Growth and survival of lung cancer cells: regulation by kallikrein-related peptidase 6 via activation of proteinase-activated receptor 2 and the epidermal growth factor receptor.

The dysregulated expression of kallikrein-related peptidase 6 (KLK6) is involved in non-small cancer (NSCLC) cell growth. However, the mechanism that sustains KLK6 signaling remains unknown. We used an isogenic non-small cell lung cancer (NSCLC) cell model system to demonstrate that KLK6 promotes the proliferation of lung tumoral cells and restrains their apoptosis in vitro via ligand-dependent EGFR transactivation. KLK6 activated the ERK and Akt pathways and triggered the nuclear translocation of β-catenin. The stimulating effects of KLK6 required its proteolytic activity and were dependent on the protease-activated receptor 2 (PAR2). These observations support the concept of a role for KLK6 in the oncogenesis of NSCLC.