Expression and structural features of endoglin (CD105), a transforming growth factor beta1 and beta3 binding protein, in human melanoma

Br J Cancer. 1996 Nov;74(10):1586-91. doi: 10.1038/bjc.1996.593.


Human endoglin (CD105) is a member of the transforming growth factor beta (TGF-beta) receptor family that binds TGF-beta1 and -beta3, but not TGF-beta2, on human endothelial cells. Immunohistochemical analyses demonstrated that CD105 is expressed on normal and neoplastic cells of the melanocytic lineage. The anti-CD105 MAb, MAEND3, stained 50, 25 and 34% of intradermal naevi, primary and metastatic melanomas investigated, respectively, and nine out of 12 melanoma cell lines. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed that CD105 expressed by melanoma cells consists of a homodimeric protein with an apparent molecular weight of 180 and 95 kDa under non-reducing and reducing conditions. Cross-linking of 125I-labelled TGF-beta1 to melanoma cells, Mel 97, by disuccinimidyl suberate (DSS) demonstrated that CD105 expressed on pigmented cells binds TGF-beta1; the pattern of binding of TGF-beta1 to melanoma cells was found to be similar to that of human umbilical vein endothelial cells. The addition of exogenous, bioactive TGF-beta1 significantly (P<0.05) inhibited the growth of CD105-positive melanoma cells, Mel 97, but did not affect that of CD105-negative melanoma cells, F0-1. These data, altogether, demonstrate that CD105 is expressed on pigmented cells and might play a functionally relevant role in the biology of human melanoma cells by regulating their sensitivity to TGF-betas.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD
  • Cell Division / drug effects
  • Electrophoresis, Polyacrylamide Gel
  • Endoglin
  • Fluorescent Antibody Technique, Indirect
  • Humans
  • Immunohistochemistry
  • Iodine Radioisotopes
  • Melanoma / metabolism*
  • Melanoma / pathology
  • Mice
  • Mice, Inbred BALB C
  • Neoplasm Proteins / metabolism*
  • Nevus / metabolism
  • Receptors, Cell Surface
  • Skin Diseases / metabolism
  • Skin Neoplasms / metabolism*
  • Skin Neoplasms / pathology
  • Transforming Growth Factor beta / metabolism*
  • Transforming Growth Factor beta / pharmacology
  • Tumor Cells, Cultured / drug effects
  • Vascular Cell Adhesion Molecule-1 / chemistry
  • Vascular Cell Adhesion Molecule-1 / metabolism*


  • Antigens, CD
  • ENG protein, human
  • Endoglin
  • Iodine Radioisotopes
  • Neoplasm Proteins
  • Receptors, Cell Surface
  • Transforming Growth Factor beta
  • Vascular Cell Adhesion Molecule-1