A key axis of the N-WASP signaling pathway promotes distant metastasis in pancreatic cancer: LOXL2-FAK-N-WASP

Abstract

Abstract BackgroundPancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive solid malignancies. A specific mechanism of its metastasis is not established. In our present study, we investigated whether Neural Wiskott-Aldrich Syndrome Protein (N-WASP) plays a role in distant metastasis of PDAC.MethodsPancreatic cancer cell lines MIA PaCa-2, PANC-1, AsPC-1, and BxPC-3 were used for in vitro and in vivo study. To evaluate the endogenous expression level of N-WASP, we purified the whole RNA and protein to perform the qPCR, RT-PCR and Western blot. And we confirmed the motility and invasiveness and the RNA-seq assays. By using of pancreatic cancer cell lines, orthotopic mouse model of pancreatic cancer was established.ResultsWe found that N-WASP is markedly expressed in clinical patients with PDAC. Through the analysis of clinical patient samples, N-WASP positive group had a much more distant metastatic-pattern than N-WASP negative group. Moreover, it was turned out that N-WASP is a novel mediator of epithelial–mesenchymal transition (EMT) via gene expression profile studies. In addition, knockdown of N-WASP in pancreatic cancer cells had significantly inhibited cell invasion, migration, and EMT. We also observed that the lysyl oxidase-like 2 (LOXL2) and focal adhesion kinase (FAK) are positively associated with the N-WASP-mediated response, thereby modulating EMT and invadopodia. Both N-WASP and LOXL2 depletion significantly reduced the incidence of liver and lung metastatic lesions in orthotopic mouse models of pancreatic cancer.ConclusionsThese results clarify a new role for N-WASP signaling associated with LOXL2 in EMT and invadopodia that regulates intercellular communication in tumor cells to promote pancreatic cancer metastasis. These findings may aid in the development of therapeutic strategies against pancreatic cancer.