Abstract P2-05-04: Gene expression associated with poor prognosis of young TNBC patients
Abstract Background: Among TNBC patients those of very young age (<40 years) display a significantly worse prognosis (Liedtke et al. 2013 Breast Cancer Res Treat). We verified this result in 1161 TNBC samples with full Affymetrix gene expression data of which 845 patients had both detailed age and follow up information. Materials and Methods: We split the full sample set into a finding cohort of 394 TNBC and a validation cohort of 767 TNBC encompassing 309 and 536 samples, respectively, with both age and follow up data. We then used significance analysis of microarrays (SAM) in the finding cohort to look for genes whose expression is associated with young age (<40 years). Iden…
CtIP silencing as a novel mechanism of tamoxifen resistance in breast cancer.
AbstractAcquired resistance to the antiestrogen tamoxifen constitutes a major clinical challenge in breast cancer therapy. However, the mechanisms involved are still poorly understood. Using serial analysis of gene expression, we identified CtIP, a BRCA1- and CtBP-interacting protein, as one of the most significantly down-regulated transcripts in estrogen receptor α–positive (ER+) MCF-7 tamoxifen-resistant breast cancer cells. We further confirmed the association of CtIP down-regulation with tamoxifen resistance in an additional ER+ breast cancer line (T47D), strengthening the relevance of the phenomenon observed. In additional studies, we found CtIP protein expression in a majority of ER+ …