RIPK4/PEBP1 axis promotes pancreatic cancer cell migration and invasion by activating RAF1/MEK/ERK signaling.

Pancreatic cancer is a lethal disease with a high metastatic potential. In our previous study, we identified a specific subgroup of patients with pancreatic cancer with a serum signature of carcinoembryonic antigen (CEA)+/cancer antigen (CA)125+/CA19-9 ≥1,000 U/ml. In this study, by using high-throughput screening analysis, we found that receptor-interacting protein kinases 4 (RIPK4) may be a key molecule involved in the high metastatic potential of this subgroup of patients with pancreatic cancer. A high RIPK4 expression predicted a poor prognosis and promoted pancreatic cancer cell migration and invasion via the RAF1/MEK/ERK pathway. Moreover, RIPK4 activated the RAF1/MEK/ERK pathway by regulating proteasome-mediated phosphatidylethanolamine binding protein 1 (PEBP1) degradation. The suppression of PEBP1 degradation eliminated the RIPK4-induced activation of RAF1/MEK/ERK signaling and pancreatic cancer cell migration or invasion. Thus, on the whole, the findings of this study indicated that RIPK4 was upregulated in the subgroup of pancreatic cancer with a high metastatic potential. RIPK4 overexpression promoted pancreatic cancer cell migration and invasion via the PEBP1 degradation-induced activation of the RAF1/MEK/ERK pathway.