19 research outputs found
Childhood Adrenocortical Tumours: a Review
Childhood adrenocortical tumour (ACT) is not a common disease, but in southern Brazil the prevalence is 15 times higher than in other parts of the world. One hundred and thirty-seven patients have been identified and followed by our group over the past four decades. Affected children are predominantly girls, with a female-to-male ratio of 3.5:1 in patients below 4 years of age. Virilization alone (51.6%) or mixed with Cushing's syndrome (42.0%) was the predominant clinical picture observed in these patients. Tumours are unilateral, affecting both glands equally. TP53 R337H germline mutations underlie most childhood ACTs in southern Brazil. Epidemiological data from our casuistic studies revealed that this mutation has ~10% penetrance for ACT. Surgery is the definitive treatment, and a complete resection should always be attempted. Although adjuvant chemotherapy has shown some encouraging results, its influence on overall outcome is small. The survival rate is directly correlated to tumour size; patients with small, completely excised tumours have survival rates close to 90%, whereas in those patients with inoperable tumours and/or metastatic disease it is less than 10%. In the group of patients with large, excisable tumours, half of them have an intermediate outcome. Recent molecular biology techniques and genomic approaches may help us to better understand the pathogenesis of ACT, the risk of developing a tumour when TP53 R337H is present, and to predict its outcome. An ongoing pilot study consisting of close monitoring of healthy carriers of the TP53 R337H mutation - siblings and first-degree relatives of known affected cases - aims at the early detection of ACTs and an improvement of the cure rate
The Tyrosine Phosphatase hPTPRβ Controls the Early Signals and Dopaminergic Cells Viability via the P2X7 Receptor
ATP, one of the signaling molecules most commonly secreted in the nervous system and capable of stimulating multiple pathways, binds to the ionotropic purinergic receptors, in particular, the P2X7 receptor (P2X7R) and stimulates neuronal cell death. Given this effect of purinergic receptors on the viability of dopaminergic neurons model cells and that Ras GTPases control Erk1/2-regulated mitogen-activated cell proliferation and survival, we have investigated the role of the small GTPases of the Ras superfamily, together with their regulatory and effector molecules as the potential molecular intermediates in the P2X7R-regulated cell death of SN4741 dopaminergic neurons model cells. Here, we demonstrate that the neuronal response to purinergic stimulation involves the Calmodulin/RasGRF1 activation of the small GTPase Ras and Erk1/2. We also demonstrate that tyrosine phosphatase PTPRβ and other tyrosine phosphatases regulate the small GTPase activation pathway and neuronal viability. Our work expands the knowledge on the intracellular responses of dopaminergic cells by identifying new participating molecules and signaling pathways. In this sense, the study of the molecular circuitry of these neurons is key to understanding the functional effects of ATP, as well as considering the importance of these cells in Parkinson’s Disease.This work were supported by: A.A.S. is a recipient of a predoctoral Basque Government fellowship: PRE_2017_1_0016; M.L.M. is a recipient of a fellowship from Foundation “Jesús de Gangoiti y Barrera”: Foundation “Jesús de Gangoiti y Barrera”; J.L.Z. was supported by the Instituto de Salud Carlos III: (PI18/00207); J.L.Z. was supported by the Basque Government: (PIBA_2020_1_0048); J.L.Z. was supported by the University of Basque Country Grant: (US19/04). A.A.S. is a recipient of a predoctoral fellowship (PRE_2017_1_0016) from the Basque Government; M.L.M. is a recipient of a fellowship from Foundation “Jesús de Gangoiti y Barrera”; J.L.Z. was supported by the Instituto de Salud Carlos III (PI18/00207), Basque Government (PIBA_2020_1_0048) and University of Basque Country Grant (US19/04)
Small GTPases of the Rab and Arf Families: Key Regulators of Intracellular Trafficking in Neurodegeneration
Small guanosine triphosphatases (GTPases) of the Rab and Arf families are key regulators of vesicle formation and membrane trafficking. Membrane transport plays an important role in the central nervous system. In this regard, neurons require a constant flow of membranes for the correct distribution of receptors, for the precise composition of proteins and organelles in dendrites and axons, for the continuous exocytosis/endocytosis of synaptic vesicles and for the elimination of dysfunctional proteins. Thus, it is not surprising that Rab and Arf GTPases have been associated with neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Both pathologies share characteristics such as the presence of protein aggregates and/or the fragmentation of the Golgi apparatus, hallmarks that have been related to both Rab and Arf GTPases functions. Despite their relationship with neurodegenerative disorders, very few studies have focused on the role of these GTPases in the pathogenesis of neurodegeneration. In this review, we summarize their importance in the onset and progression of Alzheimer’s and Parkinson’s diseases, as well as their emergence as potential therapeutical targets for neurodegeneration.A.A.S. is a recipient of a predoctoral fellowship (PRE_2017_1_0016) from the Basque Government. M.L.M. is a recipient of a fellowship from Foundation “Jesús de Gangoiti y Barrera”. J.L.Z. was supported by the Instituto de Salud Carlos III (PI18/00207) and the University of Basque Country Grant (US19/04)
Case–control study of HLA-G promoter methylation status, HPV infection and cervical neoplasia in Curitiba, Brazil: a pilot analysis
BACKGROUND: The causal association between persistent human papillomavirus (HPV) infection and cervical cancer has been established, but the mechanisms that favor HPV persistence in cervical cells are still unknown. The diminished capability of the immune system to control and resolve HPV infection is one of several hypotheses. The tolerogenic protein HLA-G has shown aberrant expression in a variety of cancers, which has been suggested as a mechanism for tumor escape from immunosurveillance. In the present study we evaluate the role of epigenetic modification (promoter de-methylation) of the HLA-G gene on susceptibility to HPV infection and development of high-grade cervical lesions. METHODS: A case–control study was carried out in Curitiba, Brazil, between February and June 2010. A total of 789 women aged 15–47 years were recruited: 510 controls with normal cervical cytology, and 279 cases with histologically confirmed cervical intraepithelial neoplasia grade 2 (CIN2, N = 150) or grade 3 (CIN3, N = 129). All women were administered a questionnaire by interview, which collected information on demographic and lifestyle factors, and a cervical sample was collected. HPV DNA detection was performed by GP5+/GP6+ primer-mediated PCR. HPV-positive samples were genotyped by multiplex PCR. A pilot analysis of HLA-G promoter methylation was carried out in a subset of the study population (96 cases and 76 controls) by pyrosequencing. HLA-G methylation and HPV infection status of cases and controls were compared, and confounding factors were computed by t Student and non-parametric Wilcoxon tests. Comparison of HLA-G methylation between cases and controls was assessed by the Bonferroni correction. The association of HLA-G methylation with CIN2/3 was evaluated by logistic regression. RESULTS: HPV prevalence was 19.6% in controls and 94.3% in CIN2/3 cases. HPV16, 31, 33, 35 and 18 were the most prevalent types. Methylation analysis of seven CpGs in the HLA-G promoter did not reveal any spontaneous de-methylation events in CIN2/3 cases (mean proportion of methylation: 75.8%) with respect to controls (mean 73.7%; odds ratio 1.01, 95% confidence interval 0.96, 1.07). CONCLUSIONS: This study did not support the hypothesis that spontaneous de-methylation events in the HLA-G promoter play a primary role in promoting escape from immunosurveillance in the development of precancerous cervical lesions
Rac1/p21-activated kinase pathway controls retinoblastoma protein phosphorylation and E2F transcription factor activation in B lymphocytes
Small GTPases of the Ras superfamily are capable of activating E2F-dependent transcription leading to cell proliferation, but the molecular mechanisms are poorly understood. In this study, using immortalized chicken DT40 B cell lines to investigate the role of the Vav/Rac signalling cascade on B cell proliferation, it is shown that the proliferative response triggered by B cell receptor activation is dramatically reduced in the absence of Vav3 expression. Analysis of this proliferative defect shows that in the absence of Vav3 expression, retinoblastoma protein (RB) phosphorylation and the subsequent E2F activation do not take place. By combining pharmacological and genetic approaches, phosphatidylinositol-3-kinase and phospholipase CÎł2 (PLCÎł2) were identified as the key regulatory signalling molecules upstream of the Vav3/Rac pathway leading to RB phosphorylation and E2F transcription factor activation. Additionally, vav3(-/-) and plcÎł2(-/-) DT40 B cells were not able to activate the RB-E2F complex wild-type phenotype when these genetically modified cells were transfected with constitutively active forms of RhoA or Cdc42. However, when these knockout cells were transfected with different constitutively active versions of PLCÎł, Vav or Rac1, not only activation of the RB-E2F complex wild-type phenotype was recovered but also the cellular proliferation. Furthermore, by evaluating the effect of two known effector mutants of Rac1 (Rac1(Q61L/F37A) and Rac1(Q61L/Y40C)), the RB-E2F complex activation dependency on p21-activated kinase (PAK) and protein kinase Cε (PKCε) activities was established, being independent of both actin cytoskeleton reorganization and Ras activity. These results suggest that PAK1 and PKCε may be potential therapeutic targets to stop uncontrolled B cell proliferation mediated by the Vav/Rac pathway.Fil: Zaldua, Natalia. Bizkaia Science and Technology Park; EspañaFil: LLavero, Francisco. Universidad del PaĂs Vasco; España. Bizkaia Science and Technology Park; EspañaFil: Artaso, Alain. Universidad del PaĂs Vasco; EspañaFil: Gálvez, Patricia. Technological Park of Health Sciences; EspañaFil: Lacerda, Hadriano M.. Bizkaia Science and Technology Park; EspañaFil: Parada, Luis Antonio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Salta. Instituto de PatologĂa Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de PatologĂa Experimental; ArgentinaFil: Zugaza, JosĂ© L.. Universidad del PaĂs Vasco; España. Bizkaia Science and Technology Park; Españ
Characteristics of the cohort of mothers of cryptorchid boys.
<p>Characteristics of the cohort of mothers of cryptorchid boys.</p
Age-specific standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) of biliary tract/liver, lung and ovarian cancer among mothers of cryptorchid boys.
<p>*Due to a different age-distribution in incidence age cut-offs differed for lung cancer.</p
McArdle Disease: New Insights into Its Underlying Molecular Mechanisms
McArdle disease, also known as glycogen storage disease type V (GSDV), is characterized by exercise intolerance, the second wind phenomenon, and high serum creatine kinase activity. Here, we recapitulate PYGM mutations in the population responsible for this disease. Traditionally, McArdle disease has been considered a metabolic myopathy caused by the lack of expression of the muscle isoform of the glycogen phosphorylase (PYGM). However, recent findings challenge this view, since it has been shown that PYGM is present in other tissues than the skeletal muscle. We review the latest studies about the molecular mechanism involved in glycogen phosphorylase activity regulation. Further, we summarize the expression and functional significance of PYGM in other tissues than skeletal muscle both in health and McArdle disease. Furthermore, we examine the different animal models that have served as the knowledge base for better understanding of McArdle disease. Finally, we give an overview of the latest state-of-the-art clinical trials currently being carried out and present an updated view of the current therapies.Gobierno Vasco (PRE_2017_1_0016).Instituto de Salud Carlos III (PI18 / 00207).Beca de la Universidad del PaĂs Vasco (US19 / 04).4.556 JCR (2019) Q1, 74/297 Biochemistry & Molecular Biology1.317 SJR (2019) Q1, 9/71 Inorganic ChemistryNo data IDR 2019UE
Standardized incidence ratios (SIRs), and corresponding 95% confidence intervals (CI) of cancer among mothers of cryptorchid boys.
<p>Note: SIR: Standardized Incidence Ratio; CI: Confidence Interval; Obs.: Observed; Exp.: Expected.</p