Involvement of ERK1/2 in Invasiveness and Metastatic Development of Rat Prostatic Adenocarcinoma

Extracellular signal-regulated kinase (ERK) activation has been implicated in cell motility and invasion. In this study, we demonstrated that the steady-state levels of activated ERK1/2 correlated with the degree of invasiveness and metastatic potential of three Dunning cancer cell lines, originating from the same parental tumor. Inhibition of mitogen-activated protein kinase kinase 1 (MEK1), an upstream regulator of ERK1/2, with PD98059 resulted in a dose-dependent reduction of invasiveness with different IC ₅₀ values in the three Dunning cell lines. These results suggest that ERK is, at least in part, responsible for regulating invasiveness and may underlie the differences in the metastatic ability of the cell lines.