Amplified in
breast cancer 1 (AIB1) is a member of p160
steroid receptor coactivator (SRC) family that mediates the transcriptional activities of
nuclear receptors and other
transcription factors. It acts as a major oncogene in diverse
cancers, whereas biological function of AIB1 in
gastric cancer remains largely unclear. This study was designed to explore the role of AIB1 in gastric
tumorigenesis and its potential as a useful prognostic marker and therapeutic target in this
cancer. Our data demonstrated that AIB1 was significantly up-regulated in
gastric cancer tissues as compared with control subjects. Moreover, AIB1 amplification was found in 47 of 133 (35.3%)
gastric cancer cases, but not in control subjects. AIB1 amplification was positively associated with its
protein expression, and was significantly correlated with poor patient survival. AIB1 knockdown in
gastric cancer cells dramatically inhibited cell proliferation, invasiveness and tumorigenic potential in nude mice, and induced cell cycle arrest and apoptosis. Mechanically, AIB1 promotes
gastric cancer cell proliferation, survival and invasiveness through modulating major signaling pathways such as ErbB and Wnt/β-
catenin pathways. Collectively, these findings suggest that AIB1 plays an important role in the pathogenesis of
gastric cancer and represents a potential prognostic marker and therapeutic target for this
cancer.