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1.
Front Oncol ; 11: 724104, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34956861

RESUMO

Despite the promising activity of poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) in many cancer types with defects in the DNA damage response the majority of the treated patients acquire PARPi resistance and succumb to their diseases. Consequently, there is an urgent need to identify the mechanisms of PARPi resistance. Here, we show that PARPi treatment promotes STAT3 activation in ovarian cancer cells, tumor-associated immune cells and fibroblasts, resulting in PARPi resistance and immunosuppression. Comparison of ovarian cancer patient-matched tumor biopsies before and after PARPi therapy revealed that STAT3 activity was significantly higher in tumor cells and tumor-associated immune cells and fibroblasts post PARPi treatment. Moreover, one-time PARPi treatment activated STAT3 both in tumor cells as well as diverse immune subsets and fibroblasts. PARPi-treated immune cells exhibited decreased expression of immunostimulatory interferon (IFN)-γ and Granzyme B while increasing immunosuppressive cytokine IL-10. Finally, we demonstrate that the acquisition of PARPi resistance in ovarian cancer cells was accompanied by increased STAT3 activity. Ablating STAT3 inhibited PARPi-resistant ovarian tumor cell growth and/or restored PARPi sensitivity. Therefore, our study has identified a critical mechanism intrinsic to PARPi that promotes resistance to PARPi and induces immunosuppression during PARPi treatment by activating STAT3 in tumor cells and tumor-associated immune cells/fibroblasts.

2.
Front Immunol ; 12: 639221, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34211457

RESUMO

Clinically, immune cell function is correlated with pathogenesis of endometrial polyp (EP) and infertility of women of reproductive-age. However, the underlying immune cell hallmark in EP patients remains unclear. Here, we focused on analyzing circulating immune cells, and attempted to reveal the correlation between peripheral immune cell functional phenotypes and fertility in EP patients. Through comparison of circulating CD4+/CD8+ T cells, NK cells, and γδ T cells between 64 EP patients and 68 healthy females, we found that γδ T cells, but not CD4+/CD8+ T cells and NK cells, were immunologically correlated with conception rate and conception interval time. Specifically, total γδ T cells and the Vδ1+PD1+ γδ T subpopulation decreased whereas the Vδ1/Vδ2 ratio increased in EP patients compared to healthy controls. Moreover, the patients with the higher Vδ1/Vδ2 ratio (median value equals 1.04) had a poorer fertility and longer interval time of conception (210 days versus 158 days for control). Meanwhile, higher Vδ1+PD1+ γδ T cell proportion (median equals 15.7) was positively correlative with both higher conception rate and shortened median conception interval time (130 days for Vδ1+PD1high group versus 194 days for Vδ1+PD1low group). Notably, in healthy controls, both Vδ1/Vδ2 ratio and Vδ1+PD1+ γδ T cell proportion correlated with pregnancy rate oppositely, comparing to EP patients. Together, our results suggested that imbalanced γδ T cell population occurred in EP patients, and that Vδ1/Vδ2 ratio and PD-1 expression of Vδ1+ γδ T cells could be potentially developed into valuable predictors for fertility in EP patients.


Assuntos
Endométrio/imunologia , Fertilidade/imunologia , Linfócitos Intraepiteliais/imunologia , Pólipos/sangue , Pólipos/imunologia , Receptor de Morte Celular Programada 1/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Adulto , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Masculino , Gravidez , Adulto Jovem
3.
Zool Res ; 42(1): 28-42, 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33420763

RESUMO

Depression is a prevalent mental disorder that is associated with aging and contributes to increased mortality and morbidity. The overall prevalence of geriatric depression with clinically significant symptoms is currently on the rise. Recent studies have demonstrated that altered expressions of long non-coding RNAs (lncRNAs) in the brain affect neurodevelopment and manifest modulating functions during the depression. However, most lncRNAs have not yet been studied. Herein, we analyzed the transcriptome of dysregulated lncRNAs to reveal their expressions in a mouse model exhibiting depressive-like behaviors, as well as their corresponding response following antidepressant fluoxetine treatment. A chronic unpredictable mild stress (CUMS) mouse model was applied. A six-week fluoxetine intervention in CUMS-induced mice attenuated depressive-like behaviors. In addition, differential expression analysis of lncRNAs was performed following RNA-sequencing. A total of 282 lncRNAs (134 up-regulated and 148 down-regulated) were differentially expressed in CUMS-induced mice relative to non-stressed counterparts ( P<0.05). Moreover, 370 differentially expressed lncRNAs were identified in CUMS-induced mice after fluoxetine intervention. Gene Ontology (GO) analyses showed an association between significantly dysregulated lncRNAs and protein binding, oxygen binding, and transport activity, while the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that these dysregulated lncRNAs might be involved in inflammatory response pathways. Fluoxetine effectively ameliorated the symptoms of depression in CUMS-induced mice by regulating the expression of lncRNAs in the hippocampus. The findings herein provide valuable insights into the potential mechanism underlying depression in elderly people.


Assuntos
Transtorno Depressivo/tratamento farmacológico , Fluoxetina/uso terapêutico , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Antidepressivos de Segunda Geração/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos BALB C , RNA Longo não Codificante/genética , Estresse Psicológico
4.
Artigo em Inglês | MEDLINE | ID: mdl-33465798

RESUMO

BACKGROUND: The aim of this study is to test if the newly proposed 45 mm size criterion for ascending aortic replacement (AAR) in bicuspid aortic valve (BAV) patients undergoing aortic valve replacement (AVR) is predictive of improved early outcomes. METHODS: Data of 306 BAV patients with an aortic diameter of ≥45 mm undergoing AVR alone or with AAR were retrospectively analyzed. Patients were divided into groups of AVR + AAR (n = 220) and AVR only (n = 86) based on if surgery was performed according to the 45 mm criterion. End point was early adverse events, including 30-day and in-hospital mortality, cardiac events, acute renal failure, stroke, and reoperation for bleeding. Cox regression was used to assess if conformance to 45 mm criterion could predict fewer early adverse events. RESULTS: AVR + AAR group had significantly higher postoperative left ventricular ejection fraction (LVEF) (0.59 ± 0.09 vs. 0.55 ± 0.11, p = 0.006) and longer cardiopulmonary bypass (CPB) time (128 vs. 111 minutes, p = 0.002). Early adverse events occurred in 45 patients (14.7%), which was more prevalent in the AVR-only group (22.1% vs. 11.8%, p = 0.020). Conformance to the 45 mm criterion predicted lower rate of early adverse events (hazard ratio [HR]: 0.53, 95% confidence interval [CI]: 0.28-0.98, p = 0.042). After adjustment for gender, age, AAo diameter, sinuses of Valsalva diameter, preoperative LVEF, Sievers subtypes, BAV valvulopathy, and CPB and cross-clamp times, conformance to the 45 mm size criterion still predicted lower incidence of early adverse events (HR: 0.37, 95% CI: 0.15-0.90, p = 0.028). CONCLUSIONS: This study shows that conformance to 45 mm size cutoff for preemptive AAR during aortic valve replacement in patients with BAV was not associated with increased risk for adverse events and may improve early surgical outcomes.

5.
JCI Insight ; 6(2)2021 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-33491667

RESUMO

To date, there are no inhibitors that directly and specifically target activated STAT3 and c-Myc in the clinic. Although peptide-based inhibitors can selectively block activated targets, their clinical usage is limited because of low cell penetration and/or serum stability. Here, we generated cell-penetrating acetylated (acet.) STAT3, c-Myc, and Gp130 targeting peptides by attaching phosphorothioated (PS) polymer backbone to peptides. The cell-penetrating peptides efficiently penetrated cells and inhibited activation of the intended targets and their downstream genes. Locally or systemically treating tumor-bearing mice with PS-acet.-STAT3 peptide at low concentrations effectively blocked STAT3 in vivo, resulting in significant antitumor effects in 2 human xenograft models. Moreover, PS-acet.-STAT3 peptide penetrated and activated splenic CD8+ T cells in vitro. Treating immune-competent mice bearing mouse melanoma with PS-acet.-STAT3 peptide inhibited STAT3 in tumor-infiltrating T cells, downregulating tumor-infiltrating CD4+ T regulatory cells while activating CD8+ T effector cells. Similarly, systemic injections of the cell-penetrating c-Myc and Gp130 peptides prevented pancreatic tumor growth and induced antitumor immune responses. Taken together, we have developed therapeutic peptides that effectively and specifically block challenging cancer targets, resulting in antitumor effects through both direct tumor cell killing and indirectly through antitumor immune responses.


Assuntos
Antineoplásicos/farmacologia , Peptídeos Penetradores de Células/farmacologia , Fator de Transcrição STAT3/antagonistas & inibidores , Acetilação , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Peptídeos Penetradores de Células/química , Receptor gp130 de Citocina/química , Desenho de Fármacos , Células HCT116 , Humanos , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/imunologia , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/imunologia , Melanoma Experimental/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias Pancreáticas/tratamento farmacológico , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/farmacologia , Multimerização Proteica , Proteínas Proto-Oncogênicas c-myc/química , Proteínas Proto-Oncogênicas c-myc/farmacologia , Fator de Transcrição STAT3/química , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Front Oncol ; 10: 589601, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33335857

RESUMO

Despite significant progress in cancer therapy over the last decades, ovarian cancer remains the most lethal gynecologic malignancy worldwide with the five-year overall survival rate less than 30% due to frequent disease recurrence and chemoresistance. CD44 is a non-kinase transmembrane receptor that has been linked to cancer metastatic progression, cancer stem cell maintenance, and chemoresistance development via multiple mechanisms across many cancers, including ovarian, and represents a promising therapeutic target for ovarian cancer treatment. Moreover, CD44-mediated signaling interacts with other well-known pro-tumorigenic pathways and oncogenes during cancer development, such as signal transducer and activator of transcription 3 (STAT3). Given that both CD44 and STAT3 are strongly implicated in the metastatic progression and chemoresistance of ovarian tumors, this review summarizes currently available evidence about functional crosstalk between CD44 and STAT3 in human malignancies with an emphasis on ovarian cancer. In addition to the role of tumor cell-intrinsic CD44 and STAT3 interaction in driving cancer progression and metastasis, we discuss how CD44 and STAT3 support the pro-tumorigenic tumor microenvironment and promote tumor angiogenesis, immunosuppression, and cancer metabolic reprogramming in favor of cancer progression. Finally, we review the current state of therapeutic CD44 targeting and propose superior treatment possibilities for ovarian cancer.

7.
Cell Metab ; 31(1): 148-161.e5, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31761565

RESUMO

Although obesity is known to be critical for cancer development, how obesity negatively impacts antitumor immune responses remains largely unknown. Here, we show that increased fatty acid oxidation (FAO) driven by activated STAT3 in CD8+ T effector cells is critical for obesity-associated breast tumor progression. Ablating T cell Stat3 or treatment with an FAO inhibitor in obese mice spontaneously developing breast tumor reduces FAO, increases glycolysis and CD8+ T effector cell functions, leading to inhibition of breast tumor development. Moreover, PD-1 ligation in CD8+ T cells activates STAT3 to increase FAO, inhibiting CD8+ T effector cell glycolysis and functions. Finally, leptin enriched in mammary adipocytes and fat tissues downregulates CD8+ T cell effector functions through activating STAT3-FAO and inhibiting glycolysis. We identify a critical role of increased oxidation of fatty acids driven by leptin and PD-1 through STAT3 in inhibiting CD8+ T effector cell glycolysis and in promoting obesity-associated breast tumorigenesis.


Assuntos
Neoplasias da Mama/imunologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Carcinogênese/imunologia , Ácidos Graxos/metabolismo , Obesidade/metabolismo , Fator de Transcrição STAT3/metabolismo , Adipócitos/metabolismo , Tecido Adiposo/metabolismo , Animais , Neoplasias da Mama/metabolismo , Carcinogênese/genética , Carcinogênese/metabolismo , Linhagem Celular , Proliferação de Células/genética , Imunoprecipitação da Cromatina , Feminino , Glicólise/genética , Glicólise/fisiologia , Humanos , Interferon gama/metabolismo , Leptina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Obesidade/imunologia , Oxirredução/efeitos dos fármacos , Receptor de Morte Celular Programada 1/metabolismo , Fator de Transcrição STAT3/genética
8.
JCI Insight ; 4(14)2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31341104

RESUMO

Despite their well-recognized success in the clinic, antibodies generally do not penetrate cellular membranes to target intracellular molecules, many of which underlie incurable diseases. Here we show that covalently conjugating phosphorothioated DNA oligonucleotides to antibodies enabled their efficient cellular internalization. Antibody cell penetration was partially mediated by membrane potential alteration. Moreover, without an antigen to bind, intracellular levels of the modified antibodies underwent cellular clearance, which involved efflux and lysosomal degradation, enabling detection of intended intracellular molecules as tested in fibroblasts, tumor cells, and T cells. This target-dependent cellular retention of modified antibodies extended to in vivo studies. Both local and systemic administrations of low doses of modified antibodies effectively inhibited intracellular targets, such as transcription factors Myc, interferon regulatory factor 4, and tyrosine-protein kinase SRC, and expression of their downstream genes in tumors, resulting in tumor cell apoptosis and tumor growth inhibition. This simple modification enables the use of antibodies to detect and modulate intracellular molecules in both cultured living cells and in whole animals, forming the foundation for a new paradigm for antibody-based research, diagnostics, and therapeutics.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Permeabilidade da Membrana Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos/métodos , Imunoconjugados/administração & dosagem , Oligodesoxirribonucleotídeos/farmacologia , Animais , Anticorpos Monoclonais/química , Linhagem Celular Tumoral , Humanos , Imunoconjugados/química , Imunoconjugados/farmacologia , Melanoma/tratamento farmacológico , Melanoma/patologia , Camundongos , Oligodesoxirribonucleotídeos/química , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Cell Chem Biol ; 26(2): 278-288.e6, 2019 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-30581133

RESUMO

Ubiquitin-like (Ubl) post-translational modifications are potential targets for therapeutics. However, the only known mechanism for inhibiting a Ubl-activating enzyme is through targeting its ATP-binding site. Here we identify an allosteric inhibitory site in the small ubiquitin-like modifier (SUMO)-activating enzyme (E1). This site was unexpected because both it and analogous sites are deeply buried in all previously solved structures of E1s of ubiquitin-like modifiers (Ubl). The inhibitor not only suppresses SUMO E1 activity, but also enhances its degradation in vivo, presumably due to a conformational change induced by the compound. In addition, the lead compound increased the expression of miR-34b and reduced c-Myc levels in lymphoma and colorectal cancer cell lines and a colorectal cancer xenograft mouse model. Identification of this first-in-class inhibitor of SUMO E1 is a major advance in modulating Ubl modifications for therapeutic aims.


Assuntos
Sumoilação , Enzimas Ativadoras de Ubiquitina/antagonistas & inibidores , Regulação Alostérica , Sítio Alostérico , Animais , Linhagem Celular Tumoral , Ensaios de Triagem em Larga Escala , Humanos , Camundongos , Camundongos SCID , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Sumoilação/efeitos dos fármacos , Transplante Heterólogo , Ubiquitina/metabolismo , Enzimas Ativadoras de Ubiquitina/metabolismo , Ubiquitinação/efeitos dos fármacos
10.
Nucleic Acids Res ; 46(14): 7108-7123, 2018 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-29893976

RESUMO

The miR-34 family of microRNAs suppresses the expression of proteins involved in pluripotency and oncogenesis. miR-34 expression is frequently reduced in cancers; however, the regulation of their expression is not well understood. We used genome-wide miRNA profiling and mechanistic analysis to show that SUMOylation regulates miR-34b/c expression, which impacts the expression of c-Myc and other tested miR-34 targets. We used site-directed mutagenesis and other methods to show that protein kinase B (also known as Akt) phosphorylation of FOXO3a plays an important role in SUMOylation-dependent expression of miR-34b/c. This study reveals how the miR-34-targeted gene expression program is regulated by SUMOylation and shows that SUMOylation need not regulate target proteins through direct modification, but instead can act through the expression of their targeting miRNAs.


Assuntos
Regulação Neoplásica da Expressão Gênica , MicroRNAs/metabolismo , Sumoilação , Animais , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Proteína Forkhead Box O3/metabolismo , Camundongos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Enzimas Ativadoras de Ubiquitina
12.
Biochemistry ; 57(11): 1807-1813, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29481054

RESUMO

Streptonigrin (CAS no. 3930-19-6) is a natural product shown to have antitumor activities in clinical trials conducted in the 1960s-1970s. However, its use in clinical studies eventually faded, and the molecular mechanisms of streptonigrin antitumor effects remain poorly defined. Despite its lack of current clinical use, efforts on its total synthesis have continued. Here, we show that streptonigrin binds and inhibits the SUMO-specific protease SENP1. NMR studies identified that streptonigrin binds to SENP1 on the surface where SUMO binds and disrupts SENP1-SUMO1 interaction. Site-directed mutations in combination with NMR chemical shift perturbation suggest key roles of aromatic π stacking interactions in binding streptonigrin. Treatment of cells with streptonigrin resulted in increased global SUMOylation levels and reduced level of hypoxia inducible factor alpha (HIF1α). These findings inform both the design of SENP1 targeting strategy and the modification of streptonigrin to improve its efficacy for possible future clinical use.


Assuntos
Cisteína Endopeptidases , Subunidade alfa do Fator 1 Induzível por Hipóxia , Proteína SUMO-1 , Estreptonigrina , Sumoilação/efeitos dos fármacos , Linhagem Celular Tumoral , Cisteína Endopeptidases/química , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/química , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Espectroscopia de Ressonância Magnética , Proteína SUMO-1/química , Proteína SUMO-1/genética , Proteína SUMO-1/metabolismo , Estreptonigrina/química , Estreptonigrina/farmacologia , Sumoilação/genética
13.
Cell Metab ; 27(1): 136-150.e5, 2018 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-29249690

RESUMO

Cancer stem cells (CSCs) are critical for cancer progression and chemoresistance. How lipid metabolism regulates CSCs and chemoresistance remains elusive. Here, we demonstrate that JAK/STAT3 regulates lipid metabolism, which promotes breast CSCs (BCSCs) and cancer chemoresistance. Inhibiting JAK/STAT3 blocks BCSC self-renewal and expression of diverse lipid metabolic genes, including carnitine palmitoyltransferase 1B (CPT1B), which encodes the critical enzyme for fatty acid ß-oxidation (FAO). Moreover, mammary-adipocyte-derived leptin upregulates STAT3-induced CPT1B expression and FAO activity in BCSCs. Human breast-cancer-derived data suggest that the STAT3-CPT1B-FAO pathway promotes cancer cell stemness and chemoresistance. Blocking FAO and/or leptin re-sensitizes them to chemotherapy and inhibits BCSCs in mouse breast tumors in vivo. We identify a critical pathway for BCSC maintenance and breast cancer chemoresistance.


Assuntos
Neoplasias da Mama/patologia , Autorrenovação Celular , Resistencia a Medicamentos Antineoplásicos , Janus Quinases/metabolismo , Células-Tronco Neoplásicas/patologia , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Adipócitos/metabolismo , Idoso , Animais , Neoplasias da Mama/genética , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Linhagem Celular Tumoral , Ácidos Graxos/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Leptina/metabolismo , Metabolismo dos Lipídeos/genética , Metabolômica , Camundongos , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/metabolismo , Oxirredução , Transcrição Genética
14.
Chin Med J (Engl) ; 129(22): 2683-2690, 2016 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-27824000

RESUMO

BACKGROUND: Among HIV-infected patients initiating antiretroviral therapy (ART), early changes in CD4+ T-cell subsets are well described. However, HIV-infected late presenters initiating treatment present with a suboptimal CD4+ T-cell reconstitution and remain at a higher risk for AIDS and non-AIDS events. Therefore, factors associated with CD4+ T-cell reconstitution need to be determined in this population, which will allow designing effective immunotherapeutic strategies. METHODS: Thirty-one adult patients with baseline CD4+ T-cell count <350 cells/mm3 exhibiting viral suppression after ART initiation were followed in the HIV/AIDS research center of Peking Union Medical College Hospital in Beijing, China, from October 2002 to September 2013. Changes in T-cell subsets and associated determinants were measured. RESULTS: Median baseline CD4+ T-cell count was 70 cells/mm3. We found a biphasic reconstitution of T-cell subsets and immune activation: a rapid change during the first 6 months followed by a more gradual change over the subsequent 8 years. Baseline CD4+ T-cell count >200 cells/mm3 in comparison to CD4+ T-cell count ≤200 cells/mm3 was associated with more complete immune Reconstitution (77.8% vs. 27.3% respectively; P = 0.017) and normalized CD4/CD8 ratio. We showed that the baseline percentage of naive CD4+ T-cell was a predictive marker for complete immune reconstitution (area under receiver operating characteristic curve 0.907), and 12.4% as cutoff value had a sensitivity of 84.6% and a specificity of 88.2%. CONCLUSIONS: Baseline naive CD4+ T-cell percentage may serve as a predictive marker for optimal immune reconstitution during long-term therapy. Such study findings suggest that increasing thymic output should represent an avenue to improve patients who are diagnosed late in the course of infection.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Adulto , Terapia Antirretroviral de Alta Atividade/métodos , Contagem de Linfócito CD4 , Relação CD4-CD8 , Feminino , Infecções por HIV/metabolismo , HIV-1/efeitos dos fármacos , HIV-1/imunologia , HIV-1/patogenicidade , Humanos , Masculino , Estudos Prospectivos , Subpopulações de Linfócitos T/imunologia
15.
Nat Commun ; 7: 12326, 2016 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-27465491

RESUMO

Cancer stem cells (CSCs) have key roles in treatment resistance, tumour metastasis and relapse. Using colorectal cancer (CC) cell lines, patient-derived xenograft (PDX) tissues and patient tissues, here we report that CC CSCs, which resist chemoradiation, have higher SUMO activating enzyme (E1) and global SUMOylation levels than non-CSCs. Knockdown of SUMO E1 or SUMO conjugating enzyme (E2) inhibits CC CSC maintenance and self-renewal, while overexpression of SUMO E1 or E2 increases CC cell stemness. We found that SUMOylation regulates CSCs through Oct-1, a transcription factor for aldehyde dehydrogenases (ALDHs). ALDH activity is not only a marker for CSCs but also important in CSC biology. SUMO does not modify Oct-1 directly, but regulates the expression of TRIM21 that enhances Oct-1 ubiquitination and, consequently, reducing Oct-1 stability. In summary, our findings suggest that SUMOylation could be a target to inhibit CSCs and ultimately to reduce treatment resistance, tumour metastasis and relapse.


Assuntos
Carcinoma/enzimologia , Autorrenovação Celular , Neoplasias Colorretais/enzimologia , Células-Tronco Neoplásicas/enzimologia , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo , Aldeído Desidrogenase/metabolismo , Animais , Células HCT116 , Células HT29 , Humanos , Camundongos , Fator 1 de Transcrição de Octâmero/metabolismo , Ribonucleoproteínas/metabolismo , Sumoilação , Ubiquitina-Proteína Ligases/metabolismo
16.
Data Brief ; 7: 195-200, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27408909

RESUMO

Post-translational modifications by the small ubiquitin-like modifiers (SUMO), in particular the formation of poly-SUMO-2 and -3 chains, regulates essential cellular functions and its aberration leads to life-threatening diseases (Geoffroy and Hay, 2009) [1]. It was shown previously that the non-covalent interaction between SUMO and the conjugating enzyme (E2) for SUMO, known as Ubc9, is required for poly-SUMO-2/3 chain formation (Knipscheer et al., 2007) [2]. However, the structure of SUMO-Ubc9 non-covalent complex, by itself, could not explain how the poly-SUMO-2/3 chain forms and consequently a Ubc9 homodimer, although never been observed, was proposed for poly-SUMO-2/3 chain formation (Knipscheer et al., 2007) [2]. Here, we solved the crystal structure of a heterotrimer containing a homodimer of Ubc9 and the RWD domain from RWDD3. The asymmetric Ubc9 homodimer is mediated by the N-terminal region of one Ubc9 molecule and a surface near the catalytic Cys of the second Ubc9 molecule (Fig. 1A). This N-terminal surface of Ubc9 that is involved in the homodimer formation also interacts with the RWD domain, the ubiquitin-fold domain of the SUMO activating enzyme (E1), SUMO, and the E3 ligase, RanBP2 (Knipscheer et al., 2007; Tong et al.. 1997; Tatham et al., 2005; Reverter and Lima, 2005; Capili and Lima, 2007; Wang et al., 2009, 2010; Wang and Chen, 2010; Alontaga et al., 2015) [2], [3], [4], [5], [6], [7], [8], [9], [10]. The existence of the Ubc9 homodimer in solution is supported by previously published solution NMR studies of rotational correlation time and chemical shift perturbation (Alontaga et al., 2015; Yuan et al., 1999) [10], [11]. Site-directed mutagenesis and biochemical analysis suggests that this dimeric arrangement of Ubc9 is likely important for poly-SUMO chain formation (Fig. 1B and C). The asymmetric Ubc9 homodimer described for the first time in this work could provide the critical missing link in the poly-SUMO chain formation mechanism. The data presented here are related to the research article entitled, "RWD domain as an E2 (Ubc9) interaction module" (Alontaga et al., 2015) [10]. The data of the crystal structure has been deposited to RCSB protein data bank with identifier: 4Y1L.

17.
Medicine (Baltimore) ; 95(15): e3401, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27082616

RESUMO

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital coronary abnormality associated with early infant mortality and sudden death in adults. Transthoracic echocardiography (TTE) plays an important role in early detection and diagnosis of ALCAPA as a noninvasive modality. However, its diagnostic value is not well studied. The purpose of this study is to determine the performance of TTE in the diagnostic assessment of ALCAPA as compared with coronary CT and invasive coronary angiography. A total of 22 patients (13 women and 9 men, mean age, 12.9 ±â€Š19.5 years) with ALCAPA who underwent echocardiographic examination for clinical diagnosis were retrospectively reviewed and analyzed. Transthoracic echocardiographic features of ALCAPA were analyzed and its diagnostic value was compared with invasive coronary angiography and coronary CT angiography (CTA) with surgical findings serving as the gold standard. Surgery was performed in all of the patients to establish the dual coronary artery system. Five underwent the Takeuchi procedure and 17 had re-implantation of the anomalous left coronary artery. Of 20 patients, echocardiographic diagnoses were in good agreement with findings at surgery, resulting in the diagnostic accuracy of 90.9%. Two cases were misdiagnosed-one as the right coronary artery to pulmonary artery fistula and the other as rheumatic heart disease. The echocardiographic features of these patients with ALCAPA included: abnormal left coronary ostium arising from the pulmonary trunk with retrograde coronary artery flow in 20 patients; enlargement of the right coronary artery in 17 patients; abundant intercoronary septal collaterals in 17 patients; and moderate and significant mitral regurgitation in 14 patients. The diagnostic accuracy of invasive coronary angiography (in 17 patients) and coronary CTA (in 9 patients) was 100%. This study shows that TTE is an accurate, noninvasive imaging modality for displaying the origin of coronary arteries and demonstrating the coronary courses as well as other associated abnormalities in patients with ALCAPA.


Assuntos
Síndrome de Bland-White-Garland/diagnóstico por imagem , Síndrome de Bland-White-Garland/diagnóstico , Adolescente , Adulto , Criança , Pré-Escolar , Ecocardiografia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto Jovem
18.
Ultrasound Med Biol ; 42(1): 272-81, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26520563

RESUMO

Speckle-tracking echocardiography was used to assess retrograde coronary venous infusion of mesenchymal stem cells (MSCs) combined with basic fibroblast growth factor (bFGF) in a canine model of acute myocardial infarction (AMI). AMI was induced by ligation of the left anterior descending coronary artery. Coronary venous retroperfusion was performed at 1 wk after AMI. Twenty-eight animals were randomized into four groups: saline, bFGF+saline, saline+MSCs and bFGF+MSCs. Echocardiography was performed before AMI, at 7 d post-AMI and 40 d after retroperfusion. Apoptotic cardiomyocytes in the border zone of the ischemic region were evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling. Vascular endothelial growth factor and factor VIII concentrations were measured by western blotting. The left ventricular end-systolic volume increased significantly, whereas the left ventricular ejection fraction and global and segmental strain values decreased significantly after AMI. After retroperfusion, the strain values of the infarct zone, but not conventional echocardiographic parameters, were significantly different between control and bFGF+MSC groups. Cardiomyocyte apoptosis decreased, whereas vascular endothelial growth factor and factor VIII concentrations were higher in the bFGF+MSC, bFGF and MSC groups. Cardiomyocyte apoptosis was well correlated with the strain values. Although retrograde coronary venous infusion of bFGF and MSCs promoted neo-vascularization of the infarcted myocardium and inhibited apoptosis, there was only a slight strain improvement without a substantial increase in global cardiac functions.


Assuntos
Vasos Coronários/diagnóstico por imagem , Fator 2 de Crescimento de Fibroblastos/uso terapêutico , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais , Infarto do Miocárdio/terapia , Doença Aguda , Animais , Western Blotting , Modelos Animais de Doenças , Cães , Feminino , Marcação In Situ das Extremidades Cortadas , Masculino , Infarto do Miocárdio/diagnóstico por imagem , Cloreto de Sódio/administração & dosagem , Ultrassonografia
19.
Sci Rep ; 5: 17808, 2015 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-26643614

RESUMO

We have recently identified a chemotype of small ubiquitin-like modifier (SUMO)-specific protease (SENP) inhibitors. Prior to the discovery of their SENP inhibitory activity, these compounds were found to inhibit HIV replication, but with an unknown mechanism. In this study, we investigated the mechanism of how these compounds inhibit HIV-1. We found that they do not affect HIV-1 viral production, but significantly inhibited the infectivity of the virus. Interestingly, virions produced from cells treated with these compounds could gain entry and carry out reverse transcription, but could not efficiently integrate into the host genome. This phenotype is different from the virus produced from cells treated with the class of anti-HIV-1 agents that inhibit HIV protease. Upon removal of the SUMO modification sites in the HIV-1 integrase, the compound no longer alters viral infectivity, indicating that the effect is related to SUMOylation of the HIV integrase. This study identifies a novel mechanism for inhibiting HIV-1 integration and a new class of small molecules that inhibits HIV-1 via such mechanism that may contribute a new strategy for cure of HIV-1 by inhibiting the production of infectious virions upon activation from latency.


Assuntos
Antivirais/farmacologia , HIV-1/efeitos dos fármacos , HIV-1/fisiologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Integrase de HIV/metabolismo , Inibidores de Integrase de HIV/farmacologia , Humanos , Sumoilação/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
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