Biopsia con aguja gruesa para la determinación del perfil de expresión génica tumoral, mediante la plataforma de 70 genes / Core needle biopsy for determining tumour gene expression profile through the 70 gene signature

Objetivos Evaluar la utilidad de la biopsia ecoguiada con aguja gruesa diagnóstica (BAG1) para la determinación del perfil de expresión génica tumoral (PEG), en los tumores malignos de mama. Materiales y métodos Revisión de 130 biopsias ecoguiadas con aguja gruesa (BAG), con resultado de malignidad. Se consideraron «aptas» las muestras con, al menos, un 30% de células tumorales. Se estudió la influencia del tamaño tumoral (menor de 1 cm, entre 1-2 cm y mayor de 2 cm) y se analizaron las causas que motivaron muestras no aptas. Se utilizó la plataforma MammaPrint® (70 genes). Se evaluó la influencia del grado histológico y del riesgo genómico en los resultados. Resultados En la BAG1 se obtuvieron muestras aptas en 100 biopsias (76,92%). Entre los 36 casos en los que se utilizó la BAG para obtener el PEG, en 32 (88,89%) se realizó a partir de la BAG1. Entre los 30 casos en los que la BAG1 no resultó apta, en 26 casos no se obtuvo el porcentaje mínimo de células tumorales en la muestra. Ni el grado histológico ni el riesgo genómico influyeron en los resultados. Conclusiones Las muestras diagnósticas de la biopsia ecoguiada con aguja gruesa (BAG1) pueden ser válidas para la determinación del perfil de expresión génica. Ello facilita y acelera el proceso de evaluación pronóstica en los tumores infiltrantes de mama. Por ello, proponemos que, de manera rutinaria y ante el diagnóstico de tumor maligno infiltrante, conste el porcentaje de células tumorales en los informes anatomopatológicos. (AU)

Objectives To assess the utility of diagnostic ultrasound-guided core needle biopsy (CNB1) for determining tumour gene expression profile (GEP) in malignant breast tumours. Materials and Methods Review of 130 diagnostic ultrasound-guided core needle biopsies (CNB1) indicating malignancy. Samples with at least 30% tumour cells were considered suitable. The influence of tumour size (less than 1 cm, between 1-2 cm and greater than 2 cm) was studied and the causes of unsuitable samples were analysed. The MammaPrint® platform (70 genes) was used. The influence of histological grade and genomic risk was evaluated. Results Suitable CNB1 samples were obtained in 100 biopsies (76.92%). Among the 36 cases in which CNB was used to obtain the GEP, in 32 (88.89%) it was performed using the CNB1. Among the 30 cases in which CNB1 was not suitable, the minimum percentage of tumour cells in the sample was not obtained in 26 cases. Neither histological grade nor genomic risk influenced the results. Conclusions Diagnostic samples from ultrasound-guided biopsy (CNB1) can be valid to determine GEP. This facilitates and accelerates the prognostic evaluation process in infiltrating breast tumours. Therefore, we propose that, when diagnosing an infiltrating malignant tumour, the percentage of tumour cells should be routinely recorded in the pathology reports. (AU)

A structure-based approach towards the identification of novel antichagasic compounds: Trypanosoma cruzi carbonic anhydrase inhibitors.

Trypanosoma cruzi carbonic anhydrase (TcCA) has recently emerged as an interesting target for the design of new compounds to treat Chagas disease. In this study we report the results of a structure-based virtual screening campaign to identify novel and selective TcCA inhibitors. The combination of properly validated computational methodologies such as comparative modelling, molecular dynamics and docking simulations allowed us to find high potency hits, with KI values in the nanomolar range. The compounds also showed trypanocidal effects against T. cruzi epimastigotes and trypomastigotes. All the candidates are selective for inhibiting TcCA over the human isoform CA II, which is encouraging in terms of possible therapeutic safety and efficacy.

Cascade Ligand- and Structure-Based Virtual Screening to Identify New Trypanocidal Compounds Inhibiting Putrescine Uptake.

Chagas disease is a neglected tropical disease endemic to Latin America, though migratory movements have recently spread it to other regions. Here, we have applied a cascade virtual screening campaign combining ligand- and structure-based methods. In order to find novel inhibitors of putrescine uptake in Trypanosoma cruzi, an ensemble of linear ligand-based classifiers obtained by has been applied as initial screening filter, followed by docking into a homology model of the putrescine permease TcPAT12. 1,000 individual linear classifiers were inferred from a balanced dataset. Subsequently, different schemes were tested to combine the individual classifiers: MIN operator, average ranking, average score, average voting, with MIN operator leading to the best performance. The homology model was based on the arginine/agmatine antiporter (AdiC) from Escherichia coli as template. It showed 64% coverage of the entire query sequence and it was selected based on the normalized Discrete Optimized Protein Energy parameter and the GA341 score. The modeled structure had 96% in the allowed area of Ramachandran's plot, and none of the residues located in non-allowed regions were involved in the active site of the transporter. Positivity Predictive Value surfaces were applied to optimize the score thresholds to be used in the ligand-based virtual screening step: for that purpose Positivity Predictive Value was charted as a function of putative yields of active in the range 0.001-0.010 and the Se/Sp ratio. With a focus on drug repositioning opportunities, DrugBank and Sweetlead databases were subjected to screening. Among 8 hits, cinnarizine, a drug frequently prescribed for motion sickness and balance disorder, was tested against T. cruzi epimastigotes and amastigotes, confirming its trypanocidal effects and its inhibitory effects on putrescine uptake. Furthermore, clofazimine, an antibiotic with already proven trypanocidal effects, also displayed inhibitory effects on putrescine uptake. Two other hits, meclizine and butoconazole, also displayed trypanocidal effects (in the case of meclizine, against both epimastigotes and amastigotes), without inhibiting putrescine uptake.