6 resultados para glucose transporter 3

em Universidade Federal do Rio Grande do Norte(UFRN)


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The expression of glucose transporter protein 1 (GLUT-1), as well the angiogenesis has been associated to clinical behavior and aggressiveness in tumors of various origin. It is believed that the expression of this protein denotes metabolic demand of the tumor cells and, thus its influence upon the formation of new blood vessels. Pleomorphic adenoma (PA) and the adenoid cystic carcinoma (ACC) and mucoepidermoid carcinoma (MEC) represent, respectively, the most commom benign and malignant tumors of salivary glands. The aim of this study was to analyze and compare the immunohistochemical expression of GLUT-1 and its correlation with angiogenesis in cases of PAs, ACCs and MECs considering their histological grades. The sample consisted of 20 PAs, 20 ACCs and 10 MECs. The cases were analyzed and classified according to their histological grades. The expression of GLUT-1 was evaluated in the parenchyma lesions, establishing the percentage of immunopositive cells, according to the following scores: 0 (no cell immunomarked), 1 (up to 25% of tumor cells immunostained), 2 (25 - 50% of tumor cells immunostained) and 3 (more than 50% of tumor cells immunostained). The angiogenic index was analyzed by counting the microvessels immunostained by anti-CD34 antibody, in 5 fields (200X). The analysis of the expression of GLUT-1 in tumor parenchyma showed statistically significant differences between benign and malignant groups (p = 0.022). The average number of microvessels in PAs was 40.4, 21.2 in ACCs and 66.5 in MECs, with significant differences between groups (p <0.001). When compared to the expression of GLUT-1 and angiogenic index as a whole, there was no significant correlation between the number of microvessels and the expression of GLUT-1 (r = 0.211, p = 0.141). In conclusion, the results of this study suggest not only that differences in biological behavior between PAs, ACCs and MECs may be associated to the expression of GLUT-1, but also that benign and malignant salivary gland present differences in the average number of microvessels, with higher levels considered more aggressive tumors. Furthermore, the number of newly formed microvessels can be independent of the metabolic demand of the tumor cells

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The correct histological diagnosis of vascular lesions in the oral mucosa is critical, especially in defining the treatment and prognosis, as some vascular lesions show spontaneous involution and others do not show such behavior. This study analyzed the expression immunohistochemistry of human glucose transporter protein (GLUT-1), in oral benign vascular tumors and to reclassify such lesions according to with his immunoexpression. In addition, we evaluated the immunohistochemical expression of hypoxia-inducible factor 1 alpha (HIF-1α), the main transcription factor involved in cellular adaptation to hypoxia. We analyzed 60 cases of benign oral vascular tumors: 30 cases with histological diagnosis of HEM and 30 cases of oral pyogenic granuloma (PG). The results of this research showed that of the 30 lesions initially classified as HEM, only 7 showed immuno-positivity for GLUT-1, remaining with the initial diagnosis. The remaining 23 were reclassified as vascular malformation (VM) (13 cases) and PG (10 cases). All cases in the sample with an initial diagnosis of PG were negative for GLUT-1, demonstrating the accuracy of histological diagnosis of these lesions. Concerning to the immunoexpression of HIF-1α, the Mann-Whitney test revealed a statistically significant difference between the cases of GP and MV (p = 0.002), where the median of GP (m=78) was higher than the MV (m=53). Based on these results, this study showed that a histological diagnosis alone is not always sufficient for the correct diagnosis of oral HEM and that HIF-1α participates in the pathogenesis of vascular lesions

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Vascular anomalies constitute a distinct group of lesions, but they may present similar clinical and histopatological characteristics, which can lead to diagnostic mistakes. This study aimed by histopathology and immunohistochemical expression of human glucose transporter protein (GLUT-1), correctly identify and classify oral vascular anomalies, besides analyzing the immunoexpression of markers proliferation and apoptosis (Ki-67 and Bcl-2). All cases diagnosed as "oral hemangiomas" belonging to the archives of the Service of Pathological Anatomy from the subject of Oral Pathology of the Department of Dentistry (DOD), of the Federal University of Rio Grande do Norte (UFRN) were reviewed, totalizing 77 cases. Immunohistochemical analysis for GLUT-1 showed that only 26 (33.8%) of the specimens were true infantile hemangiomas (IHs). The 51 (66.2%%) GLUT-1 negative specimens were then reclassified as pyogenic granulomas (PGs) and vascular malformations (VMs) from their histopathologic characteristics,totalizing 26 (33.8%) cases of IHs, 20 (26.0%) of PGs and 31 (40.2) cases of oral VMs. The cases analyzed by the marker Ki-67 showed different median IH (13,85), PG (33,70) and VM (4.55) with statistically significant differences between them (p <0.001). In relation to the protein Bcl-2, the groups also showed different median of the established scores IH (1.00), PG (1.50), VMs (0.0) demonstrating statistically significant differences between them (p<0,001). No statistically significant correlation between the indexes of positivity for Ki-67 and the scores of immunoexpression of Bcl-2 were observed in any group. Thus, we can conclude that it is necessary a careful and parameterized review of cases of vascular anomalies making use of auxiliary tools such as GLUT-1, since the histopathological findings alone, sometimes, are not sufficient to differentiate some anomalies. Furthermore, analysis of the expressions of markers involved in the levels of proliferation of lesions is important for a better understanding of its biological behavior aspect

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The screening for genes in metagenomic libraries from soil creates opportunities to explore the enormous genetic and metabolic diversity of microorganisms. Rivers are ecosystems with high biological diversity, but few were examined using the metagenomic approach. With this objective, a metagenomic library was constructed from DNA soil samples collected at three different points along the Jundiaí-river (Rio Grande do Norte-Brazil). The points sampled are from open area, rough terrain and with the direct incidence of sunlight. This library was analyzed functionally and based in sequence. For functional analysis Luria-Bertani solid medium (LB) with NaCl concentration varied from 0.17M to 0.85M was used for functional analysis. Positives clones resistant to hypersaline medium were obtained. The recombinant DNAs were extracted and transformed into Escherichia coli strain DH10B and survival curves were obtained for quantification of abiotic stress resistance. The sequences of clones were obtained and submitted to the BLASTX tool. Some clones were found to hypothetical proteins of microorganisms from both Archaea and Bacteria division. One of the clones showed a complete ORF with high similarity to glucose-6-phosphate isomerase which participates in the synthesis of glycerol pathway and serves as a compatible solute to balance the osmotic pressure inside and outside of cells. Subsequently, in order to identify genes encoding osmolytes or enzymes related halotolerance, environmental DNA samples from the river soil, from the water column of the estuary and ocean were collected and pyrosequenced. Sequences of osmolytes and enzymes of different microorganisms were obtained from the UniProt and used as RefSeqs for homology identification (TBLASTN) in metagenomic databases. The sequences were submitted to HMMER for the functional domains identification. Some enzymes were identified: alpha-trehalose-phosphate synthase, L-ectoina synthase (EctC), transaminase L-2 ,4-diaminobutyric acid (EctB), L-2 ,4-diaminobutyric acetyltransferase (EctA), L-threonine 3 dehydrogenase (sorbitol pathway), glycerol-3-phosphate dehydrogenase, inositol 3-phosphate dehydrogenase, chaperones, L-proline, glycine betaine binding ABC transporter, myo-inositol-1-phosphate synthase protein of proline simportadora / PutP sodium-and trehalose-6-phosphate phosphatase These proteins are commonly related to saline environments, however the identification of them in river environment is justified by the high salt concentration in the soil during prolonged dry seasons this river. Regarding the richness of the microbiota the river substrate has an abundance of halobacteria similar to the sea and more than the estuary. These data confirm the existence of a specialized response against salt stress by microorganisms in the environment of the Jundiaí river

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The Epidermoid Carcinoma (EC) is the most common lesions located in the region of the head and neck and, despite advances in treatment modalities, the prognosis is still poor. The malignant cells show an increase in glucose uptake, process mediated by glucose transporters (GLUTs). Increased expression of GLUT 1 and GLUT 3 is related to the aggressive behavior of this lesion. The aim of this study was to evaluate, through immunohistochemistry, the expression of GLUTs 1 and 3 in EC of the lower lip. The sample consisted of 40 cases of EC of the lower lip, of which 20 had regional lymph node metastasis and the remaining 20 with absence of metastasis. The percentages of immunostained cells in front of tumor invasion and in the center of tumor were evaluated. These results were related to the presence and absence of lymph node metastasis, TNM classification and histological grading. The percentage of cytoplasmic/membranous expression of GLUT 1 ranged from 77.35% to 100%, while for GLUT 3 this value ranged from 0.79% to 100%. As for nuclear staining for GLUT 1, this percentage ranged from 0 to 0.42%, however. GLUT 3 showed only one case with nuclear staining. Despite the significant expression of tumor cells related to the proteins studied, we observed no statistically significant relationship between the variables and the antibodies analyzed, regardless of the region evaluated. However, there was a moderate positive correlation between cytoplasmic/membranous immunoexpressions of GLUT 1 in invasion front and in the tumor center (r = 0.679, p <0.001). Similarly, moderate positive correlation was found between the nuclear immunoexpressions of GLUT 1 in the invasion front and in the tumor center (r = 0.547, p <0.001). For GLUT 3, was also observed a moderate statistically significant positive correlation between cytoplasmic/membranous expression in tumor invasion front and in tumor center (r = 0.589, p <0.001). We also observed that the immunoreactivity for GLUT 1 was higher than GLUT 3 expression in invasion front (p <0.001) and tumor center (p <0.001). From these results, this study suggests that tumor hypoxia is a remarkable characteristic of the EC of the lower lip and GLUT 1 may be primarily responsible for glucose uptake into the interior of the malignant cells

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The screening for genes in metagenomic libraries from soil creates opportunities to explore the enormous genetic and metabolic diversity of microorganisms. Rivers are ecosystems with high biological diversity, but few were examined using the metagenomic approach. With this objective, a metagenomic library was constructed from DNA soil samples collected at three different points along the Jundiaí-river (Rio Grande do Norte-Brazil). The points sampled are from open area, rough terrain and with the direct incidence of sunlight. This library was analyzed functionally and based in sequence. For functional analysis Luria-Bertani solid medium (LB) with NaCl concentration varied from 0.17M to 0.85M was used for functional analysis. Positives clones resistant to hypersaline medium were obtained. The recombinant DNAs were extracted and transformed into Escherichia coli strain DH10B and survival curves were obtained for quantification of abiotic stress resistance. The sequences of clones were obtained and submitted to the BLASTX tool. Some clones were found to hypothetical proteins of microorganisms from both Archaea and Bacteria division. One of the clones showed a complete ORF with high similarity to glucose-6-phosphate isomerase which participates in the synthesis of glycerol pathway and serves as a compatible solute to balance the osmotic pressure inside and outside of cells. Subsequently, in order to identify genes encoding osmolytes or enzymes related halotolerance, environmental DNA samples from the river soil, from the water column of the estuary and ocean were collected and pyrosequenced. Sequences of osmolytes and enzymes of different microorganisms were obtained from the UniProt and used as RefSeqs for homology identification (TBLASTN) in metagenomic databases. The sequences were submitted to HMMER for the functional domains identification. Some enzymes were identified: alpha-trehalose-phosphate synthase, L-ectoina synthase (EctC), transaminase L-2 ,4-diaminobutyric acid (EctB), L-2 ,4-diaminobutyric acetyltransferase (EctA), L-threonine 3 dehydrogenase (sorbitol pathway), glycerol-3-phosphate dehydrogenase, inositol 3-phosphate dehydrogenase, chaperones, L-proline, glycine betaine binding ABC transporter, myo-inositol-1-phosphate synthase protein of proline simportadora / PutP sodium-and trehalose-6-phosphate phosphatase These proteins are commonly related to saline environments, however the identification of them in river environment is justified by the high salt concentration in the soil during prolonged dry seasons this river. Regarding the richness of the microbiota the river substrate has an abundance of halobacteria similar to the sea and more than the estuary. These data confirm the existence of a specialized response against salt stress by microorganisms in the environment of the Jundiaí river