New recurrent deletions in the PPAR gamma and TP53 genes are associated with childhood myelodysplastic syndrome

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Expressão diferencial dos genes VuUCP1a e VuUCP1b em caupi sob estresse salino

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

microRNA evaluation of unknown primary lesions in the head and neck

Unknown primary malignancy in the head and neck is not an infrequent diagnosis for patients with metastatic cervical lymph nodes. Although linked with a relatively good prognosis following radiation treatment, widespread radiation is coupled with significant morbidity. Altered microRNA (miRNA) expression has been associated with both cancer progression and metastasis. We sought to determine whether miRNA expression analysis could be used as a diagnostic tool to discover the primary site of malignancy, within the head and neck. We used quantitative real-time PCR to identify miRNA expression profiles of squamous cell carcinoma of the tonsil, base of tongue and post-nasal space, as well as their corresponding metastatic lymph nodes, from 6 patients. Our results revealed that each cancer maintained its expression profile between the primary site and the nodal metastasis (r = 0.82, p < 0.0001). In addition, each anatomical sub-site maintained a distinct miRNA profile between individual patients (r = 0.79, p < 0.0001). Finally, between sub-sites, the miRNA profiles were distinct (p < 0.0001). As proof of principle, our study provides an indication that miRNA expression analysis may be useful to compare the primary lesion and local metastatic disease. This may be clinically relevant to predict the primary site of origin of metastatic disease, when the primary site remains obscure.

Role of endothelial cell apoptosis in regulation of skeletal muscle angiogenesis during high and low salt intake

Angiogenesis, under normal conditions, is a tightly regulated balance between pro- and antiangiogenic factors. The goal of this study was to investigate the mechanisms involved in the control of the skeletal muscle angiogenic response induced by electrical stimulation during the suppression of plasma renin activity (PRA) with a high-salt diet. Rats fed 0.4% or 4% salt diets were exposed to electrical stimulation for 7 days. The tibialis anterior ( TA) muscles from stimulated and unstimulated hindlimbs were removed and prepared for gene expression analysis, CD31-terminal deoxynucleotide transferase-mediated dUTP nick-end labeling ( TUNEL) double-staining assay, and Bcl-2 and Bax protein expression by Western blot. Rats fed a low-salt diet showed a dramatic angiogenesis response in the stimulated limb compared with the unstimulated limb. This angiogenesis response was significantly attenuated when rats were placed on a high-salt diet. Microarray analysis showed that in the stimulated limb of rats fed a low-salt diet many genes related to angiogenesis were upregulated. In contrast, in rats fed a high-salt diet most of the genes upregulated in the stimulated limb function in apoptosis and cell cycle arrest. Endothelial cell apoptosis, as analyzed by CD31-TUNEL staining, increased by fourfold in the stimulated limb compared with the unstimulated limb. There was also a 48% decrease in the Bcl-2-to-Bax ratio in stimulated compared with unstimulated limbs of rats fed a high-salt diet, confirming severe apoptosis. This study suggests that the increase in endothelial cell apoptosis in TA muscle might contribute to the attenuation of angiogenesis response observed in rats fed a high-salt diet.

Identification and complete sequencing of novel human transcripts through the use of mouse orthologs and testis cDNA sequences

The correct identification of all human genes, and their derived transcripts, has not yet been achieved, and it remains one of the major aims of the worldwide genomics community. Computational programs suggest the existence of 30,000 to 40,000 human genes. However, definitive gene identification can only be achieved by experimental approaches. We used two distinct methodologies, one based on the alignment of mouse orthologous sequences to the human genome, and another based on the construction of a high-quality human testis cDNA library, in an attempt to identify new human transcripts within the human genome sequence. We generated 47 complete human transcript sequences, comprising 27 unannotated and 20 annotated sequences. Eight of these transcripts are variants of previously known genes. These transcripts were characterized according to size, number of exons, and chromosomal localization, and a search for protein domains was undertaken based on their putative open reading frames. In silico expression analysis suggests that some of these transcripts are expressed at low levels and in a restricted set of tissues.

MGMT and MLH1 methylation in Helicobacter pylori-infected children and adults

AIM: To evaluate the association between Helicobacter pylori(H. pylori) infection and MLH1 and MGMT methylation and its relationship with microsatellite instability (MSI). METHODS: The methylation status of the MLH1 and MGMT promoter region was analysed by methylation specific methylation-polymerase chain reaction (MSPPCR) in gastric biopsy samples from uninfected or H. pylori -infected children (n = 50), from adults with chronic gastritis (n = 97) and from adults with gastric cancer (n = 92). MLH1 and MGMT mRNA expression were measured by real-time PCR and normalised to a constitutive gene (β actin). MSI analysis was performed by screening MSI markers at 4 loci (Bat-25, Bat-26, D17S250 and D2S123) with PCR; PCR products were analysed by single strand conformation polymorphism followed by silver staining. Statistical analyses were performed with either the χ 2 test with Yates continuity correction or Fisher's exact test, and statistical significance for expression analysis was assessed using an unpaired Student's t -test. RESULTS: Methylation was not detected in the promoter regions of MLH1 and MGMT in gastric biopsy samples from children, regardless of H. pylori infection status. The MGMT promoter was methylated in 51% of chronic gastritis adult patients and was associated with H. pylori infection (P < 0.05); this region was methylated in 66% of gastric cancer patients, and the difference in the percentage of methylated samples between these patients and those from H. pylori -infected chronic gastritis patients was statistically significant (P < 0.05). MLH1 methylation frequencies among H. pylori -infected and non-infected chronic gastritis adult patients were 13% and 7%, respectively. We observed methylation of the MLH1 promoter (39%) and increased MSI levels (68%) in samples from gastric cancer patients in comparison to samples from H. pylori -infected adult chronic gastritis patients (P < 0.001 and P < 0.01, respectively). The frequency of promoter methylation for both genes was higher in gastric cancer samples than in H. pylori -positive chronic gastritis samples (P < 0.05). The levels of MLH1 and MGMT mRNA were significantly reduced in chronic gastritis samples that were also hypermethylated (P < 0.01). MGMT promoter region was analysed by methylation specific methylation-polymerase chain reaction (MSPPCR) in gastric biopsy samples from uninfected or H. pylori -infected children (n = 50), from adults with chronic gastritis (n = 97) and from adults with gastric cancer (n = 92). MLH1 and MGMT mRNA expression were measured by real-time PCR and normalised to a constitutive gene (β actin). MSI analysis was performed by screening MSI markers at 4 loci (Bat-25, Bat-26, D17S250 and D2S123) with PCR; PCR products were analysed by single strand conformation polymorphism followed by silver staining. Statistical analyses were performed with either the χ 2 test with Yates continuity correction or Fisher's exact test, and statistical significance for expression analysis was assessed using an unpaired Student's t -test. RESULTS: Methylation was not detected in the promoter regions of MLH1 and MGMT in gastric biopsy samples from children, regardless of H. pylori infection status. The MGMT promoter was methylated in 51% of chronic gastritis adult patients and was associated with H. pylori infection (P < 0.05); this region was methylated in 66% of gastric cancer patients, and the difference in the percentage of methylated samples between these patients and those from H. pylori -infected chronic gastritis patients was statistically significant (P < 0.05). MLH1 methylation frequencies among H. pylori -infected and non-infected chronic gastritis adult patients were 13% and 7%, respectively. We observed methylation of the MLH1 promoter (39%) and increased MSI levels (68%) in samples from gastric cancer patients in comparison to samples from H. pylori -infected adult chronic gastritis patients (P < 0.001 and P < 0.01, respectively). The frequency of promoter methylation for both genes was higher in gastric cancer samples than in H. pylori -positive chronic gastritis samples (P < 0.05). The levels of MLH1 and MGMT mRNA were significantly reduced in chronic gastritis samples that were also hypermethylated (P < 0.01). CONCLUSION: In summary, MGMT and MLH1 methylation did not occur in earlier-stage H. pylori infections and thus might depend on the duration of infection. © 2013 Baishideng. All rights reserved.

Exploring the multifactorial nature of autism through computational systems biology: Calcium and the Rho GTPase RAC1 under the spotlight

Autism is a neurodevelopmental disorder characterized by impaired social interaction and communication accompanied with repetitive behavioral patterns and unusual stereotyped interests. Autism is considered a highly heterogeneous disorder with diverse putative causes and associated factors giving rise to variable ranges of symptomatology. Incidence seems to be increasing with time, while the underlying pathophysiological mechanisms remain virtually uncharacterized (or unknown). By systematic review of the literature and a systems biology approach, our aims were to examine the multifactorial nature of autism with its broad range of severity, to ascertain the predominant biological processes, cellular components, and molecular functions integral to the disorder, and finally, to elucidate the most central contributions (genetic and/or environmental) in silico. With this goal, we developed an integrative network model for gene-environment interactions (GENVI model) where calcium (Ca2+) was shown to be its most relevant node. Moreover, considering the present data from our systems biology approach together with the results from the differential gene expression analysis of cerebellar samples from autistic patients, we believe that RAC1, in particular, and the RHO family of GTPases, in general, could play a critical role in the neuropathological events associated with autism. © 2013 Springer Science+Business Media New York.

A fast cholinergic modulation of the primary acoustic startle circuit in rats

Cochlear root neurons (CRNs) are the first brainstem neurons which initiate and participate in the full expression of the acoustic startle reflex. Although it has been suggested that a cholinergic pathway from the ventral nucleus of the trapezoid body (VNTB) conveys auditory prepulses to the CRNs, the neuronal origin of the VNTB-CRNs projection and the role it may play in the cochlear root nucleus remain uncertain. To determine the VNTB neuronal type which projects to CRNs, we performed tract-tracing experiments combined with mechanical lesions, and morphometric analyses. Our results indicate that a subpopulation of non-olivocochlear neurons projects directly and bilaterally to CRNs via the trapezoid body. We also performed a gene expression analysis of muscarinic and nicotinic receptors which indicates that CRNs contain a cholinergic receptor profile sufficient to mediate the modulation of CRN responses. Consequently, we investigated the effects of auditory prepulses on the neuronal activity of CRNs using extracellular recordings in vivo. Our results show that CRN responses are strongly inhibited by auditory prepulses. Unlike other neurons of the cochlear nucleus, the CRNs exhibited inhibition that depended on parameters of the auditory prepulse such as intensity and interstimulus interval, showing their strongest inhibition at short interstimulus intervals. In sum, our study supports the idea that CRNs are involved in the auditory prepulse inhibition of the acoustic startle reflex, and confirms the existence of multiple cholinergic pathways that modulate the primary acoustic startle circuit. © 2013 Springer-Verlag Berlin Heidelberg.

Genotoxic evaluation of the antimalarial drugs artemisinin and artesunate in human HepG2 cells and effects on CASP3 and SOD1 gene expressions

The malaria treatment recommended by the World Health Organization involves medicines derived from artemisinin, an active compound extracted from the plant Artemisia annua, and some of its derivatives, such as artesunate. Considering the lack of data regarding the genotoxic effects of these compounds in human cells, the objective of this study was to evaluate the cytotoxicity and genotoxicity, and expressions of the CASP3 and SOD1 genes in a cultured human hepatocellular liver carcinoma cell line (HepG2 cells) treated with artemisinin and artesunate. We tested concentrations of 2.5, 5, 7.5, 10, and 20 μg/mL of both substances with a resazurin cytotoxicity assay, and the concentrations used in the genotoxicity experiments (2.5, 5, and 10 μg/mL) and gene expression analysis (5 mg/mL) were determined. The results of the comet assay in cells treated with artemisinin and artesunate showed a significant dosedependent increase (P < 0.001) in the number of cells with DNA damage at all concentrations tested. However, the gene expression analysis revealed no significant change in expression of CASP3 or SOD1. Our data showed that although artemisinin and artesunate exhibited genotoxic effects in cultured HepG2 cells, they did not significantly alter expression of the CASP3 and SOD1 genes at the doses tested. ©FUNPEC-RP.

Efeitos da temperatura na expressão de genes relacionados ao crescimento muscular em tilápias do Nilo (Oreochromis niloticus) linhagem Gift

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Metabolismo de glicogênio e relógio biológico em Neurospora crassa: fatores e cofatores de transcrição envolvidos nos processos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A proteína quinase dependente de ciclina NcPHO85 de Neurospora crassa. Estudos de caracterização molecular e bioquímica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Valor prognóstico da expressão gênica e proteica do ATM, p53 e VEGF em cadelas com neoplasias mamárias

Pós-graduação em Medicina Veterinária - FCAV

Sequenciamento do RNAm codificante da hepcidina e análise de sua expressão gênica em diferentes tecidos de ovinos saudáveis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo do efeito do extrato hidroglicólico de Bidens pilosa na expressão de genes relacionados à intergridade da pele

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)