N-WASP Control of LPAR1 Trafficking Establishes Response to Self-Generated LPA Gradients to Promote Pancreatic Cancer Cell Metastasis
DEVELOPMENTAL CELL
Authors: Juin, Amelie; Spence, Heather J.; Martin, Kirsty J.; McGhee, Ewan; Neilson, Matthew; Cutiongco, Marie F. A.; Gadegaard, Nikolaj; Mackay, Gillian; Fort, Loic; Lilla, Sergio; Kalna, Gabriela; Thomason, Peter; Koh, Yvette W. H.; Norman, Jim C.; Insall, Robert H.; Machesky, Laura M.
Abstract
Pancreatic ductal adenocarcinoma is one of the most invasive and metastatic cancers and has a dismal 5-year survival rate. We show that N-WASP drives pancreatic cancer metastasis, with roles in both chemotaxis and matrix remodeling. lysophosphatidic acid, a signaling lipid abundant in blood and ascites fluid, is both a mitogen and chemoattractant for cancer cells. Pancreatic cancer cells break lysophosphatidic acid down as they respond to it, setting up a self-generated gradient driving tumor egress. N-WASP-depleted cells do not recognize lysophosphatidic acid gradients, leading to altered RhoA activation, decreased contractility and traction forces, and reduced metastasis. We describe a signaling loop whereby N-WASP and the endocytic adapter SNX18 promote lysophosphatidic acid-induced RhoA-mediated contractility and force generation by controlling lysophosphatidic acid receptor recycling and preventing degradation. This chemotactic loop drives collagen remodeling, tumor invasion, and metastasis and could be an important target against pancreatic cancer spread.
Systematic generation of in vivo G protein-coupled receptor mutants in the rat
PHARMACOGENOMICS JOURNAL
Authors: van Boxtel, R.; Vroling, B.; Toonen, P.; Nijman, I. J.; van Roekel, H.; Verheul, M.; Baakman, C.; Guryev, V.; Vriend, G.; Cuppen, E.
Abstract
G-protein-coupled receptors (GPCRs) constitute a large family of cell surface receptors that are involved in a wide range of physiological and pathological processes, and are targets for many therapeutic interventions. However, genetic models in the rat, one of the most widely used model organisms in physiological and pharmacological research, are largely lacking. Here, we applied N-ethyl-N-nitrosourea (ENU)-driven target-selected mutagenesis to generate an in vivo GPCR mutant collection in the rat. A pre-selected panel of 250 human GPCR homologs was screened for mutations in 813 rats, resulting in the identification of 131 non-synonymous mutations. From these, seven novel potential rat gene knockouts were established as well as 45 lines carrying missense mutations in various genes associated with or involved in human diseases. We provide extensive in silico modeling results of the missense mutations and show experimental data, suggesting loss-of-function phenotypes for several models, including Mc4r and Lpar1. Taken together, the approach used resulted not only in a set of novel gene knockouts, but also in allelic series of more subtle amino acid variants, similar as commonly observed in human disease. The mutants presented here may greatly benefit studies to understand specific GPCR function and support the development of novel therapeutic strategies. The Pharmacogenomics Journal (2011) 11, 326-336; doi:10.1038/tpj.2010.44; published online 8 June 2010