The functional loss of the retinoblastoma tumour suppressor is a common event in basal-like and luminal B breast carcinomas

Introduction Breast cancers can be classified using whole genome expression into distinct subtypes that show differences in prognosis. One of these groups, the basal-like subtype, is poorly differentiated, highly metastatic, genomically unstable, and contains specific genetic alterations such as the loss of tumour protein 53 (TP53). The loss of the retinoblastoma tumour suppressor encoded by the RB1 locus is a well-characterised occurrence in many tumour types; however, its role in breast cancer is less clear with many reports demonstrating a loss of heterozygosity that does not correlate with a loss of RB1 protein expression. Methods We used gene expression analysis for tumour subtyping and polymorphic markers located at the RB1 locus to assess the frequency of loss of heterozygosity in 88 primary human breast carcinomas and their normal tissue genomic DNA samples. Results RB1 loss of heterozygosity was observed at an overall frequency of 39%, with a high frequency in basal-like (72%) and luminal B (62%) tumours. These tumours also concurrently showed low expression of RB1 mRNA. p16INK4a was highly expressed in basal-like tumours, presumably due to a previously reported feedback loop caused by RB1 loss. An RB1 loss of heterozygosity signature was developed and shown to be highly prognostic, and was potentially a predictive marker of response to neoadjuvant chemotherapy. Conclusions These results suggest that the functional loss of RB1 is common in basal-like tumours, which may play a key role in dictating their aggressive biology and unique therapeutic responses

Relação entre Consciência Fonológica e os Níveis de Escrita de escolares da 1ª série do Ensino Fundamental de escola pública do Município de Porto Real - RJ Relation between phonological awareness and the writing levels concerning first grade students of the Elementary Education in a public school of Porto Real Municipal District

OBJETIVO: comparar o nível de Consciência Fonológica com os níveis de escrita dos escolares de 1ª série do Ensino Fundamental da rede pública do Município de Porto Real. MÉTODOS: foram avaliados 30 escolares de 1ª série, de ambos os sexos, idade entre sete e 11 anos, avaliados individualmente através da aplicação da prova de Consciência Fonológica (Capovilla&Capovilla) e de um autoditado de cinco gravuras. RESULTADO: o grupo silábico-alfabético/ alfabético apresentou melhor desempenho em 6 provas do teste em relação ao grupo de nível pré-silábico/ silábico. CONCLUSÃO: a partir dos resultados obtidos, concluiu-se que há relação significante entre as habilidades de Consciência Fonológica e os Níveis de Escrita dos escolares de 1ª série do Ensino Fundamental da rede pública do Município de Porto Real.<br>PURPOSE: to compare the level of phonological awareness with the writing levels concerning first grade students of the elementary education of a public school of Porto Real Municipal District. METHODS: thirty first grade students of both genders, between seven and eleven-year old, were assessed individually through a phonological awareness test (Capovilla and Capovilla) and through a writing test consisting of five pictures. RESULTS: the syllabic-alphabetic/alphabetic group showed a better performance in six tasks of the test than the presyllabic/syllabic group. CONCLUSION: from the achieved results the outcome is that, there is a significant relation between the abilities of phonological awareness and the writing levels of first grade students of the elementary education in a public school of Porto Real Municipal District