Knockdown of the β 1 integrin subunit reduces primary tumor growth and inhibits pancreatic cancer metastasis

Abstract

To address the role of β 1 integrins in pancreatic cancer progression, we stably knocked down β 1 integrin subunit expression in human FG-RFP pancreatic cancer cells using lentiviral-based RNA interference. We then examined the effects of β 1 integrin subunit knockdown on pancreatic cancer cell adhesion, migration and proliferation on tumor microenvironment-specific extracellular matrix proteins in vitro and on tumor progression in vivo using a clinically relevant fluorescent orthotopic mouse model of pancreatic cancer. Knockdown of the β 1 integrin subunit inhibited cell adhesion, migration and proliferation on types I and IV collagen, fibronectin and laminin in vitro. In vivo, knockdown of the β 1 integrin subunit reduced primary tumor growth by 50% and completely inhibited spontaneously occurring metastasis. These observations indicate a critical role for the β 1 integrin subunit in pancreatic cancer progression and metastasis in particular. Our results suggest the β 1 integrin subunit as a therapeutic target for the treatment of pancreatic cancer, especially in the adjuvant setting to prevent metastasis of this highly aggressive cancer. Copyright © 2011 UICC.