HAGE (DDX43) protein expression as an independent biomarker of poor clinical outcome of breast cancer (BC) and potential as a therapeutic target for ER-negative BC.

1013 Background: Recently, we have confirmed that HAGE is involved in promoting proliferation as assessed by increased thymidine incorporation and our preliminary results using shRNA to permanently knockdown HAGE expression also suggests the involvement of HAGE in tumor motility and metastasis. In this study we aimed to analyze the expression of HAGE in large well-characterized BC cohorts to determine its relationship with other clinico-pathological parameters and to investigate its prognostic value. Methods: HAGE protein expression was assessed in: a) 40 normal breast tissue (NBT), b) 60 invasive BCs and their matching NBT, c) BC cell lines, d) A series of 1650 consecutive cases of primary BC who treated with adjuvant CMF and/or endocrine therapies. Further validation was performed in 2 independent series of high risk ER- BC: a) 300 ER –BC who did not received any CT and b) 396 ER- BC treated with adjuvant anthracycline (ATC) based CT. Results: The NBT showed negative HAGE expression (HAGE-) throughout. ...