Expression of methylthioadenosine phosphorylase (MTAP) in pilocytic astrocytomas

BACKGROUND/OBJECTIVES Pilocytic astrocytomas (PAs) are the most frequent astrocytomas in children and adolescents. Methilthioadenosine phosphorylase(MTAP) is a tumor-suppressor gene, the loss of expression of which is associated with a poor prognosis and better response to specific chemotherapy in leukemia and non-small-cell lung cancer. The expression of MTAP in brain tumors remains largely unknown and its biological role in PA is still unexplored. Our aims were to describe the immunohistochemical MTAP expression in a series of PAs and relate it to the clinicopathological features of the patients. METHODS We assessed MTAP expression on immunohistochemistry in 69 pediatric and adult patients with PA in a tissue microarray platform. RESULTS Retained expression of MTAP was seen in >85% of the tumors compared to in the nonneoplastic adjacent tissue. Only 3 supratentorial tumors showed a complete loss of MTAP expression. No significant association with clinicopathological features or overall survival of the patients was found. CONCLUSIONS MTAP expression is retained in PAs and is not an outcome predictor for these tumors. Nevertheless, a subset of patients with PAs exhibiting a loss of MTAP could potentially benefit from treatment with specific chemotherapy, especially when lesions are recurrent or surgical resection is not recommended.This study was partially supported by the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (2012/19590-0) and an HCB program of financial support (Programa de Apoio e Incentivo a Pesquisa)

Expressão de caspase-3 e Bcl-2 em glioblastomas: um estudo imunohistoquímico

The unfavorable prognosis of malignant gliomas can also be explained by the incomplete knowledge of their molecular pathways. Studies regarding the regulatory process of apoptosis in glioblastoma (GBM), the most common malignant glioma, are few, and better knowledge of the expression of pro and anti-apoptotic proteins could collaborate with the development of new treatments founded on molecular basis. The objective of this study was to evaluate by immunohistochemistry the expression of caspase-3 and Bcl-2 in 30 samples of GBMs. The expression of caspase-3 (mean 17.67%) was lower than Bcl-2 (mean 30.92%), a statistically significant result (p<0.0001), suggesting low apoptotic activity in these tumors. Other studies of proteins related to the intrinsic and extrinsic pathway of apoptosis are required to provide additional information of this mechanism in GBMs.O prognóstico desfavorável dos gliomas malignos também pode ser explicado pelo pouco conhecimento dos seus mecanismos moleculares. Estudos relacionados à regulação do processo de apoptose em glioblastoma (GBM), o glioma maligno mais comum, são poucos, e o melhor conhecimento da expressão de proteínas pró e anti-apoptóticas poderia colaborar com o desenvolvimento de novos tratamentos fundamentados sobre a base molecular. O objetivo deste estudo foi avaliar por imunohistoquímica, a expressão de caspase-3 e Bcl-2 em 30 amostras de GBM. A expressão de caspase-3 (média de 17,67%) foi menor que a de Bcl-2 (média de 30,92%), com resultado estatisticamente significante (p<0.0001), sugerindo menor atividade apoptótica nestes tumores. Outros estudos envolvendo proteínas relacionadas à via extrínseca e intrínseca da apoptose são necessários para fornecer informações complementares deste mecanismo em GBMs

KIAA1549: BRAF gene fusion and FGFR1 hotspot mutations are prognostic factors in pilocytic astrocytomas

Up to 20% of patients with pilocytic astrocytoma (PA) experience a poor outcome. BRAF alterations and Fibroblast growth factor receptor 1 (FGFR1) point mutations are key molecular alterations in Pas, but their clinical implications are not established. We aimed to determine the frequency and prognostic role of these alterations in a cohort of 69 patients with PAs. We assessed KIAA1549:BRAF fusion by fluorescence in situ hybridization and BRAF (exon 15) mutations by capillary sequencing. In addition, FGFR1 expression was analyzed using immunohistochemistry, and this was compared with gene amplification and hotspot mutations (exons 12 and 14) assessed by fluorescence in situ hybridization and capillary sequencing. KIAA1549:BRAF fusion was identified in almost 60% of cases. Two tumors harbored mutated BRAF. Despite high FGFR1 expression overall, no cases had FGFR1 amplifications. Three cases harbored a FGFR1 p.K656E point mutation. No correlation was observed between BRAF and FGFR1 alterations. The cases were predominantly pediatric (87%), and no statistical differences were observed in molecular alterations-related patient ages. In summary, we confirmed the high frequency of KIAA1549:BRAF fusion in PAs and its association with a better outcome. Oncogenic mutations of FGFR1, although rare, occurred in a subset of patients with worse outcome. These molecular alterations may constitute alternative targets for novel clinical approaches, when radical surgical resection is unachievable.This study was partially supported by CNPq/Universal (475358/2011-2), and FAPESP (2012/19590-0) grants to RMR and to the NIH- P30CA046934 (CCSG Molecular Pathology/Cytogenetics) to MVG and DL

Copy number profiling of Brazilian astrocytomas

Copy number alterations (CNA) are one of the driving mechanisms of glioma tumorigenesis, and are currently used as important biomarkers in the routine setting. Therefore, we performed CNA profiling of 65 astrocytomas of distinct malignant grades (WHO grade I-IV) of Brazilian origin, using array-CGH and microsatellite instability analysis (MSI), and investigated their correlation with TERT and IDH1 mutational status and clinico-pathological features. Furthermore, in silico analysis using the Oncomine database was performed to validate our findings and extend the findings to gene expression level. We found that the number of genomic alterations increases in accordance with glioma grade. In glioblastomas (GBM), the most common alterations were gene amplifications (PDGFRA, KIT, KDR, EGFR, and MET) and deletions (CDKN2A and PTEN). Log-rank analysis correlated EGFR amplification and/or chr7 gain with better survival of the patients. MSI was observed in 11% of GBMs. A total of 69% of GBMs presented TERT mutation, whereas IDH1 mutation was most frequent in diffuse (85.7%) and anaplastic (100%) astrocytomas. The combination of 1p19q deletion and TERT and IDH1 mutational status separated tumor groups that showed distinct age of diagnosis and outcome. In silico validation pointed to less explored genes that may be worthy of future investigation, such as CDK2, DMRTA1, and MTAP. Herein, using an extensive integrated analysis, we indicated potentially important genes, not extensively studied in gliomas, that could be further explored to assess their biological and clinical impact in astrocytomas.This study was partially supported by the Universal/National Counsel of Technological and Scientific Development (CNPq) (475358/2011-2 – R.M.R.), São Paulo Research Foundation (FAPESP) (2012/19590-0 and 2016/09105-8 – R.M.R.) and the Fundação para a Ciência e a Tecnologia (FCT) (PTDC/SAU-ONC/115513/2009-FCMO-01-0124FEDER-015949). L.T.B. was recipient of FAPESP fellowships (2011/ 08523-7 and 2012/08287-4), N.C.C.was recipient of a FAPESP fellowship (2013/25787-3), M.L.S. was recipient of a CNPq/Programa Institucional de Bolsas de Iniciação Científica (PIBIC) fellowship (100707/ 2014-9), W.M. was recipient of FAPESP (2013/15515-6) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)/ Programa de Suporte à Pós-Graduação de Instituições de Ensino Particulares (Prosup) fellowships, and M.V.P. was a Postdoctoral research fellow under the FCT project PTDC/SAU-ONC/115513/2009. R.M.R. has a CNPq scholarship. C.J. and A.M. acknowledge National Health Service funding to the National Institute for Health Research Biomedical Research Centre at The Royal Marsden and the Institute of Cancer Research.info:eu-repo/semantics/publishedVersio

Safety profile, antimicrobial and antibiofilm activities of a nanostructured lipid carrier containing oil and butter from Astrocaryum vulgare: in vitro studies

Ethnopharmacological relevance: Tucumã (Astrocaryum vulgare)is a fruit native to the Amazon region. Extracts from the peel and pulp are thought of as promising treatments for bacterial infections. The primary constituents of Tucumã oil and butter possess unsaturated carbon chains that are susceptible to oxidation by light or heat. The oils have high volatility and low aqueous solubility that limits their use without a vehicle. Nanotechnology refers to techniques to solve these problems. Nanostructured lipid carriers (NLC), for example, protect fixed oils degradation by heat or light, as well as from oxidation and evaporation, ensuring greater stability and function, thereby prolonging the useful life of the final product. Study objectives: The objective of this study was to evaluate the hemolytic, cytotoxic, antimicrobial and antibiofilm properties of an NLC containing Tucumã butter and oil soasto improve the solubility and photosensitivity of the compounds, generating better pharmacological efficacy. Materials and methods: The NLC was assessed for stability for 60 days. The cytotoxicity of nanoparticles in peripheral blood mononucleated cells was determined in culture using assays for cell viability, DNA damage, oxidative metabolism and damage to human erythrocytes. Antimicrobial activity was determined using the broth microdilution technique and antibiofilm activity according to standardized protocols. Results: The Tucumã NLC remained stable throughout the evaluated period, with pH between 5.22–5.35, monodisperse distribution (PDI&lt;0.3) and average particle size of 170.7 ± 3nm. Cytotoxicity studies revealed that the NLC is safe and modulates inflammatory processes, demonstrated by increased cell viability and nitric oxide levels. There was low hemolytic activity of the NLC against human erythrocytes almost concentrations tested. Conclusion: Taken together, the data suggest that NLC containing Tucumã oil and butter showed antimicrobial and antibiofilm activity against organisms that cause morbidity and mortality in humans. They may be alternative solutions to public health problems related to bacterial infections

Fas, FasL, and cleaved caspases 8 and 3 in glioblastomas: A tissue microarray-based study

This investigation analyzed the immunoexpression of FasL, Fas, cleaved caspase-8, and cleaved caspase-3 in glioblastomas. Formalin-fixed and paraffin-embedded glioblastoma tissues and control brain tissues from 97 patients were analyzed by tissue microarrays and immunohistochemistry. Patients with glioblastomas that were negative or weakly stained (<50% of cells positive) for cleaved caspase-8 had worse cancer-specific overall survival (median=8.5 months) than did patients with tumors that highly expressed cleaved caspase-8 (median=11.7 months; P=0.0325), independent of clinical variables. There was no association of other markers with survival, treatment, sex, age, tumor size, and primary site. Among the tumors, there were reasonable to good positive correlations between the expression of FasL and Fas (r=0.47) and between Fas and cleaved caspase-8 (r=0.41), and there were poor positive correlations between Fas and cleaved caspase-3 (r=0.26), FasL and cleaved caspase-8 (r=0.22), and cleaved caspase-8 and -3 (r=0.31). Our results suggest that Fas-Fas-ligand signal transduction could be inhibited, especially at the stage of caspase-8 activation, thereby establishing a major mechanism for evasion of apoptosis by these tumors. the absence or low expression of cleaved caspase-8 in the tumors was a negative prognostic indicator for patient survival. (C) 2014 Elsevier GmbH. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ São Paulo FMRR USP, Fac Med Ribeirao Preto, Dept Pathol, Ribeirao Preto, SP, BrazilUniversidade Federal de São Paulo UNIFESP EPM, Dept Pathol, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP EPM, Dept Neurol, São Paulo, BrazilHosp Canc AC Camargo, Dept Pathol, São Paulo, BrazilUniv São Paulo FMRP USP, Fac Med Ribeirao Preto, Dept Surg, Ribeirao Preto, SP, BrazilUniversidade Federal de São Paulo UNIFESP EPM, Dept Pathol, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP EPM, Dept Neurol, São Paulo, BrazilFAPESP: 04/09932-4Web of Scienc