Cloning and characterization of murine EDF-1

Murine endothelial differentiation-related factor (mEDF-1) encodes a basic intracellular protein of 148 amino acids which is highly homologous to the human and rat polypeptides. mEDF-1 is expressed in most murine tissues test ed and is evolutionary conserved. mEDF-1 expression is modulated in mouse d evelopment, since its expression is high early in development and decreases thereafter. Because EDF-1 has been isolated as a gene differentially expre ssed by exposure of endothelial cells to the Tat protein of HIV, we evaluat ed mEDF-1 expression in different cell lines derived from tumors which spon taneously develop in Tat transgenic mice. Cells isolated from adenocarcinom as and leiomyosarcomas express very high amounts of EDF-1, independently fr om their capability to secrete Tat. Tat transgenic mice also develop skin l esions which closely resemble human Kaposi's sarcoma. Since Kaposi spindle cells, which are the proliferative component of the sarcoma, differentiate from an endothelial precursor, it is noteworthy that spindle cells derived from Kaposi-like lesions of the Tat transgenic mice downregulate EDF-1 when compared to microvascular endothelial cells isolated from the same tissue. (C) 2001 Elsevier Science B.V. All rights reserved.