120 research outputs found

    High glucose concentration stimulates intracellular renin activity and angiotensin II generation in rat mesangial cells

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    Increased intrarenal renin-angiotensin system activity contributes to diabetic nephropathy. ANG II generation in mesangial cells (MC) is increased by high-glucose (HG) exposure. This study assessed the mechanisms involved in the glucose-induced ANG II generation in rat MC. Under basal conditions, MC mainly secreted prorenin. HG decreased prorenin secretion and induced a striking 30-fold increase in intracellular renin activity. After 72 h of HG exposure, only the mRNA levels for angiotensinogen and angiotensin-converting enzyme (ACE) were significantly elevated. However, after shorter periods of 24 h of HG stimulation the mRNA levels of the enzymes prorenin and cathepsin B, besides that for ACE, were significantly increased. the results suggest that the HG-induced increase in ANG II generation in MC results from an increase in intracellular renin activity mediated by at least three factors: a time-dependent stimulation of ( pro) renin gene transcription, a reduction in prorenin enzyme secretion, and an increased rate of conversion of prorenin to active renin, probably mediated by cathepsin B. the increase in angiotensinogen mRNA in parallel to increased renin activity indicates that HG also increased the availability of the renin substrate. the consistent upregulation of ACE mRNA suggests that, besides renin, ACE is directly involved in the increased mesangial ANG II generation induced by HG.UNIFESP, Div Renal, BR-04023900 São Paulo, BrazilUNIFESP, Div Renal, BR-04023900 São Paulo, BrazilWeb of Scienc

    Peritumoural, but not intratumoural, lymphatic vessel density and invasion correlate with colorectal carcinoma poor-outcome markers

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    To evaluate whether lymphatic vessel density (LVD) and lymphatic vessel invasion (LVI) are useful markers of worse outcome in colorectal carcinoma and if LVD and LVI correlate to the classical clinical-pathological parameters, we analysed 120 cases of colorectal carcinomas selected from the files of Division of Pathology, Hospital das Clinicas, São Paulo University, Brazil. Assessment of LVD and LVI was performed by immunohistochemical detection of lymphatic vessels, using the monoclonal antibody D2-40. Higher LVD was found in the intratumoural area, when comparing with normal and peritumoural areas (p < 0.001). However, peritumoural LVD, but not intratumoural, correlated with both colonic-wall-invasion depth (p = 0.037) and liver metastasis (p = 0.012). Remarkably, LVI was found associated with local invasion (p = 0.016), nodal metastasis (p = 0.022) and hepatic metastasis (p < 0.001). Peritumoural LVD and LVI are directly related to histopathological variables indicative of poor outcome such as lymph-node status and liver metastasis

    Mutational profile of driver genes in Brazilian melanomas

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    Mutation testing of the key genes involved in melanoma oncogenesis is now mandatory for the application of targeted therapeutics. However, knowledge of the mutational profile of melanoma remains largely unknown in Brazil. PURPOSE Mutation testing of the key genes involved in melanoma oncogenesis is now mandatory for the application of targeted therapeutics. However, knowledge of the mutational profile of melanoma remains largely unknown in Brazil. PATIENTS AND METHODS In this study, we assessed the mutation status of melanoma driver genes BRAF, NRAS, TERT, KIT, and PDGFRA in a cohort of 459 patients attended at Barretos Cancer Hospital between 2001 and 2012. We used polymerase chain reaction followed by Sanger sequencing to analyze the hot spot mutations of BRAF exon 15 (V600E), NRAS (codons 12/13 and 61), TERT (promoter region), KIT (exons 9, 11, 13, and 17), and PDGFRA (exons 12, 14, and 18) in tumors. The mutational profile was investigated for associations with demographic, histopathologic, and clinical features of the disease. RESULTS The nodular subtype was most frequent (38.9%) followed by the superficial spreading subtype (34.4%). The most frequent tumor location was in the limbs (50.0%). The mutation rates were 34.3% for TERT and 34.1% for BRAF followed by NRAS (7.9%), KIT (6.2%), and PDGFRA (2.9%). The BRAF (P = .014) and TERT (P = .006) mutations were associated with younger patients and with different anatomic locations, particularly in the trunk, for the superficial spreading and nodular subtypes, respectively (P = .0001 for both). PDGFRA mutations were associated with black skin color (P = .023) and TERT promoter mutations with an absence of ulceration (P = .037) and lower levels of lactate dehydrogenase. There was no association between patient survival rates and mutational status. CONCLUSION The similar mutational profile we observe in melanomas in Brazil compared with other populations will help to guide precision medicine in this country.CAPES -Coordenação de Aperfeiçoamento de Pessoal de Nível Superior(2012/04194-1

    Hippocampal Astrocytes in Migrating and Wintering Semipalmated Sandpiper

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    Seasonal migratory birds return to the same breeding and wintering grounds year after year, and migratory long-distance shorebirds are good examples of this. These tasks require learning and long-term spatial memory abilities that are integrated into a navigational system for repeatedly locating breeding, wintering, and stopover sites. Previous investigations focused on the neurobiological basis of hippocampal plasticity and numerical estimates of hippocampal neurogenesis in birds but only a few studies investigated potential contributions of glial cells to hippocampal-dependent tasks related to migration. Here we hypothesized that the astrocytes of migrating and wintering birds may exhibit significant morphological and numerical differences connected to the long-distance flight. We used as a model the semipalmated sandpipe

    Mutational profile of TP53 in esophageal squamous cell carcinoma associated with chagasic megaesophagus

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    Chaga's disease is an important communicable neglected disease that is gaining wider attention due to its increasing incidence worldwide. Achalasia due to chagasic megaesophagus (CM), a complication of this disease, is a known-yet, poorly understood-etiological factor for esophageal squamous cell carcinoma (ESCC) development. In this study, we aimed to perform the analysis of TP53 mutations in a series of Brazilian patients with ESCC that developed in the context CM (ESCC/CM), and to compare with the TP53 mutation profile of patients with benign CM and patients with nonchagasic ESCC. Additionally, we intended to correlate the TP53 mutation results with patient's clinical pathological features. By polymerase chain reaction (PCR) followed by direct sequencing of the hotspot regions of TP53 (exon 5 to 8), we found that TP53 mutations were present in 40.6% (13/32) of the ESCC/CM group, 45% (18/40) of the nonchagasic ESCC group, and in only 3% (1/33) of the benign CM group. Missense mutations were the most common in the three groups, yet, the type and mutated exon mutation varied significantly among the groups. Clinically, the groups exhibited distinct features, with both cancer groups (ESCC and ESCC/CM) been significantly associated higher consumption of alcohol and tobacco, older age, worse Karnofsky performance status, poor outcome than the patients with benign CM. No significant association was found between TP53 mutation profile and clinical-pathological features in any of the three groups. We describe first the time the analysis of TP53 mutations in ESCC that developed in the context of CM, and the observed high frequency of mutations, suggest that TP53 also plays an important role in the tumorigenic process of this unexplored etiological condition.Supported by Barretos Cancer Hospital internal research funds (PAIP). Rui M Reis is recipient of a CNPq Produtividade em Pesquisa grantinfo:eu-repo/semantics/publishedVersio

    Clinical characteristics of women diagnosed with carcinoma who tested positive for cervical and anal high-risk human papillomavirus DNA and E6 RNA

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    High-risk human papillomavirus (hrHPV) is an essential cause of cervical carcinoma and is also strongly related to anal cancer development. The hrHPV E6 oncoprotein plays a major role in carcinogenesis. We aimed to evaluate the frequency of hrHPV DNA and E6 oncoprotein in the anuses of women with cervical carcinoma. We analyzed 117 women with cervical cancer and 103 controls for hrHPV and the E6 oncogene. Positive test results for a cervical carcinoma included 66.7 % with hrHPV-16 and 7.7 % with hrHPV-18. One case tested positive for both HPV variants (0.9 %). The samples from the anal canal were positive for HPV-16 in 59.8 % of the cases. Simultaneous presence of HPV in the cervix and anal canal was found in 53.8 % of the cases. Regarding expression of E6 RNA, positivity for HPV-16 in the anal canal was found in 21.2 % of the cases, positivity for HPV-16 in the cervix was found in 75.0 %, and positivity for HPV-18 in the cervix was found in 1.9 %. E6 expression in both the cervix and anal canal was found in 19.2 % of the cases. In the controls, 1 % tested positive for HPV-16 and 0 % for HPV-18. Anal samples from the controls showed a hrHPV frequency of 4.9 % (only HPV16). The presence of hrHPV in the anal canal of women with cervical cancer was detected at a high frequency. We also detected E6 RNA expression in the anal canal of women with cervical cancer, suggesting that these women are at risk for anal hrHPV infection.We acknowledge the Research Support Fund of the State of São Paulo (FAPESP), process number 2010/16795–4), for the financial support grants. FAPESP had no other type of influence on this manuscript beyond the financial suppor

    Loss of Raf kinase inhibitor protein expression is associated with human papillomavirus 16 infection in anal tumors

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    There has been an increase in the incidence of anal cancer in the past two decades, with squamous cell carcinoma (SCC) being the most frequent histological type identified. Among the risk factors, high-risk human papillomavirus (HPV) infection is the most pervasive. Raf kinase inhibitor protein (RKIP) is expressed in a number of normal human tissues and previous studies have demonstrated the prognostic value of the loss of RKIP expression in several gastrointestinal tumors. Therefore, the present study aimed to evaluate the clinical implications of RKIP expression in a series of neoplastic lesions of the anal canal. The resected tumors of 48 patients [8 high-grade intraepithelial lesions (HSILs), 14 adenocarcinomas and 26 squamous cell carcinomas (SCCs)] were immunohistochemically evaluated for RKIP expression, and the results were correlated with clinicopathological data. The results identified a decreased 5-year overall survival rate in patients with adenocarcinoma (40.8%) compared with patients with SCC (76.7%), and a decreased 5-year disease-free survival rate in patients at clinical stages III/IV (37.3 vs. 62.5 and 82.6% for clinical stages 0 and I/II, respectively). Low RKIP expression was revealed in 62.5% of HSILs, 88.5% of SCCs and 100.0% of the adenocarcinomas. High RKIP expression was associated with patient ethnicity (37.5% in non-Caucasians vs. 7.5% in Caucasians) and patient age (33.3% in younger patients vs. 0.0% in older patients). Finally, high RKIP expression was correlated with HPV16 infection status (40% in HPV- vs. 5.3% in HPV+ patients). A correlation was identified between high RKIP expression and lesions with a generally improved prognosis, such as those diagnosed in younger patients, in situ lesions and lesions of lower clinical grades; there was also a negative correlation between high RKIP expression and HPV16 positivity in patients.São Paulo Research Foundation (grant nos. 2010/16795-4 and 2011/08523-7) and Ministry of Science, Technology, Innovation and Communication (grant no. MCT/FINEP/CT-INFRA-PROINFRA 01/2011)info:eu-repo/semantics/publishedVersio

    Low mutation percentage of KRAS and BRAF genes in Brazilian anal tumors

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    Anal cancer is a rare type of digestive tract disease, which has had a crescent incidence in a number of regions. Carcinomas are most frequently found, with squamous cell carcinoma (SCC) comprising similar to 95% of all anal tumors. The major risk factor for development of this type of tumor is human papillomavirus (HPV) infection. However, previous studies have identified patients with anal cancer that are HPV-/p16-and observed that they have a poorer outcome compared with HPV+/p16+ patients. This suggests that molecular profile may drive anal cancer progression. The aim of the present study was to evaluate the mutational status of two important oncogenes, KRAS and BRAF, in a series of anal cancer lesions. Resected tumors of the anal canal (n=43) were evaluated, nine of these were high-grade squamous intra-epithelial lesion cases (HSIL), 11 were adenocarcinomas, and 23 SCCs. Direct sequencing of KRAS proto-oncogene, GTPase (KRAS; codons 12 and 13) and B-Raf proto-oncogene, serine/threonine kinase (BRAF; codon 600) was performed and associated with patient clinicopathological and molecular features. There was a trend of poorer prognosis of adenocarcinoma compared with HSIL and SCC. Analysis indicated one SCC patient (2.3%) exhibited a KRAS p.G13D mutation, and one adenocarcinoma patient (2.3%) exhibited a BRAF p.V600E mutation. It was observed that, these mutations are rare in anal tumors, and certain patients may be at a disadvantage using targeted therapies based on KRAS and BRAF mutational status. As there is a low mutation percentage in SCCs, adenocarcinomas and HSIL, there may exist other underlying molecular alterations that result in anal cancer development, which require further elucidation.The present study was partially supported by the São Paulo Research Foundation (grant no. 2010/16795-4 to Dr Adhemar Longatto-Filho) and the Ministério da Ciência e Tecnologia/Financiadora de Estudos e Projetos (grant no. CT-INFRA-PROINFRA 01/2011). Dr Lucas Tadeu Bidinotto received a São Paulo Research Foundation fellow-ship (grant no. 2011/08523-7).info:eu-repo/semantics/publishedVersio

    The metabolic microenvironment of melanomas: prognostic value of MCT1 and MCT4

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    BRAF mutations are known drivers of melanoma development and, recently, were also described as players in the Warburg effect, while this reprogramming of energy metabolism has been identified as a possible strategy for treating melanoma patients. Therefore, the aim of this work was to evaluate the expression and prognostic value of a panel of glycolytic metabolism-related proteins in a series of melanomas. The immunohistochemical expression of MCT1, MCT4, GLUT1, and CAIX was evaluated in 356 patients presenting melanoma and 20 patients presenting benign nevi. Samples included 20 benign nevi, 282 primary melanomas, 117 lymph node and 54 distant metastases samples. BRAF mutation was observed in 29/92 (31.5%) melanoma patients and 17/20 (85%) benign nevi samples. NRAS mutation was observed in 4/36 (11.1%) melanoma patients and 1/19 (5.3%) benign nevi samples. MCT4 and GLUT1 expression was significantly increased in metastatic samples, and MCT1, MCT4 and GLUT1 were significantly associated with poor prognostic variables. Importantly, MCT1 and MCT4 were associated with shorter overall survival. In conclusion, the present study brings new insights on metabolic aspects of melanoma, paving the way for the development of new-targeted therapies.This work was supported by FAPESP grant to VLV (2012/04194-1) and CP (2015/25351-6). VMG received a doctoral fellowship (SFRH/BD/51997/2012) from Fundacao para a Ciencia e a Tecnologia (FCT) and ON. 2 SR&TD Integrated Program (NORTE-07-0124-FEDER-000017) co-funded by Programa Operacional Regional do Norte (ON.2- O Novo Norte), Quadro de Referencia Estrategico Nacional (QREN), through Fundo Europeu de Desenvolvimento Regional (FEDER).info:eu-repo/semantics/publishedVersio

    Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

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    Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts
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