Deletion of laminin-8 results in increased tumor neovascularization and metastasis in mice

Laminin-8 (alpha4beta1gamma1) is one of the major laminin isoforms expressed in vascular endothelial basement membranes. Here we show that deletion of laminin-8 in mice affects angiogenesis under pathological conditions. Murine tumor models used in laminin alpha4-deficient mice results in hyperneovascularization and significant promotion of tumor growth and metastasis. The higher tumor growth rates in mutant mice correlate with decreased tumor cell apoptosis. Depletion of laminin alpha4 chain may alter the structure of vascular basement membranes, leading to increased angiogenesis. Our data suggest that the laminin-8 plays a critical role in the regulation of pathological angiogenesis.