N-WASP Control of LPAR1 Trafficking Establishes Response to Self-Generated LPA Gradients to Promote Pancreatic Cancer Cell Metastasis

Abstract

SummaryPancreatic 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.

Loss of Wasl improves pancreatic cancer outcome

“…We recently showed that Wasl deletion impairs ADM by inhibiting fluid-phase endocytosis in pancreatic acinar cells (6). Juin and colleagues created a conditional mouse model with a mosaic deletion of Wasl and concomitant activation of oncogenic Kras and mutated p53 (Trp53 R172H ) (KPCN mice) (9). In this KPCN model, Wasl loss deregulated vesicular transport, reduced metastasis, and improved survival.…”

“…Mice. Ptf1a Cre/wt , Kras LSL-G12D/wt , Trp53 fl/fl , and Wasl fl/fl strains have previously been described (6,9,20,34,68,69).…”

“…We further showed that this ADM is dependent on the neural Wiskott-Aldrich syndrome protein (N-WASP, encoded by the Wasl gene). N-WASP is an indicator of poor prognosis in several cancers and has been implicated in the regulation of metastasis via the promotion of cell migration and remodeling of the extracellular matrix (6)(7)(8)(9)(10)(11). At the cellular level, N-WASP interacts with components of the actin cytoskeleton, including the ARP2/3 complex and CDC42, as well as with PIP2 (12,13).…”

WHIMP links the actin nucleation machinery to Src-family kinase signaling during protrusion and motility

“…The significance of the ubiquitously-expressed N-WASP in protrusion is less clear. N-WASP appears to be critical for 3D invasion [94][95][96], and N-WASP may contribute to 2D motility by some cells [89], but knockouts in mouse fibroblasts and knockdowns in several cancer cell lines suggest that N-WASP is dispensable for lamellipodial assembly [20,97,98]. On the other hand, phylogenetic and functional analyses indicate that the presence of both the WAVE and WASP subfamilies is necessary for fast pseudopod-based amoeboid-like motility [27].…”

Lysophosphatidic acid provokes fibroblast chemotaxis through combinatorial regulation of myosin II

“…LPA, a bioactive phospholipid binds to a variety of GPCRs to trigger multiple cellular processes such as survival, differentiation, embryonic development and migration (Aikawa et al, 2015). A major constituent of serum, LPA has been implicated in initiation and progression of malignant diseases and is a potent chemoattractant to different cell types including tumor cells (Muinonen-Martin et al, 2014;Juin et al, 2019). Upon stimulation, LPA receptors couple to multiple heterotrimeric G proteins (Gi, Gq, G12/13 alpha subunits) to elicit cellular responses, but the specific pathway that triggers chemotaxis in fibroblasts is unclear (Moolenaar et al, 1997;Mills and Moolenaar, 2003).…”