Secreted 70 kDa lumican stimulates growth and inhibits invasion of human pancreatic cancer

Lumican expression in the stromal tissues of pancreatic ductal adenocarcinoma (PDAC) correlates with tumor invasion, and tends to correlate with poor prognosis. We used gene transfection techniques to examine the biological roles of lumican secreted from PDAC cells. Lumican-transfected PANC-1 cells secreted a 70-kDa lumican protein and had an active ERK pathway. Transfection stimulated PANC-1 cell growth, increased cell adhesion to laminin, inhibited cell invasion, and decreased active matrix metalloproteinase-9. Down-regulation of lumican using siRNA resulted in opposite cell behavior. Thus, the 70-kDa lumican secreted by PDAC cells plays important roles in cell growth and invasion.