Correction to: The Cancer, Educate to Prevent Model-the Potential of School Environment for Primary Prevention of Cancer.

The affiliation address of Dr. Helena Santos should be Faculty of Economics, University of Porto, Portugal and Dr. Luís Moreira's should be Research Unit in Education and Community Intervention - RECI & Health School of Vila Nova de Gaia - Piaget Institute.

The Cancer, Educate to Prevent Model-the Potential of School Environment for Primary Prevention of Cancer.

Cancer represents one of the main causes of death worldwide; consequently, preventive interventions are of utmost importance in public health education. The leading model of cancer prevention campaigns is based on general and undifferentiated actions mediated by health professionals, focusing on the technical and scientific information but rather ineffective in changing the symbolic, cognitive and practical relationship with the disease. New intervention models are thus required to address cancer literacy, being early interventions targeted to specific groups an elective counterpoint to contribute to positive and durable changes in cancer prevention. Our aim is to evaluate the feasibility and impact of cancer prevention programmes planned as focused interventions in restricted targets and mediated by non-healthcare professionals to increase cancer literacy and promote preventive behaviours. This pilot study evaluates schools' potential as a vehicle for cancer prevention education in a reality shaped by traditional health prevention campaigns. We developed a protocol of systematic surveying in order to review and, in the future, optimize and replicate this ecological model of intervention to other groups and contexts. The implementation of this model has been successful in which concerns to the effectiveness of the training programme for teachers. This led to the development of impactful cancer prevention education projects by trainees targeted to their students, allowing us to argue that it contributes to knowledge and practice in this complex as consensual priority area of intervention.

The prion-related protein (testis-specific) gene (PRNT) is highly polymorphic in Portuguese sheep.

The objective of this study was to search for polymorphisms in the ovine prion-related protein (testis-specific) gene (PRNT). Sampling included 567 sheep from eight Portuguese breeds. The PRNT gene-coding region was analyzed by single-strand conformation polymorphism and sequencing, allowing the identification of the first ovine PRNT polymorphisms, in codons 6, 38, 43 and 48: c.17C>T (p.Ser6Phe, which disrupts a consensus arginine-X-X-serine/threonine motif); c.112G>C (p.Gly38>Arg); c.129T>C and c.144A>G (synonymous) respectively. Polymorphisms in codons 6, 38 and 48 occur simultaneously in 50.6% of the animals, 38.8% presenting as heterozygous. To study the distribution of the polymorphism in codon 43, a restriction fragment length polymorphism analysis was performed. Polymorphic variant c.129C, identified in 89.8% of the animals with 32.8% presented as heterozygous, was considered the wild genotype in Portuguese sheep. Eight different haplotypes which have comparable distribution in all breeds were identified for the PRNT gene. In conclusion, the PRNT coding region is highly polymorphic in sheep, unlike the prion protein 2 dublet gene (PRND), in which we previously found only one synonymous substitution (c.78G>A), in codon 26. The absence or reduced number of PRND heterozygotes (c.78G>A) was significantly associated with three PRNT haplotypes (17C-112G-129T-144A,17CT-112GC-129CT-144AG and 17T-112C-129C-144G), and the only three animals found homozygous at c.78A had the 17C-112G-129C-144A PRNT haplotype. These results constitute evidence of an association between polymorphic variation in PRND and PRNT genes, as has already been observed for PRND and prion protein gene (PRNP).

Prion-like Doppel gene polymorphisms and scrapie susceptibility in Portuguese sheep breeds.

The establishment of an association between prion protein gene (PRNP) polymorphisms and scrapie susceptibility in sheep has enabled the development of breeding programmes to increase scrapie resistance in the European Union. Intense selection for PRNP genotype may lead to correlated selection for genes linked to PRNP. We intended to investigate if any association exists between genetic variation in prion-like protein Doppel gene (PRND) and scrapie susceptibility, determined through PRNP genotyping. Sampling included 460 sheep from eight Portuguese breeds and the PRND gene coding region was analysed by multiple restriction fragment-single strand conformation polymorphism (MRF-SSCP), whereas PRNP genotyping was carried out by primer extension. A synonymous substitution (c.78G>A) was detected in codon 26 of the PRND gene, in all breeds except Churra Mondegueira. Linkage disequilibrium was found between the PRND and PRNP loci (P = 0.000). Specifically, PRND was monomorphic in the 45 animals with the more resistant ARR/ARR PRNP genotype (P = 0.003), whereas a higher frequency of PRND heterozygotes (GA) was associated with ARQ/AHQ (P = 0.029). These results constitute preliminary evidence of an association between a polymorphism in the PRND gene and scrapie susceptibility, and indicate that the possibility of undesirable consequences from widespread selection for PRNP genotype on genetic diversity and reproduction traits needs to be further investigated.

Doppel gene polymorphisms in Portuguese sheep breeds: insights on ram fertility.

Transgenic knockout of the gene encoding the prion-like protein Doppel leads to male infertility in mice. The precise role of Doppel in male fertility is still unclear, but sperm from Doppel-deficient mice appear to be unable to undergo the normal acrosome reaction necessary to penetrate the zona pellucida of the oocyte. The objective of this study was to characterize Doppel (Prnd) gene polymorphisms in eight Portuguese sheep breeds and to determine a possible relationship between these polymorphisms and ram fertility. Ovine genomic DNA of 364 animals of different breeds (Bordaleira entre Douro e Minho, Churra Badana, Churra Galega Mirandesa, Churra Mondegueira, Merino da Beira Baixa, Merino Branco, Saloia and Serra da Estrela) were analysed by multiple restriction fragment-single-strand conformation polymorphism (MRF-SSCP). This analysis revealed a synonymous substitution G-->A in codon 26 of Prnd gene. Churra Galega Mirandesa and Saloia breeds were more polymorphic (P=0.005 and P=0.04, respectively) than the overall population, while Serra da Estrela and Merino Branco animals were less polymorphic (P=0.007 and P=0.04). No polymorphism was found in Churra Mondegueira breed. Semen from 11 rams of Churra Galega Mirandesa breed (7 homozygous wildtype GG and 4 heterozygous GA) routinely used in the Portuguese Animal Germoplasm Bank was collected and frozen for fertility tests. A classification function was estimated, using data from post-swim-up semen motility and concentration and Day 6 embryo production rate, allowing the identification of the Doppel homozygous GG genotype with 86.7% of accuracy. This preliminary study detected the presence of only one polymorphism in codon 26 of Prnd gene in the Portuguese sheep breeds. In the polymorphic Churra Galega Mirandesa breed, GG genotype could be characterized through a model using three fertility traits, suggesting a relationship with male reproduction. Any future research should investigate not only AA genotype and its influence on ram fertility but also the possible consequences of the European Community selection program to eradicate Scrapie on the Prnd genotypes and indirectly on sheep breed's viability and preservation.

Key elements of the BMP/SMAD pathway co-localize with CDX2 in intestinal metaplasia and regulate CDX2 expression in human gastric cell lines.

Helicobacter pylori infection induces intestinal metaplasia of the stomach, a preneoplastic lesion associated with an increased risk for gastric cancer development. Intestinal metaplasia is induced by the intestine-specific transcription factor CDX2 but the mechanisms responsible for this ectopic expression have never been described. We hypothesized that the BMP/SMAD pathway has a role in CDX2 regulation, in this context, for the following reasons: (1) the BMP pathway is crucial for normal intestinal differentiation and (2) there is an influx of BMP2 and BMP4-producing cells to the stomach upon Helicobacter pylori infection. We evaluated the expression of key elements of the BMP pathway in human stomach specimens with IM. Growth factor treatments, with BMP2 and BMP4, were performed in cultured cells and a knock-down experiment of SMAD4 was done using RNAi. We showed overexpression in IM of BMP2/4, BMPR1A, and SMAD4 in 56% of IM foci, and pSMAD1/5/8 in 100% of IM foci as compared to adjacent mucosa. In vitro, treatment of AGS cells with BMP2 and BMP4 increased endogenous CDX2 expression as well as the intestinal differentiation markers MUC2 and LI-cadherin. On the other hand, SMAD4 knock-down led to decreased endogenous CDX2, MUC2, and LI-cadherin in AGS. Treatment of the SMAD4 knock-down cells had no influence on CDX2 expression as opposed to wild-type cells. A 9.3 kb CDX2 promoter could be transactivated by SMAD4 and SMAD1 in a cell-dependent manner. In conclusion, we identified for the first time that the BMP pathway is active in intestinal metaplasia and that BMP2 and BMP4 regulate CDX2 expression and promote intestinal differentiation through the canonical signal transducers.

Thomsen-Friedenreich antigen expression in gastric carcinomas is associated with MUC1 mucin VNTR polymorphism.

Aberrant glycosylation of mucins is a common phenomenon associated with oncogenic transformation. We investigated the association between expression of the tumor-associated antigens T, Tn, and sialyl-Tn and polymorphism in the length of the MUC1 mucin tandem repeat in a series of gastric carcinomas. We further evaluated the relevance of MUC1 tandem repeat length on the expression of these tumor-associated carbohydrate antigens (TACAs) using a gastric carcinoma cell line model expressing recombinant MUC1 constructs carrying 0, 3, 9, and 42 repeats. Gastric carcinomas showed a high prevalence of Tn and sialyl-Tn antigens, whereas T antigen was less frequently expressed. The expression of T antigen was significantly higher in gastric carcinomas from patients homozygous for MUC1 large tandem repeat alleles. No significant associations were found for Tn and sialyl-Tn antigens. This novel association was reinforced by the gastric carcinoma cell line model experiments, where de novo expression of T antigen was detected in clones transfected with larger VNTR regions. Our results indicate that polymorphism in the MUC1 tandem repeat influences the expression of TACAs in gastric cancer cells and may therefore allow the identification of subgroups of patients that develop more aggressive tumors expressing T antigen.

Microsatellite instability in medullary breast carcinomas.

Microsatellite instability (MSI) has been reported to occur in a wide variety of sporadic tumours, such as colorectal and gastric cancers. MSI positivity has been associated with a particular clinico-pathologic profile, including the presence of abundant lymphoid infiltration, poor differentiation and a relatively good outcome for the patients. Since medullary breast carcinomas (MBCs) share these clinico-pathologic features with the MSI-positive tumours described above, we evaluated MSI in this particular histologic type of breast cancer. DNA of 24 MBC cases was extracted from formalin-fixed, paraffin-embedded tissue. The presence of MSI was analysed using BAT-26. We also searched mutations in 2 target genes: TGF-beta RII and BAX. Five cases of the series were also analysed for 1 (CA) dinucleotide tandem repeat sequence (D1S158), 8 tetranucleotide repeat sequences (D3S1358, D5S818, D7S820, D8S1179, D13S317, D21S11, FGA and VWA) and 1 pentanucleotide repeat (dAAAAT), localized in intron 1 of p53 gene. We found 2 carcinomas (8.3%) with BAT-26 instability. None of the cases had mutations in the "target genes", TGF-beta RII and BAX, including the 2 cases with BAT-26 instability. No MSI was observed using the panel of tetra- and pentanucleotide markers. Loss of heterozygosity was found in some loci. No significant difference in mean MIB-1 index according to RER status was observed. The low frequency of MSI in MBC is similar to that of other histologic types of breast cancer. Although MBCs share some clinico-pathologic features with colorectal and gastric carcinomas, which exhibit a high frequency of MSI, the underlying genetic events leading to this breast tumour are different from those leading to tumours of the digestive tract.