Epiregulin promotes migration and invasion of salivary adenoid cystic carcinoma cell line SACC-83 through activation of ERK and Akt.

Hematogenous metastasis is one of the most important factors determining the outcome of the patients with salivary adenoid cystic carcinoma (SACC). In the present study, we examined expression profile of genes in SACC cell lines to look for molecules responsible for its unique metastatic trait. A transcriptomic microarray analysis between the lower lung-metastatic rate cell line SACC-83 and the higher lung-metastatic rate cell line SACC-LM were performed, and eight genes, showed by microarray to be highly expressed in SACC-LM, were picked for validation by quantitative real-time PCR. Among the genes, the expression of epiregulin, a novel member of epidermal growth factor family, was 350-folds higher in SACC-LM than in SACC-83. Accordingly, we examined the effects of epiregulin on migration and invasion in SACC-83 as well as its targeted downstream molecules, and found that epiregulin could promote in vitro migration and invasion in SACC-83. Furthermore, epiregulin not only induced activation of both ERK1/2 and Akt, but also expression of COX-2. In addition, all these effects could be partially blocked by U0126, a specific inhibitor of mitogen-activated protein kinase kinase (MEK or MAPKK), or LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K). Conclusively, the results suggest that epiregulin may play an important role in lung metastasis of SACC.