RESUMEN
BACKGROUND: Deregulation of receptor tyrosine kinases (RTK) contributes to the initiation and progression of intestinal-derived epithelial cancers, including colorectal cancer (CRC). However, the roles of the proximal signaling molecules engaged by RTKs in different oncogenic functions of CRC remain unclear. METHODS: Herein, the functional impact of expressing variant forms of the oncogenic Met receptor (Tpr-Met) that selectively recruit the adaptor proteins Grb2 or Shc was investigated in a model derived from normal intestinal epithelial cells (IEC-6). An RNA interference (RNAi) approach was used to define the requirement of Grb2 or Shc in Tpr-Met-transformed IEC-6 cells. Since Grb2 and Shc couple RTKs to the activation of the Ras/MEK/Erk and PI3K/Akt pathways, Erk and Akt phosphorylation/activation states were monitored in transformed IEC-6 cells, and a pharmacological approach was employed to provide insights into the roles of these pathways in oncogenic processes evoked by activated Met, and downstream of Grb2 and Shc. RESULTS: We show, for the first time, that constitutive activation of either Grb2 or Shc signals in IEC-6 cells, promotes morphological transformation associated with down-regulation of E-cadherin, as well as increased cell growth, loss of growth contact inhibition, anchorage-independent growth, and resistance to serum deprivation and anoikis. Oncogenic activation of Met was revealed to induce morphological transformation, E-cadherin down-regulation, and protection against anoikis by mechanisms dependent on Grb2, while Shc was shown to be partly required for enhanced cell growth. The coupling of activated Met to the Ras/MEK/Erk and PI3K/Akt pathways, and the sustained engagement of Grb2 or Shc in IECs, was shown to trigger negative feedback, limiting the extent of activation of these pathways. Nonetheless, morphological alterations and E-cadherin down-regulation induced by the oncogenic Tpr-Met, and by Grb2 or Shc signals, were blocked by MEK, but not PI3K, inhibitors while the enhanced growth and resistance to anoikis induced by Tpr-Met were nearly abolished by co-treatment with both inhibitors. CONCLUSION: Overall, these results identify Grb2 and Shc as central signaling effectors of Met-driven progression of intestinal epithelial-derived cancers. Notably, they suggest that Grb2 may represent a promising target for the design of novel CRC therapies.
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Neoplasias Colorrectales/genética , Proteína Adaptadora GRB2/biosíntesis , Proteínas Proto-Oncogénicas c-met/metabolismo , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Cadherinas/metabolismo , Línea Celular , Transformación Celular Neoplásica/genética , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/terapia , Células Epiteliales/metabolismo , Proteína Adaptadora GRB2/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Mucosa Intestinal/metabolismo , Intestinos/patología , Proteínas Proto-Oncogénicas c-met/genética , Proteínas Adaptadoras de la Señalización Shc/metabolismo , Transducción de Señal/genéticaRESUMEN
RATIONALE: Inactivation of the p66Shc adaptor protein confers resistance to oxidative stress and protects mice from aging-associated vascular diseases. However, there is limited information about the negative regulating mechanisms of p66Shc expression in the vascular system. OBJECTIVE: In this study, we investigated the role of SIRT1, a class III histone deacetylase, in the regulation of p66Shc expression and hyperglycemia-induced endothelial dysfunction. METHODS AND RESULTS: Expressions of p66Shc gene transcript and protein were significantly increased by different kinds of class III histone deacetylase (sirtuin) inhibitors in human umbilical vein endothelial cells and 293A cells. Adenoviral overexpression of SIRT1 inhibited high-glucose-induced p66Shc upregulation in human umbilical vein endothelial cells. Knockdown of SIRT1 increased p66Shc expression and also increased the expression levels of plasminogen activator inhibitor-1 expression, but decreased manganese superoxide dismutase expression in high-glucose conditions. However, knockdown of p66Shc significantly reversed the effects of SIRT1 knockdown. In addition, p66Shc overexpression significantly decreased manganese superoxide dismutase expression and increased plasminogen activator inhibitor-1 expression in high-glucose conditions, which were recovered by SIRT1 overexpression. Moreover, compared to streptozotocin-induced wild-type diabetic mice, endothelium-specific SIRT1 transgenic diabetic mice had decreased p66Shc expression at both the mRNA and the protein levels, improved endothelial function, and reduced accumulation of nitrotyrosine and 8-OHdG (markers of oxidative stress). We further found that SIRT1 was able to bind to the p66Shc promoter (-508 bp to -250 bp), resulting in a decrease in the acetylation of histone H3 bound to the p66Shc promoter region. CONCLUSION: Our findings indicate that repression of p66Shc expression by SIRT1 contributes to the protection of hyperglycemia-induced endothelial dysfunction.
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Regulación hacia Abajo/genética , Endotelio Vascular/metabolismo , Hiperglucemia/genética , Proteínas Adaptadoras de la Señalización Shc/antagonistas & inhibidores , Sirtuina 1/fisiología , Envejecimiento/genética , Animales , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Endotelio Vascular/patología , Células HEK293 , Humanos , Hiperglucemia/patología , Hiperglucemia/prevención & control , Inmunidad Innata/genética , Masculino , Ratones , Ratones Transgénicos , Estrés Oxidativo/genética , Estabilidad Proteica , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de SrcRESUMEN
Previously, we have identified a panel of breast cancer antiestrogen resistance (BCAR) genes. Several of these genes have clinical relevance because mRNA or protein levels associate with tamoxifen resistance or tumor aggressiveness. We postulated that changes in activation status of protein signaling networks induced by BCAR genes may provide better insight into the mechanisms underlying antiestrogen resistance. Key signal transduction pathways were analyzed for changes in activation or expression using reverse-phase protein microarrays probed with 78 antibodies against signaling proteins with known roles in tumorigenesis. We used ZR-75-1-derived cell lines transduced with AKT1, AKT2, BCAR1, BCAR3, BCAR4, EGFR, GRB7, HRAS, HRAS(v12) or HEF1 and MCF7-derived cell lines transduced with BCAR3, BCAR4 or EGFR. In the antiestrogen-resistant cell lines, we observed increased phosphorylation of several pathways involved in cell proliferation and survival. All tamoxifen-resistant cell lines contained high levels of phosphorylated AKT and its biochemically linked substrates Forkhead box O1/3. The activation of ERBB2, ERBB3 and the downstream modulators focal adhesion kinase and SHC were activated in cells with overexpression of BCAR4. Remarkable differences were observed for the levels of activated AMPK alpha1, cyclins, STAT5, STAT6, ERK1/2 and BCL2. The comparison of the cell signaling networks in estrogen-dependent and -independent cell lines revealed biochemically linked kinase-substrate markers that comprised systemically activated signaling pathways involved in tamoxifen resistance. Our results show that this model provides insights into the molecular and cellular mechanisms of breast cancer progression and antiestrogen resistance. This knowledge may help the development of novel targeted treatments.
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Neoplasias de la Mama/metabolismo , Resistencia a Antineoplásicos , Moduladores de los Receptores de Estrógeno/farmacología , Mapeo de Interacción de Proteínas , Transducción de Señal , Tamoxifeno/farmacología , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Neoplasias de la Mama/tratamiento farmacológico , Línea Celular Tumoral , Proliferación Celular , Supervivencia Celular , Proteína Sustrato Asociada a CrK/genética , Receptor alfa de Estrógeno/metabolismo , Femenino , Proteína-Tirosina Quinasas de Adhesión Focal/biosíntesis , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Fosforilación , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptor ErbB-2/metabolismo , Proteínas Adaptadoras de la Señalización Shc/biosíntesisRESUMEN
The adaptor protein Shc is phosphorylated downstream of many cell surface receptors, including Ag and cytokine receptors. However, the role of Shc in B cell development has not been addressed. Here, through conditional expression of a dominant negative Shc mutant and conditional loss of Shc protein expression, we tested a role for Shc during early B lymphopoiesis. We identified a requirement for Shc beginning at the transition from the pre-pro-B to pro-B stage, with a strong reduction in the number of pre-B cells. This developmental defect is due to increased cell death rather than impaired proliferation or commitment to the B lineage. Additional studies suggest a role for Shc in IL-7-dependent signaling in pro-B cells. Shc is phosphorylated in response to IL-7 stimulation in pro-B cells, and pro-B cells from mice with impaired Shc signaling display increased apoptosis. Together, these data demonstrate a critical role for Shc in early B lymphopoiesis with a requirement in early B cell survival. In addition, we also identify Shc as a required player in signaling downstream of the IL-7R in early B cells.
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Diferenciación Celular/inmunología , Células Precursoras de Linfocitos B/citología , Células Precursoras de Linfocitos B/metabolismo , Proteínas Adaptadoras de la Señalización Shc/fisiología , Animales , Diferenciación Celular/genética , Supervivencia Celular/genética , Supervivencia Celular/inmunología , Marcación de Gen , Ratones , Ratones Noqueados , Ratones Transgénicos , Mutación , Células Precursoras de Linfocitos B/inmunología , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Proteínas Adaptadoras de la Señalización Shc/deficiencia , Proteínas Adaptadoras de la Señalización Shc/genética , Transducción de Señal/genética , Transducción de Señal/inmunología , Células Madre/citología , Células Madre/inmunología , Células Madre/metabolismoRESUMEN
Esophageal cancer (EC) is known as a type of common malignant tumor, with the incidence ranking eighth worldwide. Because of the high metastasis of advanced EC, the total survival rate has been quite low. Esophageal squamous cell carcinoma (ESCC) is a main type of EC. Targeted therapy for ESCC has become a new direction; however, newly therapeutic targets are also badly needed. Shc SH2 domain-binding protein (SHCBP1) is located on 16q11.2, which is a downstream protein of the Shc adaptor. SHCBP1 participates in the regulation of several physiological and pathologic processes, such as cytokinesis. Recent studies have found that SHCBP1 was abnormally upregulated in multiple types of tumors, such as breast cancer and liver cancer, and that it affects the proliferation and motility of cancer cells in vitro. However, it remains unclear whether SHCBP1 is related to the progression of EC. Herein, we found the upregulation of SHCBP1 in human EC tissues. Our findings further demonstrated that SHCBP1 expression was related to the clinical features of ESCC patients. We found that SHCBP1 depletion inhibited the proliferation and motility of ESCC cells via the transforming growth factor ß pathway and that it suppressed the growth of tumors in mice. We, therefore, concluded that SHCBP1 could serve as a promising EC molecular target.
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Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas de Esófago/metabolismo , Regulación Neoplásica de la Expresión Génica , Proteínas de Neoplasias/metabolismo , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Transducción de Señal , Factor de Crecimiento Transformador beta/metabolismo , Línea Celular Tumoral , Neoplasias Esofágicas/patología , Carcinoma de Células Escamosas de Esófago/patología , HumanosRESUMEN
The transcription factor, p53, and the adaptor protein, p66shc, both play essential roles in promoting oxidative stress in the vascular system. However, the relationship between the two in the context of endothelium-dependent vascular tone is unknown. Here, we report a novel, evolutionarily conserved, p53-mediated transcriptional mechanism that regulates p66shc expression and identify p53 as an important determinant of endothelium-dependent vasomotor function. We provide evidence of a p53 response element in the promoter of p66shc and show that angiotensin II-induced upregulation of p66shc in endothelial cells is dependent on p53. In addition, we demonstrate that downregulation of p66shc expression, as well as inhibition of p53 function in mice, mitigates angiotensin II-induced impairment of endothelium-dependent vasorelaxation, decrease in bioavailable nitric oxide, and hypertension. These findings reveal a novel p53-dependent transcriptional mechanism for the regulation of p66shc expression that is operative in the vascular endothelium and suggest that this mechanism is important in impairing endothelium-dependent vascular relaxation.
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Endotelio Vascular/fisiopatología , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Transcripción Genética/fisiología , Proteína p53 Supresora de Tumor/fisiología , Regulación hacia Arriba/fisiología , Sistema Vasomotor/fisiopatología , Animales , Línea Celular , Endotelio Vascular/metabolismo , Endotelio Vascular/fisiología , Humanos , Ratones , Ratas , Ratas Endogámicas WKY , Proteínas Adaptadoras de la Señalización Shc/genética , Proteínas Adaptadoras de la Señalización Shc/fisiología , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src , Vasodilatación/genética , Vasodilatación/fisiología , Sistema Vasomotor/fisiologíaRESUMEN
Gliomas are the most common primary brain tumors. Because of their high degree of malignancy, patient survival rates are unsatisfactory. Therefore, exploring glioma biomarkers will play a key role in early diagnosis, guiding treatment, and monitoring the prognosis of gliomas. We found two lncRNAs, six miRNAs, and nine mRNAs that were differentially expressed by analyzing genomic data of glioma patients. The diagnostic value of mRNA expression levels in gliomas was determined by receiver operating characteristic (ROC) curve analysis. Among the nine mRNAs, the area under the ROC curve values of only CEP55 and SHCBP1 were >0.7, specifically 0.834 and 0.816, respectively. Additionally, CEP55 and SHCBP1 were highly expressed in glioma specimens and showed increased expression according to the glioma grade, and outcomes of high expression patients were poor. CEP55 was enriched in the cell cycle, DNA replication, mismatch repair, and P53 signaling pathway. SHCBP1 was enriched in the cell cycle, DNA replication, ECM receptor interaction, and P53 signaling pathway. Age, grade, IDH status, chromosome 19/20 cogain, and SHCBP1 were independent factors for prognosis. Our findings suggest the PART1-hsa-miR-429-SHCBP1 regulatory network plays an important role in gliomas.
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Neoplasias Encefálicas , Regulación Neoplásica de la Expresión Génica , Glioma , MicroARNs/biosíntesis , Proteínas de Neoplasias/biosíntesis , ARN Neoplásico/biosíntesis , ARN no Traducido/biosíntesis , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/mortalidad , Neoplasias Encefálicas/patología , Supervivencia sin Enfermedad , Femenino , Glioma/metabolismo , Glioma/mortalidad , Glioma/patología , Humanos , Masculino , Persona de Mediana Edad , Tasa de SupervivenciaRESUMEN
Papillary thyroid carcinoma (PTC) is the most common thyroid cancer with a rapidly increasing incidence globally. Bioinformatics analyses suggested that SHCBP1 (SHC SH2 Domain-Binding Protein 1) was significantly up-regulated in PTC tumor tissues, which was further confirmed by immunohistochemical staining and qPCR analyses in Xuzhou cohort. Moreover, the results indicated that the mRNA level of SHCBP1 was negatively associated with patients' disease-free survival rate, and further analysis reveals that patients with high SHCBP1 expression tend to have more lymph node metastasis. Afterward, MTT, colony formation, cell-cycle assay, FACS apoptosis assay, invasion, migration, as well as scratch assay were performed to study the phenotypes change of PTC cells after knocking down SHCBP1. The in vivo subcutaneous tumor model was developed to study the proliferation ability of PTC cells after SHCBP1 knockdown. We show that knock down of SHCBP1 significantly inhibits PTC cell proliferation, cell cycle, invasion and migration in vivo and in vitro. Western blot and qRT-PCR showed that knockdown of SHCBP1 could significantly reduce MYC, KLF4, CD44, ITGA6, ITGB1, ITGB5, and COL4A2 expression at both RNA and protein levels, which indicated that SHCBP1 might be involved in PTC carcinogenesis and progression through targeting formation of integrin and collagen and cell stemness pathways, and can be a potential diagnosis biomarker and therapeutic target for PTC.
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Colágeno/metabolismo , Integrinas/metabolismo , Células Madre Neoplásicas/metabolismo , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Cáncer Papilar Tiroideo/metabolismo , Neoplasias de la Tiroides/metabolismo , Animales , Biomarcadores de Tumor/biosíntesis , Biomarcadores de Tumor/deficiencia , Línea Celular Tumoral , Estudios de Cohortes , Progresión de la Enfermedad , Femenino , Humanos , Factor 4 Similar a Kruppel , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Invasividad Neoplásica/patología , Células Madre Neoplásicas/patología , Proteínas Adaptadoras de la Señalización Shc/deficiencia , Cáncer Papilar Tiroideo/patología , Neoplasias de la Tiroides/patologíaRESUMEN
OBJECTIVE: Prostate cancer (PCa) is an aggressive tumor. SHC SH2-domain-binding protein 1 (SHCBP1) has been identified frequently upregulated in various cancers, in addition to PCa. The aims of this study were to determine the relationships between SHCBP1 and clinicopathological characteristics of PCa and to explore the role of SHCBP1 in PCa proliferation and progression. METHODS: Tissue microarray and immunohistochemistry were used to determine the prognostic significance of SHCBP1. The relationship between clinicopathological characteristics of PCa and SHCBP1 was then analyzed using Cox regression analyses. To investigate SHCBP1 functions in vitro and in vivo, we knocked down SHCBP1 in PCa cell lines and established xenograft mice models. A series of cytological function assays were utilized to determine the role of SHCBP1 in cell proliferation, migration, invasion, and apoptosis. RESULTS: SHCBP1 was significantly upregulated in PCa tissues compared with BPH tissues. Patients with a higher expression of SHCBP1 were associated with poor survival outcomes than those with a lower expression of SHCBP1. Lentivirus-mediated shRNA knockdown of SHCBP1 in prostate cancer cell lines diminished cell growth, migration, and invasion dramatically both in vitro and in vivo, accompanied by an enhanced expression of large tumor suppressor 1 (LATS1) and tumor protein P53 (TP53) and inhibition of MDM2 proto-oncogene (MDM2), which suggested that SHCBP1 may promote proliferation and invasion in vitro via the LATS1-MDM2-TP53 pathway. The results of cycloheximide (CHX) and MG-132 assays indicated that SHCBP1 knockdown could attenuate the degradation of TP53 by the proteasome, prolong the half-life of TP53, and enhance the stabilization of TP53. CONCLUSION: These findings suggest that SHCBP1 overexpression contributes to PCa progression and that targeting SHCBP1 might be therapeutically beneficial to patients with PCa.
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Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Proteínas Adaptadoras de la Señalización Shc/metabolismo , Ciclo Celular/fisiología , Movimiento Celular/fisiología , Proliferación Celular/fisiología , Bases de Datos Genéticas , Regulación hacia Abajo , Técnicas de Silenciamiento del Gen , Xenoinjertos , Humanos , Inmunohistoquímica , Masculino , Células PC-3 , Pronóstico , Neoplasias de la Próstata/genética , Proteínas Serina-Treonina Quinasas/biosíntesis , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas c-mdm2/biosíntesis , Proteínas Proto-Oncogénicas c-mdm2/genética , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Proteínas Adaptadoras de la Señalización Shc/genética , Análisis de Matrices Tisulares , Proteína p53 Supresora de Tumor/biosíntesis , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Regulación hacia ArribaRESUMEN
We have identified a series of novel non-peptide compounds that activate the thrombopoietin-dependent cell line Ba/F3-huMPL. The compounds stimulated proliferation of Ba/F3-huMPL in the absence of other growth factors, but did not promote proliferation of the thrombopoietin-independent parent cell line Ba/F3. The thrombopoietin-mimetic compounds elicited signal-transduction responses comparable with recombinant human thrombopoietin, such as tyrosine phosphorylation of the thrombopoietin receptor, JAK (Janus kinase) 2, Tyk2 (tyrosine kinase 2), STAT (signal transducer and activator of transcription) 3, STAT5, MAPKs (mitogen-activated protein kinases), PLCgamma (phospholipase Cgamma), Grb2 (growth-factor-receptor-bound protein 2), Shc (Src homology and collagen homology), Vav, Cbl and SHP-2 (Src homology 2 domain-containing protein tyrosine phosphatase 2) and increased the number of CD41(+) cells (megakaryocyte lineage) in cultures of human CD34(+) bone-marrow cells (haematopoietic stem cells). These findings suggest that this series of compounds are novel agonists of the human thrombopoietin receptor and are possible lead compounds for the generation of anti-thrombocytopaenia drugs.
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Materiales Biomiméticos/farmacología , Células de la Médula Ósea/metabolismo , Receptores de Trombopoyetina/agonistas , Transducción de Señal/efectos de los fármacos , Trombopoyesis/efectos de los fármacos , Trombopoyetina/farmacología , Animales , Células de la Médula Ósea/citología , Línea Celular , Proteína Adaptadora GRB2/biosíntesis , Humanos , Ratones , Fosfolipasa C gamma/biosíntesis , Proteínas Quinasas/biosíntesis , Proteína Tirosina Fosfatasa no Receptora Tipo 11/biosíntesis , Proteínas Proto-Oncogénicas c-cbl/biosíntesis , Proteínas Proto-Oncogénicas c-vav/biosíntesis , Receptores de Trombopoyetina/metabolismo , Factor de Transcripción STAT3/biosíntesis , Factor de Transcripción STAT5/biosíntesis , Proteínas Adaptadoras de la Señalización Shc/biosíntesisRESUMEN
The p66Shc adaptor protein is an important regulator of lifespan in mammals, but the mechanisms responsible are still unclear. Here, we show that expression of p66Shc, p52Shc, and p46Shc is regulated at the post-transcriptional level by the microRNA let-7a. The levels of let-7a correlated inversely with the levels of Shc proteins without affecting Shc mRNA levels. We identified 'seedless' let-7a interaction elements in the coding region of Shc mRNA; mutation of the 'seedless' interaction sites abolished the regulation of Shc by let-7a. Our results further revealed that repression of Shc expression by let-7a delays senescence of human diploid fibroblasts (HDFs). In sum, our findings link let-7a abundance to the expression of p66Shc, which in turn controls the replicative lifespan of HDFs.
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Senescencia Celular/genética , MicroARNs/metabolismo , Biosíntesis de Proteínas , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Diploidia , Fibroblastos/metabolismo , Humanos , Sistemas de Lectura Abierta/genética , Unión Proteica , ARN Mensajero/genética , ARN Mensajero/metabolismo , Secuencias Reguladoras de Ácidos Nucleicos/genética , Proteínas Adaptadoras de la Señalización Shc/genética , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de SrcRESUMEN
BACKGROUND: Aging is an independent risk factor for cardiovascular and cerebrovascular disease. To date, little is known about the mechanisms of aging of cerebral arteries and whether the aging gene p66(Shc) is implicated in it. The present study was designed to assess age-induced vascular dysfunction in cerebral and systemic arteries of wild type (wt) and p66(Shc-/-) mice. METHODS: Basilar arteries and size matched second order femoral arteries of 3-month (3M), 6-month (6M) and 2-year old (2Y) mice were studied in wt and p66(Shc-/-) mice. To assess vascular function, arterial rings mounted in a myograph for isometric tension recordings were exposed to increasing concentrations of acetylcholine and sodium nitroprusside. Reactive oxygen species (ROS) generation was assessed in femoral and basilar arteries using the spin trap 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine. RESULTS: In wt mice, endothelial function of the femoral artery was not affected by age unlike in the basilar artery where an age-dependent dysfunction was observed. In p66(Shc-/-) a similar response was observed in the femoral artery; however, age-dependent endothelial dysfunction of the basilar artery was blunted as compared to wt. Levels of ROS were comparable in the femoral arteries of 3M and 2Y of wt and p66(Shc-/-) mice. Differently, ROS levels in the basilar artery of wt mice were strongly increased by age unlike in p66(Shc-/-) mice where they remained comparable irrespective of age. CONCLUSIONS: Endothelial function in cerebral arteries, but not in size-matched systemic ones, is heavily impaired by aging. This process is paralleled by an increased ROS production and is mediated by the p66(Shc) gene.
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Envejecimiento/metabolismo , Trastornos Cerebrovasculares/metabolismo , Endotelio Vascular/metabolismo , Proteínas Adaptadoras de la Señalización Shc/fisiología , Envejecimiento/patología , Animales , Arteria Basilar/metabolismo , Arteria Basilar/patología , Trastornos Cerebrovasculares/patología , Endotelio Vascular/patología , Arteria Femoral/metabolismo , Arteria Femoral/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Técnicas de Cultivo de Órganos , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de SrcRESUMEN
Hippocampal neuronal oxidative stress and apoptosis have been reported to be involved in cognitive impairment, and angiotensin II could induce hippocampal oxidative stress and apoptosis. Propofol is a widely used intravenous anesthetic agent in clinical practice, and it demonstrates significant neuroprotective activities. In this study, we investigated the mechanism how propofol protected mouse hippocampal HT22 cells against angiotensin II-induced oxidative stress and apoptosis. Cell viability was evaluated with CCK8 kit. Protein expressions of active caspase 3, cytochrome c, p66(Shc), p-p66(shc)-Ser(36), protein kinase C ßII (PKCßII), Pin-1 and phosphatase A2 (PP2A) were measured by Western blot. Superoxide anion (O2(.-)) accumulation was measured with the reduction of ferricytochrome c. Compared with the control group, angiotensin II up-regulated expression of PKCßII, Pin-1 and PP2A, induced p66(Shc)-Ser(36) phosphorylation, and facilitated p66(Shc) mitochondrial translocation, resulting in O2(.-) accumulation, mitochondrial cytochrome c release, caspase 3 activation, and the inhibition of cell viability. Importantly, we found propofol inhibited angiotensin II-induced PKCßII and PP2A expression and improved p66(Shc) mitochondrial translocation, O2(.-) accumulation, mitochondrial cytochrome c release, caspase 3 activation, inhibition of cell viability. On the other hand, propofol had no effects on angiotensin II-induced Pin-1 expression and p66(Shc)-Ser(36) phosphorylation. Moreover, the protective effects of propofol on angiotensin II-induced HT22 apoptosis were similar with calyculin A, an inhibitor of PP2A and CGP53353, an inhibitor of PKCßII. However, the protective effect of propofol could be reversed by FTY720, an activator of PP2A, rather than PMA, an activator of PKCßII. Our data indicated that propofol down-regulated PP2A expression, inhibiting dephosphorylation of p66(Shc)-Ser(36) and p66(Shc) mitochondrial translocation, decreasing O2(.-) accumulation, reducing mitochondrial cytochrome c release, inhibiting caspase 3 activation. By these mechanisms, it protects mouse hippocampal HT22 cells against angiotensin II-induced apoptosis.
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Angiotensina II/toxicidad , Mitocondrias/metabolismo , Fármacos Neuroprotectores/farmacología , Propofol/farmacología , Proteínas Adaptadoras de la Señalización Shc/antagonistas & inhibidores , Animales , Apoptosis/efectos de los fármacos , Caspasa 3/biosíntesis , Caspasa 3/genética , Células Cultivadas , Citocromos c/metabolismo , Activación Enzimática/efectos de los fármacos , Inducción Enzimática/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Hipocampo/citología , Ratones , Peptidilprolil Isomerasa de Interacción con NIMA , Estrés Oxidativo/efectos de los fármacos , Isomerasa de Peptidilprolil/biosíntesis , Isomerasa de Peptidilprolil/genética , Proteína Quinasa C beta/antagonistas & inhibidores , Proteína Quinasa C beta/biosíntesis , Proteína Quinasa C beta/genética , Inhibidores de Proteínas Quinasas/farmacología , Proteína Fosfatasa 2/antagonistas & inhibidores , Proteína Fosfatasa 2/biosíntesis , Proteína Fosfatasa 2/genética , Transporte de Proteínas/efectos de los fármacos , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Proteínas Adaptadoras de la Señalización Shc/genética , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src , Superóxidos/metabolismoRESUMEN
Reactive oxygen species (ROS), mainly originated from mitochondrial respiration, are critical inducers of oxidative damage and involved in tissue dysfunction. It is not clear, however, whether oxidative stress is the result of an active gene program or it is the by-product of physiological processes. Recent findings demonstrate that ROS are produced by mitochondria in a controlled way through specialized enzymes, including p66Shc, and take part in cellular process aimed to ensure adaptation and fitness. Therefore, genes generating specifically ROS are selected determinants of life span in response to different environmental conditions.
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Mitocondrias Hepáticas/efectos de los fármacos , Especies Reactivas de Oxígeno/agonistas , Proteínas Adaptadoras de la Señalización Shc/farmacología , Animales , Apoptosis/efectos de los fármacos , Regulación de la Temperatura Corporal/fisiología , Ciclosporina/farmacología , Técnicas Electroquímicas , Escherichia coli/genética , Escherichia coli/metabolismo , Etilmaleimida/farmacología , Humanos , Ratones , Mitocondrias Hepáticas/metabolismo , Proteínas de Transporte de Membrana Mitocondrial/antagonistas & inhibidores , Proteínas de Transporte de Membrana Mitocondrial/metabolismo , Poro de Transición de la Permeabilidad Mitocondrial , Oxidación-Reducción , Estrés Oxidativo , Isoformas de Proteínas/biosíntesis , Isoformas de Proteínas/genética , Isoformas de Proteínas/farmacología , Especies Reactivas de Oxígeno/metabolismo , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacología , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Proteínas Adaptadoras de la Señalización Shc/genética , Transducción de Señal , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de SrcRESUMEN
Overexpression of Shc adaptor proteins is associated with mitogenesis, carcinogenesis and metastasis. Multiple copies in T-cell malignancy 1 (MCT-1) oncoprotein promotes cell proliferation, survival and tumorigenic effects. Our current data show that MCT-1 is a novel regulator of Shc-Ras-MEK-ERK signaling and MCT-1 is significantly co-activated with Shc gene in human carcinomas. The knockdown of MCT-1 enhances apoptotic cell death accompanied with the activation of caspases and cleavage of caspase substrates under environmental stress. The cancer cell proliferation, chemo-resistance and tumorigenic capacity are proved to be effectively suppressed by targeting MCT-1. Accordingly, an important linkage between MCT-1 oncogenicity and Shc pathway in tumor development has now been established. Promoting MCT-1 expression by gene hyperactivation may be recognized as a tumor marker and MCT-1 may serve as a molecular target of cancer therapy.
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Proteínas de Ciclo Celular/antagonistas & inhibidores , Proteínas Oncogénicas/antagonistas & inhibidores , Proteínas Adaptadoras de la Señalización Shc/antagonistas & inhibidores , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Neoplasias de la Mama/terapia , Caspasa 3/metabolismo , Proteínas de Ciclo Celular/biosíntesis , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Procesos de Crecimiento Celular/efectos de los fármacos , Procesos de Crecimiento Celular/fisiología , Línea Celular Tumoral , Femenino , Técnicas de Silenciamiento del Gen , Humanos , Inmunohistoquímica , Integrina beta4/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/terapia , Sistema de Señalización de MAP Quinasas , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Proteínas Oncogénicas/biosíntesis , Proteínas Oncogénicas/genética , Proteínas Oncogénicas/metabolismo , Paclitaxel/farmacología , Poli(ADP-Ribosa) Polimerasas/metabolismo , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Proteínas Adaptadoras de la Señalización Shc/genética , Proteínas Adaptadoras de la Señalización Shc/metabolismo , Transfección , Ensayos Antitumor por Modelo de Xenoinjerto , Proteínas ras/metabolismoRESUMEN
Prenatal exposure to BPA disturbs mammary gland histoarchitecture and increases the carcinogenic susceptibility to chemical challenges administered long after BPA exposure. Our aim was to assess the effect of prenatal BPA exposure on mammary gland angiogenesis and steroid hormone pathways in virgin cycling rats. Pregnant Wistar rats were exposed to either 25 or 250 g/kg/day (25 and 250 BPA, respectively) or to vehicle. Female offspring were autopsied on postnatal day (PND) 50 or 110. Ovarian steroid serum levels, the expression of steroid receptors and their co-regulators SRC-3 and SMRT in the mammary gland, and angiogenesis were evaluated. At PND 50, all BPA-treated animals had lower serum levels of progesterone, while estradiol levels remained unchanged. The higher dose of BPA increased mammary ERα and decreased SRC-3 expression at PND 50 and PND 110. SMRT protein levels were similar among groups at PND 50, whereas at PND 110, animals exposed to 250 BPA showed a lower SMRT expression. Interestingly, in the control and 25 BPA groups, SMRT increased from PND 50 to PND 110. At PND 50, an increased vascular area associated with higher VEGF expression was observed in the 250 BPA-treated rats. At PND 110, the vascular area was still increased, but VEGF expression was similar to that of control rats. The present results demonstrate that prenatal exposure to BPA alters the endocrine environment of the mammary gland and its angiogenic process. Increased angiogenesis and altered steroid hormone signals could explain the higher frequency of pre-neoplastic lesions found later in life. This article is part of a Special Issue entitled 'Endocrine disruptors'.
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Disruptores Endocrinos/efectos adversos , Glándulas Mamarias Animales/efectos de los fármacos , Neovascularización Fisiológica/efectos de los fármacos , Fenoles/efectos adversos , Efectos Tardíos de la Exposición Prenatal/metabolismo , Animales , Compuestos de Bencidrilo , Estradiol/sangre , Receptor alfa de Estrógeno/biosíntesis , Femenino , Glándulas Mamarias Animales/irrigación sanguínea , Glándulas Mamarias Animales/patología , Embarazo , Progesterona/sangre , Ratas , Ratas Wistar , Proteínas Adaptadoras de la Señalización Shc/biosíntesis , Proteína Transformadora 3 que Contiene Dominios de Homología 2 de SrcRESUMEN
OBJECTIVE: To construct a recombinant adenovirus vector for SH2-DED fusion gene and assess its inhibitory effect on the proliferation of K562 cells. METHODS: SH2-DED fusion gene and its mutant SH2mt-DED were amplified by splicing PCR and cloned into pAdTrack-CMV plasmid separately to construct the shuttle plasmids pAdT-SD-EGFP and pAdT-SmD-EGFP, respectively. After Pme I digestion, the shuttle plasmids were transformed into ultra-competent pAd5F35-BJ5183 cells to generate defective adenovirus vectors pAd5F35-SD-EGFP and pAd5F35- SmD-EGFP by homologous recombination. The vectors, linearized by Pac I digestion, were further transfected into AD293 cells for packaging and amplified by infecting AD293 cells repeatedly. K562 cells were then infected by the recombinant adenoviruses and the expression of SD was detected by Western blotting. MTT assay and flow cytometry were used to investigate the effect of Ad5F35-SD-EGFP and Ad5F35-SmD-EGFP on the proliferation of K562 cells. RESULTS: The recombinant adenovirus vectors pAd5F35-SD-EGFP and pAd5F35-SmD-EGFP were constructed correctly, with a titer reaching 1.5×10(12) pfu/ml after amplification. Western blotting demonstrated that the target proteins were effectively expressed in transfected K562 cells. MTT assay and flow cytometry showed that transfection with pAd5F35-SD-EGFP resulted in growth inhibition rate of 55.21% in K562 cells, significantly higher than the inhibition rate of 17.95% following transfection with pAd5F35- SmD-EGFP and 7.33% following PBS treatment (P<0.05). CONCLUSION: The recombinant adenovirus vector Ad5F35-SD-EGFP we constructed can significantly inhibit the proliferation of K562 cells in vitro.