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BACKGROUND AND AIMS: Major genomic drivers of hepatocellular carcinoma (HCC) are nowadays well recognized, although models to establish their roles in human HCC initiation remain scarce. Here, we used human liver organoids in experimental systems to mimic the early stages of human liver carcinogenesis from the genetic lesions of TP53 loss and L3 loop R249S mutation. In addition, chromatin immunoprecipitation sequencing (ChIP-seq) of HCC cell lines shed important functional insights into the initiation of HCC consequential to the loss of tumor-suppressive function from TP53 deficiency and gain-of-function activities from mutant p53. APPROACH AND RESULTS: Human liver organoids were generated from surgical nontumor liver tissues. CRISPR knockout of TP53 in liver organoids consistently demonstrated tumor-like morphological changes, increased in stemness and unrestricted in vitro propagation. To recapitulate TP53 status in human HCC, we overexpressed mutant R249S in TP53 knockout organoids. A spontaneous increase in tumorigenic potentials and bona fide HCC histology in xenotransplantations were observed. ChIP-seq analysis of HCC cell lines underscored gain-of-function properties from L3 loop p53 mutants in chromatin remodeling and overcoming extrinsic stress. More importantly, direct transcriptional activation of PSMF1 by mutant R249S could increase organoid resistance to endoplasmic reticulum stress, which was readily abrogated by PSMF1 knockdown in rescue experiments. In a patient cohort of primary HCC tumors and genome-edited liver organoids, quantitative polymerase chain reaction corroborated ChIP-seq findings and verified preferential genes modulated by L3 mutants, especially those enriched by R249S. CONCLUSIONS: We showed differential tumorigenic effects from TP53 loss and L3 mutations, which together confer normal hepatocytes with early clonal advantages and prosurvival functions.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinogênese/genética , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Mutação , Proteína Supressora de Tumor p53/genética , OrganoidesRESUMO
Venetoclax, a Bcl-2 inhibitor, in combination with the hypomethylating agent azacytidine, achieves complete remission with or without count recovery in â¼70% of treatment-naive elderly patients unfit for conventional intensive chemotherapy. However, the mechanism of action of this drug combination is not fully understood. We discovered that venetoclax directly activated T cells to increase their cytotoxicity against acute myeloid leukemia (AML) in vitro and in vivo. Venetoclax enhanced T-cell effector function by increasing reactive oxygen species generation through inhibition of respiratory chain supercomplexes formation. In addition, azacytidine induced a viral mimicry response in AML cells by activating the STING/cGAS pathway, thereby rendering the AML cells more susceptible to T cell-mediated cytotoxicity. Similar findings were seen in patients treated with venetoclax, as this treatment increased reactive oxygen species generation and activated T cells. Collectively, this study presents a new immune-mediated mechanism of action for venetoclax and azacytidine in the treatment of AML and highlights a potential combination of venetoclax and adoptive cell therapy for patients with AML.
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Antineoplásicos/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Sulfonamidas/farmacologia , Linfócitos T/efeitos dos fármacos , Adulto , Antineoplásicos/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Células Cultivadas , Humanos , Imunidade Celular/efeitos dos fármacos , Leucemia Mieloide Aguda/imunologia , Espécies Reativas de Oxigênio/imunologia , Sulfonamidas/uso terapêutico , Linfócitos T/imunologia , Células Tumorais CultivadasRESUMO
BACKGROUND & AIMS: The hepatic manifestation of the metabolic syndrome, non-alcoholic fatty liver disease (NAFLD), can lead to the development of hepatocellular carcinoma (HCC). Despite a strong causative link, NAFLD-HCC is often underrepresented in systematic genome explorations. METHODS: Herein, tumor-normal pairs from 100 patients diagnosed with NAFLD-HCC were subject to next-generation sequencing. Bioinformatic analyses were performed to identify key genomic, epigenomic and transcriptomic events associated with the pathogenesis of NAFLD-HCC. Establishment of primary patient-derived NAFLD-HCC culture was used as a representative human model for downstream in vitro investigations of the underlying CTNNB1 S45P driver mutation. A syngeneic immunocompetent mouse model was used to further test the involvement of CTNNB1mutand TNFRSF19 in reshaping the tumor microenvironment. RESULTS: Mutational processes operative in the livers of patients with NAFLD inferred susceptibility to tumor formation through defective DNA repair pathways. Dense promoter mutations and dysregulated transcription factors accentuated activated transcriptional regulation in NAFLD-HCC, in particular the enrichment of MAZ-MYC activities. Somatic events common in HCCs arising from NAFLD and viral hepatitis B infection underscore similar driver pathways, although an incidence shift highlights CTNNB1mut dominance in NAFLD-HCC (33%). Immune exclusion correlated evidently with CTNNB1mut. Chromatin immunoprecipitation-sequencing integrated with transcriptome and immune profiling revealed a unique transcriptional axis, wherein CTNNB1mut leads to an upregulation of TNFRSF19 which subsequently represses senescence-associated secretory phenotype-like cytokines (including IL6 and CXCL8). This phenomenon could be reverted by the Wnt-modulator ICG001. CONCLUSIONS: The unique mutational processes in the livers of patients with NAFLD and NAFLD-HCC allude to a "field effect" involving a gain-of-function role of CTNNB1 mutations in immune exclusion. LAY SUMMARY: The increasing prevalence of metabolic syndrome in adult populations means that NAFLD is poised to be the major cause of liver cancer in the 21st century. We showed a strong "field effect" in the livers of patients with NAFLD, wherein activated ß-catenin was involved in reshaping the tumor-immune microenvironment.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Síndrome Metabólica , Hepatopatia Gordurosa não Alcoólica , Receptores do Fator de Necrose Tumoral , beta Catenina , Adulto , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Hepatite B , Humanos , Evasão da Resposta Imune , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Camundongos , Mutação , Hepatopatia Gordurosa não Alcoólica/genética , Receptores do Fator de Necrose Tumoral/genética , Microambiente Tumoral , beta Catenina/genética , beta Catenina/metabolismoRESUMO
BACKGROUND: Although human papillomavirus (HPV) infection has been regarded as the cause of cervical cancer in over 99% of cases, only a small fraction of HPV-infected women develop this malignancy. Emerging evidence suggests that alterations of mitochondrial DNA copy number (mtCN) may contribute to carcinogenesis. However, the relationship between mtCN and cervical cancer remains undetermined. METHODS: The current study included 591 cervical cancer cases and 373 cancer-free controls, all of whom were infected with high-risk HPV. Relative mtCN in cervical cancer exfoliated cells was measured by qRT-PCR assays, and logistic regression analysis was performed to compute odds ratios (ORs) and 95% confidence intervals (CIs). Interaction between mtCN and HPV types was assessed by using the Wald test in logistic regression models. RESULTS: HPV16, 18, 52, and 58 were the most common types in both case and control groups. Median mtCN in cases was significantly higher than that in controls (1.63 vs. 1.23, P = 0.03). After adjustment for age and HPV types, the highest quartile of mtCN was associated with increased odds of having cervical cancer (OR = 1.77, 95% CI = 1.19, 2.62; P < 0.01), as compared to the lowest quartile. A dose-response effect of mtCN on cervical cancer was also observed (Ptrend < 0.001). The interaction between mtCN and HPV types was statistically nonsignificant. CONCLUSIONS: In women who test HPV positive, the increase of mtCN in cervical exfoliated cells is associated with cervical cancer. This suggests a potential role of mtCN in cervical carcinogenesis.
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Variações do Número de Cópias de DNA , DNA Mitocondrial/genética , Papillomaviridae/genética , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/complicações , Displasia do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Adulto , Idoso , Estudos de Casos e Controles , China/epidemiologia , DNA Viral/genética , Feminino , Humanos , Pessoa de Meia-Idade , Papillomaviridae/classificação , Infecções por Papillomavirus/epidemiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Risco , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/virologia , Displasia do Colo do Útero/epidemiologiaRESUMO
Plant growth-promoting rhizobacteria (PGPR) are a specific category of microbes that improve plant growth and promote greater tolerance to metal stress through their interactions with plant roots. We evaluated the effects of phytoremediation combining the cadmium accumulator Solanum nigrum L. and two Cd- and Pb-resistant bacteria isolates. To understand the interaction between PGPR and their host plant, we conducted greenhouse experiments with inoculation treatments at Nanjing Agricultural University (Jiangsu Province, China), in June 2018. Two Cd- and Pb-resistant PGPR with various growth-promoting properties were isolated from heavy metal-contaminated soil. 16S rRNA analyses indicated that the two isolates were Bacillus genus, and they were named QX8 and QX13. Pot experiments demonstrated that inoculation may improve the rhizosphere soil environment and promote absorption of Fe and P by plants. Inoculation with QX8 and QX13 also enhanced the dry weight of shoots (1.36- and 1.7-fold, respectively) and roots (1.42- and 1.96-fold) of plants growing in Cd- and Pb-contaminated soil, and significantly increased total Cd (1.28-1.81 fold) and Pb (1.08-1.55 fold) content in aerial organs, compared to non-inoculated controls. We also detected increases of 23% and 22% in the acid phosphatase activity of rhizosphere soils inoculated with QX8 and QX13, respectively. However, we did not detect significant differences between inoculated and non-inoculated treatments in Cd and Pb concentrations in plants and available Cd and Pb content in rhizosphere soils. We demonstrated that PGPR-assisted phytoremediation is a promising technique for remediating heavy metal-contaminated soils, with the potential to enhance phytoremediation efficiency and improve soil quality.
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Cádmio/análise , Chumbo/análise , Rhizobiaceae/metabolismo , Microbiologia do Solo , Poluentes do Solo/análise , Solanum nigrum/efeitos dos fármacos , Biodegradação Ambiental , Cádmio/metabolismo , China , Chumbo/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , RNA Ribossômico 16S , Rizosfera , Solo/química , Poluentes do Solo/metabolismo , Solanum nigrum/crescimento & desenvolvimento , Solanum nigrum/metabolismoRESUMO
BACKGROUND AND AIMS: Type 2 diabetes (T2D) is a global and complex public health challenge, and dietary management is acknowledged as critical in its prevention. Recent studies have highlighted the involvement of micronutrients in T2D pathophysiology; our study aims to assess the association between B vitamin intake and T2D risks and the mediating role of inflammation. METHODS: In a prospective cohort design, data on B vitamins intake, including thiamine (B1), riboflavin (B2), niacin (B3), pyridoxine (B6), folate (B9), and cobalamin (B12), was obtained using a validated food frequency questionnaire (FFQ), and blood inflammatory biomarkers were analyzed according to standard protocol in the local hospitals at baseline from 44,960 adults in the Shanghai Suburban Adult Cohort and Biobank (SSACB). Incident T2D cases were identified according to a physician's diagnosis or medication records from the electronic medical information system. We employed logistic and weighted quantile sum regression models to explore the associations of single and combined levels of B vitamins with T2D and mediation analyses to investigate the effects of inflammation. RESULTS: Negative correlations between B vitamins and T2D were observed in the single-exposure models, except for B3. The analyses of joint exposure (B1, B2, B6, B9, and B12) also showed an inverse association (OR 0.80, 95% CI 0.71 to 0.88), with vitamin B6 accounting for 45.58% of the effects. Further mediation analysis indicated a mediating inflammatory impact, accounting for 6.72% of the relationship. CONCLUSIONS: Dietary intake of B vitamins (B1, B2, B6, B9, B12) was associated with a reduced T2D risk partially mediated by inflammation in Shanghai residents.
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Diabetes Mellitus Tipo 2 , Inflamação , Complexo Vitamínico B , Humanos , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/sangue , China/epidemiologia , Feminino , Pessoa de Meia-Idade , Masculino , Inflamação/sangue , Estudos Prospectivos , Complexo Vitamínico B/administração & dosagem , Complexo Vitamínico B/sangue , Adulto , Fatores de Risco , Biomarcadores/sangue , Idoso , Dieta/efeitos adversos , Estudos de CoortesRESUMO
Hepatocellular carcinoma (HCC) is a highly prevalent cancer with a significant impact on human health. Curcumin, a natural compound, induces cytoskeletal changes in liver cancer cells and modifies the distribution of lipids, proteins, and polysaccharides on plasma membranes, affecting their mechanical and electrical properties. In this study, we used nanomechanical indentation techniques and Kelvin probe force microscopy (KPFM) based on atomic force microscopy (AFM) to investigate the changes in surface nanomechanical and electrical properties of nuclear and cytoplasmic regions of HepG2 cells in response to increasing curcumin concentrations. CCK-8 assays and flow cytometry results demonstrated time- and concentration-dependent inhibition of HepG2 cell proliferation by curcumin. Increasing curcumin concentration led to an initial increase and then decrease in the mechanical properties of nuclear and cytoplasmic regions of HepG2 cells, represented by the Young's modulus (E), as observed through nanoindentation. KPFM measurements indicated decreasing trends in both cell surface potential and height. Fluorescence microscopy results indicated a positive correlation between curcumin concentration and phosphatidylserine translocation from the inner to the outer membrane, which influenced the electrical properties of HepG2 cells. This study provides valuable insights into curcumin's mechanisms against cancer cells and aids nanoscale evaluation of therapeutic efficacy and drug screening.
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Carcinoma Hepatocelular , Curcumina , Neoplasias Hepáticas , Humanos , Microscopia de Força Atômica/métodos , Curcumina/farmacologia , Células Hep G2 , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológicoRESUMO
Ischemic stroke accounts for nearly 80% of stroke cases. Recanalization with thrombolysis is a currently crucial therapeutic strategy for re-building blood supply, but the thrombolytic therapy often companies with cerebral ischemia-reperfusion injury, which are mediated by free radicals. As an important component of free radicals, reactive nitrogen species (RNS), including nitric oxide (NO) and peroxynitrite (ONOO(-)), play important roles in the process of cerebral ischemia-reperfusion injury. Ischemia-reperfusion results in the production of nitric oxide (NO) and peroxynitrite (ONOO(-)) in ischemic brain, which trigger numerous molecular cascades and lead to disruption of the blood brain barrier and exacerbate brain damage. There are few therapeutic strategies available for saving ischemic brains and preventing the subsequent brain damage. Recent evidence suggests that RNS could be a therapeutic target for the treatment of cerebral ischemia-reperfusion injury. Herein, we reviewed the recent progress regarding the roles of RNS in the process of cerebral ischemic-reperfusion injury and discussed the potentials of drug development that target NO and ONOO(-) to treat ischemic stroke. We conclude that modulation for RNS level could be an important therapeutic strategy for preventing cerebral ischemia-reperfusion injury.
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Isquemia Encefálica/tratamento farmacológico , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Descoberta de Drogas/métodos , Terapia de Alvo Molecular/métodos , Espécies Reativas de Nitrogênio/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , HumanosRESUMO
The chromatin organization modifier domain (chromodomain) is an evolutionally conserved motif across eukaryotic species. The chromodomain mainly functions as a histone methyl-lysine reader to modulate gene expression, chromatin spatial conformation and genome stability. Mutations or aberrant expression of chromodomain proteins can result in cancer and other human diseases. Here, we systematically tag chromodomain proteins with green fluorescent protein (GFP) using CRISPR/Cas9 technology in C. elegans. By combining ChIP-seq analysis and imaging, we delineate a comprehensive expression and functional map of chromodomain proteins. We then conduct a candidate-based RNAi screening and identify factors that regulate the expression and subcellular localization of the chromodomain proteins. Specifically, we reveal an H3K9me1/2 reader, CEC-5, both by in vitro biochemistry and in vivo ChIP assays. MET-2, an H3K9me1/2 writer, is required for CEC-5 association with heterochromatin. Both MET-2 and CEC-5 are required for the normal lifespan of C. elegans. Furthermore, a forward genetic screening identifies a conserved Arginine124 of CEC-5's chromodomain, which is essential for CEC-5's association with chromatin and life span regulation. Thus, our work will serve as a reference to explore chromodomain functions and regulation in C. elegans and allow potential applications in aging-related human diseases.
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Envelhecimento , Caenorhabditis elegans , Animais , Humanos , Envelhecimento/genética , Caenorhabditis elegans/genética , Cromatina/genética , Proteínas de Fluorescência Verde , Longevidade , Histonas/metabolismoRESUMO
The roles of caveolin-1 (cav-1) in regulating blood-brain barrier (BBB) permeability are unclear yet. We previously reported that cav-1 was down-regulated and the production of nitric oxide (NO) induced the loss of cav-1 in focal cerebral ischemia and reperfusion injury. The present study aims to address whether the loss of cav-1 impacts on BBB permeability and matrix metalloproteinases (MMPs) activity during cerebral ischemia-reperfusion injury. We found that focal cerebral ischemia-reperfusion down-regulated the expression of cav-1 in isolated cortex microvessels, hippocampus, and cortex of ischemic brain. The down-regulation of cav-1 was correlated with the increased MMP-2 and -9 activities, decreased tight junction (TJ) protein zonula occludens (ZO)-1 expression and enhanced BBB permeability. Treatment of N(G) -nitro-L-arginine methyl ester [L-NAME, a non-selective nitric oxide synthase (NOS) inhibitor] reserved the expression of cav-1, inhibited MMPs activity, and reduced BBB permeability. To elucidate the roles of cav-1 in regulating MMPs and BBB permeability, we used two approaches including cav-1 knockdown in cultured brain microvascular endothelial cells (BMECs) in vitro and cav-1 knockout (KO) mice in vivo. Cav-1 knockdown remarkably increased MMPs activity in BMECs. Meanwhile, with focal cerebral ischemia-reperfusion, cav-1 deficiency mice displayed higher MMPs activities and BBB permeability than wild-type mice. Interestingly, the effects of L-NAME on MMPs activity and BBB permeability was partly reversed in cav-1 deficiency mice. These results, when taken together, suggest that cav-1 plays important roles in regulating MMPs activity and BBB permeability in focal cerebral ischemia and reperfusion injury. The effects of L-NAME on MMPs activity and BBB permeability are partly mediated by preservation of cav-1.
Assuntos
Barreira Hematoencefálica/fisiopatologia , Isquemia Encefálica/enzimologia , Isquemia Encefálica/fisiopatologia , Caveolina 1/fisiologia , Metaloproteinases da Matriz/metabolismo , Óxido Nítrico/fisiologia , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/fisiopatologia , Animais , Western Blotting , Química Encefálica/efeitos dos fármacos , Capilares/efeitos dos fármacos , Capilares/enzimologia , Corantes , Inibidores Enzimáticos/farmacologia , Azul Evans , Infarto da Artéria Cerebral Média/enzimologia , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase Tipo I/antagonistas & inibidores , Permeabilidade , Ratos , Ratos Sprague-DawleyRESUMO
This study aimed to elucidate the impacts of carrier oil types (long chain triglycerides (LCT), medium chain triglycerides (MCT), and orange oil (indigestible oil)) on the micellization and cellular uptake of ß-carotene (BC) formulated in O/W emulsions, with an emphasis on the role of intestinal transporters. The micellization and cellular uptake of BC in the gastrointestinal tract were evaluated via an in vitro digestion model and a Caco-2 cell monolayer. And the interactions between lipids and intestinal transporters were monitored by nontargeted lipidomics, RT-PCR, and Western blot. The BC micellization rates followed a decreasing trend in emulsions: corn oil (69.47 ± 4.19%) > MCT (22.22 ± 0.89%) > orange oil (11.01 ± 2.86%), whereas the cellular uptake rate of BC was significantly higher in MCT emulsion (56.30 ± 20.13%) than in corn oil emulsion (14.01 ± 1.04%, p < 0.05). The knockdown of SR-B1 led to a 31.63% loss of BC cellular uptake from MCT micelles but had no effect on corn oil micelles. Lipidomics and transporter analysis revealed that TG (10:0/10:0/12:0) and TG (10:0/12:0/12:0) might be the fingerprint lipids that promoted the cellular absorption of BC-MCT micelles via stimulating the mRNA expression of SR-B1.
Assuntos
Óleo de Milho , beta Caroteno , Disponibilidade Biológica , Células CACO-2 , Emulsões/metabolismo , Humanos , Micelas , Triglicerídeos , beta Caroteno/metabolismoRESUMO
Dietary restriction usually suppresses biosynthesis but activates catabolic pathways in animals. However, the short-term starvation enhances biosynthetic activities and promotes ribosomal biogenesis in adult Caenorhabditis elegans. The mechanism underlying the processes remains largely unknown. Here, we find that the short-term starvation enhances the SL1 trans-splicing of translation-related genes in adult C. elegans by transcriptome analysis. The small nuclear RNA-activating protein complex (SNAPc) promotes SL RNA production and mediates starvation-induced trans-splicing. TOFU-5, a core factor in the upstream sequence transcription complex (USTC) essential for piRNA production, is also involved in the starvation-induced trans-splicing processes. Knocking down components of the SNAPc complex and tofu-5 extends worm survival under starvation conditions. Taken together, our study highlights the importance of SL trans-splicing in the nutrition response and reveals a mechanism of the survival regulation by food deprivation via SNAPc and TOFU-5.
Assuntos
Caenorhabditis elegans , Trans-Splicing , Animais , Trans-Splicing/genética , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , RNA Líder para Processamento/genética , RNA Líder para Processamento/metabolismo , RNA Nuclear Pequeno/metabolismo , RNA Interferente PequenoRESUMO
Time-related cognitive function refers to the capacity of the brain to store, extract, and process specific information. Previous studies demonstrated that the cerebellar cortex participates in advanced cognitive functions, but the role of the cerebellar cortex in cognitive functions is unclear. We established a behavioral model using classical eyeblink conditioning to study the role of the cerebellar cortex in associative learning and memory and the underlying mechanisms. We performed an investigation to determine whether eyeblink conditioning could be established by placing the stimulating electrode in the middle cerebellar peduncle. Behavior training was performed using a microcurrent pulse as a conditioned stimulus to stimulate the middle cerebellar peduncle and corneal blow as an unconditioned stimulus. After 10 consecutive days of training, a conditioned response was successfully achieved in the Delay, Trace-200-ms, and Trace-300-ms groups of guinea pigs, with acquisition rates of >60%, but the Trace-400-ms and control groups did not achieve a conditioned stimulus-related blink conditioned response. It could be a good model for studying the function of the cerebellum during the establishment of eyeblink conditioning.
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Uracil misincorporation during DNA replication is a major cell toxic event, of which cancer cells overcome by activating the dUTPase enzyme. The DUT gene is the only known dUTPase in human. Despite reports on common upregulations in cancers, the role of DUT in human hepatocellular carcinoma (HCC) remains largely undetermined. In this study, we investigated the mechanism underlying DUT biology in HCC and tumor susceptibility to drug targeting dUTPase. Overexpression of DUT was found in 42% of HCC tumors and correlated with advanced stage HCC. Knockout of DUT in HCC cell lines showed suppressed proliferation through cell cycle arrest and a spontaneous induction of DNA damage. A protective effect from oxidative stress was also demonstrated in both knockout and overexpression DUT assays. Transcriptome analysis highlighted the NF-κB survival signaling as the downstream effector pathway of DUT in overriding oxidative stress-induced cell death. Interestingly, stably expressed DUT in liver progenitor organoids conferred drug resistance to TKI Sorafenib. Targeting dUTPase activity by TAS-114, could potentiate suppression of HCC growth that synergized with Sorafenib for better treatment sensitivity. In conclusion, upregulated DUT represents a nucleotide metabolic weakness and therapeutic opportunity in HCC.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , NF-kappa B , Nucleotídeos , Pirofosfatases , Sorafenibe/farmacologia , Uracila/metabolismoRESUMO
Although the relationship between hypercholesterolemia and oxidative stress has been extensively investigated, direct evidence regarding to the roles of cholesterol accumulation in the generations of reactive oxygen species (ROS) and apoptotic cell death under oxidative stress is lack. In this study, we investigated productions of superoxide anions (O(2)(-)) and nitric oxide (NO), and apoptotic cell death in wild type Chinese hamster ovary (CHO) cells and cholesterol accumulated CHO cells genetically and chemically. Oxidative stress was induced by menadione challenge. The results revealed that abundance of free cholesterol (FC) promoted menadione-induced O(2)(-) and NO productions. FC accumulation down-regulated eNOS expression but up-regulated NADPH oxidases, and inhibited the activities of superoxide dismutase (SOD) and catalase. Treatment of menadione increased the expressions of iNOS and qp91 phox, enhanced the activities of SOD and catalase in the wild-type CHO cells but inhibited the activity of glutathione peroxidase in the cholesterol accumulated CHO cells. Moreover, FC abundance promoted apoptotic cell death in these cells. Taken together, those results suggest that free cholesterol accumulation aggravates menadione-induced oxidative stress and exacerbates apoptotic cell death.
Assuntos
Apoptose , Colesterol/metabolismo , Óxido Nítrico/metabolismo , Estresse Oxidativo , Superóxidos/metabolismo , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Células CHO , Colesterol/genética , Cricetinae , Cricetulus , Regulação da Expressão Gênica , Mutação , NADPH Oxidases/genética , Óxido Nítrico Sintase Tipo II/genética , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/genética , Vitamina K 3/efeitos adversos , Vitaminas/efeitos adversosRESUMO
Tafazzin is a mitochondrial enzyme necessary for the remodeling of the phospholipid cardiolipin. Seneviratne and Xu et al. demonstrated that Tafazzin-mediated phospholipid production regulates stemness in Acute Myeloid Leukemia (AML). Tafazzin influenced intracellular levels of phospholipids to control AML stemness. Thus, inhibiting mitochondrial phospholipid production could be a new therapeutic strategy for AML.
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Tafazzin (TAZ) is a mitochondrial transacylase that remodels the mitochondrial cardiolipin into its mature form. Through a CRISPR screen, we identified TAZ as necessary for the growth and viability of acute myeloid leukemia (AML) cells. Genetic inhibition of TAZ reduced stemness and increased differentiation of AML cells both in vitro and in vivo. In contrast, knockdown of TAZ did not impair normal hematopoiesis under basal conditions. Mechanistically, inhibition of TAZ decreased levels of cardiolipin but also altered global levels of intracellular phospholipids, including phosphatidylserine, which controlled AML stemness and differentiation by modulating toll-like receptor (TLR) signaling.
Assuntos
Leucemia Mieloide Aguda/metabolismo , Mitocôndrias/enzimologia , Fosfolipídeos/metabolismo , Fatores de Transcrição/metabolismo , Aciltransferases , Animais , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Feminino , Humanos , Leucemia Mieloide Aguda/patologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Camundongos Transgênicos , Transdução de Sinais/efeitos dos fármacos , Receptores Toll-Like/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/deficiênciaRESUMO
The authors of the above article wish to retract their paper. Subsequently to its publication, in addition to certain irreconcilable differences in opinion shared among the authors, they have realized that, in their analysis of the role of peroxisome proliferatoractivated receptor γ in brain microvascular endothelial (bEnd.3) cells, certain of the results presented have been found to be incomplete and unrepeatable. Therefore, they wish to retract the paper in order to maintain the integrity of the scientific record. The authors regret any inconvenience that this retraction will caused to the Editor of the journal, and the readership. [the original article was published in Molecular Medicine Reports 16: 88828890, 2017; DOI: 10.3892/mmr.2017.7750].
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Cerebral ischemia is a leading cause of ischemic stroke, which may lead to severe disability and mortality worldwide. There are some key factors concerned in cardioprotection, such as peroxisome proliferatoractivated receptor γ (PPARγ), a ligand binding transcription factor involved in various biological functions including atherosclerosis, vascular dysfunction and hypertension, and baculoviral IAP repeatcontaining 5 (BIRC5), which may protect human brain endothelial cells from ischemiainduced apoptosis. To determine the potential roles of PPARγ in brain microvascular endothelial (bEnd.3) cells during cerebral ischemia and the relationship between PPARγ and BIRC5, a cerebral ischemia model was established with bEnd.3 cells cells by oxygenglucose deprivation (OGD) treatment. OGD treatment reduced proliferation and enhanced apoptosis of bEnd.3 cells in a timedependent manner. PPARγ expression levels were decreased in bEnd.3 cells following OGD treatment. Upregulation of PPARγ expression protected bEnd.3 cells from ischemia injury and also upregulated BIRC5 expression. PPARγspecific binding sites in the BIRC5 promoter were predicted bioinformatically and verified by luciferase reporter experiments. Results from electrophoretic mobility shift/supershift and chromatin immunoprecipitation assays suggested that BIRC5 may be a novel target of PPARγ transcriptional regulation during ischemic injury. The present results indicated that PPARγ may serve a protective role on bEnd.3 cells and that BIRC5 may be a downstream target of PPARγ regulation during cerebral ischemia.