Diabetes mellitus stimulates pancreatic cancer growth and epithelial-mesenchymal transition-mediated metastasis via a p38 MAPK pathway

Diabetes mellitus (DM) and its accompanying chronic inflammation promote tumor progression. p38 mitogen-activated protein kinase (MAPK) is an essential kinase for inflammation. The effects of p38 MAPK on epithelial-mesenchymal transition (EMT)-mediated diabetic pancreatic cancer metastasis remain unclear. Here, we demonstrate that p38 MAPK phosphorylation was significantly increased in pancreatic cancer cells treated with high glucose and in pancreatic tumors from diabetic animals. A p38 MAPK inhibitor significantly suppressed the proliferation and invasion of pancreatic cancer cells under high-glucose conditions. Moreover, p38 MAPK inhibition not only significantly decreased both the tumor volume monitored by magnetic resonance imaging and EMT-related metastasis but also increased the survival of diabetic mice bearing pancreatic tumors. Furthermore, the inflammation in diabetic animals bearing pancreatic tumors was also significantly lower after therapy. Collectively, our findings reveal that p38 MAPK inhibitors may provide a novel intervention strategy for diabetic pancreatic cancer treatment.