c-Met expression in a gastric cancer cell line producing alpha-fetoprotein.

Purpose: We previously reported a higher frequency of c-Met protein expression and high proliferative status in gastric cancers producing alpha-fetoprotein (AFP) than in those not producing AFP.

Methods: To investigate this further, we established an AFP-producing gastric cancer cell line, designated as AME-1, from the primary tumor of a patient with AFP-producing gastric cancer.

Results: alpha-Fetoprotein production in the AME-1 cell line was confirmed at the protein level by immunocytochemistry and at the mRNA level by reverse transcription-polymerase chain reaction (RT-PCR). A high amount of AFP was also detected in the supernatant of cultured AME-1. The AME-1 cell line expressed c-Met both at the mRNA and protein levels. A semiquantitative RT-PCR method indicated that AME-1 had a higher amount of c-Met mRNA than well-known gastric cancer cell lines (MKN-28, MKN-45) with strong c-Met expression. Hepatocyte growth factor (HGF), a ligand for the c-Met receptor, was not detected in the mRNA or protein of AME-1. The AME-1 cell line showed a proliferative response to exogenous HGF treatment in a dose-dependent manner, but the activity of migration was not stimulated by exogenous HGF.

Conclusions: The AME-1 cell line may be a useful model for elucidating aggressive behavior, especially related to regulation of the c-Met/HGF system, in AFP-producing gastric cancers.