Endoneurial Macrophages Induce Perineural Invasion of Pancreatic Cancer Cells by Secretion of GDNF and Activation of RET Tyrosine Kinase Receptor

作者：Oren Cavel, Olga Shomron, Ayelet Shabtay, Joseph Vital, Leonor Trejo‐Leider, Noam Weizman, Yakov Krelin, Yuman Fong, Richard J. Wong, Moran Amit, Ziv Gil · 发表于：Cancer Research · 年份：2012 · DOI：10.1158/0008-5472.can-12-0764 · 被引用次数：183 · 研究领域：Immune cells in cancer、Phagocytosis and Immune Regulation、Cancer Cells and Metastasis

Perineural invasion of cancer cells (CPNI) is found in most patients with pancreatic adenocarcinomas (PDA), prostate, or head and neck cancers. These patients undergo palliative rather than curative treatment due to dissemination of cancer along nerves, well beyond the extent of any local invasion. Although CPNI is a common source of distant tumor spread and a cause of significant morbidity, its exact mechanism is undefined. Immunohistochemical analysis of specimens excised from patients with PDAs showed a significant increase in the number of endoneurial macrophages (EMΦ) that lie around nerves invaded by cancer compared with normal nerves. Video microscopy and time-lapse analysis revealed that EMΦs are recruited by the tumor cells in response to colony-stimulated factor-1 secreted by invading cancer cells. Conditioned medium (CM) of tumor-activated EMΦs (tEMΦ) induced a 5-fold increase in migration of PDA cells compared with controls. Compared with resting EMΦs, tEMΦs secreted higher levels of glial-derived neurotrophic factor (GDNF), inducing phosphorylation of RET and downstream activation of extracellular signal-regulated kinases (ERK) in PDA cells. Genetic and pharmacologic inhibition of the GDNF receptors GFRA1 and RET abrogated the migratory effect of EMΦ-CM and reduced ERK phosphorylation. In an in vivo CPNI model, CCR2-deficient mice that have reduced macrophage recruitment and activation showed minimal nerve invasion, whereas wild-type mice developed complete sciat...