Key points are not available for this paper at this time.
BACKGROUND: Aberrant activation of beta-catenin contributes to the onset of a variety of tumours. There are many tumours that display beta-catenin accumulation in the absence of mutations in its gene. Recently, abnormal accumulation of wild-type beta-catenin has been associated with mutational inactivation of the p53 tumour suppressor. OBJECTIVES: To investigate the potential role of p53 and its homologue p63 in beta-catenin deregulation and to correlate this with disease outcome. METHODS: We analysed a panel of 24 samples of mycosis fungoides (MF), the most frequent manifestation of cutaneous T-cell lymphoma (CTCL), for beta-catenin, p53 and p63 protein expression by immunohistochemistry. Based on the immunostaining results for beta-catenin protein, 11 positive cases were selected for laser microdissection, genomic DNA isolation and subsequent mutation analysis of beta-catenin exon 3 and p53 exons 4-8. RESULTS: Our findings revealed overexpression of beta-catenin, p53 and p63 in 46%, 38% and 17% of cases, respectively. The number of p53-positive cases of MF was significantly higher (P 0.05). CONCLUSIONS: We found an association of beta-catenin and p53 overexpression without detection of structural alteration in the genes, suggesting that p53 mutation is not an important mechanism for beta-catenin activation in primary CTCL. Additionally, we speculate that the p53 codon 72 polymorphism may influence negative feedback control involving beta-catenin and p53.
Bellei et al. (2006) studied this question.