erastin and Pancreatic-Neoplasms

Pancreatic ductal adenocarcinoma (PDAC) is a fatal malignancy due to the lack of early detection method, therapeutic drug and target. We noticed that the expression of Protein Tyrosine Phosphatase Mitochondria1(PTPMT1) is upregulated in PDAC. However, its role in pancreatic cancer remains unknown.. We first analyzed the expression of PTPMT1 from 50 PDAC patients. Secondly, the survival proportions of different PTPMT1-expressed patients were analyzed. Then, the role and mechanism of PTPMT1 in PDAC were studied by lentivirus transduction system.. PTPMT1 was upregulated in PDAC and patients with high PTPMT1 expression displayed lower overall survival rate. Knockdown of PTPMT1 increased the sensitivity to erastin or RSL3 induced ferroptosis. Mechanically, knockdown of PTPMT1 resulted in upregulated Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4) and downregulated Solute Carrier Family 7 Member 11 (SLC7A11). In addition, SLC7A11 was upregulated in PDAC tumor tissue and correlated positively with the expression of PTPMT1. However, the expression of ACSL4 was downregulated in PDAC and negatively correlated with the expression of PTPMT1.. Our study demonstrates that PTPMT1 is upregulated in PDAC and PTPMT1 inhibits ferroptosis by suppressing the expression of ACSL4 and upregulating SLC7A11 in Panc-1 cells, suggesting PTPMT1 might be a potential prognosis biomarker and therapeutic target in PDAC.

Topics: Biomarkers; Carcinoma, Pancreatic Ductal; Coenzyme A; Ferroptosis; Humans; Ligases; Pancreatic Neoplasms; Piperazines; Protein Tyrosine Phosphatases; PTEN Phosphohydrolase

Topics: AMP-Activated Protein Kinases; Ascorbic Acid; Ferroptosis; Glutathione; Heme Oxygenase-1; Humans; Iron; NF-E2-Related Factor 2; Nuclear Respiratory Factor 1; Pancreatic Neoplasms; Piperazines

Ferroptosis is considered as a potential target in cancer treatment including chemotherapy and radiotherapy, however, its regulatory mechanism on pancreatic cancer (PC) is not fully understood. Herein, we explored the role of upstream stimulatory factor 2 (USF2) and pyruvate kinase M2 (PKM2) in ferroptosis in PC cells. USF2 and PKM2 were highly expressed in PC tissues and USF2 was positively correlated with PKM2. PC cell lines BxpC-3 and AsPC-1 were transfected with small interfering RNAs against USF2/PKM2 or USF2 overexpressing plasmids or co-transfected with small interfering RNAs against PKM2 and USF2 overexpressing plasmids. Twenty-four hours after cell transfection, ferroptotic cell death was induced by incubation with 20 μmol/l erastin for 24 h. Ferroptotic cell death was promoted by USF2 knockdown and inhibited by USF2 overexpression. USF2 knockdown increased lipid reactive oxygen species and malonaldehyde generation and decreased glutathione concentration and glutathione peroxidase 4 expressions, indicating the enhanced lipid peroxidation. USF2 knockdown also increased ferrous iron levels and ferritin heavy chain expressions and reduced solute carrier family 7 member 11 expressions. However, USF2 overexpression reversed these changes. Furthermore, dual-luciferase reporter assay, chromatin immunoprecipitation assay and DNA pull down assay validated that USF2 transcriptionally regulated PKM2 expression through binding to its promoter. Interestingly, PKM2 also negatively regulated ferroptosis and PKM2 knockdown markedly impaired the effects of USF2 on lipid peroxidation and ferroptotic cell death. This study demonstrated that USF2 negatively regulated ferroptosis in PC cells through transcriptional regulation of PKM2, providing new evidences for uncovering the regulatory mechanism of ferroptosis on PC.

Topics: Apoferritins; Cell Line, Tumor; DNA; Ferroptosis; Glutathione; Humans; Iron; Lipids; Luciferases; Malondialdehyde; Pancreatic Neoplasms; Phospholipid Hydroperoxide Glutathione Peroxidase; Pyruvate Kinase; Reactive Oxygen Species; Thyroid Hormone-Binding Proteins

In pancreatic cancer tissues, hypoxic areas exist due to poor blood flow. Attenuation of the pharmacological efficacy of existing anticancer drugs in these hypoxic areas necessitates the search for novel anticancer compounds. We aimed to determine whether erastin exhibits anticancer effects in a hypoxic environment.. Pancreatic cancer cell lines were subjected to cobalt chloride, a hypoxia-mimicking agent. Cell viability assay, measurement of reactive oxygen species, and western blotting analysis were conducted to investigate the efficacy of erastin under hypoxic environments.. Erastin exhibited remarkable cytotoxicity and induced apoptosis under hypoxic conditions. Furthermore, erastin triggered the intracellular accumulation of reactive oxygen species in a hypoxic environment. Subsequent treatment with N-acetylcysteine, an antioxidant, markedly attenuated cytotoxicity, and apoptosis.. Erastin induces cell death by accumulation of intracellular reactive oxygen species and inducing apoptosis under hypoxic conditions, proving its potential for further development as a novel anticancer compound.

Topics: Antineoplastic Agents; Apoptosis; Cell Hypoxia; Cell Line, Tumor; Cell Proliferation; Cell Survival; Humans; Hypoxia; Oxidation-Reduction; Pancreatic Neoplasms; Piperazines; Reactive Oxygen Species

Ferroptosis is identified as a regulated cell death mediated by iron accumulation and lipid peroxidation. The disturbances of mitochondrial morphology and function have been shown in this process. Mitochondrial Lon peptidase 1 (LONP1) is one of the main multi-function enzymes in regulating the mitochondrial function and cytological stability. To evaluate whether LONP1 take a role in ferroptosis, we applied erastin to initiate the ferroptosis in human pancreatic ductal adenocarcinoma (PDAC) cells. Here we show that erastin triggers cell death in both of oncogenic RAS mutant PANC1 cells and wild KRAS BxPC3 cells and the expression of LONP1 was up-regulated in this process. Gene inhibition of LONP1 only negatively regulates erastin-induced cell death and the alterations of molecular indicators in PANC1 cells. Furthermore, we show that inhibition of LONP1 activates the Nrf2/Keap1 signal pathway and up-regulates the expression of GPX4, a key peroxidase in regulating ferroptosis. Together, our results uncover a previously unappreciated mechanism coupling LONP1 to ferroptosis.

Topics: ATP-Dependent Proteases; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cytoprotection; Ferroptosis; Humans; Kelch-Like ECH-Associated Protein 1; Mitochondrial Proteins; NF-E2-Related Factor 2; Pancreatic Neoplasms; Phospholipid Hydroperoxide Glutathione Peroxidase; Piperazines; Signal Transduction

In cancer cells the small compounds erastin and RSL3 promote a novel type of cell death called ferroptosis, which requires iron-dependent accumulation of lipid reactive oxygen species. Here we assessed the contribution of lipid peroxidation activity of lipoxygenases (LOX) to ferroptosis in oncogenic Ras-expressing cancer cells. Several 12/15-LOX inhibitors prevented cell death induced by erastin and RSL3. Furthermore, siRNA-mediated silencing of ALOX15 significantly decreased both erastin-induced and RSL3-induced ferroptotic cell death, whereas exogenous overexpression of ALOX15 enhanced the effect of these compounds. Immunofluorescence analyses revealed that the ALOX15 protein consistently localizes to cell membrane during the course of ferroptosis. Importantly, treatments of cells with ALOX15-activating compounds accelerated cell death at low, but not high doses of erastin and RSL3. These observations suggest that tumor ferroptosis is promoted by LOX-catalyzed lipid hydroperoxide generation in cellular membranes.

Topics: Arachidonate 15-Lipoxygenase; Carbolines; Cell Death; Cell Line, Tumor; Fibrosarcoma; Gene Expression Regulation, Neoplastic; Humans; Lipid Peroxidation; Pancreatic Neoplasms; Piperazines; RNA, Small Interfering

Cancer-selective drug delivery is an important concept in improving treatment while minimizing off-site toxicities, and sigma-2 receptors, which are overexpressed in solid tumors, represent attractive pharmacologic targets. Select sigma-2 ligands have been shown to be rapidly internalized selectively into cancer cells while retaining the capacity to deliver small molecules as drug cargoes. We utilized the sigma-2-based drug delivery concept to convert Erastin, a clinically underperforming drug, into a potent pancreatic cancer therapeutic. The Erastin derivative des-methyl Erastin (dm-Erastin) was chemically linked to sigma-2 ligand SV119 to create SW V-49. Conjugation increased the killing capacity of dm-Erastin by nearly 35-fold in vitro and reduced the size of established tumors and doubled the median survival in syngeneic and patient-derived xenograft models when compared to non-targeted dm-Erastin. Mechanistic analyses demonstrated that cell death was associated with robust reactive oxygen species production and could be efficiently antagonized with antioxidants. Mass spectrometry was employed to demonstrate selective uptake into pancreatic cancer cells. Thus, targeted delivery of dm-Erastin via conjugation to the sigma-2 ligand SV119 produced efficient tumor control and prolonged animal survival with minimal off-target toxicities, and SW V-49 represents a promising new therapeutic with the potential to advance the fight against pancreatic cancer.

Topics: Animals; Antineoplastic Agents; Azabicyclo Compounds; Carbamates; Cell Line, Tumor; Disease Models, Animal; Drug Delivery Systems; Humans; Ligands; Mice; Mice, Inbred C57BL; Mice, Nude; Pancreatic Neoplasms; Piperazines; Receptors, sigma; Xenograft Model Antitumor Assays

Macroautophagy/autophagy is an evolutionarily conserved degradation pathway that maintains homeostasis. Ferroptosis, a novel form of regulated cell death, is characterized by a production of reactive oxygen species from accumulated iron and lipid peroxidation. However, the relationship between autophagy and ferroptosis at the genetic level remains unclear. Here, we demonstrated that autophagy contributes to ferroptosis by degradation of ferritin in fibroblasts and cancer cells. Knockout or knockdown of Atg5 (autophagy-related 5) and Atg7 limited erastin-induced ferroptosis with decreased intracellular ferrous iron levels, and lipid peroxidation. Remarkably, NCOA4 (nuclear receptor coactivator 4) was a selective cargo receptor for the selective autophagic turnover of ferritin (namely ferritinophagy) in ferroptosis. Consistently, genetic inhibition of NCOA4 inhibited ferritin degradation and suppressed ferroptosis. In contrast, overexpression of NCOA4 increased ferritin degradation and promoted ferroptosis. These findings provide novel insight into the interplay between autophagy and regulated cell death.

Topics: Animals; Apoptosis; Autophagy; Autophagy-Related Protein 5; Autophagy-Related Protein 7; Ferritins; Fibroblasts; Homeostasis; Humans; Iron; Lipid Peroxidation; Mice; Mice, Knockout; Nuclear Receptor Coactivators; Pancreatic Neoplasms; Piperazines; Reactive Oxygen Species