Critical role of aquaporin-3 in the human epidermal growth factor-induced migration and proliferation in the human gastric adenocarcinoma cells

Abstract

Background: Aquaporins (AQPs) are expressed in many different tumor cell types in human. New evidence for the involvement of AQPs in cell migration and proliferation adds AQPs to an expanding list of effectors in tumor biology.Aims: The aim of this study was to investigate whether AQP3 expression in the human gastric carcinoma cell lines, AGS and SGC7901, enhances cell migration and proliferation. Methods: Cultured AGS or SGC7901 cells were treated with human epidermal growth factor (hEGF) and subjected to cell migration assay and cell proliferation assay. The expression or activation level of proteins was analyzed by western blot. AQP3 knockdown was obtained by small interfering (si) RNA.Results: Here, we showed that AQP3 is expressed in the human gastric cancer cell lines, AGS and SGC7901. The hEGF induced AQP3 expression in a time- and dose-dependent manner and increased gastric cancer cell migration and proliferation. AQP3 knockdown by siRNA inhibited hEGF-induced AQP3 expression and thus cell migration and proliferation. Furthermore, a mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) inhibitor U0126 inhibited hEGF-induced AQP3 expression and cell migration or proliferation. Conclusions: Collectively, our findings provide for the first time that AQP3 plays a critical role in hEGF-induced cancer cell migration and proliferation and that hEGF induces AQP3 expression via ERK signal transduction pathways. These finds provide evidence for a novel role of AQP3 in human gastric carcinoma as a potentially important determinant of tumor growth and spread.