Project description:Ferroptosis, a recently discovered form of regulated cell death, has been closely linked to tumor progression. However, the underlying mechanism of ferroptosis in non-small cell lung cancer (NSCLC) remains unclear. In this study, we conducted transcriptome sequencing on NSCLC samples. Overall, our study suggests that suppressing LCN2 can effectively inhibit the development of NSCLC by promoting ferroptosis
Project description:Circular RNAs (circRNAs) have been implicated in the tumorigenesis of non-small cell lung cancer (NSCLC). Ferroptosis is considered a mechanism to suppress tumorigenesis. Herein, we identified a novel downregulated circRNA, circPOLA2 (hsa_circ_0004291), in NSCLC tissues and found that it was correlated with advanced clinical stage in patients. Nuclear-cytoplasmic fractionation assays and FISH assays confirmed that circPOLA2 was predominantly localized in the cytoplasm. Overexpression of circPOLA2 promoted lipid peroxidation and ferroptosis in NSCLC cells, thereby inhibiting cell proliferation and migration, while knockdown of circPOLA2 exerted the opposite effects. Mechanistically, circPOLA2 interacted with Merlin, a critical regulator of the Hippo pathway, and restricted Merlin phosphorylation at S518, leading to the activation of the Hippo pathway. In addition, circPOLA2 enhanced ferroptosis in NSCLC cells by activating the Hippo pathway. Together, circPOLA2 sensitizes cells to ferroptosis and suppresses tumorigenesis in NSCLC by facilitating Merlin-mediated activation of the Hippo signaling pathway.
Project description:Evidence supports the contribution of long non-coding RNAs (lncRNAs) and ferroptosis to traumatic brain injury (TBI) pathogenesis. However, lncRNA regulation in TBI-induced ferroptosis remains poorly understood. Herein, we identified an lncRNA, named noncoding transcript of chemokine (C-C motif) ligand 4 (Ccl4) overlapping (Ntoco), which was upregulated in TBI mice. The upregulation was initiated by hypoxia ischemia induced lower enrichment of H3K27me3 on the Ntoco promoter. Ntoco knockdown inhibited neuron ferroptosis, ameliorated spatial memory and lesion volume following TBI. Ntoco overexpression promoted neuron ferroptosis and recruited microglia to provoke an inflammatory response via Ccl4. Mechanistically, Ntoco facilitated K48-linked ubiquitination and protein degradation by binding to Hnrnpab, which suppressed NF-κB/Lcn2 signal axis activation, including decreased phosphorylation of IkBα, increased phosphorylation of IKKα/β, nuclear translocation of the NF-κB p65 subunit, and elevated Lcn2 expression. These data indicated that targeting Ntoco to mitigate ferroptosis might be a potential therapeutic strategy for TBI.
Project description:Knockout or inhibition of glutathione peroxidase 4 (GPX4) induces ferroptosis which has been proposed as a potential therapeutic strategy for cancer. Here we unexpectedly found that inducible knockout of GPX4 in tumor cells significantly promotes non-small cell lung cancer (NSCLC) progression in the autochthonous KrasLSL-G12D/+Lkb1fl/fl (KL) and KrasLSL-G12D/+Tp53fl/fl (KP) mouse models, whereas inducible overexpression of GPX4 in tumor cells had an opposite effect. Mechanistically, knockout of GPX4 in tumor cells results in the accumulation of triacylglycerol (TAG) that was stored in lipid droplets in tumor cells and the efflux of TAG that induces ferroptosis of macrophages in the tumor microenvironment (TME), thereby igniting an immunoinhibitory TME characterized by the dysfunction of anti-tumor T cells and the decrease of antigen-presenting macrophages. Consistently, treatment with liprostatin-1 or inducible overexpression of GPX4 in tumor cells significantly rescues the ferroptosis of macrophages and ignites the activation of T cells in the TME, thereby inhibiting NSCLC progression. These findings highlight a previously uncharacterized role of tumor cell-specific GPX4 in NSCLC progression by modulating TAG metabolism in the TME and provide potential therapeutic strategies for NSCLC.
Project description:Background: Autologous fat grafting is hampered by unpredictable graft survival, which is potentially regulated by ferroptosis. Glutathione (GSH), a powerful antioxidant used in tissue preservation, has ferroptosis-regulating activity; however, its effects on fat grafts are unclear. This study investigated the effects and mechanisms of GSH in fat graft survival. Methods: Human lipoaspirates were transplanted subcutaneously into the backs of normal saline-treated (control) or GSH-treated nude mice. Graft survival was evaluated by magnetic resonance imaging and histology. RNA sequencing was performed to identify differentially expressed genes and enriched pathways. GSH activity was evaluated in vitro using an oxygen and glucose deprivation (OGD) model of adipose-derived stem cells. Results: Compared with control group, GSH induced better outcomes, including superior graft retention, appearance, and histological structures. RNA sequencing suggested enhanced negative regulation of ferroptosis in the GSH-treated grafts, which showed reduced lipid peroxides, better mitochondrial ultrastructure, and SLC7A11/GPX4 axis activation. In vitro, OGD-induced ferroptosis was ameliorated by GSH, which restored cell proliferation, reduced oxidative stress, and upregulated ferroptosis defense factors. Conclusions: Our study confirms that ferroptosis participates in regulating fat graft survival and that GSH exerts a protective effect by inhibiting ferroptosis. GSH-assisted lipotransfer is a promising therapeutic strategy for future clinical application.
Project description:Transcriptional profiling of mouse primary astrocytes comparing control untreated astrocytes with astrocytes treated with recombinant LCN2 protein (10 micro gram/ml). Goal was to determine the effects of LCN2 treatment on global gene expression in astrocytes. A secreted protein lipocalin-2 (LCN2) has been implicated in diverse cellular processes including cell morphology and migration. We have previously demonstrated that lcn2 mediates reactive astrocytosis. In order to further understand the role of lcn2 in the CNS, astrocyte transcriptome was analyzed following LCN2 treatment. Chemokines were the major group of genes upregulated by LCN2. Two-condition experiment, control untreated astrocytes vs. LCN2 protein treated astrocytes. Biological replicates: 1 control replicates, 1 treated replicates.
Project description:Ferroptosis, an emerging nonapoptotic, regulated cell death process distinguished by iron accumulation and subsequent lipid peroxidation, is intricately implicated in the development and progression of multiple cancer types. Here, we aimed to reveal that triggering ferroptosis is a promising treatment strategy for ovarian cancer. In this study, we not only validated that daphnetin caused ferroptosis, but evaluated the effects of daphnetin (and/or cisplatin) in vitro and vivo.Here, we elucidated that daphnetin, a natural product isolated from Daphne Korean Nakai, can exert antitumor effects by inducing the death and suppressing the migration of ovarian cancer cells. Subsequently, transcriptome analysis and ferroptosis inhibitor (Fer-1 and DFO) experiments revealed that there is a close correlation between daphnetin and ferroptosis in ovarian cancer. We further found that daphnetin induced ferroptosis in ovarian cancer cells, as evidenced by the accumulation of intracellular ferrous iron (Fe2+), reactive oxygen species (ROS) and lipid peroxides, as well as the depletion of glutathione (GSH) and ferroptosis indicators (SLC7A11 and GPX4). In particular, daphnetin effectively reduced the mRNA and protein levels of NQO1 (a ubiquitous flavoenzyme), and a high expression level of NQO1 was significantly associated with poor prognosis and ferroptosis resistance in ovarian cancer patients. Furthermore, NQO1 activation markedly attenuated daphnetin-induced cell death, migration and ferroptotic events in vitro and vivo. Interestingly, we also found that treatment with daphnetin, a negative regulator of NQO1, in combination with cisplatin synergistically induced ovarian cancer cell cytotoxicity. This study demonstrated that daphnetin induces ferroptosis by inhibiting NQO1 in ovarian cancer cells. Our findings identified NQO1 as a new daphnetin target and suggested that targeting NQO1 might have therapeutic effects on ovarian cancer.
Project description:Transcriptional profiling of mouse primary astrocytes comparing control untreated astrocytes with astrocytes treated with recombinant LCN2 protein (10 micro gram/ml). Goal was to determine the effects of LCN2 treatment on global gene expression in astrocytes. A secreted protein lipocalin-2 (LCN2) has been implicated in diverse cellular processes including cell morphology and migration. We have previously demonstrated that lcn2 mediates reactive astrocytosis. In order to further understand the role of lcn2 in the CNS, astrocyte transcriptome was analyzed following LCN2 treatment. Chemokines were the major group of genes upregulated by LCN2.