258 Interleukin 6 signalling in endovascular progenitors is a driver of melanoma vascularisation and metastasis

Abstract

The development of new vascular structures is a pre-requisite for melanoma growth and spread. Previous studies have shown that tumour vessels arise from endovascular progenitor (EVP) forming transit amplifying (TA) and then differentiated (D) endothelial cells in various melanoma models. RNA-seq of EVPs as compared to D cells pointed to IL-6/JAK/STAT signalling as significantly upregulated in the EVP. This was validated using P-STAT3 staining on sorted cells. Of importance IL6Ra was upregulated substantially in tumour EVPs but not in other vascular beds such as the aorta.