Biomedical Engineering Reference
In-Depth Information
the surface of the endothelium, increasing the likelihood that the molecules on
the cell will interact with adhesion molecules of the endothelium (Gassmann and
Haier 2008). Regardless of the mechanism involved in localization of tumor cells
to specii c sites, endothelial cell adhesion molecules play an important role.
ENDOTHELIAL CELL ADHESION MOLECULES IN
CANCER PROGRESSION
h ere are several molecules involved in adhesion to endothelial cells. h e i rst
interactions in the rolling mechanism involve selectins. Selectins are a family of
glycoproteins, each containing a lectin domain for ligand interactions
(Fig. 4)
.
Among the family members, E-selectin is expressed on endothelial cells, P-selectin
is expressed on endothelial cells and platelets, and L-selectin is expressed on
leukocytes. h e selectin molecules each contain an amino terminal lectin domain,
an epidermal growth factor (EGF)-like domain, and several short consensus
repeat (SCR) domains in the extracellular region (Tedder
et al.
1995). h e selectin
family members recognize carbohydrate moieties, binding to oligosaccharides and
glycoproteins, ot en called mucins (Tedder
et al.
1995). For example, L-selectin can
interact with the glycoprotein CD34 expressed by endothelial cells. As leukocyte-
endothelial interactions are discussed elsewhere in this text, we will focus mainly
on E-selectin and P-selectin. Stronger adhesion to the endothelium is mediated
Fig. 4
h e structures of the selectin family. h e three members of the selectin family are
L-selectin, E-selectin, and P-selectin. L-selectin is expressed on leukocytes, E-selectin is expressed
on endothelial cells, and P-selectin is expressed on endothelial cells and platelets. Each contains in
the extracellular region an amino terminal lectin domain, an epidermal growth factor (EGF)-like
domain, and several short consensus repeat (SCR) domains.
