Supporting local initiatives in the fight against desertification.

Este documento reflete o escopo do Projeto de Cooperação Técnica, que tem como um de seus objetivos imediatos o fortalecimento da capacidade técnica/operacional das instituições e entidades que atuam nas Áreas Suscetíveis à Desertificação (ASD) no Brasil para o aumento e divulgação de conhecimentos, técnicas e práticas de manejo sustentável de dois recursos naturais e convivência no semiárido. Apresenta um resumo das atividades realizadas, os desafios enfrentados e os resultados alcançados pelos projetos, iniciativa que se desenvolve de acordo com as diretrizes do Projeto de Cooperação Técnica e em plena sintonia com as linhas temáticas do IICA e os princípios da artes marciais mistas.This document reflects the scope of the Technical Cooperation Project, which has as one of its immediate objectives the strengthening of the technical/operational capacity of the institutions and entities that act in the Areas Susceptible to Desertification (ASD) in Brazil for the increase and dissemination of knowledge, techniques and practices of sustainable management of two natural resources and coexistence in the semi-arid region. Presents a summary of the activities carried out, the challenges faced and the results achieved by the projects, an initiative that is carried out in accordance with the guidelines of the Technical Cooperation Project and in full harmony with the thematic lines of IICA and the principles of arts mixed martial

RAD51 expression as a biomarker of homologous recombination deficiency in ovarian cancer

Abstract RAD51 is a critical component of the homologous recombination pathway, forming a nucleoprotein filament that enables strand exchange and templated error-free DNA repair. The tumor suppressors BRCA1 and BRCA2 interact with RAD51 to control its activity on DNA. Defects in homologous recombination in tumors are clinically relevant, with evidence of synthetic lethality of such cancers to poly ADP ribose polymerase (PARP) inhibitors. Mutations in RAD51 are uncommon in cancer, but aberrant over-expression of RAD51 has been reported as a mechanism to overcome a recombination defect in in-vitro models. However there are no large scale studies on RAD51 expression in clinically annotated data sets. Here we report a series of experiments to study RAD51 protein expression in ovarian cancer, a tumor type where recombination defects are prominent and being evaluated in several clinical trials of PARP inhibition. Analysis of DNA repair protein expression in formalin fixed clinical tissue is challenging, and our experiments highlight recent advances in quantitative microscopy that are generalizable to other clinical scenarios as well. We first evaluated several commercially available monoclonal antibodies to RAD51 using siRNA depleted cell blocks, to identify an appropriate reagent and staining conditions for formalin fixed paraffin embedded (FFPE) material. We then analyzed RAD51 expression in a collection of 600 ovarian cancer samples obtained through the British Columbia Cancer Agency (BCCA) OvCare consortium, using a combination of multiplexed immunofluorescence staining and automated spectral microscopy to quantify staining on a per-cell basis. We find that RAD51 expression displays a Gaussian distribution in this cohort of high grade epithelial cancers, with no obvious correlation to BRCA mutation status. RAD51 sub-nuclear foci, which are a commonly used measure of homologous recombination in-vitro, did not prove to be accurately quantifiable in FFPE material. We then stained for RAD51 in a collection of approximately 250 ovarian cancer samples obtained from the SCOTROC4 trial. This clinical trial enrolled women with ovarian cancer into two treatment arms with fixed dose and escalated doses of carboplatin. Platinum sensitivity has been shown to correlate with sensitivity to PARP inhibitors, due to the requirement of homologous recombination for repair of platinum adducts. Therefore this trial offers a unique opportunity to study the predictive significance of biomarkers of homologous recombination in-vivo. In our analysis of this data set, we find that samples in the lowest quartile of RAD51 expression displayed a significantly improved survival after platinum chemotherapy, consistent with decreased HR in these cases. These are the first data on RAD51 in a clinical trial dataset of platinum sensitivity. Our study highlights methods and technical challenges for the quantitative analysis of DNA repair proteins in human clinical trial specimen, and describes a potential biomarker for synthetic lethal approaches targeting homologous recombination deficiency. Citation Format: Michal M. Hoppe, David SP Tan, Diana GZ Lim, Anthony Karnezis, David Huntsman, Jennifer Steel, Xinxue Liu, James Paul, Liz-Anne Lewsley, Nadeem Siddiqui, Robert Brown, Anand D. Jeyasekharan. RAD51 expression as a biomarker of homologous recombination deficiency in ovarian cancer [abstract]. In: Proceedings of the AACR Precision Medicine Series: Opportunities and Challenges of Exploiting Synthetic Lethality in Cancer; Jan 4-7, 2017; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2017;16(10 Suppl):Abstract nr B04.</jats:p

Quantitative imaging of RAD51 expression as a marker of platinum resistance in ovarian cancer

Early relapse after platinum chemotherapy in epithelial ovarian cancer (EOC) portends poor survival. A-priori identification of platinum resistance is therefore crucial to improve on standard first-line carboplatin-paclitaxel treatment. The DNA repair pathway homologous recombination (HR) repairs platinum-induced damage, and the HR recombinase RAD51 is overexpressed in cancer. We therefore designed a REMARK-compliant study of pre-treatment RAD51 expression in EOC, using fluorescent quantitative immunohistochemistry (qIHC) to overcome challenges in quantitation of protein expression in situ. In a discovery cohort (n = 284), RAD51-High tumours had shorter progression-free and overall survival compared to RAD51-Low cases in univariate and multivariate analyses. The association of RAD51 with relapse/survival was validated in a carboplatin monotherapy SCOTROC4 clinical trial cohort (n = 264) and was predominantly noted in HR-proficient cancers (Myriad HRDscore < 42). Interestingly, overexpression of RAD51 modified expression of immune-regulatory pathways in vitro, while RAD51-High tumours showed exclusion of cytotoxic T cells in situ. Our findings highlight RAD51 expression as a determinant of platinum resistance and suggest possible roles for therapy to overcome immune exclusion in RAD51-High EOC. The qIHC approach is generalizable to other proteins with a continuum instead of discrete/bimodal expression

NUSAP method for evaluating the data quality in a quantitative microbial risk assessment model for Salmonella in the pork production chain.

&lt;p&gt;The numeral unit spread assessment pedigree (NUSAP) system was implemented to evaluate the quality of input parameters in a quantitative microbial risk assessment (QMRA) model for Salmonella spp. in minced pork meat. The input parameters were grouped according to four successive exposure pathways: (1) primary production (2) transport, holding, and slaughterhouse, (3) postprocessing, distribution, and storage, and (4) preparation and consumption. An inventory of 101 potential input parameters was used for building the QMRA model. The characteristics of each parameter were defined using a standardized procedure to assess (1) the source of information, (2) the sampling methodology and sample size, and (3) the distributional properties of the estimate. Each parameter was scored by a panel of experts using a pedigree matrix containing four criteria (proxy, empirical basis, method, and validation) to assess the quality, and this was graphically represented by means of kite diagrams. The parameters obtained significantly lower scores for the validation criterion as compared with the other criteria. Overall strengths of parameters related to the primary production module were significantly stronger compared to the other modules (the transport, holding, and slaughterhouse module, the processing, distribution, and storage module, and the preparation and consumption module). The pedigree assessment contributed to select 20 parameters, which were subsequently introduced in the QMRA model. The NUSAP methodology and kite diagrams are objective tools to discuss and visualize the quality of the parameters in a structured way. These two tools can be used in the selection procedure of input parameters for a QMRA, and can lead to a more transparent quality assurance in the QMRA.&lt;/p&gt;</p