Y-box binding protein-1 contributes to both HER2/ErbB2 expression and lapatinib sensitivity in human gastric cancer cells.

Gene amplification of HER2/ErbB2 occurs in gastric cancer and the therapeutic efficacy of the HER2-targeted antibody, trastuzumab, has recently been improved against HER2-positive advanced stomach cancer. Here, we examined whether Y-box-binding protein-1 (YB-1) could selectively control HER2 gene expression and cellular sensitivity to EGF receptor (EGFR) family protein-targeted drugs in human gastric cancer cells. HER2 expression was specifically downregulated by YB-1 silencing using its cognate siRNA, whereas there was less change in the expression of EGFR and HER3.