Integrin α3β1 Is Not Required for Onset of Dysplasia in Genetic Model of Colon Cancer but Promotes Motility of Colon Cancer Cells.

BACKGROUND/

objectivesThe progression of colorectal cancer through clinically and histopathologically well-defined stages is driven by specific mutations that activate oncogenes or inactivate tumor-suppressor genes. In addition, pre-cancerous/cancer cells respond to cues from the tissue microenvironment that support tumorigenesis and progression, many of which are transmitted through integrin receptors for the extracellular matrix. Integrin α3β1 has pro-tumorigenic/pro-metastatic roles in many cancers, but it also has suppressive roles in some cancers or at specific stages of progression, indicating that its potential value as a therapeutic target cannot be extrapolated across cancer types or stages. In this study, we investigated roles for α3β1 in colorectal cancer using cellular and genetic models that represent different stages.

methodsWe generated mice with colon-specific α3 knockout in a tamoxifen-inducible model of

resultsGenetic deletion of α3β1 in the colon did not alter dysplasia in mice predisposed to

conclusionsOur findings that α3β1 is not required for pre-cancerous dysplasia but promotes colorectal cancer cell motility/invasion indicate an important role for pro-migratory functions of this integrin at later stages of progression when cells invade from the primary tumor, suggesting that strategies to target α3β1 in colorectal cancer should be aimed at distinct stages of disease progression.