23 research outputs found
Investigation of prognostic value of polymorphisms within estrogen metabolizing genes in Lithuanian breast cancer patients
Gene expression profile and response to trastuzumab–docetaxel-based treatment in breast carcinoma
Associations between null mutations in GSTT1 and GSTM1, the GSTP1 Ile105Val polymorphism, and mortality in breast cancer survivors
Frequent allelic losses at 11q24.1–q25 in young women with breast cancer: association with poor survival
The transcription factor GATA-1 is overexpressed in breast carcinomas and contributes to survivin upregulation via a promoter polymorphism.
Expression of survivin, a member of the inhibitor of apoptosis protein family, is elevated in human cancers and considered as a new therapeutic target. Mechanism upregulating survivin expression in tumour cells is poorly understood. In this study, we show that breast cancer patients harbouring a polymorphism G235A in the survivin promoter present a higher level of survivin expression. This polymorphism creates a binding site for the transcription factor GATA-1 inducing a second GATA-1-binding site in survivin promoter. At the mRNA level, GATA-1 was present in breast carcinomas and adjacent normal tissues, whereas the protein was only detected in carcinomas by western blot and immunohistochemistry. Transfection of wild-type and different constitutively active GATA-1 mutants (serine 26, 178 or 310) showed that only phospho-serine 26 GATA-1 was able to increase survivin expression. This increase was higher in G235A than in G235G cell lines. Phospho-serine 26 GATA-1 bound directly survivin promoter, with a stronger interaction in G235A than in G235G polymorphism indicating that both GATA-1-binding sites are functional. These data identify GATA-1 as a key feature in tumour aggressiveness by enhancing survivin expression and delineate its targeting as a possible new therapeutic strategy in breast carcinomas