Chemotaxis in Pacreatic Ductal Adenocarcinoma Metastasis: An Unexpected Role of NWASP in Maintaining Self-Generated Gradients and LPA Receptor Recycling

Abstract

Pancreatic ductal adenocarcinoma is one of the most invasive and metastatic cancers and has a dismal 5-year survival rate. Here we show that N-WASP is required for the metastatic process, with roles in both chemotaxis, steering cells out of the tumour, and matrix remodelling, allowing them to escape. Lysophosphatidic acid, a signalling lipid abundant in blood and ascites fluid, is both a mitogen and chemoattractant for PDAC cells. We find they efficiently break LPA down as they respond to it, setting up a self-generated gradient that directs cells out of the tumour. N-WASP depleted cells are unable to respond to LPA gradients and show altered RhoA activation, leading to a loss of cell contractility and traction forces, and reduced metastasis in vitro and in vivo. N-WASP couples LPA receptor signalling to RhoA via the endocytic adapter SNX18, and promotes sensitivity by recycling the receptor back to the surface. Coordinated by N-WASP, the LPA-LPAR signalling loop promotes RhoA-mediated contractility and force generation. Perturbing this pathway chemically or by CRISPR deletion causes PDAC cells to lose their ability to invade through complex 3D environments or peritoneal explants, and remodel fibrillar collagen. We thus reveal N-WASP as a central controller of a chemotactic loop between PDAC cells and microenvironmental conditions that drives metastasis.