ABSTRACT
Purpose: Due to intrinsic defensive response, ferroptosis-activating targeted therapy fails to achieve satisfactory clinical benefits. Though p62-Keap1-Nrf2 axis is activated to form a negative feedback loop during ferroptosis induction, how p62 is activated remains largely unknown. Methods: MTS assay was applied to measure cell growth. Lipid ROS was detected with C11-BODIPY reagent by flow cytometer. Quantitative real-time PCR (qPCR) and western blotting were performed to determine mRNA and protein level. Immunofluorescence (IF) was performed to examine the distribution of proteins. Fluorescence recovery after photobleaching (FRAP) was adopted to evaluate p62 phase separation. Immunoprecipitation (IP), co-IP and Proximal ligation assay (PLA) were performed to detected protein posttranslational modifications and protein-protein interactions. Tumor xenograft model was employed to inspect in vivo growth of pancreatic cancer cells. Results: Upon ferroptosis induction, Nuclear Factor E2 Related Factor 2 (Nrf2) protein and its downstream genes such as HMOX1 and NQO1 were upregulated. Knockdown of p62 significantly reversed Nrf2 upregulation and Keap1 decrease after ferroptosis induction. Knockdown of either p62 or Nrf2 remarkably sensitized ferroptosis induction. Due to augmented p62 phase separation, formation of p62 bodies were increased to recruit Keap1 after ferroptosis induction. Protein arginine methyltransferase 6 (PRMT6) mediated asymmetric dimethylarginine (ADMA) of p62 to increase its oligomerization, promoting p62 phase separation and p62 body formation. Knockdown of p62 or PRMT6 notably sensitized pancreatic cancer cells to ferroptosis both in vitro and in vivo through suppressing Nrf2 signaling. Conclusion: During ferroptosis induction, PRMT6 mediated p62 ADMA to promote its phase separation, sequestering Keap1 to activate Nrf2 signaling and inhibit ferroptosis. Therefore, targeting PRMT6-mediated p62 ADMA could be a new option to sensitize ferroptosis for cancer treatment.
Subject(s)
Arginine , Ferroptosis , Kelch-Like ECH-Associated Protein 1 , NF-E2-Related Factor 2 , Protein-Arginine N-Methyltransferases , Protein-Arginine N-Methyltransferases/metabolism , Protein-Arginine N-Methyltransferases/genetics , Humans , Animals , Arginine/metabolism , Arginine/analogs & derivatives , NF-E2-Related Factor 2/metabolism , NF-E2-Related Factor 2/genetics , Mice , Cell Line, Tumor , Kelch-Like ECH-Associated Protein 1/metabolism , Kelch-Like ECH-Associated Protein 1/genetics , Feedback, Physiological , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/pathology , Pancreatic Neoplasms/genetics , Sequestosome-1 Protein/metabolism , Sequestosome-1 Protein/genetics , Mice, Nude , Signal Transduction , Phase Separation , RNA-Binding ProteinsABSTRACT
Ferroptosis is an iron-dependent programmed cell death process that involves lipid oxidation via the Fenton reaction to produce lipid peroxides, causing disruption of the lipid bilayer, which is essential for cellular survival. Ferroptosis has been implicated in the occurrence and treatment response of various types of cancer, and targeting ferroptosis has emerged as a promising strategy for cancer therapy. However, cancer cells can escape cellular ferroptosis by activating or remodeling various signaling pathways, including oxidative stress pathways, thereby limiting the efficacy of ferroptosis-activating targeted therapy. The key anti-oxidative transcription factor, nuclear factor E2 related factor 2 (Nrf2 or NFE2L2), plays a dominant role in defense machinery by reprogramming the iron, intermediate, and glutathione peroxidase 4 (GPX4)-related network and the antioxidant system to attenuate ferroptosis. In this review, we summarize the recent advances in the regulation and function of Nrf2 signaling in ferroptosis-activated cancer therapy and explore the prospect of combining Nrf2 inhibitors and ferroptosis inducers as a promising cancer treatment strategy.
ABSTRACT
Myocardial ischemia-reperfusion injury (MIRI) is a common clinic scenario that occurs in the context of reperfusion therapy for acute myocardial infarction. It has been shown that cocaine and amphetamine-regulated transcript (CART) can ameliorate cerebral ischemia-reperfusion (I/R) injury, but the effect of CART on MIRI has not been studied yet. Here, we revealed that CART protected the heart during I/R process by inhibiting apoptosis and excessive autophagy, indicating that CART would be a potential drug candidate for the treatment of MIRI. Further analysis showed that CART upregulated the activation of phospho-AKT, leading to downregulation of lactate dehydrogenase (LDH) release, apoptosis, oxidative stress and excessive autophagy after I/R, which was inhibited by PI3K inhibitor, LY294002. Collectively, CART attenuated MIRI through inhibition of cardiomyocytes apoptosis and excessive autophagy, and the protective effect was dependent on PI3K/AKT signalling pathway.
Subject(s)
Apoptosis , Autophagy , Myocardial Reperfusion Injury , Nerve Tissue Proteins , Phosphatidylinositol 3-Kinases , Proto-Oncogene Proteins c-akt , Signal Transduction , Myocardial Reperfusion Injury/drug therapy , Myocardial Reperfusion Injury/metabolism , Myocardial Reperfusion Injury/pathology , Animals , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction/drug effects , Phosphatidylinositol 3-Kinases/metabolism , Apoptosis/drug effects , Nerve Tissue Proteins/metabolism , Male , Autophagy/drug effects , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology , Rats , Oxidative Stress/drug effects , Rats, Sprague-DawleyABSTRACT
Heart failure is associated with histone deacetylase (HDAC) regulation of gene expression, the inhibition of which is thought to be beneficial for heart failure therapy. Here, we explored the cardioprotective effects and underlying mechanism of a novel selenium-containing HDAC inhibitor, Se-SAHA, on isoproterenol (ISO)-induced heart failure. We found that pretreatment with Se-SAHA attenuated ISO-induced cardiac hypertrophy and fibrosis in neonatal rat ventricular myocytes (NRVMs). Se-SAHA significantly attenuated the generation of ISO-induced reactive oxygen species (ROS) and restored the expression levels of superoxide dismutase 2 (SOD2) and heme oxygenase-1 (HO-1) in vitro. Furthermore, Se-SAHA pretreatment prevented the accumulation of autophagosomes. Se-SAHA reversed the high expression of HDAC1 and HDAC6 induced by ISO incubation. However, after the addition of the HDAC agonist, the effect of Se-SAHA on blocking autophagy was inhibited. Using ISO-induced mouse models, cardiac ventricular contractile dysfunction, hypertrophy, and fibrosis was reduced treated by Se-SAHA. In addition, Se-SAHA inhibited HDAC1 and HDAC6 overexpression in ISO-treated mice. Se-SAHA treatment significantly increased the activity of SOD2 and improved the ability to eliminate free radicals. Se-SAHA hindered the excessive levels of the microtubule-associated protein 1 light chain 3 (LC3)-II and Beclin-1 in heart failure mice. Collectively, our results indicate that Se-SAHA exerts cardio-protection against ISO-induced heart failure via antioxidative stress and autophagy inhibition.
Subject(s)
Autophagy , Heart Failure , Histone Deacetylase Inhibitors , Isoproterenol , Mice, Inbred C57BL , Myocytes, Cardiac , Oxidative Stress , Rats, Sprague-Dawley , Animals , Isoproterenol/toxicity , Heart Failure/chemically induced , Heart Failure/prevention & control , Heart Failure/pathology , Heart Failure/drug therapy , Autophagy/drug effects , Histone Deacetylase Inhibitors/pharmacology , Oxidative Stress/drug effects , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/pathology , Myocytes, Cardiac/metabolism , Male , Rats , Mice , Superoxide Dismutase/metabolism , Reactive Oxygen Species/metabolism , Antioxidants/pharmacology , Fibrosis , Cells, Cultured , Cardiomegaly/chemically induced , Cardiomegaly/prevention & control , Cardiomegaly/pathologyABSTRACT
SCOPE: Early diabetic retinopathy (DR) is characterized by chronic inflammation, excessive oxidative stress, and retinal microvascular damage. Syringaresinol (SYR), as a natural polyphenolic compound, has been proved to inhibit many disease progression due to its antiinflammatory and antioxidant properties. The present study focuses on exploring the effect of SYR on hyperglycemia-induced early DR as well as the underlying mechanisms. METHODS AND RESULTS: Wild-type (WT) and nuclear factor erythroid 2-related factor 2 (Nrf2)-knockout C57BL/6 mice of type 1 diabetes and high glucose (HG)-induced RF/6A cells are used as in vivo and in vitro models, respectively. This study finds that SYR protects the retinal structure and function in diabetic mice and reduces the permeability and apoptosis of HG-treated RF/6A cells. Meanwhile, SYR distinctly mitigates inflammation and oxidative stress in vivo and vitro. The retinal microvascular damages are suppressed by SYR via downregulating hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) pathway. Whereas, SYR-provided protective effects are diminished in Nrf2-knockout mice, indicating that SYR improves DR progression by activating Nrf2. Similarly, SYR cannot exert protective effects against HG-induced oxidative stress and endothelial injury in small interfering RNA (siRNA)-Nrf2-transfected RF/6A cells. CONCLUSION: In summary, SYR suppresses oxidative stress via activating Nrf2 antioxidant pathway, which ameliorates retinal microvascular damage by downregulating HIF-1α/VEGF, thereby alleviating early DR progression.
Subject(s)
Diabetes Mellitus, Experimental , Diabetic Retinopathy , Furans , Lignans , Mice , Animals , Diabetic Retinopathy/drug therapy , Diabetic Retinopathy/metabolism , Vascular Endothelial Growth Factor A/metabolism , Antioxidants/pharmacology , Antioxidants/metabolism , NF-E2-Related Factor 2/genetics , NF-E2-Related Factor 2/metabolism , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Experimental/metabolism , Mice, Inbred C57BL , Inflammation , Oxidative StressABSTRACT
AIMS: Diabetic cardiomyopathy (DCM) is a major cause of mortality in patients with diabetes, and the potential strategies for treating DCM are insufficient. Melatonin (Mel) has been shown to attenuate DCM, however, the underlying mechanism remains unclear. The role of vascular endothelial growth factor-B (VEGF-B) in DCM is little known. In present study, we aimed to investigate whether Mel alleviated DCM via regulation of VEGF-B and explored its underlying mechanisms. METHODS AND RESULTS: We found that Mel significantly alleviated cardiac dysfunction and improved autophagy of cardiomyocytes in type 1 diabetes mellitus (T1DM) induced cardiomyopathy mice. VEGF-B was highly expressed in DCM mice in comparison with normal mice, and its expression was markedly reduced after Mel treatment. Mel treatment diminished the interaction of VEGF-B and Glucose-regulated protein 78 (GRP78) and reduced the interaction of GRP78 and protein kinase RNA -like ER kinase (PERK). Furthermore, Mel increased phosphorylation of PERK and eIF2α, then up-regulated the expression of ATF4. VEGF-B-/- mice imitated the effect of Mel on wild type diabetic mice. Interestingly, injection with Recombinant adeno-associated virus serotype 9 (AAV9)-VEGF-B or administration of GSK2656157 (GSK), an inhibitor of phosphorylated PERK abolished the protective effect of Mel on DCM. Furthermore, rapamycin, an autophagy agonist displayed similar effect with Mel treatment; while 3-Methyladenine (3-MA), an autophagy inhibitor neutralized the effect of Mel on high glucose-treated neonatal rat ventricular myocytes. CONCLUSIONS: These results demonstrated that Mel attenuated DCM via increasing autophagy of cardiomyocytes, and this cardio-protective effect of Mel was dependent on VEGF-B/GRP78/PERK signaling pathway.
Subject(s)
Diabetes Mellitus, Experimental , Diabetic Cardiomyopathies , Melatonin , Humans , Mice , Rats , Animals , Diabetic Cardiomyopathies/drug therapy , Diabetic Cardiomyopathies/etiology , Diabetic Cardiomyopathies/prevention & control , Myocytes, Cardiac , Vascular Endothelial Growth Factor B , Melatonin/pharmacology , Endoplasmic Reticulum Chaperone BiP , Diabetes Mellitus, Experimental/drug therapy , Signal Transduction , Autophagy , GlucoseABSTRACT
BACKGROUND: Energy balance has long been known to extend lifespans and inhibit carcinogenesis in multiple species by slowing age-related epigenetic changes while the underlying mechanisms remain largely unknown. Herein, we found that starvation activated autophagy to remodel the DNA methylation profile by inhibiting DNMT3a expression. METHODS: Illumina Infinium MethylationEPIC BeadChip and dot blot assay were performed to quantify the global DNA methylation level. Protein-RNA interactions were validated through RNA immunoprecipitation and RNA pull-down assay. In vitro and in vivo experiments were carried out to testify the effect of DNMT3a on chemoresistance. RESULTS: Autophagy is impaired in chemoresistance which was associated with differential DNA methylation and could be reversed by DNMT3a inhibition. Autophagy activation decreases the expression of DNMT3a mRNA, accompanied with the downregulation of chemoresistance-related Linc00942. Knockdown of Linc00942 reduces DNMT3a expression and genome-wide DNA methylation while Linc00942 overexpression increased DNMT3a expression and correlated hypermethylation in cancer cells and primary tumour tissues. Mechanistically, Linc00942 recruits RNA methyltransferase METTL3 to stimulate N6-methyladenosine (m6A) deposit on DNMT3a transcripts, triggering IGF2BP3/HuR to recognize modified mRNA for reinforced stability. SQSTM1/p62 recruits Linc00942 for autophagic degradation which can be abrogated after autophagy inhibition by p62 knockdown or chloroquine treatment. CONCLUSIONS: Inhibition of autophagy increases Linc00942 expression to promote chemoresistance and autophagy activation or hypomethylating agent decitabine restores chemosensitivity by reducing global DNA methylation. Overall, this study identifies a novel methylation cascade linking impaired RNautophagy to global hypermethylation in chemoresistance, and provides a rationale for repurposing decitabine to overcome chemoresistance in cancer treatment.
Subject(s)
DNA Methylation , Stomach Neoplasms , Humans , DNA Methylation/genetics , Stomach Neoplasms/drug therapy , Stomach Neoplasms/genetics , Stomach Neoplasms/pathology , Drug Resistance, Neoplasm/genetics , Decitabine , RNA , RNA, Messenger , Methyltransferases/geneticsABSTRACT
Background: Severe acute pancreatitis (SAP) can progress to lung and kidney dysfunction, and blood clotting within 48 hours of its onset, and is associated with a high mortality rate. The aim of this study was to establish a reliable diagnostic prediction model for the early stage of severe pancreatitis. Methods: The clinical data of patients diagnosed with acute pancreatitis from October 2017 to June 2022 at the Shangluo Central Hospital were collected. The risk factors were screened by least absolute shrinkage and selection operator (LASSO) regression analysis. A novel nomogram model was then established by multivariable logistic regression analysis. Results: The data of 436 patients with acute pancreatitis, 45 (10.3%) patients had progressed to SAP. Through univariate and LASSO regression analyses, the neutrophils (P <0.001), albumin (P < 0.001), blood glucose (P < 0.001), serum calcium (P < 0.001), serum creatinine (P < 0.001), blood urea nitrogen (P < 0.001) and procalcitonin (P = 0.005) were identified as independent predictive factors for SAP. The nomogram built on the basis of these factors predicted SAP with sensitivity of 0.733, specificity of 0.9, positive predictive value of 0.458 and negative predictive value of 0.967. Furthermore, the concordance index of the nomogram reached 0.889 (95% CI, 0.837-0.941), and the area under the curve (AUC) in receiver operating characteristic curve (ROC) analysis was significantly higher than that of the APACHEII and ABISAP scoring systems. The established model was validated by plotting the clinical decision curve analysis (DCA) and clinical impact curve (CIC). Conclusion: We established a nomogram to predict the progression of early acute pancreatitis to SAP with high discrimination and accuracy.
ABSTRACT
INTRODUCTION: Cuproptosis and ferroptosis are the two newly defined metal-related regulated cell death. However, the crosstalk between cuproptosis and ferroptosis is obscure. MATERIALS AND METHODS: We analyzed the effect of ferroptosis inducers on copper ionophores-induced cell death through CCK-8 assay. Cuproptosis was studied using immunofluorescence and protein soluble-insoluble fraction isolation. GSH assay, qRT-PCR and western blot were adopted to explore the machinery of ferroptosis inducers enhanced cuproptosis. And mouse xenograft model was built to detect the synergy effect of elesclomol-Cu and sorafenib in vivo. RESULTS: Herein we found that ferroptosis inducers sorafenib and erastin could enhance cuproptosis in primary liver cancer cells by increasing copper dependent lipoylated protein aggregation. Mechanically, sorafenib and erastin upregulated protein lipoylation via suppressing mitochondrial matrix-related proteases mediated ferredoxin 1 (FDX1) protein degradation, and reduced intracellular copper chelator glutathione (GSH) synthesis through inhibiting cystine importing. DISCUSSION/CONCLUSION: Our findings proposed that combination of ferroptosis inducers and copper ionophores to co-targeting ferroptosis and cuproptosis could be a novel therapeutic strategy for primary liver cancer.
Subject(s)
Ferroptosis , Liver Neoplasms , Humans , Animals , Mice , Copper , Sorafenib , Disease Models, Animal , Ionophores , Liver Neoplasms/genetics , ApoptosisABSTRACT
Diabetic nephropathy (DN) is one of the serious chronic microvascular complications of diabetes, and leads to the increased morbidity and mortality in diabetic patients. Gasdermin E (GSDME)-dependent pyroptosis signaling pathway plays important roles in a variety of physiological and pathological processes. However, its role and mechanism in DN are still unclear. In this study, we established a rat DN model by intraperitoneal injection of streptozotocin (STZ) successfully. Structural and functional disorders in the kidney were exhibited on the 12th week after STZ injection; the expressions of caspase-3 and GSDME at protein level in renal cortex were significantly up-regulated. At the 20th week, GSDME-N increased significantly, accompanied by the upregulation of caspase-1 in renal cortex and the release of mature IL-1ß (mIL-1ß) in serum. Furthermore, we found the protein levels of GSDME, caspase-3, caspase-1 and IL-1ß were all increased in HK2 and HBZY-1 cells under high-glucose conditions. We also found that the expression of GSDME-N significantly decreased when caspase-3 was knockdown. In contrast, knockdown of GSDME has no effect on caspase-3. Interestingly, either caspase-3, caspase-1 or GSDME knockdown reduced the release of mIL-1ß. Finally, injection of adeno-associated virus (AAV) 9-shGSDME into the rat kidney reduced kidney damage and renal cell pyroptosis in comparison with wild-type diabetic rats. These results indicated that the activation of caspase-1 induced IL-1ß maturation, and the activation of caspase-3 mediated cleavage of GSDME responsible for the formation of plasma membrane pore, followed by cytoplasmic release of mIL-1ß. Overall, we identified a pro-pyroptosis role for GSDME in DN, which does provide an important basis for clinical therapeutic studies.
ABSTRACT
Regulatory T cells (Tregs) are critical for generating and maintaining peripheral tolerance. Treg-based immunotherapy is valuable for the clinical management of diseases resulting from dysregulation of immune tolerance. However, the lack of potency is a potential limitation of Treg therapy. In addition, CD69 positive-Treg (CD69+ Treg) represent a newly identified subset of Tregs with potent immune suppressive capability. Methods: Foxp3 YFP-Cre CD69 fl/fl and CD4 Cre CD69 fl/fl mice were generated to determine the relevance of CD69 to Treg. Chromatin Immunoprecipitation Assay (ChIP) and luciferase Assay were performed to detect the regulation of CD69 transcription by heat shock transcription factor 1(HSF1). Gene expression was measured by western blotting and qRT-PCR. The differentiation of naive T cells to CD69+Foxp3+ iTregs was determined by flow cytometry. The immunosuppressive ability of Tregs was analyzed by ELISA and flow cytometry. Colon inflammation in mice was reflected by changes in body weight and colon length, the disease activity index (DAI), and H&E staining of colon tissues. Results: Induced Tregs (iTregs) from CD4 Cre CD69 fl/fl mice failed to alleviate colitis. The transcription factor HSF1 interacted with the promoter of the CD69 gene to prompt its transcription during Treg differentiation. Genetic and chemical inhibition of HSF1 impaired CD69+ Treg differentiation and promoted the pathogenesis of colitis in mice. In contrast, HSF1 protein stabilized by inhibiting its proteasomal degradation promoted CD69+ Treg differentiation and alleviated colitis in mice. Moreover, adoptive transfer of iTregs with HSF1 stabilization by proteasome inhibitor (PSI) dramatically prevented the development of colitis in mice and was accompanied by decreased production of pro-inflammatory cytokines and reduced accumulation of pro-inflammatory lymphocytes in colitis tissue, whereas Tregs induced in the absence of PSI were less stable and ineffective in suppressing colitis. Conclusions: HSF1 promotes CD69+ Tregs differentiation by activating the CD69 transcription, which is critical for the immunosuppressive function of Tregs. Stabilization of HSF1 by PSIs results in the efficient generation of Tregs with high potency to treat colitis and probably other autoimmune diseases involving Tregs deficiency.
Subject(s)
Colitis , T-Lymphocytes, Regulatory , Mice , Animals , Heat Shock Transcription Factors/metabolism , Colitis/pathology , Cell Differentiation , Forkhead Transcription Factors/metabolism , Mice, Inbred C57BLABSTRACT
Diabetic nephropathy (DN) is one of the serious complications of diabetes that has limited treatment options. As a lytic inflammatory cell death, pyroptosis plays an important role in the pathogenesis of DN. Syringaresinol (SYR) possesses anti-inflammatory and antioxidant properties. However, the therapeutic effects and the underlying mechanism of SYR in DN remain unclear. Herein, we showed that SYR treatment ameliorated renal hypertrophy, fibrosis, mesangial expansion, glomerular basement membrane thickening, and podocyte foot process effacement in streptozotocin (STZ)-induced diabetic mice. Mechanistically, SYR prevented the abundance of pyroptosis-related proteins such as NOD-like receptor family pyrin domain containing 3 (NLRP3), cysteinyl aspartate-specific proteinase 1 (Caspase-1), and gasdermin D (GSDMD), and the biosynthesis of inflammatory cytokines interleukin 1ß (IL-1ß) and interleukin 18 (IL-18). In addition, SYR promoted the nuclear translocation of nuclear factor E2-related factor 2 (NRF2) and enhanced the downstream antioxidant enzymes heme oxygenase 1 (HO-1) and manganese superoxide dismutase (MnSOD), thereby effectively decreasing excess reactive oxygen species (ROS). Most importantly, knockout of NRF2 abolished SYR-mediated renoprotection and anti-pyroptotic activities in NRF2-KO diabetic mice. Collectively, SYR inhibited the NLRP3/Caspase-1/GSDMD pyroptosis pathway by upregulating NRF2 signaling in DN. These findings suggested that SYR may be promising a therapeutic option for DN.
Subject(s)
Diabetes Mellitus, Experimental , Diabetic Nephropathies , Mice , Animals , Diabetic Nephropathies/drug therapy , Antioxidants/pharmacology , NF-E2-Related Factor 2/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Experimental/metabolism , Pyroptosis , CaspasesABSTRACT
Estrogen receptor positive (ER+) breast cancer patients exhibit poorer responsiveness to nab-paclitaxel compared to ER negative (ER-) patients, with the underlying mechanisms remaining unknown. Caveolin 1 (CAV1) is a membrane invagination protein critical for the endocytosis of macromolecules including albumin-bound chemotherapeutic agents. Here, we demonstrate that ERα limits the efficacy of nab-paclitaxel in breast cancer cells while genetic or pharmacological inhibition of ERα increased the sensitivity of ER+ breast cancer cells to nab-paclitaxel. Notably, CAV1 expression inversely correlates with ERα and relates to improved clinical outcomes from nab-paclitaxel treatment. Importantly, ERα stimulates m6A dependent maturation of miR199a-5p, which is elevated in ER+ breast cancer, to inhibit CAV1 translation by antagonizing m6A modification of CAV1 mRNA. Together, our findings reveal a novel role of ERα in promoting m6A modification and subsequent maturation of miR199a-5p, which is upregulated in ER+ breast cancer, leading to the suppression of m6A modification of CAV1 and its mRNA translation, thereby contributing to nab-paclitaxel resistance. Thus, combining an ER antagonist with nab-paclitaxel could offer a promising strategy for treating ER+ breast cancer patients.
ABSTRACT
Differentiation blockade is a hallmark of acute myeloid leukemia (AML). A strategy to overcome such a blockade is a promising approach against the disease. The lack of understanding of the underlying mechanisms hampers development of such strategies. Dysregulated ribonucleotide reductase (RNR) is considered a druggable target in proliferative cancers susceptible to deoxynucleoside triphosphate (dNTP) depletion. Herein, we report an unanticipated discovery that hyperactivating RNR enables differentiation and decreases leukemia cell growth. We integrate pharmacogenomics and metabolomics analyses to identify that pharmacologically (eg, nelarabine) or genetically upregulating RNR subunit M2 (RRM2) creates a dNTP pool imbalance and overcomes differentiation arrest. Moreover, R-loop-mediated DNA replication stress signaling is responsible for RRM2 activation by nelarabine treatment. Further aggravating dNTP imbalance by depleting the dNTP hydrolase SAM domain and HD domain-containing protein 1 (SAMHD1) enhances ablation of leukemia stem cells by RRM2 hyperactivation. Mechanistically, excessive activation of extracellular signal-regulated kinase (ERK) signaling downstream of the imbalance contributes to cellular outcomes of RNR hyperactivation. A CRISPR screen identifies a synthetic lethal interaction between loss of DUSP6, an ERK-negative regulator, and nelarabine treatment. These data demonstrate that dNTP homeostasis governs leukemia maintenance, and a combination of DUSP inhibition and nelarabine represents a therapeutic strategy.
Subject(s)
Leukemia, Myeloid, Acute , Ribonucleotide Reductases , DNA Replication , Homeostasis , Humans , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/genetics , Polyphosphates , Ribonucleotide Reductases/genetics , Ribonucleotide Reductases/metabolismABSTRACT
BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most fatal cancers. Due to limited strategies for effective treatments, patients with advanced HCC have a very poor prognosis. This study aims to identify new insights in HCC to develop novel strategies for HCC management. METHODS: The role of WIP1 (wild type p53 induced protein phosphatase1) in HCC was analyzed in HCC cells, xenograft model, DEN (Diethylnitrosamine) induced mice liver cancer model with WIP1 knockout mice, and TCGA database. DNA damage was evaluated by Gene Set Enrichment Analysis, western blotting, comet assay, and Immunofluorescence. RESULTS: High expression of WIP1 is associated with the poor prognosis of patients with HCC. Genetically and chemically suppression of WIP1 drastically reduced HCC cell proliferation. Besides, WIP1 knockout retarded DEN induced mice hepato-carcinogenesis. Mechanically, WIP1 inhibition induced DNA damage by increasing H2AX phosphorylation (γH2AX). Therefore, suppression of WIP1 and PARP induced synthetic lethality in HCC in vitro and in vivo by augmenting DNA damage. CONCLUSION: WIP1 plays an oncogenic effect in HCC development, and targeting WIP1-dependent DNA damage repair alone or in combination with PARP inhibition might be a reasonable strategy for HCC management. Video abstract.
Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Animals , Carcinoma, Hepatocellular/genetics , Liver Neoplasms/genetics , Mice , Phosphoprotein Phosphatases/genetics , Phosphoprotein Phosphatases/metabolism , Poly(ADP-ribose) Polymerase Inhibitors , Protein Phosphatase 2C/genetics , Protein Phosphatase 2C/metabolism , Synthetic Lethal MutationsABSTRACT
BACKGROUND: Chemoresistance to cisplatin (DDP) remains a major challenge in advanced gastric cancer (GC) treatment. Although accumulating evidence suggests an association between dysregulation of long non-coding RNAs (lncRNAs) and chemoresistance, the regulatory functions and complexities of lncRNAs in modulating DDP-based chemotherapy in GC remain under-investigated. This study was designed to explore the critical chemoresistance-related lncRNAs in GC and identify novel therapeutic targets for patients with chemoresistant GC. METHODS: Chemoresistance-related lncRNAs were identified through microarray and verified through a quantitative real-time polymerase chain reaction (qRT-PCR). Proteins bound by lncRNAs were identified through a human proteome array and validated through RNA immunoprecipitation (RIP) and RNA pull-down assays. Co-immunoprecipitation and ubiquitination assays were performed to explore the molecular mechanisms of the Musashi2 (MSI2) post-modification. The effects of LINC00942 (LNC942) and MSI2 on DDP-based chemotherapy were investigated through MTS, apoptosis assays and xenograft tumour formation in vivo. RESULTS: LNC942 was found to be up-regulated in chemoresistant GC cells, and its high expression was positively correlated with the poor prognosis of patients with GC. Functional studies indicated that LNC942 confers chemoresistance to GC cells by impairing apoptosis and inducing stemness. Mechanically, LNC942 up-regulated the MSI2 expression by preventing its interaction with SCFß-TRCP E3 ubiquitin ligase, eventually inhibiting ubiquitination. Then, LNC942 stabilized c-Myc mRNA in an N6-methyladenosine (m6 A)-dependent manner. As a potential m6 A recognition protein, MSI2 stabilized c-Myc mRNA with m6 A modifications. Moreover, inhibition of the LNC942-MSI2-c-Myc axis was found to restore chemosensitivity both in vitro and in vivo. CONCLUSIONS: These results uncover a chemoresistant accelerating function of LNC942 in GC, and disrupting the LNC942-MSI2-c-Myc axis could be a novel therapeutic strategy for GC patients undergoing chemoresistance.
Subject(s)
Cisplatin/metabolism , Drug Resistance/drug effects , Genes, myc/drug effects , RNA, Long Noncoding/agonists , RNA-Binding Proteins/antagonists & inhibitors , Cisplatin/therapeutic use , Genes, myc/physiology , Humans , RNA, Long Noncoding/genetics , RNA, Long Noncoding/therapeutic use , RNA-Binding Proteins/genetics , RNA-Binding Proteins/pharmacology , Stomach Neoplasms/drug therapy , Stomach Neoplasms/geneticsABSTRACT
BACKGROUND: Exercise training (ET) has a protective effect on the progression of heart failure, however, the specific mechanism has not been fully explored. Myeloid-derived suppressor cells (MDSCs) are a group of myeloid-derived immunosuppressive cells, which showed a protective effect in the progression of heart failure. Thus, we hypothesized that the protective effect of ET on heart failure may be related to the infiltration of MDSCs. METHODS: C57BL/6 mice were made to run on a treadmill 6× a week for 4 weeks followed by isoproterenol injection from third week. Heart function was evaluated by echocardiography and the proportion of MDSCs was detected by flow cytometry. Hypertrophic markers, cardiac fibrosis, and inflammatory factors were detected by real-time PCR, ELISA, histological staining, and Western blot. RESULTS: ET treatment in isoproterenol-induced heart failure mice (n=7) enhanced cardiac function (57% increase in FS%, P=0.002) and improved morphological changes compared with isoproterenol mice (n=17). ET further caused 79% increasing in cardiac MDSCs in isoproterenol mice (P<0.001). In addition, depletion of MDSCs by 5-Fluorouracil blunted the cardio-protective effect of ET. T-cell proliferation assay showed that ET did not affect the suppressive activity of MDSCs. Furthermore, we found that ET activated the secretion of IL (interleukin)-10 by macrophages in isoproterenol mice. MDSCs expansion and cardio protection was not present in tamoxifen-inducible macrophage-specific IL-10 knockout mice. Western blot results confirmed that IL-10 regulated the differentiation of MDSCs through the translocation of p-STAT3 (signal transducer and activator of transcription 3)/S100A9 (S100 calcium-binding protein A9) to the nucleus. CONCLUSIONS: ET could increase MDSCs by stimulating the secretion of IL-10 from macrophage, which was through IL-10/STAT3/S100A9 signaling pathway, thereby achieving the role of heart protection.
Subject(s)
Calgranulin B , Heart Failure , Interleukin-10 , Myeloid-Derived Suppressor Cells , Physical Conditioning, Animal , STAT3 Transcription Factor , Animals , Calgranulin B/genetics , Calgranulin B/metabolism , Heart Failure/metabolism , Heart Failure/prevention & control , Interleukin-10/genetics , Interleukin-10/metabolism , Isoproterenol , Mice , Mice, Inbred C57BL , Myeloid-Derived Suppressor Cells/metabolism , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/metabolismABSTRACT
Colorectal cancer (CRC) is one of the most common malignant gastrointestinal cancers. Metastasis is the major leading cause of death in patients with CRC, and many patients treated with radical surgery were diagnosed with metastasis during follow-up. However, the underlying molecular mechanisms regulating CRC metastasis are still elusive. Sterol o-acyltransferase 1 (SOAT1) is a critical participant in maintaining intracellular cholesterol balance. Here, by analyzing the clinical specimens and in vitro cell line experiments, we evaluated the clinical relevance and role of SOAT1 in regulating CRC metastasis. The results revealed that SOAT1 was overexpressed in colon cancer tissues compared to peritumor tissues at mRNA and protein levels. High intratumor SOAT1 expression correlates to lymph node metastasis and indicates poor patient disease-free survival and overall survival. The silencing of SOAT1 strongly inhibited the migration and invasion ability of CRC tumor cells. These results demonstrated that SOAT1 was upregulated in colon cancer. Upregulation of SOAT1 expression may promote CRC progression by enhancing the migration and invasion ability of CRC. Our results indicate that targeting SOAT1 activity may be applied as a promising therapeutic strategy for preventing the metastasis of CRC after radical surgical treatment.
Subject(s)
Colorectal Neoplasms , Sterol O-Acyltransferase , Biomarkers, Tumor/genetics , Cell Line, Tumor , Cell Movement , Colorectal Neoplasms/diagnosis , Colorectal Neoplasms/genetics , Colorectal Neoplasms/surgery , Humans , Prognosis , Sterol O-Acyltransferase/geneticsABSTRACT
Numerous studies have found that chronic stress could promote tumor progression and this may be related to inhibtion of immune system. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells with immunosuppressive activity. MDSCs may represent a key link between chronic stress and tumor progression. However, the role of stress-induced MDSCs in breast cancer progression is unclear. The present study showed that pre-exposure of chronic stress could lead to MDSCs elevation and facilitated breast cancer metastasis in tumor-bearing mice. Adoptive transfer of MDSCs could significantly increase lung metastatic foci. In contrast, lung metastasis could be alleviated by depleting endogenous MDSCs with Gr-1 antibody. The concentration of norepinephrine in serum and the expression of tyrosine hydroxylase in bone marrow could be significantly elevated by chronic stress. Moreover, propranolol, an inhibitor of ß-adrenergic signaling, could inhibit breast carcinoma metastasis and prevent the expansion of chronic stress-induced MDSCs. Further study revealed that the expressions of IL-6 and JAK/STAT3 signaling pathways were upregulated by chronic stress in mice, and this upregulation could be inhibited by propranolol. Blocking the IL-6 signal or inhibiting the activation of the JAK/STAT3 signaling pathway could reduce tumor growth and metastasis by attenuating the accumulation of MDSCs in vivo. Besides, propranolol inhibited the expression of IL-6 in supernatant of 4T1 cells induced by isoproterenol and reduced the proportion of inducible MDSCs in vitro. Taken together, these data indicated that chronic stress may accumulate MDSCs via activation of ß-adrenergic signaling and IL-6/STAT3 pathway, thereby promoting breast carcinoma metastasis.
Subject(s)
Carcinoma , Myeloid-Derived Suppressor Cells , Adrenergic Agents , Animals , Mice , Propranolol/pharmacology , Signal TransductionABSTRACT
Cancer is a complex disease extremely dependent on its microenvironment and is highly regulated by a variety of stimuli inside and outside the cell. Evidence suggests that active camel whey fraction (TR35) confer anti-tumor effects in non-small cell lung cancer (NSCLC). However, its exact mechanisms remain elusive. Here, we investigated the mechanisms underlying suppression of NSCLC cell growth and proliferation by TR35. Treatment of A549 and H1299 cells with TR35 suppressed their growth and enhanced apoptosis, as revealed by CCK-8, colony formation and flow cytometric analyses. We find that TR35 suppresses tumor growth in a xenograft nude mouse model without losses in body weight. RNA-seq and KEGG pathway analyses showed that the DEGs were enriched in mitogen-activated protein kinase (MAPK) and Jak-STAT signaling pathways. After test the key factors' activity associated with these pathways by Immunohistochemical (IHC) staining and western blotting, the activation of JNK phosphorylation and inhibition of p38 and STAT3 phosphorylation was observed both in TR35 treated lung cancer cell and tumor tissue. Taken together, these results showed that TR35 play a significant role in the NSCLC progression in the tumor microenvironment via MAPK and Jak-STAT signaling, highlighting TR35 as a potential therapeutic agent against lung cancer.