Tenascin-C promotes tumor angiogenesis through pro-angiogenic and anti-angiogenic effects involving YAP, Ephrin-B2 and CXCL12 signaling

ABSTRACT: In the tumor microenvironment the extracellular matrix molecule tenascin-C is highly expressed which correlates with worsened survival prognosis. Tenascin-C promotes multiple steps in cancer progression. In particular, tenascin-C promotes the tumor angiogenic switch and the formation of more but poorly functional blood vessels by ill defined mechanisms. Here, we studied tenascin-C angio-modulatory functions by tumor and stromal cells. Unexpectedly, we observed that direct contact of endothelial cells with tenascin-C impairs angiogenesis through disruption of actin polymerization. This resulted in cytoplasmic retention of the F-actin sensor and co-transcription factor YAP and led to downregulation of YAP pro-angiogenic target genes. Conversely, tumor cells and carcinoma associated fibroblasts exposed to tenascin-C secreted pro-angiogenic factors that promoted endothelial cell survival and tubulogenesis. We identified and functionally validated CXCL12 and Ephrin- B2 as important pro-angiogenic effectors of tenascin-C. Proteomic analysis of the secretome of tumor cells exposed to tenascin-C revealed a signature that predicts shorter survival of patients with low grade glioma and glioblastoma with a particular significance for a combined expression of tenascin-C and Ephrin-B2. Altogether, we demonstrated a dual mechanism of action of tenascin-C in tumor angiogenesis where direct contact of endothelial cells with tenascin-C impairs angiogenesis, and paracrine signals derived from contact of tumor cells and carcinoma associated fibroblasts with tenascin-C promotes angiogenesis. These opposing effects provide for the first time an explanation of divergent mechanisms controlled by tenascin-C which can result in a denser but less functional tumor blood vasculature and might unveil new targeting and prediction opportunities.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human) Mus Musculus (mouse)

SUBMITTER: Oliver Schilling  

LAB HEAD: Dr Oliver Schilling

PROVIDER: PXD005217 | Pride | 2016-11-07

REPOSITORIES: Pride