Abstract:
Angiogenesis is a closely controlled biological process that takes place during fetal development of
blood vessels and wound healing, and includes the development of new blood vessels from preexisting blood
vessels. Tumor angiogenesis is a means by which tumors obtain oxygen, nutrition and promote tumor growth.
Angiogenesis-regulating proteins are therefore ideal biomarkers in the study of tumor pathophysiology. In our
laboratory, a new in silico-designed analogue of 2-methoxyestradiol has been synthesized with angiogenic
properties, namely 2-ethyl-3-O-sulfamoyl-estra-1,3,5(10)16-tetraene (ESE-16). The ex vivo influence of ESE-16
on angiogenesis and morphology in platelets of healthy participants was investigated. Scanning electron
microscopy revealed no morphological changes in ESE-16-treated platelets. The possible antiangiogenic effect of
ESE-16-exposed platelets was determined by means of flow cytometry measurement of angiogenic protein levels,
which were significantly increased after platelets were added to tumorigenic breast epithelial cells. This indicates
that binding of platelets to cancer cells causes differential release of platelet constituents. Vascular endothelial
growth factor levels were decreased in platelets, whereas platelet-derived growth factor and matrix
metallopeptidase-9 levels were not significantly affected in platelets. In light of the above-mentioned data,
further investigation of ESE-16’s influence on morphology and angiogenic markers in platelets of cancer patients
is warranted.
