Regulation of vascular endothelial growth factor production and angiogenesis by the cytoplasmic tail of tissue factor

Regulation of vascular endothelial growth factor production and angiogenesis by the cytoplasmic tail of tissue factor

^*Emory University School of Medicine and the ^†Centers for Disease Control and Prevention, Atlanta, GA 30333; ^**Section of Vascular Medicine, Department of Internal Medicine IV, University of Tuebingen, 72076 Tuebingen, Germany; and the ^‡Third Department of Internal Medicine, Hokkaido University School of Medicine, Sapporo 060-0815, Hokkaido, Japan

Edited by Earl W. Davie, University of Washington, Seattle, WA, and approved May 19, 1999 (received for review November 3, 1997)

Abstract

Tissue factor (TF), a transmembrane receptor for coagulation factor VII/VIIa, is aberrantly expressed in human cancers. We demonstrated a significant correlation between TF and vascular endothelial growth factor (VEGF) production in 13 human malignant melanoma cell lines (r ² = 0.869, P < 0.0001). Two of these cell lines, RPMI-7951, a high TF and VEGF producer, and WM-115, a low TF and VEGF producer, were grown s.c. in severe combined immunodeficient mice. The high-producer cell line generated solid tumors characterized by intense vascularity, whereas the low producer generated relatively avascular tumors, as determined by immunohistologic staining of tumor vascular endothelial cells with anti-von Willebrand factor antibody. To investigate the structure-function relationship of TF and VEGF, a low-producer melanoma cell line (HT144) was transfected with a TF cDNA containing the full-length sequence, a cytoplasmic deletion mutant lacking the coding sequence for the distal three serine residues (potential substrates for protein kinase C), or an extracellular domain mutant, which has markedly diminished function for activation of factor X. Cells transfected with the full-length sequence produced increased levels of both TF and VEGF. Transfectants with the full-length sequence and the extracellular domain mutant produced approximately equal levels of VEGF mRNA. However, cells transfected with the cytoplasmic deletion mutant construct produced increased levels of TF, but little or no VEGF. Thus, the cytoplasmic tail of TF plays a role in the regulation of VEGF expression in some tumor cells.

Footnotes

↵ § K.A. and M.S. contributed equally to this work.
↵ ¶ Present address: Sapporo Kampo Kenshin Center, Kita 7 Nishi 5, Kita-ku, Sapporo 060-0807, Japan.
↵ ‖ To whom reprint requests should be addressed at: 1003 Woodruff Memorial Building, Division of Hematology/Oncology, Department of Medicine, Emory University, 1639 Pierce Drive, Atlanta, GA 30322. e-mail: mshoji{at}emory.edu.
↵ ‡‡ Present address: The George Washington University Medical Center, Ross Hall 712E, 2300 Eye Street, NW, Washington, DC 20037.
This paper was submitted directly (Track II) to the Proceedings Office.
ABBREVIATIONS:

TF,

tissue factor;

VEGF,

vascular endothelial growth factor;

VEC,

vascular endothelial cell;

SCID,

severe combined immunodeficient;

PKC,

protein kinase C;

RT,

reverse transcriptase;

GAPDH,

glyceraldehyde-3-phosphate dehydrogenase