ERBB4 promotes the proliferation of gastric cancer cells via the PI3K/Akt signaling pathway

ERBB4 is one of the members of the epidermal growth factor receptor (EGFR) family. ERBB4 is a large transmembrane glycoprotein and has tyrosine kinase activity. Once combined with epidermal growth factor (EGF), ERBB4 can activate the related genes in the nucleus, thus promoting cell division and proliferation. In the present study, we investigated the effect of ERBB4 in the proliferation of gastric cancer cells. We found that high ERBB4 levels were closely related to the poor prognosis of gastric cancer patients. Furthermore, ERBB4 was highly expressed in gastric cancer cell lines when compared to the normal stomach cell line, GES. Clinical samples provided the same results. Two gastric cancer cell lines, SGC-7901 and MNK-45 were used to study the underlying mechanism of ERBB4 in the promotion of cell proliferation in gastric cancer cells both in vitro and in vivo. It was observed that after the expression of ERBB4 was suppressed, the proliferation of gastric cancer cells was markedly inhibited both in vitro and in vivo. Moreover, treatment with lentiviral vector siRNA-ERBB4 (Lv-siRNA-ERBB4) or the ERBB4 inhibitor AST-1306, markedly inhibited gastric cancer cell proliferation. Further experiments revealed that inhibition of the expression of ERBB4 could inhibit the activation of the PI3K/Akt signaling pathway. In addition, the use of the PI3K/Akt signaling pathway inhibitor LY294002 demonstrated the aforementioned results. Therefore, we believe that ERBB4 regulates cell proliferation mainly through the PI3K signaling pathway. Finally, nude mice xenografted with gastric cancer cells with low expression of ERBB4 exhibited smaller tumors and longer survival than those engrafted with control gastric cancer cells. These data indicated that ERBB4 promoted cell proliferation and is thus a potential therapeutic target for the treatment of gastric cancer.