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1.
Heliyon ; 10(7): e29295, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38617954

RESUMO

It is crucial to employ scientifically sound models for assessing the quality of the ecological environment and revealing the strengths and weaknesses of ecosystems. This process is vital for identifying regional ecological and environmental issues and devising relevant protective measures. Among the widely acknowledged models for evaluating ecological quality, the ecological index (EI) and remote sensing ecological index (RSEI) stand out; however, there is a notable gap in the literature discussing their differences, characteristics, and reasons for selecting either model. In this study, we focused on Fangshan District, Beijing, China, to examine the differences between the two models from 2017 to 2021. We summarized the variations in evaluation indices, importance, quantitative methods, and data acquisition times, proposing application scenarios for both models. The results indicate that the ecological environment quality in Fangshan District, Beijing, remained favorable from 2017 to 2021. There was a discernible trend of initially declining quality followed by subsequent improvement. The variation in the calculation results is evident in the overall correlation between the RSEI and EI. Particularly noteworthy is the significantly smaller correlation between EI and the RSEI in 2021 than in the other two years. This discrepancy is attributed to shifts in the contribution of the evaluation indices within the RSEI model. The use of diverse quantitative methods for evaluating indicators has resulted in several variations. Notably, the evaluation outcomes of the EI model exhibit a stronger correlation with land cover types. This correlation contributes to a more pronounced fluctuation in RSEI levels from 2017 to 2021, with the EI model's evaluation results in 2019 notably surpassing those of the RSEI model. Ultimately, the most prominent disparities lie in the calculation results for water areas and construction land. The substantial difference in water areas is attributed to the distinct importance assigned to evaluation indicators between the two models. Moreover, the notable difference in construction land arises from the use of different quantification methods for evaluation indicators. In general, the EI model has suggested to be more comprehensive and effectively captures the annual comprehensive status of the ecological environment and the multiyear change characteristics of the administrative region. On the other hand, RSEI models exhibit greater flexibility and ease of implementation, independent of spatial and temporal scales. These findings contribute to a clearer understanding of the models' advantages and limitations, offering guidance for decision makers and valuable insights for the improvement and development of ecological environmental quality evaluation models.

2.
ACS Nano ; 18(4): 3553-3574, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38226901

RESUMO

Large full-thickness skin lesions have been one of the most challenging clinical problems in plastic surgery repair and reconstruction. To achieve in situ skin regeneration and perfect clinical outcomes, we must address two significant obstacles: angiogenesis deficiency and inflammatory dysfunction. Recently, black phosphorus has shown great promise in wound healing. However, few studies have explored the bio-effects of BP to promote in situ skin regeneration based on its nanoproperties. Here, to investigate whether black phosphorus nanosheets have positive bio-effects on in situ skin repair, we verified black phosphorus nanosheets' positive effects on angiogenic and anti-inflammatory abilities in vitro. Next, the in vivo evaluation performed on the rat large full-thickness excisional wound splinting model more comprehensively showed that the positive bio-effects of black phosphorus nanosheets are multilevel in wound healing, which can effectively enhance anti-inflammatory ability, angiogenesis, collagen deposition, and skin re-epithelialization. Then, multiomics analysis was performed to explore further the mechanism of black phosphorus nanosheets' regulation of endothelial cells in depth. Molecular mechanistically, black phosphorus nanosheets activated the JAK-STAT-OAS signaling pathway to promote cellular function and mitochondrial energy metabolism in endothelial cells. This study can provide a theoretical basis for applying two-dimensional black phosphorus nanosheets as nanomedicine to achieve in situ tissue regeneration in complex human pathological microenvironments, guiding the subsequent optimization of black phosphorus.


Assuntos
Células Endoteliais , Fósforo , Ratos , Humanos , Animais , Fósforo/farmacologia , Cicatrização , Pele , Anti-Inflamatórios/farmacologia
3.
Int J Biochem Cell Biol ; 168: 106529, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38246262

RESUMO

Gene fusions have had a significant role in the development of various types of cancer, oftentimes involved in oncogenic activities through dysregulation of gene expression or signalling pathways. Some cancer-associated chromosomal translocations can undergo backsplicing, resulting in fusion-circular RNAs, a more stable isoform immune to RNase degradation. This stability makes fusion circular RNAs a promising diagnostic biomarker for cancer. While the detection of linear fusion RNAs and their function in certain cancers have been described in literature, fusion circular RNAs lag behind due to their low abundance in cancer cells. This review highlights current literature on the role of linear and circular fusion transcripts in cancer, tools currently available for detecting of these chimeric RNAs and their function and how they play a role in tumorigenesis.


Assuntos
Neoplasias , RNA Circular , Humanos , RNA Circular/genética , Patologia Molecular , RNA/metabolismo , Neoplasias/genética , Neoplasias/diagnóstico , Fusão Gênica
4.
PeerJ ; 11: e15814, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37663298

RESUMO

Osteosarcoma (OS) is a rare primary malignant bone tumor in adolescents and children with a poor prognosis. The identification of prognostic genes lags far behind advancements in treatment. In this study, we identified differential genes using mRNA microarray analysis of five paired OS tissues. Hub genes, gene set enrichment analysis, and pathway analysis were performed to gain insight into the pathway alterations of OS. Prognostic genes were screened using the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) dataset, then overlapped with the differential gene dataset. The carboxypeptidase E (CPE) gene, found to be an independent risk factor, was further validated using RT-PCR and Gene Expression Omnibus (GEO) datasets. Additionally, we explored the specific expression of CPE in OS tissues by reanalyzing single-cell genomics. Interestingly, CPE was found to be co-expressed with osteoblast lineage cell clusters that expressed RUNX2, SP7, SPP1, and IBSP marker genes in OS. These results suggest that CPE could serve as a prognostic factor in osteoblastic OS and should be further investigated as a potential therapeutic target.


Assuntos
Neoplasias Ósseas , Osteossarcoma , Adolescente , Criança , Humanos , Carboxipeptidase H/genética , Prognóstico , Osteossarcoma/genética , Neoplasias Ósseas/genética , Biomarcadores
5.
Cell Death Discov ; 9(1): 231, 2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37419907

RESUMO

Osteosarcoma is the most common malignant bone tumor, tending to be aggressive and recurrent. The therapeutic development for treating osteosarcoma has been largely hampered by the lack of effective and specific targets. Using kinome-wide CRISPR-Cas9 knockout screens, we systematically revealed a cohort of kinases essential for the survival and growth of human osteosarcoma cells, in which Polo-like kinase 1 (PLK1) appeared as a specific prominent hit. PLK1 knockout substantially inhibited proliferation of osteosarcoma cells in vitro and the tumor growth of osteosarcoma xenograft in vivo. Volasertib, a potent experimental PLK1 inhibitor, can effectively inhibit the growth of the osteosarcoma cell lines in vitro. It can also disrupt the development of tumors in the patient-derived xenograft (PDX) models in vivo. Furthermore, we confirmed that the mode of action (MoA) of volasertib is primarily mediated by the cell-cycle arrest and apoptosis triggered by DNA damage. As PLK1 inhibitors are entering phase III clinical trials, our findings provide important insights into the efficacy and MoA of the relevant therapeutic approach for combating osteosarcoma.

6.
PLoS Biol ; 21(7): e3001862, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37406020

RESUMO

The induction of ferroptosis in tumor cells is one of the most important mechanisms by which tumor progression can be inhibited; however, the specific regulatory mechanism underlying ferroptosis remains unclear. In this study, we found that transcription factor HBP1 has a novel function of reducing the antioxidant capacity of tumor cells. We investigated the important role of HBP1 in ferroptosis. HBP1 down-regulates the protein levels of UHRF1 by inhibiting the expression of the UHRF1 gene at the transcriptional level. Reduced levels of UHRF1 have been shown to regulate the ferroptosis-related gene CDO1 by epigenetic mechanisms, thus up-regulating the level of CDO1 and increasing the sensitivity of hepatocellular carcinoma and cervical cancer cells to ferroptosis. On this basis, we constructed metal-polyphenol-network coated HBP1 nanoparticles by combining biological and nanotechnological. MPN-HBP1 nanoparticles entered tumor cells efficiently and innocuously, induced ferroptosis, and inhibited the malignant proliferation of tumors by regulating the HBP1-UHRF1-CDO1 axis. This study provides a new perspective for further research on the regulatory mechanism underlying ferroptosis and its potential role in tumor therapy.


Assuntos
Ferroptose , Neoplasias Hepáticas , Humanos , Fatores de Transcrição/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Regulação da Expressão Gênica , Proteínas de Grupo de Alta Mobilidade/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
7.
Gene ; 877: 147568, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37328077

RESUMO

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disease with obscure aetiology. The underdiagnosis rate of ME/CFS is high due to the lack of diagnostic criteria based on objective markers. In recent years, circRNAs have emerged as potential genetic biomarkers for neurological diseases, including Parkinson's disease and Alzheimer's disease, making them likely to have the same prospect of being biomarkers in ME/CFS. However, despite the extensive amount of research that has been performed on the transcriptomes of ME/CFS patients, all of them are solely focused on linear RNAs, and the profiling of circRNAs in ME/CFS has been completely omitted. In this study, we investigated the expression profiles of circRNAs, comparing ME/CFS patients and controls before and after two sessions of cardiopulmonary exercise longitudinally. In patients with ME/CFS, the number of detected circRNAs was higher compared to healthy controls, indicating potential differences in circRNA expression associated with the disease. Additionally, healthy controls showed an increase in the number of circRNAs following exercise testing, while no similar pattern was evident in ME/CFS patients, further highlighting physiological differences between the two groups. A lack of correlation was observed between differentially expressed circRNAs and their corresponding coding genes in terms of expression and function, suggesting the potential of circRNAs as independent biomarkers in ME/CFS. Specifically, 14 circRNAs were highly expressed in ME/CFS patients but absent in controls throughout the exercise study, indicating a unique molecular signature specific to ME/CFS patients and providing potential diagnostic biomarkers for the disease. Significant enrichment of protein and gene regulative pathways were detected in relation to five of these 14 circRNAs based on their predicted miRNA target genes. Overall, this is the first study to describe the circRNA expression profile in peripheral blood of ME/CFS patients, providing valuable insights into the molecular mechanisms underlying the disease.


Assuntos
Síndrome de Fadiga Crônica , Humanos , Síndrome de Fadiga Crônica/genética , Síndrome de Fadiga Crônica/diagnóstico , RNA Circular/genética , Regulação da Expressão Gênica , Marcadores Genéticos
8.
Aging (Albany NY) ; 14(21): 8763-8782, 2022 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-36326689

RESUMO

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease that is highly prevalent worldwide and characterized by glucose and lipid metabolism disorders. However, the pathogenic mechanisms have not been fully established. Here, we found that HMG-box transcription factor 1 (HBP1) is involved in T2DM and that its deficiency in mice aggravates the features of diabetes. In addition, we undertook screening by RNA sequencing and found that HBP1 activates the transcription of the insulin-like growth factor binding protein 1 (IGFBP1) gene. Moreover, Insulin and palmitic acid reduced HBP1 protein expression and inhibited its binding to the IGFBP1 promoter. Furthermore, HBP1 reduced the serum free insulin-like growth factor 1 (IGF-1) concentration through IGFBP1 and inhibited the PI3K/AKT signaling pathway. This forms an insulin/HBP1/IGFBP1 negative feedback regulatory loop to dynamically regulate blood glucose and insulin concentrations. These findings have elucidated a mechanism whereby HBP1 and its negative feedback regulatory loop influence the development of T2DM, thereby providing a new theoretical basis and potential therapeutic target for T2DM.


Assuntos
Diabetes Mellitus Tipo 2 , Animais , Camundongos , Glicemia , Diabetes Mellitus Tipo 2/genética , Insulina , Fosfatidilinositol 3-Quinases , Ativação Transcricional , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo
9.
Oncogenesis ; 11(1): 45, 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35941115

RESUMO

HBP1 is a sequence-specific transcription factor which generally considered as a crucial growth inhibitor. Posttranslational modification of HBP1 is vital for its function. In this study, we demonstrate that HBP1 is methylated at R378 by PRMT1, which decreases HBP1 protein stability by promoting its ubiquitination and proteasome-mediated degradation. PRMT1-mediated methylation of HBP1 alleviates the repressive effects of HBP1 on tumor metastasis and growth. GSN is identified as a novel target gene of HBP1. Methylation of HBP1 promotes actin cytoskeleton remodeling, glycolysis and tumor progression by downregulating GSN (a vital actin-binding protein) levels. The methylated HBP1-GSN axis is associated with the clinical outcomes of cancer patients. This investigation elucidates the mechanism of how methylated HBP1 facilitates actin cytoskeleton remodeling, thus attenuates its tumor-suppressive function and promotes tumor progression. Targeting methylated HBP1-GSN axis may provide a therapeutic strategy for cancer.

10.
Oncogenesis ; 10(10): 69, 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34650031

RESUMO

Golgi protein 73 (GP73) and alpha fetoprotein (AFP) serve as biomarkers for the diagnosis of hepatocellular carcinoma (HCC), and their serum levels correlate with patients' outcomes. However, the mechanisms underlying these correlations are unknown. Here we show that GP73 increased the secretion of AFP through direct binding to AFP, thereby promoting the proliferation and metastasis of HCC cells that expressed AFP and its receptor (AFPR). Extracellular GP73 contributed to the proliferation and metastasis of HCC cells independent of AFP and AFPR. Moreover, extracellular AFP and GP73 synergized to enhance the malignant phenotype of HCC cells. Furthermore, extracellular GP73 and AFP inhibited the antitumor effects of sorafenib and synergistically increased the drug resistance of HCC cells. These findings, which reveal the mechanism of GP73-mediated secretion of AFP and its effects on the malignant phenotype of HCC cells, provide a comprehensive theoretical basis for the diagnosis and treatment of HCC and identify potential drug targets.

11.
J Exp Clin Cancer Res ; 40(1): 118, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33794968

RESUMO

BACKGROUND: Hepatoma is a common malignancy of the liver. The abnormal high expression of alpha-fetoprotein (AFP) is intimately associated with hepatoma progress, but the mechanism of transcriptional regulation and singularly activation of AFP gene in hepatoma is not clear. METHODS: The expression of transcription factor HBP1 and AFP and clinical significance were further analyzed in hepatoma tissues from the patients who received surgery or TACE and then monitored for relapse for up 10 years. HBP1-mediated transcriptional regulation of AFP was analyzed by Western blotting, Luciferase assay, Realtime-PCR, ChIP and EMSA. After verified the axis of HBP-AFP, its impact on hepatoma was measured by MTT, Transwell and FACS in hepatoma cells and by tumorigenesis in HBP1-/- mice. RESULTS: The relative expressions of HBP1 and AFP correlated with survival and prognosis in hepatoma patients. HBP1 repressed the expression of AFP gene by directly binding to the AFP gene promoter. Hepatitis B Virus (HBV)-encoded protein HBx promoted malignancy in hepatoma cells through binding to HBP1 directly. Icaritin, an active ingredient of Chinese herb epimedium, inhibited malignancy in hepatoma cells through enhancing HBP1 transrepression of AFP. The repression of AFP by HBP1 attenuated AFP effect on PTEN, MMP9 and caspase-3, thus inhibited proliferation and migration, and induced apoptosis in hepatoma cells. The deregulation of AFP by HBP1 contributed to hepatoma progression in mice. CONCLUSIONS: Our data clarify the mechanism of HBP1 in inhibiting the expression of AFP and its suppression in malignancy of hepatoma cells, providing a more comprehensive theoretical basis and potential solutions for the diagnosis and treatment of hepatoma.


Assuntos
Carcinoma Hepatocelular/genética , Proteínas de Grupo de Alta Mobilidade/metabolismo , Proteínas Repressoras/metabolismo , alfa-Fetoproteínas/metabolismo , Animais , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Humanos , Camundongos , Transdução de Sinais , Transfecção
12.
BMC Cancer ; 21(1): 318, 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33765973

RESUMO

BACKGROUND: Icaritin, an active ingredient of the Chinese herb Epimedium, plays an anti-tumor role in liver cancer by inhibiting the proliferation of hepatocellular cells and promoting their apoptosis. In China, phase II and a large phase III clinical trial of icaritin reagent for the treatment of hepatocellular cancer is under-going, but the specific mechanism of icaritin action was unclear. Alpha-fetoprotein (AFP), an oncofetal protein, produced in the healthy fetal liver and yolk sac. Intracellular AFP promoted cellular proliferation and inhibited cellular apoptosis in hepatocellular carcinoma (HCC). The study was aimed to investigate the effect of icaritin on HCC through p53/AFP pathway. METHODS: Real-time RT PCR and western blot were used to detect p53 and AFP expression levels in HCC cells treated with icaritin. The mechanism of icaritin affecting p53 expression was verified by ubiquitination experiment, and the binding activity of icaritin on p53 in AFP promoter region was verified by luciferase experiment. EdU, MTT and flow cytometry were used to determine whether icaritin affected HCC cellular proliferation and apoptosis through p53/ AFP pathway. Expression levels of p53 and AFP in xenograft mouse model were determined by western blotting. RESULTS: Our results showed icaritin inhibited AFP expression at mRNA and protein level. AFP was also identified as the target gene of the p53 transcription factor. Icaritin abrogated murine double minute (Mdm) 2-mediated p53 ubiquitination degradation to improve the stability of p53. Up-regulated p53 protein levels then transcriptionally inhibited the AFP promoter. Icaritin-mediated decrease of AFP through Mdm2/p53 pathways inhibited HCC cellular proliferation and promoted HCC cellular apoptosis. CONCLUSION: Our findings revealed the mechanism of icaritin in promoting apoptosis and inhibiting proliferation in liver cancer cells. The regulatory mechanism of icaritin in AFP protein down-regulation provides a theoretical and experimental basis for further research into new drugs for the treatment of liver cancer.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Flavonoides/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , alfa-Fetoproteínas/genética , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Regulação para Baixo , Flavonoides/uso terapêutico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Proteína Supressora de Tumor p53/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , alfa-Fetoproteínas/metabolismo
13.
Cancer Lett ; 471: 12-26, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-31811908

RESUMO

Alpha-fetoprotein (AFP) is a well-established biomarker for hepatocellular carcinoma (HCC). Here, we investigated the acetylation state of AFP in vivo. AFP acetylation was regulated by the acetyltransferase CBP and the deacetylase SIRT1. Acetylation of AFP at lysines 194, 211, and 242 increased the stability of AFP protein by decreasing its ubiquitination and proteasomal degradation. AFP acetylation promoted its oncogenic role by blocking binding to the phosphatase PTEN and the pro-apoptotic protein caspase-3, which increased signaling for proliferation, migration, and invasion and decreased apoptosis. High levels of acetylated AFP in HCC tissues were associated with HBV infection and correlated with poor prognosis and decreased patient survival. In HCC cells, hepatitis B virus X protein (HBx) and palmitic acid (PA) increased the level of acetylated AFP by disrupting SIRT1-mediated deacetylation. AFP acetylation plays an important role in HCC progression and provides a new potential prognostic marker and therapeutic target for HCC.


Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , alfa-Fetoproteínas/metabolismo , Acetilação/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Apoptose/fisiologia , Proteína de Ligação a CREB/metabolismo , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/virologia , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Células HEK293 , Células Hep G2 , Hepatite B Crônica/metabolismo , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Ácido Palmítico/farmacologia , Prognóstico , Sirtuína 1/metabolismo , Transativadores/biossíntese , Transativadores/genética , Transativadores/metabolismo , Transfecção , Proteínas Virais Reguladoras e Acessórias/biossíntese , Proteínas Virais Reguladoras e Acessórias/genética , Proteínas Virais Reguladoras e Acessórias/metabolismo
14.
J Environ Manage ; 243: 157-167, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31096169

RESUMO

The effectiveness of porous pavement (PP) and bio-retention cells (BCs) under the influence of potential climate change was investigated based on representative concentration pathways (RCPs). A case study of a test catchment in Guangzhou illustrated changes of peak runoff under various climate scenarios. There were distinct increases in runoff volume and peak discharge in response to RCP8.5 but only marginal increases in response to RCP2.6 (compared with present conditions). The performance of PP and BCs in terms of percentage reduction of runoff volume and peak discharge was examined for 1-, 10-, and 100-year return period and 1- and 6-h-duration storms under various climate scenarios. The effectiveness of PP and BCs varied non-linearly with the extent of PP and BCs adopted. In general, the fluctuation of hydrological performance of PP is greater than that of BCs in RCP2.6 and RCP8.5 (e.g., peak flow reductions range from -60% to 69% and from -22% to 9%, for 5% area of PP and BCs, respectively). And PP is more cost-effective for frequent storms using life cycle costing analysis. We find that PP and BCs could significantly reduce runoff volume and peak discharge in response to rainfall events with short return period, but not for heavy storms with longer return period.


Assuntos
Chuva , Movimentos da Água , Mudança Climática , Hidrologia , Porosidade
15.
Oncogene ; 38(24): 4835-4855, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30816344

RESUMO

Genome instability is a common feature of tumor cells, and the persistent presence of genome instability is a potential mechanism of tumorigenesis. The E3 ubiquitin ligase MDM2 is intimately involved in genome instability, but its mechanisms are unclear. Our data demonstrated that the transcription factor HBP1 is a target of MDM2. MDM2 facilitates HBP1 proteasomal degradation by ubiquitinating HBP1, regardless of p53 status, thus attenuating the transcriptional inhibition of HBP1 in the expression of its target genes, such as the DNA methyltransferase DNMT1 and histone methyltransferase EZH2, which results in global DNA hypermethylation and histone hypermethylation and ultimately genome instability. The repression of HBP1 by MDM2 finally promotes cell growth and tumorigenesis. Next, we thoroughly explored the regulatory mechanism of the MDM2/HBP1 axis in DNA damage repair following ionizing radiation. Our data indicated that MDM2 overexpression-mediated repression of HBP1 delays DNA damage repair and causes cell death in a p53-independent manner. This investigation elucidated the mechanism of how MDM2 promotes genome instability and enhances tumorigenesis in the absence of p53, thus providing a theoretical and experimental basis for targeting MDM2 as a cancer therapy.


Assuntos
Instabilidade Genômica , Proteínas de Grupo de Alta Mobilidade/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/fisiologia , Proteínas Repressoras/metabolismo , Ubiquitinação , Animais , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Regulação Neoplásica da Expressão Gênica , Instabilidade Genômica/genética , Células HEK293 , Células HeLa , Humanos , Células MCF-7 , Masculino , Camundongos , Camundongos Nus , Processamento de Proteína Pós-Traducional/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteína Supressora de Tumor p53/fisiologia , Ubiquitinação/genética
16.
J Biol Chem ; 292(20): 8207-8222, 2017 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-28348080

RESUMO

Oxidative stress can induce cell dysfunction and lead to a broad range of degenerative alterations, including carcinogenesis, aging, and other oxidative stress-related conditions. To avoid undergoing carcinogenesis in response to oxidative stress, cells trigger a succession of checkpoint responses, including premature senescence and apoptosis. Increasing evidence indicates that H2O2, an important cause of oxidative stress, functions as an important physiological regulator of intracellular signaling pathways that participate in regulation of cell premature senescence and apoptosis. However, the precise mechanisms underlying this process remain to be studied extensively. In this study, we describe the importance of Pim-1 kinase in this checkpoint response to oxidative stress. Pim-1 binds to and phosphorylates the transcription factor high mobility group box transcription factor 1 (HBP1), activating it. H2O2 enhances the interaction between Pim-1 and HBP1 and promotes HBP1 accumulation. In turn, HBP1 rapidly and selectively up-regulates Pim-1 expression in H2O2-stimulated cells, thereby creating a Pim-1-HBP1 positive feedback loop that regulates H2O2-induced premature senescence and apoptosis. Furthermore, the Pim-1-HBP1 positive feedback loop exerts its effect by regulating the senescence markers DNMT1 and p16 and the apoptosis marker Bax. The Pim-1-HBP1 axis thus constitutes a novel checkpoint pathway critical for the inhibition of tumorigenesis.


Assuntos
Apoptose/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Proteínas de Grupo de Alta Mobilidade/metabolismo , Peróxido de Hidrogênio/farmacologia , Proteínas Proto-Oncogênicas c-pim-1/biossíntese , Proteínas Repressoras/metabolismo , Regulação para Cima/efeitos dos fármacos , Apoptose/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Senescência Celular/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , Células HeLa , Proteínas de Grupo de Alta Mobilidade/genética , Humanos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Proteínas Proto-Oncogênicas c-pim-1/genética , Proteínas Repressoras/genética
17.
Nan Fang Yi Ke Da Xue Xue Bao ; 26(1): 105-8, 2006 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-16495189

RESUMO

OBJECTIVE: To observe the effect of a new synthetic tripeptide [Arg(NO(3))- Lys(OCH(3))- Arg(NO(3))] on L-arginine/NO pathway in the macrophage cell strain RAW246.7. METHODS: The cultured macrophages exposed to lipopolysaccharide (LPS, 1 microg/L) treatment were randomly divided into 3 groups (n=6) and treated with distilled water, 1x10(-4) mol/L tripeptide and 1x10(-4) mol/L L-arginine, NG-monomethyl-L-arginine (L-NMMA) for 24 h, respectively. The macrophages were incubated for 24 h with LPS (1 microg/L) and in the presence of different concentrations of L-arginine (0 to 2 mmol/L), or in normal culture medium (containing 0.5 mmol/L L-arginine) for 24 h with LPS (1 microg/L) and in the presence of tripeptide of 0 to 10x10(-4) mol/L. The changes of [(3)H]-L-arginine transport and NO production from the macrophages were measured. RESULT: NO release from macrophages incubated in the LPS-containing culture medium was 50 folds, and [(3)H]-L-arginine uptake 2.7 folds that in cells in normal culture medium. Tripeptide (1x10(-4) mol/L) inhibited [(3)H]-L-arginine transport and NO production by 67% and 71% respectively. The effect of tripeptide was stronger than L-NMMA (P<0.05). Extracellular L-arginine caused a concentration-dependent increase in nitrite production, which reached the maximum at concentrations above 0.5 mmol/L Km for nitrite production of 0.162+/-0.015 mmol/L and Vmax of 91.2+/-2.3 micromol/(24h.10(6) cells). L-arginine transport and NO production were inhibited by tripeptide, but their dose-dependent pattern of changes was different with EC50 of 0.21x10(-4) mol/L and 1.27x10(-4) mol/L, respectively. CONCLUSIONS: Activation of macrophages with LPS induces nitrite accumulation in the culture medium, which is dependent on the presence of extracellular L-arginine. The tripeptide induces dysfunction of L-arginine/NO pathway in macrophages, potently inhibits L-arginine transport and competitively combine the active sites of nitric oxide synthase.


Assuntos
Arginina/metabolismo , Macrófagos/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Oligopeptídeos/farmacologia , Transporte Biológico/efeitos dos fármacos , Células Cultivadas , Humanos , Lipopolissacarídeos , Macrófagos/citologia , Óxido Nítrico/biossíntese
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