Biomedical Engineering Reference
In-Depth Information
Fig. 5
h e structures of ICAM-1 and VCAM-1. ICAM-1 and VCAM-1 are members of the
immunoglobulin (Ig) gene superfamily. As such, they contain several extracellular Ig domains.
by adhesion molecules of the Immunoglobulin (Ig) gene superfamily. Members
of the Ig gene superfamily contain several Ig-like domains and, within this family,
vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule
1 (ICAM-1) are expressed on activated endothelium
(Fig. 5)
(Kobayashi
et al.
2007, Brooks
et al.
2009). h ere are other members of this family, such as platelet
endothelial cell adhesion molecule 1 (PECAM-1), but there are few studies as to
their roles in cancer progression. h e ligands for these molecules are integrins
expressed by leukocytes, and also by cancer cells (Dittmer
et al.
2008). h ere are
studies indicating that cancer cells express adhesion molecules similar to those on
endothelium, indicating that the interactions discussed could occur in the opposite
orientation, i.e., ICAM-1 on tumor cells interacting with integrins on endothelial
cells (Kobayashi
et al.
2007). However, this has not been well characterized. More
likely, expression of these molecules facilitates adhesion of tumor cells to other
tumor cells or to leukocytes, allowing the cells to migrate in a group.
E-Selectin in Cancer Progression
E-selectin is expressed mainly by endothelial cells and plays a major role in
leukocyte rolling and adhesion. h e molecules that act as ligands for E-selectin,
as well as P-selectin, belong to a group of heavily glycosylated molecules ot en
referred to as mucins. h ese mucins ot en contain carbohydrate moieties called
Lewis determinants. h ese moieties can be sialofucosylated and are then referred
