Browsing by Author "Amorim, Irina"
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- ERBB2 in Cat Mammary Neoplasias Disclosed a Positive Correlation between RNA and Protein Low Expression Levels: A Model for erbB-2 Negative Human Breast CancerPublication . Santos, Sara; Batista, Claudia S.; Abreu, Rui M.V.; Bastos, Estela; Amorim, Irina; Gut, Ivo G.; Gartner, Fátima; Chaves, RaquelHuman ERBB2 is a proto-oncogene that codes for the erbB-2 epithelial growth factor receptor. In human breast cancer (HBC), erbB-2 protein overexpression has been repeatedly correlated with poor prognosis. In more recent works, underexpression of this gene has been described in HBC. Moreover, it is also recognised that oncogenes that are commonly amplified or deleted encompass point mutations, and some of these are associated with HBC. In cat mammary lesions (CMLs), the overexpression of ERBB2 (27%–59.6%) has also been described, mostly at the protein level and although cat mammary neoplasias are considered to be a natural model of HBC, molecular information is still scarce. In the present work, a cat ERBB2 fragment, comprising exons 10 to 15 (ERBB2_10–15) was achieved for the first time. Allelic variants and genomic haplotype analyses were also performed, and differences between normal and CML populations were observed. Three amino acid changes, corresponding to 3 non-synonymous genomic sequence variants that were only detected in CMLs, were proposed to damage the 3D structure of the protein. We analysed the cat ERBB2 gene at the DNA (copy number determination), mRNA (expression levels assessment) and protein levels (in extra- and intra protein domains) in CML samples and correlated the last two evaluations with clinicopathological features. We found a positive correlation between the expression levels of the ERBB2 RNA and erbB-2 protein, corresponding to the intracellular region. Additionally, we detected a positive correlation between higher mRNA expression and better clinical outcome. Our results suggest that the ERBB2 gene is post-transcriptionally regulated and that proteins with truncations and single point mutations are present in cat mammary neoplastic lesions. We would like to emphasise that the recurrent occurrence of low erbB-2 expression levels in cat mammary tumours, suggests the cat mammary neoplasias as a valuable model for erbB-2 negative HBC.
- Growth performance of Bísaro pigs in hoop barn and confinement housing systemsPublication . Araújo, José Pedro; Cerqueira, Joaquim; Pires, Pedro; Amorim, Irina; Durão, J.; Cadavez, Vasco; Silva, J. Santos e; Domínguez, Rubén; Bermúdez Piedra, Roberto; Lorenzo Rodriguez, Jose ManuelThe goal of this study was to compare the growth performance of growing/finishing pigs housed in a hoop barn system and in traditional confinement. A total of twenty Bísaro breed pigs, with 98.6±5.71 days of age, and 25.4±4.87 kg of BW were used (beginning of experiment). The pigs were equally distributed in two groups: Gr1 - hoop barn (3.0 m2/pig) with outdoor access (200 m2/pig); and Gr2 - traditional confinement with straw bedding (1.8 m2/pig). Both groups were fed with the same diet. During the next 98 days’ period (growing phase) and until pigs reached approximately 80 kg LW, the animals were fed with a concentrate diet. In the finishing phase consisting of a final 70 days period until slaughter, the animals reached between 110-120 kg LW and were fed with concentrate and cornflour. The feed intake per group was registered daily and growth performances were collected every two weeks. During the growing phase no differences (P > 0.05) were observed in the average daily gain (ADG) between Gr1 (0.546±0.10 kg/day) and Gr2 (0.563±0.05 kg/day). However, a higher variability was observed in hoop barn group (CV of 18.1% vs. 8.8% in confinement). Similar results were observed during the finishing phase with ADG of 0.535±0.09 kg for Gr1 and 0.505±0.07 kg for Gr2 (P > 0.05). In both growing and finishing phases, the feed conversion rates (FCR) were 3.11 on the Gr1 versus 3.12 kg/kg on the Gr2, and 3.44 in Gr1 versus 3.53 in Gr2, respectively. Despite the different housing systems, ADG and FCR per period were identical in both systems. To the consumer’s point of view, the positive aspects of the hoop barn system, such as the use of uncultivated land, product image and pig welfare, are sustainably attractive and therefore could be further reflected in the market.