacerbating ox-LDL-induced artery endothelial cell damage in vitro.

The precise association between lncRNA H19 and ferroptosis in the context of atherosclerosis remains uncertain. This study is to clarify the underlying process and propose novel approaches for the advancement of therapeutic interventions targeting atherosclerosis. Assessment of ferroptosis, which entails the evaluation of cell viability using CCK-8 and the quantification of intracellular MDA, GSH, and ferrous ions. Simultaneously, the protein expression levels of assessed by western blot analysis, while the expression level of lncRNA H19 was also determined. Furthermore, HAECs that were cultured with ox-LDL were subjected to Fer-1 interference. HAECs were exposed to ox-LDL and then transfected with H19 shRNA and H19 overexpression vector pcDNA3.1. The level of ferroptosis in the cells was then measured. Then, HAECs were subjected to incubation with ox-LDL, followed by transfection with H19 shRNA and treated with Erastin to assess the levels of ferroptosis, cell viability, and inflammatory factor production. and the ability for blood vessel development. The survival rate of HAECs in the ox-LDL group was much lower. Ox-LDL resulted in an upregulation of ACSL4 expression in HAECs, while the expression of SLC7A11 and GPX4 decreased. lncRNA H19 enhances ferroptosis and exacerbates arterial endothelial cell damage induced by LDL.

Apigenin alleviates Sjögren’s syndrome-induced salivary gland epithelial cell ferroptosis via ERα signaling-mediated regulation of the ATF3/SLC7A1l axis

BackgroundIn Sjögren’s syndrome (SS)—an autoimmune disease characterized by dry mouth and eyes—salivary gland epithelial cells (SGECs) undergo ferroptosis, which disrupts their integrity and impairs saliva secretion. Apigenin, a phytoestrogen, is known to activate estrogen signalling and alleviate xerostomia in ovariectomized mice; however, its effect on SGEC survival and function in SS remains unclear. We hypothesized that apigenin alleviates SS symptoms and progression by inhibiting ferroptosis in SGECs and aimed to elucidate the underlying mechanism. MethodsApigenin (50 mg/kg) was orally gavaged to non-obese diabetic (NOD)/LtJ female mice (SS model); changes in SS functional indicators were analyzed using mRNA sequencing and bioinformatic analyses of submandibular glands. Interferon-gamma (IFN-γ)-stimulated SGECs were used to model SS in vitro; SGEC activity and aquaporin 5 (AQP5) expression were analyzed. Immunohistochemical staining, transmission electron microscopy, RT-qPCR, western blotting and other methods were used to verify the mechanisms. ResultsApigenin significantly increased salivary secretion and AQP5 expression while inhibiting ferroptosis and immune infiltration in NOD mouse submandibular glands. The oxidative stress gene ATF3 was upregulated and GPX4 was downregulated in NOD mice compared to that in control group (ICR mice); however, apigenin reversed this effect. IFN-γ treatment downregulated AQP5, SLC7A11, and GPX4 expression while promoting ATF3 expression and ferroptosis, which was mitigated by apigenin. ATF3 knockdown increased SLC7A11 and GPX4 expression, inhibiting SS and ferroptosis. Furthermore, apigenin inhibited ferroptosis in SGECs through ESR1 binding to ATF3. ConclusionApigenin alleviates SS by regulating SGEC ferroptosis via the ERα-regulated ATF3/SLC7A11 axis, highlighting its therapeutic potential in SS.

Modulating ferroptosis and mycobactericidal activity in lung epithelial cells via YY1/iNOS pathway

BackgroundMycobacterium tuberculosis infection triggers various forms of host cell death, including ferroptosis in lung epithelial cells; YY1, a critical transcription factor, plays a pivotal role in regulating ferroptosis, however, the underlying mechanisms are not fully understood. MethodsTo investigate Mycobacterium marinum (M.marinum) infection in lung epithelial cells A549 and H1299, we utilized flow cytometry to evaluate cell death and measure reactive oxygen species (ROS). Colony-forming unit (CFU) assays determined the intracellular bacterial load. Ferroptosis was analyzed using a specific detection kit to measure malondialdehyde (MDA) and glutathione (GSH) levels. The interaction between the transcription factor YY1 and the iNOS promoter was assessed through a dual-luciferase reporter assay. ResultsM.marinum induced ferroptosis in lung epithelial cells through invasion. This effect is most pronounced at 8 h of infection and decreases over time but increased with a higher multiplicity of infection (MOI). YY1 knockdown decreases the expression of SLC7A11 and GPX4, attenuates cellular ferroptosis, while YY1 overexpression has the opposite phenomenon, enhancing the expression of bactericidal molecules such as iNOS and MPEG1, thereby markedly reducing the intracellular bacterial load. We identified substantial binding of YY1 to the iNOS promoter region (−655 to −1018 bp), enhancing mycobactericidal activity in YY1-overexpressing cells. ConclusionsOur study demonstrates that YY1 inhibits ferroptosis induced by Mycobacterium marinum infection and reduces intracellular bacterial proliferation in lung epithelial cells. These findings provide a crucial basis for developing anti-tuberculosis therapies that target YY1 modulation, potentially offering new clinical avenues for the treatment of tuberculosis.

Shikonin induces ferroptosis in osteosarcomas through the mitochondrial ROS-regulated HIF-1α/HO-1 axis

BackgroundThe most common malignant bone tumour is osteosarcoma, which has an unsatisfactory prognosis and unsatisfactory treatment. Ferroptosis shows promise as an effective OS therapy. A substance extracted from the Lithospermum erythrorhizon, Shikonin (SHK), inhibits a number of tumours, including ovarian, gastric, and lung cancers. However, whether SHK induces OS ferroptosis and its mechanisms are not clear. PurposeOur study is aimed at investigating whether SHK causes ferroptosis and elucidating its molecular mechanism. MethodsCell counting Kit-8, cell cycle and cell apoptosis assay were utilised to assess therapeutic effect of SHK against OS. Normal cells, including H9C2, AML-12 and HK-2, haematoxylin and eosin staining and mice serum biomarker tests were used to assess SHK biosafety. Malondialdehyde (MDA) levels, the glutathione (GSH)/oxidized glutathione (GSSG) ratio, reactive oxygen species (ROS), lipid peroxide (LPO), and intracellular Fe2+ detection, quantitative reverse transcription PCR (qRT-PCR), Western blotting (WB) and rescue experiments were employed to confirm whether SHK induced ferroptosis in OS cells. Molecular docking, cellular thermal shift assay (CETSA), and drug affinity responsive target stability (DARTS) assay were used to evaluate the direct binding between SHK and hypoxia-inducible factor-1α (HIF-1α). Protein stability and degradation analysis, small RNA interference, flow cytometry, qRT-PCR, and WB were used to investigate the molecular mechanism of ferroptosis. In vivo xenografts of nude mouse was used to study the anti-OS effect of SHK. ResultsSHK significantly reduced OS cell viability and induced apoptosis and G2/M arrest. SHK increased intracellular levels of MDA, ROS, LPO, and Fe2+ while simultaneously reducing the GSH/GSSG ratio and GPX4 and SLC7A11 expression. CETSA and DARTS results demonstrated that SHK did not bind targetly to HIF-1α. Instead, mitochondrial ROS (MitoROS) promoted HIF-1α expression, resulting in HO-1 overexpression, excess Fe2+ production, ROS accumulation and GPX depletion, and ferroptosis. Furthermore, inhibition of MitoROS using Mito-TEMPO downregulated HIF-1α/HO-1 axis and mitigated the SHK-induced ferroptosis. In vivo, SHK effectively suppressed OS growth with favourable biosafety, confirming the molecular mechanism underlying SHK-induced ferroptosis in OS. ConclusionWe observe that HIF-1α/HO-1 axis is the crucial factor in SHK-induced OS ferroptosis. Importantly, we demonstrate that HIF-1α is indirectly regulated by MitoROS rather than SHK bound directly to HIF-1α. Our research suggest that SHK is a potential drug candidate for OS treatment and may help in identifying novel therapeutic targets for OS.

TRIB3 inhibition by palbociclib sensitizes prostate cancer to ferroptosis via downregulating SOX2/SLC7A11 expression

Palbociclib is a CDK4/6 inhibitor approved for the treatment of breast cancer by suppressing cell proliferation. However, monotherapy with palbociclib was discouraging in prostate cancer, calling for a mechanism-based effective therapy. In this study, we reported in prostate cancer that palbociclib is a potent sensitizer of ferroptosis, which is worked out by downregulating the expression of TRIB3, a gene highly expressed in prostate cancer. Specifically, TRIB3 knockdown augmented the response of prostate cancer cells to ferroptosis inducers, whereas, TRIB3 overexpression rescued prostate cancer cells from palbociclib-induced ferroptosis. Mechanistically, TRIB3 inhibition by palbociclib resulted in downregulation of SOX2, which subsequently led to compromised expression of SLC7A11, a cystine/glutamate antiporter that counteracts ferroptosis. Functionally, a combined treatment of palbociclib with ferroptosis inducer significantly suppressed prostate cancer growth in a xenograft tumor model. Together, these results uncover an essential role of TRIB3/SOX2/SLC7A11 axis in palbociclib-induced ferroptosis, suggesting palbociclib a promising targeted therapy in combine with ferroptosis induction for the treatment of prostate cancer.

USP4/CARM1 Axis Promotes the Malignant Transformation of Breast Cancer Cells by Upregulating SLC7A11 Expression

BackgroundCoactivator associated arginine methyltransferase 1 (CARM1) has been identified as a regulator of breast cancer (BC) progression, yet the underlying mechanisms remain elusive. MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) was employed to assess the mRNA expression of CARM1 and solute carrier family 7 member 11 (SLC7A11). Western blotting was conducted to detect the protein expressions of CARM1, ubiquitin specific peptidase 4 (USP4), and SLC7A11. Cell viability, apoptosis, invasion, and migration were evaluated using CCK-8 assay, flow cytometry, transwell assay, and wound-healing assay, respectively. Fe2+ and GSH levels were determined by colorimetric assay. Fluorescence microscopy and flow cytometry were utilized to quantify reactive oxygen species (ROS) production. Co-immunoprecipitation (Co-IP) assay and cycloheximide (CHX) assay were performed to investigate the relationship between USP4 and CARM1. Xenograft mouse model assay was conducted to validate the effects of USP4 silencing and CARM1 overexpression on the malignant phenotypes of BC cells. ResultsCARM1 and SLC7A11 expression was upregulated in BC tissues and cells when compared with normal breast tissues and cells. Silencing of CARM1 inhibited the malignant phenotypes of BC cells, including decreased cell viability, invasion, and migration and increased cell apoptosis, ferroptosis and oxidative stress. In addition, USP4 stabilized CARM1 protein expression through its deubiquitinating activity. Overexpression of CARM1 attenuated the effects of USP4 silencing in both MCF-7 and MDA-MB-231 cells. Furthermore, silencing of CARM1 reduced SLC7A11 expression, and SLC7A11 overexpression relieved the CARM1 silencing-induced effects. Further, overexpression of CARM1 counteracted the inhibitory effects of USP4 silencing on tumor growth in vivo. ConclusionOur study reveals a novel mechanism by which USP4-dependent CARM1 promotes the malignant growth of BC cells by interacting with SLC7A11. Targeting this axis may provide a potential therapeutic strategy for BC.

HMGA2 regulates GPX4 expression and ferroptosis in prostate cancer cells

Prostate cancer (PCa) remains a significant global health burden and an increase in oxidative stress is associated with cancer progression. High Mobility Group A2 (HMGA2), a chromatin architectural protein, increases oxidative stress and promotes sensitivity to ferroptosis inducers, however, the mechanism is unknown. We investigated the role of HMGA2 in GPX4 regulation and the impact on cellular responses to oxidative stress and ferroptosis sensitivity. We conducted UALCAN database analysis, western blot analysis, and lipid peroxidation assays to determine the relationship between HMGA2 and GPX4 and the levels of lipid reactive oxygen species in a panel of PCa cell lines, including an enzalutamide-resistant cancer cell line (C4–2B MDVR). Our results show an inverse relationship between HMGA2 and GPX4 expression with high HMGA2 and low GPX4 expression associated with higher Gleason score and lower survival probability in prostate adenocarcinoma (PRAD) patients, while low/moderate HMGA2 expression is positively associated with increased GPX4 expression and higher survival probability. Cell lines showed a moderately negative but not statistically significant correlation between HMGA2 and GPX4 expression, however, PC3 and DU145 PCa cells display higher lipid peroxides concomitant with higher endogenous levels of HMGA2 and low GPX4. Overexpression of wild-type HMGA2 in LNCaP and 22Rv1 cells leads to higher HMGA2 expression compared to Neo control and is associated with higher SLC7A11 and GPX4 expression, while interestingly truncated HMGA2 overexpression in LNCaP and 22Rv1 cells coincides with higher HMGA2 and reduced GPX4 expression, leading to increased lipid peroxides and susceptibility to ferroptosis. Overexpression of wild-type and truncated HMGA2 in 22Rv1 cells increases SLC7A11 mRNA yet differing GPX4 protein expression suggests posttranslational regulation of GPX4. Moreover, enzalutamide-resistant C4–2B MDVR cells display higher HMGA2 levels compared to C4–2B cells, as well as sensitivity to RSL3 ferroptosis inducer, which is partially reversed by ferroptosis inhibitor, ferrostatin-1. Interestingly, GPX4 expression is higher in C4–2B MDVR cells compared to C4–2B, and HMGA2 knockdown further increases its expression but does not significantly alter its susceptibility to ferroptosis. In conclusion, our study shows that HMGA2 regulation of GPX4 expression is complex and truncated HMGA2 downregulates GPX4 and increases lipid peroxides. Moreover, HMGA2-expressing cells including enzalutamide-resistant cells are susceptible to RSL-3-induced ferroptosis. Thus, ferroptosis sensitivity offers promising insights for the development of targeted therapeutic interventions for aggressive PCa.

Oleic Acid Inhibits SDC4 and Promotes Ferroptosis in Lung Cancer Through GPX4/ACSL4.

As a common malignancy, lung cancer has a relatively poor prognosis and a low survival rate. In recent years, ferroptosis, as an emerging filed, has great promise in the potential treatment of cancer. Brucea javanica oil (BJO) is often used to treat various cancers. Oleic acid (OA) is the main ingredient of BJO. In this study, we investigated the role and molecular mechanism of OA in lung cancer treatment by promoting ferroptosis. In this study, A549 cells and H1299 cells were used for invitro experiments, and a CCK-8 test, scratch test, and MTT experiment were carried out. We examined reactive oxygen species (ROS), the JC-1 probe, glutathione (GSH) expression, lipid peroxidation, SDC4 mRNA levels, and ACSL4, SLC7A11, GPX4, and SDC4 protein levels. The results showed that OA could inhibit the proliferation and migration of A549 cells and H1299 cells, SDC4 was a potential therapeutic target of OA against lung cancer, and OA treatment significantly inhibited the expression of SDC4 in A549 cells and H1299 cells. OA induces ferroptosis in A549 cells and H1299 cells, decreases GSH levels, increases lipid peroxidation levels, and decreases SDC4 mRNA expression; in addition, OA upregulates ACSL4 expression and decreases SLC7A11, GPX4, and SDC4 expression. This study confirmed that OA could inhibit SDC4 expression and promote the occurrence of ferroptosis in A549 cells and H1299 cells through the GPX4/ACSL4 pathway, providing an effective basis for the use of drugs targeting ferroptosis in lung cancer treatment.

Mechanisms and therapeutic potential of disulphidptosis in cancer.

SLC7A11 plays a pivotal role in tumour development by facilitating cystine import to enhance glutathione synthesis and counteract oxidative stress. Disulphidptosis, an emerging form of cell death observed in cells with high expression of SLC7A11 under glucose deprivation, is regulated through reduction-oxidation reactions and disulphide bond formation. This process leads to contraction and collapse of the F-actin cytoskeleton from the plasma membrane, ultimately resulting in cellular demise. Compared to other forms of cell death, disulphidptosis exhibits distinctive characteristics and regulatory mechanisms. This mechanism provides novel insights and innovative strategies for cancer treatment while also inspiring potential therapeutic approaches for other diseases. Our review focuses on elucidating the molecular mechanism underlying disulphidptosis and its connection with the actin cytoskeleton, identifying alternative metabolic forms of cell death, as well as offering insights into disulphidptosis-based cancer therapy. A comprehensive understanding of disulphidptosis will contribute to our knowledge about fundamental cellular homeostasis and facilitate the development of groundbreaking therapies for disease treatment.

Unlocking the Potential of Disulfidptosis-Related LncRNAs in Lung Adenocarcinoma: A Promising Prognostic LncRNA Model for Survival and Immunotherapy Prediction.

Disulfidptosis was stimulated in high SLC7A11 expression cells starving to glucose. We attempted to identify disulfidptosis-related lncRNAs (DRLs), built a prognostic model to predict survival, and analyzed the tumor microenvironment. The TCGA database was utilized to procure the pertinent data. By utilizing both Cox regression and the least absolute shrinkage and selection operator (LASSO) method, a risk model based on DRLs was formulated for prognostic evaluation. The ability of survival prediction was validated by multiple approaches. The biological functions were screened through GO, KEGG, and GSEA. Various methods were employed to evaluate the tumor immune environment, which included ESTIMATE, tumor mutation burden (TMB) score, CIBERSORT algorithm, and tumor immune dysfunction and exclusion (TIDE) score. Ninety-one DRLs were recognized, and lncRNA AC092718.4, AL365181.2, AL606489.1, EMSLR, and ENTPD3-AS1 were involved in the risk model. The GEO database was used to verify the influence of these lncRNAs on survival. The following analyses showed that survival could be predicted excellently by the DRLs risk model. The results of enrichment analyses pointed toward the involvement of the cell cycle and IgA production pathways. In the low-risk patient group, there was a notable surge in stromal, immune, and ESTIMATE scores, while the TMB scores took a tumble. Conversely, the high-risk patient group displayed a converse trend. Notably, the group of patients with lower risk scores and higher TMB scores showed the most favorable survival outcomes, underscoring the importance of considering both risk score and TMB in predicting the response to immune checkpoint blockade therapy. Furthermore, patients classified as high-risk might display resistance to both chemotherapy and targeted therapy. Cellular biological experiments proved that lncRNA AC092718.4 promoted invasion, migration, and proliferation abilities invitro. These results provided valuable insights into the role of DRLs in LUAD and presented a possible effective treatment approach for LUAD. We developed a disulfidptosis-related risk model with 5 lncRNAs that enables survival prediciton for LUAD patients and aids cilinical decisions by forecasting the TME, TMB, and drug sensitivity, making it a valuable tool for outcomes prediction.

Novel repurposing of sulfasalazine for the treatment of adrenocortical carcinomas, probably through the SLC7A11/xCT-hsa-miR-92a-3p-OIP5-AS1 network pathway

BackgroundRecent multigenomic analysis of adrenocortical carcinomas (ACCs) identified SLC7A11/xCT as a novel biomarker. The Food and Drug Administration–approved anti-inflammatory drug, sulfasalazine (SAS), induces ferroptosis by blocking SLC7A11 expression. We hypothesize that SAS could be repurposed to target ACC cells. MethodsExpression of SLC7A11 and its association with ACC survival was analyzed using Gene Expression Profiling Interactive Analysis (GEPIA). The validated ACC cell lines NCI-H295R, ACC1, and ACC2 were grown in 2D culture. In vitro studies included the CellTiter-Glo assay to calculate viability, Western blot (WB) analysis for apoptosis and other target protein changes, reverse transcriptase polymerase chain reaction for steroidogenic enzyme changes, C11BODIPY for lipid peroxidation, and mass spectrometry for changes in lipids. ResultsThe Cancer Genome Atlas Program database analysis in GEPIA showed that SLC7A11 and linked long noncoding RNA OAP5-AS1 are highly expressed in ACC tumors versus normal adrenals (n = 77 vs 128; P < .05). This was associated with poor overall and disease-free survival with hazard ratios of 4.3 and 5.2 for SLC7A11 and 4.8 and 2.7 for OAP5-AS1, respectively. ACC cell line half-inhibitory maximum concentration values after 72-hour SAS treatment ranged from 412 nM (ACC1) to 799 nM (ACC2), and all showed cleavage of poly (ADP-ribose) polymerase, upregulation of p-Akt and p-ERK, and downregulation of GPX4 and SLC7A11 (P < .05) by WB analysis. Sphere formation, migration, and invasion assay showed inhibition, and lipid peroxidation using C11BODIPY, increase in intracellular iron, induction of oxidative stress, and significant upregulation of oxidized polyunsaturated fatty acid phospholipids (P < .05 each) by mass spectrometry suggests induction of ferroptosis. ConclusionSAS downregulates tSLC7A11 in ACCs, targets the Akt/ERK pathway and lipid metabolism, and induces cell death in vitro, warranting additional translational studies to define its therapeutic potential in ACC.