RESUMO
The MICU1-MICU2 heterodimer regulates the mitochondrial calcium uniporter (MCU) and mitochondrial calcium uptake. Herein, we present two crystal structures of the MICU1-MICU2 heterodimer, in which Ca2+ -free and Ca2+ -bound EF-hands are observed in both proteins, revealing both electrostatic and hydrophobic interfaces. Furthermore, we show that MICU1 interacts with EMRE, another regulator of MCU, through a Ca2+ -dependent alkaline groove. Ca2+ binding strengthens the MICU1-EMRE interaction, which in turn facilitates Ca2+ uptake. Conversely, the MICU1-MCU interaction is favored in the absence of Ca2+ , thus inhibiting the channel activity. This Ca2+ -dependent switch illuminates how calcium signals are transmitted from regulatory subunits to the calcium channel and the transition between gatekeeping and activation channel functions. Furthermore, competition with an EMRE peptide alters the uniporter threshold in resting conditions and elevates Ca2+ accumulation in stimulated mitochondria, confirming the gatekeeper role of the MICU1-MICU2 heterodimer. Taken together, these structural and functional data provide new insights into the regulation of mitochondrial calcium uptake.
Assuntos
Canais de Cálcio/química , Proteínas de Ligação ao Cálcio/química , Cálcio/química , Proteínas de Transporte de Cátions/química , Proteínas de Transporte da Membrana Mitocondrial/química , Complexos Multiproteicos/química , Cálcio/metabolismo , Canais de Cálcio/genética , Canais de Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Cristalografia por Raios X , Humanos , Transporte de Íons , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismoRESUMO
To address the increased energy demand, tumor cells undergo metabolic reprogramming, including oxidative phosphorylation (OXPHOS) and aerobic glycolysis. This study investigates the role of Kruppel-like factor 4 (KLF4), a transcription factor, as a tumor suppressor in hepatocellular carcinoma (HCC) by regulating ATP synthesis. Immunohistochemistry was performed to assess KLF4 expression in HCC tissues. Functional assays, such as CCK-8, EdU, and colony formation, as well as in vivo assays, including subcutaneous tumor formation and liver orthotopic xenograft mouse models, were conducted to determine the impact of KLF4 on HCC proliferation. Luciferase reporter assay and chromatin immunoprecipitation assay were utilized to evaluate the interaction between KLF4, miR-206, and RICTOR. The findings reveal low KLF4 expression in HCC, which is associated with poor prognosis. Both in vitro and in vivo functional assays demonstrate that KLF4 inhibits HCC cell proliferation. Mechanistically, it was demonstrated that KLF4 reduces ATP synthesis in HCC by suppressing the expression of RICTOR, a core component of mTORC2. This suppression promotes glutaminolysis to replenish the TCA cycle and increase ATP levels, facilitated by the promotion of miR-206 transcription. In conclusion, this study enhances the understanding of KLF4's role in HCC ATP synthesis and suggests that targeting the KLF4/miR-206/RICTOR axis could be a promising therapeutic approach for anti-HCC therapeutics.
Assuntos
Trifosfato de Adenosina , Carcinoma Hepatocelular , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like , Neoplasias Hepáticas , MicroRNAs , Animais , Humanos , Masculino , Camundongos , Trifosfato de Adenosina/metabolismo , Trifosfato de Adenosina/biossíntese , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Progressão da Doença , Fator 4 Semelhante a Kruppel/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Camundongos Nus , MicroRNAs/genética , MicroRNAs/metabolismoRESUMO
Bacterial cryptic prophage (defective prophage) genes are known to drastically influence host physiology, such as causing cell growth arrest or lysis, upon expression. Many phages encode lytic proteins to destroy the cell envelope. As natural antibiotics, only a few lysis target proteins were identified. ydfD is a lytic gene from the Qin cryptic prophage that encodes a 63-amino-acid protein, the ectopic expression of which in Escherichia coli can cause nearly complete cell lysis rapidly. The bacterial 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway is responsible for synthesizing the isoprenoids uniquely required for sustaining bacterial growth. In this study, we provide evidence that YdfD can interact with IspG, a key enzyme involved in the MEP pathway, both in vivo and in vitro. We show that intact YdfD is required for the interaction with IspG to perform its lysis function and that the mRNA levels of ydfD increase significantly under certain stress conditions. Crucially, the cell lysis induced by YdfD can be abolished by the overexpression of ispG or the complementation of the IspG enzyme catalysis product methylerythritol 2,4-cyclodiphosphate. We propose that YdfD from the Qin cryptic prophage inhibits IspG to block the MEP pathway, leading to a compromised cell membrane and cell wall biosynthesis and eventual cell lysis.
Assuntos
Biocatálise , Eritritol/análogos & derivados , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Prófagos/metabolismo , Fosfatos Açúcares/metabolismo , Proteínas Virais/metabolismo , Sequência Conservada , Cisteína/química , Eritritol/metabolismo , Escherichia coli/ultraestrutura , Modelos Biológicos , Ligação Proteica , Estrutura Secundária de Proteína , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Soluções , Estresse Fisiológico , Proteínas Virais/químicaRESUMO
The mitochondrial calcium uniporter (MCU) complex mediates the uptake of Ca2+ into mitochondria. Its activity is regulated by a heterodimer of MICU1 and MICU2, two EF-hand-containing proteins that act as the main gatekeeper of the uniporter. Herein we report the crystal structure of human MICU2 at 1.96 Å resolution. Our structure reveals a dimeric architecture of MICU2, in which each monomer adopts the canonical two-lobe structure with a pair of EF-hands in each lobe. Both Ca2+ -bound and Ca2+ -free EF-hands are observed in our structure. Moreover, we characterize the interaction sites within the MICU2 homodimer, as well as the MICU1-MICU2 heterodimer in both Ca2+ -free and Ca2+ -bound conditions. Glu242 in MICU1 and Arg352 in MICU2 are crucial for apo heterodimer formation, while Phe383 in MICU1 and Glu196 in MICU2 significantly contribute to the interaction in the Ca2+ -bound state. Based on our structural and biochemical analyses, we propose a model for MICU1-MICU2 heterodimer formation and its conformational transition from apo to a more compact Ca2+ -bound state, which expands our understanding of this co-regulatory mechanism critical for MCU's mitochondrial calcium uptake function.
Assuntos
Canais de Cálcio/química , Canais de Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/metabolismo , Cálcio/metabolismo , Proteínas de Transporte de Cátions/química , Proteínas de Transporte de Cátions/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/química , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Dimerização , Humanos , Modelos Biológicos , Ligação ProteicaRESUMO
Proper DNA double-strand break (DSB) repair is essential for maintaining genome integrity. Microhomology-mediated end joining (MMEJ) is an error-prone repair mechanism, which introduces mutations at break sites and contributes to chromosomal translocations and telomere fusions, thus driving carcinogenesis. Mitotic kinases PLK1, CDK1 and Aurora A are important for supporting MMEJ and are often overexpressed in various tumors. However, the functional interplay between these kinases and MMEJ has not been explored. Here, we found that MMEJ is preferentially employed to fix DSBs in cells arrested in mitosis following nocodazole treatment. We further showed that the DSB repair factor CtIP is jointly phosphorylated by CDK1/Aurora A and PLK1. CDK1/Aurora A-mediated CtIP phosphorylation at serine 327 triggers CtIP binding to the PLK1 polo-box domain, which in turn facilitates PLK1 to phosphorylate CtIP mainly at serine 723. A PLK1 phosphor-mimic CtIP mutant fails to initiate extended end resection and is thus unable to mediate homologous recombination and the G2/M checkpoint but can mediate MMEJ. These data imply that PLK1 may target CtIP to promote error-prone MMEJ and inactivate the G2/M checkpoint. These findings have helped elucidate the oncogenic roles of these factors.
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Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/metabolismo , Quebras de DNA de Cadeia Dupla , Reparo do DNA por Junção de Extremidades , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Sequência de Aminoácidos , Aurora Quinase A/genética , Aurora Quinase A/metabolismo , Proteínas de Transporte/genética , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Endodesoxirribonucleases , Pontos de Checagem da Fase G2 do Ciclo Celular/genética , Células HCT116 , Células HEK293 , Recombinação Homóloga , Humanos , Proteínas Nucleares/genética , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Homologia de Sequência de Aminoácidos , Quinase 1 Polo-LikeRESUMO
Background: Despite advances in technology, glycemic outcomes in people with type 1 diabetes (T1D) remain suboptimal. The MiniMed 780G (MM780G) advanced hybrid closed-loop (AHCL) system is the latest technology for T1D management with established safety and efficacy. This study explores the cost-effectiveness of MM780G AHCL compared against multiple daily injections (MDI) plus intermittently scanned continuous glucose monitor (isCGM). Methods: A cost-utility analysis was conducted, simulating lifetime outcomes for 1000 T1D individuals, with baseline hemoglobin A1c of 8.4%, using the IQVIA Core Diabetes Model (CDM) v9.5. A Singapore health care payer perspective was taken with 2023 costs applied. Treatment effects were taken from the ADAPT study and treatment-related events from a combination of sources. T1D complication costs were derived from local literature, and health state utilities and disutilities from published literature. Scenario analyses and probabilistic sensitivity analyses (PSAs) explored uncertainty. Cost-effectiveness was assessed based on willingness-to-pay (WTP) thresholds set to Singapore Dollars (SGD) 45,000 (United States Dollars [USD] 33,087) per quality-adjusted life year (QALY) and Singapore's gross domestic product (GDP) per capita of SGD 114,165 (USD 83,941) per QALY. Results: A switch from MDI plus isCGM to MM780G resulted in expected gains in life-years (+0.78) and QALYs (+1.45). Cost savings through reduction in T1D complications (SGD 25,465; USD 18,723) partially offset the higher treatment costs in the AHCL arm (+SGD 74,538; +USD 54,805), resulting in an estimated incremental cost-effectiveness ratio of SGD 33,797 (USD 24,850) per QALY gained. Findings were robust, with PSA outputs indicating 81% and 99% probabilities of cost-effectiveness at the stated WTP thresholds. Conclusion: MM780G is a cost-effective option for people with T1D managed in a Singapore setting.
Assuntos
Automonitorização da Glicemia , Análise Custo-Benefício , Diabetes Mellitus Tipo 1 , Hipoglicemiantes , Sistemas de Infusão de Insulina , Anos de Vida Ajustados por Qualidade de Vida , Humanos , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/economia , Diabetes Mellitus Tipo 1/sangue , Singapura , Hipoglicemiantes/economia , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/uso terapêutico , Sistemas de Infusão de Insulina/economia , Masculino , Feminino , Automonitorização da Glicemia/economia , Insulina/administração & dosagem , Insulina/economia , Insulina/uso terapêutico , Adulto , Glicemia/análise , Hemoglobinas Glicadas/análise , Pessoa de Meia-IdadeRESUMO
BACKGROUND: The escalating prevalence of metabolic diseases has led to a rapid increase in non-alcoholic steatohepatitis (NASH)-related hepatocellular carcinoma (NASH-HCC). While oxaliplatin (OXA)-based hepatic arterial infusion chemotherapy (HAIC) has shown promise in advanced-stage HCC patients, its efficacy in NASH-HCC remains uncertain. This study aims to assess the effectiveness of OXA-based HAIC and elucidate the mechanisms underlying OXA resistance in NASH-HCC. METHODS: The key lncRNAs were screened through RNA-seq analysis of NASH/non-NASH and OXA-sensitive/OXA-resistant (OXA-S/R) HCC tissues. The biological functions of the lnc-OXAR (OXA resistance-related lncRNA in NASH-HCC) in NASH-HCC were verified through a series of in vitro and in vivo experiments. The molecular mechanism of lnc-OXAR was elucidated by fluorescence in situ hybridization, immunoprecipitation-mass spectrometry (FISH), Immunoprecipitation-Mass Spectrometry (IP-MS), RNA pulldown, RNA immunoprecipitation (RIP), methylated RNA immunoprecipitation sequencing (MeRIP-Seq) and a dual-luciferase reporter assay. RESULTS: NASH-HCC exhibited reduced responsiveness to OXA-based HAIC compared to non-NASH HCC. We identified and validated a novel transcript namedlnc-OXAR, which played a crucial role in conferring OXA resistance to NASH-HCC. Inhibition of lnc-OXAR suppressed HCC cell growth and restored OXA sensitivity both in NASH-HCC mouse models and in vitro. Mechanistically, lnc-OXAR recruited Ku70 and cystatin A (CSTA), preventing Ku70 degradation and facilitating DNA double-strand break (DSB) repair, thereby promoting OXA resistance in NASH-HCC. Additionally, WTAP-mediated m6A modification enhanced the stability of lnc-OXAR in an IGF2BP2-dependent manner. Notably, silencing lnc-OXAR significantly enhanced the response to OXA in patient-derived xenograft (PDX) models derived from NASH-HCC. CONCLUSIONS: The reduced responsiveness of NASH-HCC to OXA treatment can be attributed to the upregulation of lnc-OXAR. Our findings provide a rationale for stratifying HCC patients undergoing OXA-based HAIC based on etiology. Lnc-OXAR holds promise as a novel target for overcoming OXA resistance in NASH-HCC and improving prognosis.
Assuntos
Carcinoma Hepatocelular , Resistencia a Medicamentos Antineoplásicos , Autoantígeno Ku , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Oxaliplatina , RNA Longo não Codificante , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/metabolismo , Oxaliplatina/farmacologia , Oxaliplatina/uso terapêutico , Camundongos , Autoantígeno Ku/metabolismo , Autoantígeno Ku/genética , Animais , RNA Longo não Codificante/genética , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/patologia , Masculino , Feminino , Linhagem Celular Tumoral , Camundongos Nus , Pessoa de Meia-Idade , Ensaios Antitumorais Modelo de Xenoenxerto , Adenosina/análogos & derivadosRESUMO
A Mn-based nanozyme, Mn-uNF/Si, with excellent alkali phosphatase-like activity was designed by in-situ growth of ultrathin Mn-MOF on the surface of silicon spheres, and implemented as an effective solid Lewis-Brønsted acid catalyst for broad-spectrum dephosphorylation. H218O-mediated GC-MS studies confirmed the cleavage sites and the involvement of H2O in the new bonds. DRIFT NH3-IR and in-situ ATR-FTIR confirmed the coexistence of Lewis-Brønsted acid sites and the adjustment of adsorption configurations at the interfacial sites. In addition, a green transformation route of "turning waste into treasure" was proposed for the first time ("OPsâPO43-âP food additive") using edible C. reinhardtii as a transfer station. By alkali etching of Mn-uNF/Si, a nanozyme Mn-uNF with laccase-like activity was obtained. Intriguingly, glyphosate exhibits a laccase-like fingerprint-like response (+,-) of Mn-uNF, and a non-enzyme amplified sensor was thus designed, which shows a good linear relationship with Glyp in a wide range of 0.49-750 µM, with a low LOD of 0.61 µM, as well as high selectivity and anti-interference ability under the co-application of phosphate fertilizers and multiple pesticides. This work provides a controllable methodology for the design of bifunctional nanozymes, which sheds light on the highly efficient green transformation of OPs, and paves the way for the selective recognition and quantification of glyphosate. Mechanistically, we also provided deeper insights into the structure-activity relationship at the atomic scale.
Assuntos
Técnicas Biossensoriais , Glicina , Glifosato , Manganês , Glicina/análogos & derivados , Glicina/química , Manganês/química , Técnicas Biossensoriais/métodos , Compostos Organofosforados/química , Compostos Organofosforados/análise , Estruturas Metalorgânicas/química , Herbicidas/química , Herbicidas/análise , Nanoestruturas/química , Química Verde/métodos , Silício/química , CatáliseRESUMO
Background and Aims: Metastasis is a major factor associated with high recurrence and mortality in hepatocellular carcinoma (HCC) patients while the underlying mechanism of metastasis remains elusive. In our study, procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) was shown to be involved in the process of metastasis in HCC. Methods: The Cancer Genome Atlas (TCGA) database and HCC tissue microarrays were used to evaluate the expression of genes. In vitro migration, invasion, in vivo subcutaneous tumor model and in vivo lung metastasis assays were used to determine the role of PLOD2 in tumor growth and metastasis in HCC. RNA sequencing and gene set enrichment analysis were performed to uncover the downstream factor of PLOD2 in HCC cells. A luciferase reporter assay was performed to evaluate the interaction between PLOD2 and interferon regulatory factor 5 (IRF5). Results: The expression of PLOD2 in HCC tissues was higher than that in adjacent tissues, and increased PLOD2 expression was often found in advanced tumors and was correlated with poor prognosis in HCC patients. In vitro experiments, knockdown of PLOD2 reduced the migration and invasion of human HCC cells. Loss of PLOD2 suppressed human HCC growth and metastasis in a subcutaneous tumor model and a lung metastasis model. Baculoviral IAP repeat containing 3 (BIRC3) was proven to be the downstream factor of PLOD2 in human HCC cells. In addition, PLOD2 was transcriptionally regulated by IRF5 in HCC cells. Conclusions: High expression of PLOD2 was regulated by IRF5, which was correlated with the poor survival of HCC patients. PLOD2 enhanced HCC metastasis via BIRC3, suggesting that PLOD2 might be a valuable prognostic biomarker for HCC treatment.
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BACKGROUND: Hepatocellular carcinoma (HCC) cells undergo reprogramming of glucose metabolism to support uncontrolled proliferation, of which the intrinsic mechanism still merits further investigation. Although regulatory factor X6 (RFX6) is aberrantly expressed in different cancers, its precise role in cancer development remains ambiguous. METHODS: Microarrays of HCC tissues were employed to investigate the expression of RFX6 in tumour and adjacent non-neoplastic tissues. Functional assays were employed to explore the role of RFX6 in HCC development. Chromatin immunoprecipitation, untargeted metabolome profiling and sequencing were performed to identify potential downstream genes and pathways regulated by RFX6. Metabolic assays were employed to investigate the effect of RFX6 on glycolysis in HCC cells. Bioinformatics databases were used to validate the above findings. RESULTS: HCC tissues exhibited elevated expression of RFX6. High RFX6 expression represented as an independent hazard factor correlated to poor prognosis in patients with HCC. RFX6 deficiency inhibited HCC development in vitro and in vivo, while its overexpression exerted opposite functions. Mechanistically, RFX6 bound to the promoter area of phosphoglycerate mutase 1 (PGAM1) and upregulated its expression. The increased PGAM1 protein levels enhanced glycolysis and further promoted the development of HCC. CONCLUSIONS: RFX6 acted as a novel driver for HCC development by promoting aerobic glycolysis, disclosing the potential of the RFX6-PGAM1 axis for therapeutic targeting.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/metabolismo , Proliferação de Células/genética , Glicólise/genética , Neoplasias Hepáticas/metabolismo , Fosfoglicerato Mutase/genética , Fosfoglicerato Mutase/metabolismoRESUMO
Although oxaliplatin-based chemotherapy has been effective in the treatment of hepatocellular carcinoma (HCC), primary or acquired resistance to oxaliplatin remains a major challenge in the clinic. Through functional screening using CRISPR/Cas9 activation library, transcriptomic profiling of clinical samples, and functional validation in vitro and in vivo, we identify PRMT3 as a key driver of oxaliplatin resistance. Mechanistically, PRMT3-mediated oxaliplatin-resistance is in part dependent on the methylation of IGF2BP1 at R452, which is critical for the function of IGF2BP1 in stabilizing the mRNA of HEG1, an effector of PRMT3-IGF2BP1 axis. Also, PRMT3 overexpression may serve as a biomarker for oxaliplatin resistance in HCC patients. Collectively, our study defines the PRTM3-IGF2BP1-HEG1 axis as important regulators and therapeutic targets in oxaliplatin-resistance and suggests the potential to use PRMT3 expression level in pretreatment biopsy as a biomarker for oxaliplatin-resistance in HCC patients.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Metilação , Oxaliplatina/farmacologia , Oxaliplatina/uso terapêutico , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismoRESUMO
Silver nanowire ink was written on the surface of drawing paper by automatic writing method. Scanning electron microscopy was used to characterize the surface morphologies of the drawing paper before and after writing silver nanowires. The effects of fabrication parameters and measurement parameters on silver nanowires arrays were investigated. Crystal violet was selected as the probe molecule to study the SERS performance of silver nanowires arrays. The detection limit of crystal violet was as low as 10-15 mol/L. The uniformity and repeatability of the arrays were also explored, and the relative standard deviation values were about 10%. Moreover, silver nanowires arrays were also relatively stable that SERS signals were still observed after ten weeks. Detection of the crystal violet residue was further achieved on the substrates by continuously pressing nine times. In addition, silver nanowires arrays were also applied to the quantitative analyses of 2, 2'-bipyridyl.
Assuntos
Nanofios , Prata , Violeta Genciana , Nanofios/química , Prata/química , Análise Espectral Raman/métodos , RedaçãoRESUMO
Homologous recombination (HR) is an error-free DNA double-strand break (DSB) repair pathway, which safeguards genome integrity and cell viability. Human C-terminal binding protein (CtBP)-interacting protein (CtIP) is a central regulator of the pathway which initiates the DNA end resection in HR. Ubiquitination modification of CtIP is known in some cases to control DNA resection and promote HR. However, it remains unclear how cells restrain CtIP activity in unstressed cells. We show that the ubiquitin E3 ligase PPIL2 is recruited to DNA damage sites through interactions with an HR-related protein ZNF830, implying PPIL2's involvement in DNA repair. We found that PPIL2 interacts with and ubiquitinates CtIP at the K426 site, representing a hereunto unknown ubiquitination site. Ubiquitination of CtIP by PPIL2 suppresses HR and DNA resection. This inhibition of PPIL2 is also modulated by phosphorylation at multiple sites by PLK1, which reduces PPIL2 ubiquitination of CtIP. Our findings reveal new regulatory complexity in CtIP ubiquitination in DSB repair. We propose that the PPIL2-dependent CtIP ubiquitination prevents CtIP from interacting with DNA, thereby inhibiting HR.
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Recently, the albumin-bilirubin (ALBI) score, a continuous index consisting of only albumin and bilirubin, has been developed for objectively assessing liver function in patients with hepatocellular carcinoma (HCC). However, the ALBI score was arbitrarily categorized into three ALBI grades based on two artificially predetermined cutoff points with no explanation and statistical grounds, causing a considerable loss of discriminatory ability. This study aims to propose a modified ALBI (mALBI) grade for offering a detailed evaluation of hepatic reserve and specify its role during clinical practice in the HCC setting. The study population comprised 3540 HCC patients treated with mainstream therapies including hepatectomy (n=2056), thermal ablation (n=550), and transcatheter arterial chemoembolization (n=934) from 2002 to 2017. The ALBI score was stratified into four mALBI grades through a recently proposed statistical method aiming to select the optimal cutoff points of a continuous predictive variable by maximizing the discriminative ability in a multivariable Cox regression model. The mALBI grade had an overall better discriminatory ability than the ALBI grade in predicting overall survival through Harrell's C-index (0.614 vs. 0.598, P<0.001). Both visual inspections of Kaplan-Meier curves and calculation of hazard ratios displayed a more subtle evaluation of liver function using the mALBI grade. Moreover, the newly identified cut-point (ALBI score = -2.29) between the mALBI grade 2a and 2b was much closer to a 30% retention rate of indocyanine green at 15 minutes, an indicator for the performance of a subsegmentectomy. The newly proposed mALBI grade provides a more subtle assessment of liver function to guide clinical decision-making and predicts the prognosis of HCC patients more accurately than the original ALBI grade.
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Thermal ablation is a main curative therapy for early-stage hepatocellular carcinoma (HCC). However, insufficient ablation has been shown to promote HCC progression. E3 ligases have been approved to play important roles in malignant tumors. Whether E3 ligases are involved in HCC progression caused by insufficient ablation remains unclear. Herein, using RNA-sequencing coupled with an in vitro loss-of-function screen, we found that the E3 ligase Neuronal Precursor cell-expressed Developmentally Downregulated 4 (Nedd4) was upregulated in HCC insufficient ablation tissues and promoted HCC cells migration. The upregulation of Nedd4 was induced by METTL14-mediated N6-methyladenosine modification after sublethal heat treatment. Knockdown of Nedd4 inhibited HCC metastasis and growth in vitro and in vivo. Mechanistically, Nedd4 enhanced TGF-ß signal transduction mediated tumor progression by directly binding to TGF-ß type I receptor (TGFBR1) and forming K27-linked ubiquitin at Lysine 391. Additionally, the adverse effect on HCC of sublethal heat treatment was mediated by Nedd4. Clinically, high Nedd4 expression was positively correlated with aggressive tumor phenotypes and poor prognosis in HCC patients. Patient-derived xenograft (PDX) model confirmed this conclusion. Collectively, this study demonstrated that Nedd4 induced by insufficient ablation plays a crucial role in promoting HCC progression and provides a novel therapeutic target for HCC.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Ubiquitina-Proteína Ligases Nedd4/metabolismo , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/metabolismo , Ubiquitina-Proteína Ligases Nedd4/genética , Fator de Crescimento Transformador beta , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Transarterial chemoembolization (TACE) is the major treatment for advanced hepatocellular carcinoma (HCC), but it may cause hypoxic environment, leading to rapid progression after treatment. Here, using high-throughput sequencing on different models, S100 calcium binding protein A9 (S100A9) is identified as a key oncogene involved in post-TACE progression. Depletion or pharmacologic inhibition of S100A9 significantly dampens the growth and metastatic ability of HCC. Mechanistically, TACE induces S100A9 via hypoxia-inducible factor 1α (HIF1A)-mediated pathway. S100A9 acts as a scaffold recruiting ubiquitin specific peptidase 10 and phosphoglycerate mutase family member 5 (PGAM5) to form a tripolymer, causing the deubiquitination and stabilization of PGAM5, leading to mitochondrial fission and reactive oxygen species production, thereby promoting the growth and metastasis of HCC. Higher S100A9 level in HCC tissue or in serum predicts a worse outcome for HCC patients. Collectively, this study identifies S100A9 as a key driver for post-TACE HCC progression. Targeting S100A9 may be a promising therapeutic strategy for HCC patients.
Assuntos
Calgranulina B , Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Humanos , Proteínas de Ligação ao Cálcio , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/efeitos adversos , Hipóxia/terapia , Neoplasias Hepáticas/terapia , Mitocôndrias , Fosfoglicerato Mutase , Espécies Reativas de Oxigênio , Proteases Específicas de Ubiquitina , Calgranulina B/metabolismoRESUMO
BACKGROUND: The positive predictive value (PPV) of high risk factor questionnaire (HRFQ) plus fecal immunochemical test (FIT) as preliminary screening strategy for colorectal-related neoplasia is relatively low. We aim to explore independent factors associated with PPVs of HRFQ combined FIT for selecting high risk individuals for colonoscopy. METHODS: A total of 6971 residents were enrolled in a community-based screening program. Participants who had positive results of HRFQ and/or FIT and subsequently received colonoscopy were involved. The associations of socio-demographic factors, lifestyle behaviors, and high risk factors of colorectal cancer with PPVs of HRFQ, FIT, and their combination were evaluated by multivariable logistic regression models. RESULTS: Among 572 involved cases, 249 (43.5%) colorectal neoplasms were detected by colonoscopy, including 71 advanced adenoma (12.4%) and 9 colorectal cancer (CRC) (1.6%). The PPVs of preliminary screening were 43.5% for total colorectal neoplasms, 14.0% for advanced neoplasm, and 1.6% for CRC. Adding positive HRFQ to FIT could improve the PPV from 3.5 to 8.0% for detecting CRC. Preliminarily screened positive individuals who were males [adjusted odds ratio (AOR): 1.95, 95% CI 1.31, 2.90; p < 0.001], elders (> 60 years) (AOR: 1.70, 95% CI 1.17, 2.46; p = 0.005), or ex-/current smokers (AOR: 3.04, 95% CI 1.31, 7.09; p = 0.10) had higher odds of PPVs of detecting colorectal neoplasms. CONCLUSIONS: Combining HRFQ and FIT could largely improve PPVs for screening advanced neoplasm and CRC. Gender and age-specific FIT cut-off values as well as initiating ages for CRC screening might be recommended to improve the accuracy and effectiveness of current screening algorithm.
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OBJECTIVES: This study aimed to investigate the potential factors associated with adherence to colonoscopy among participants who were preliminarily screened positive in a community-based colorectal cancer screening program in China. METHODS: This study analyzed data from 1219 out of 6971 community residents who were identified as positive cases by the well-validated high-risk factor questionnaire (HRFQ) or fecal immunochemical test (FIT) in the preliminary screening stage for colorectal neoplasms. Patients showing adherence to colonoscopy were defined as those who received positive results in a preliminary screening for colorectal neoplasms and later received a colonoscopy examination as required. The associations of social-demographic factors, lifestyle behaviors, history of diabetes, body mass index (BMI), and risk factors in the HRFQ with adherence to colonoscopy were evaluated using logistic regression models. RESULTS: Among 1219 participants who preliminarily screened positive, the top five risk factors reported by the participants were chronic constipation (25.9%), hematochezia (23.5%), family history of CRC in first-degree relatives (22.1%), chronic diarrhea (21.8%), and history of polyps (16.6%). Around 14.2% of participants who preliminarily screened positive reported three or more risk factors, and the proportion was 26.2% among participants who were positive according to both HRFQ and FIT. Among all participants who were preliminarily screened positive, the multivariable results showed that those who were married (OR = 1.58, 95% CI: 1.12, 2.25, p = 0.01), had chronic diarrhea (OR = 1.34, 95% CI: 1.00, 1.78, p = 0.047), and had a positive FIT (OR = 1.60, 95% CI: 1.21, 2.10, p < 0.001 for patients who were negative according to HRFQ but positive according to FIT; OR = 2.12, 95% CI: 1.33, 2.78, p = 0.002 for patients who were positive for both HRFQ and FIT) were more likely to adhere to colonoscopy, while participants with a history of cancer (OR: 0.50, 95% CI: 0.31, 0.79, p = 0.003) were less likely to adhere to colonoscopy. The results among participants who were tested positive according to only HRFQ were similar to those among all participants who were tested positive according to HRFQ or FIT. However, among participants who were tested positive according to only FIT, we only found that those who were married (OR = 2.52, 95% CI: 1.08, 5.90, p = 0.033) had a higher odds of adhering to colonoscopy, while those with a history of diabetes (OR = 0.35, 95% CI: 0.13, 0.96, p = 0.042) were less likely to adhere to colonoscopy. CONCLUSION: Our findings provide evidence supporting the development of tailored interventional strategies that aim to improve adherence to colonoscopy for individuals with a high risk of colorectal neoplasms. Both barriers and facilitators associated with adherence to colonoscopy should be considered in supportive systems and health policies. However, further well-designed prospective studies are warranted to confirm our findings.
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Colonoscopia , Neoplasias Colorretais , Humanos , Sangue Oculto , Programas de Rastreamento/métodos , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/epidemiologia , Detecção Precoce de Câncer/métodos , DiarreiaRESUMO
AIM: Insulin-like growth factor-1 receptor (IGF-1R) is one of the main members of the tyrosine protein kinase receptor family. This receptor binds insulin-like growth factor-1 (IGF-1) with a high affinity. IGF-1 is a member of a family of proteins involved in mediating growth and development. However, the correlations of IGF-1 and IGF-1R to prognosis and tumor-infiltrating lymphocytes in different cancers remain unclear. METHOD: This research comprehensively analyzed the expression pattern of IGF-1 and IGF-1R and the influence of IGF-1 and IGF-1R on clinical significance in prognosis prediction among 33 types of malignancies using The Cancer Genome Atlas (TCGA) and the Cancer Cell Line Encyclopedia (CCLE) databases. The correlation between IGF-1, IGF-1R, and cancer immunity was explored. RESULTS: IGF-1 and IGF-1R displayed inconsistent gene expression levels among diverse cancer cell lines. Typically, high expression level of IGF-1 and IGF-1R was detected in most malignant tumors. High expression of IGF-1 was closely bound up with the unfavorable overall survival (OS) for patients in BLCA, CHOL, and LAML upon Cox and Kaplan-Meier analyses. While high expression of IGF-1R was closely bound up with the unfavorable overall survival (OS) for patients in BLCA, LIHC, and LUAD. Furthermore, high expression level of IGF-1 and IGF-1R were closely connected with high degrees of tumor infiltrates, including CD4+ T cell, dendritic cells, and macrophages. In addition, we found that IGF-1 was commonly positively correlated with the expression of gene markers including LAIR1, ICOS, CD40LG, CTLA4, CD48, CD28, CD200R1, HAVCR2, and CD86. Whereas, IGF-1R was commonly positively correlated with the expression of gene markers including NRP1 and CD276. More importantly, IGF-1 and IGF-1R expression were correlated with tumor mutation burden (TMB), microsatellite instability (MSI), mismatch repair (MMR), and DNA methyltransferase (DNMT) of different types of cancers. CONCLUSIONS: The impact of high IGF-1 and IGF-1R on prognosis and immune infiltrates differs across cancer types. Anti-IGF-1R therapy may inhibit tumor growth and contribute to immunotherapy in LIHC and KIRC.
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OBJECTIVES: The impact of heterogeneity on gender difference for achieving clinically meaningful weight loss (cmWL) remains unclear. Here, we explored the potential gender differences in factors associated with cmWL. METHODS: A total of 60,668 participants with body mass index (BMI) ≥25 kg/m2 at study entry and available BMI values at follow-up were included in this study. cmWL was defined as a weight loss of ≥5% from the study entry to follow-up. The associations of social-demographic factors, personal history of chronic diseases, lifestyle behaviors, and history of BMI with cmWL were evaluated using logistic regression models. RESULTS: During a median follow-up of 9.13 years, 26.6% of the participants had a cmWL (30.8% for females vs. 23.1% in males; p < 0.001). Participants with older age, obesity at study entry, being more physical activity compared to 10 years ago, being relapsed smokers or consistent current smokers, having a history of chronic diseases (i.e., diabetes, osteoporosis, and stroke), cancer diagnosis during the study period, and more than 10-year follow-up were more likely to achieve cmWL in both males and females (all p < 0.05). The new smoking quitters and participants with less active in physical activity compared to 10 years ago were less likely to achieve cmWL in both males and females (all p < 0.05). Specifically, males with a history of emphysema were more likely to reach cmWL, and for females, those being overweight at 20 years old and current drinkers were more likely to reach cmWL (p < 0.05). Sensitivity analyses demonstrated similar results. CONCLUSION: Age, BMI status, physical activity, smoking status, family income, and health status were independent factors in males and females for weight management. However, further well-designed prospective studies are warranted to confirm our findings.