RON and c-Met facilitate metastasis through the ERK signaling pathway in prostate cancer cells.

Prostate cancer (PCa) is a metastatic malignant cancer driven by complex pathological mechanisms and characterized by poor long-term prognosis. Metastasis is the main cause of death of PCa patients, yet the molecular mechanisms of this process are poorly understood. In the present study, positive co-expression of RON and c-Met was observed in human clinical PCa tissues (biopsy material), as detected by immunohistochemical staining and quantitative real-time PCR. We investigated this further in PCa cells, demonstrating that the inhibition of RON and c-Met with foretinib (GSK1363089) suppressed metastasis and promoted the reversal of the epithelial-to-mesenchymal transition (EMT) in PCa cells. Furthermore, the invasion and migration of PCa cells were enhanced by the exogenous activation of RON with MSP and c-Met with HGF, whereas silencing of RON and c-Met attenuated the invasion and metastasis of the PCa cells. Our data also demonstrated that HGF/c-Met, but not the MSP-RON signaling pathway may be the dominant mechanism for PCa EMT. We further revealed that RON and c-Met facilitate metastasis via ERK1/2 signaling. These findings indicate that RON and c-Met facilitate metastasis through ERK1/2 signaling and that targeting RON and c-Met with foretinib may be an attractive therapeutic option for suppressing PCa metastasis.