Biomedical Engineering Reference
In-Depth Information
metastases. Tumor cells are known to express adhesion molecules similar to those
found on leukocytes, expressing molecules containing sialyl Lewis determinants,
implicating the reciprocal endothelial cell adhesion molecules, E-selectin and
P-selectin, in this process. Indeed, E-selectin and P-selectin levels are increased
in cancer patients. h e endothelial cell adhesion molecules intercellular adhesion
molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) are found
to be upregulated in cancer patients, and tumor cells express many integrins, the
ligands for these adhesion molecules. Clinical and research data indicate that
endothelial cell adhesion molecules are major players in metastasis. h is chapter
will outline the roles that endothelial cell adhesion molecules play in cancer
progression.
INTRODUCTION
Cancer progression involves many dif erent processes and is regulated on many
dif erent levels (Gassmann and Haier 2008, Brooks
et al.
2009). At the primary site,
this involves tumor initiation and growth. Tissue reorganization occurs, mediated
by processes such as angiogenesis and immune cell ini ltration. As the tumor
progresses, the tumor cells will invade the surrounding tissues and eventually
intravasate into the circulation. From there, these cells can arrest/adhere at distant
Features). h is process is very inei cient, with the majority of tumor cells dying
before a metastatic growth can be established.
Fig. 1
Scheme of cancer progression. At the primary site, the tumor cells proliferate and secrete
factors that lead to leukocyte ini ltration. As the tumor progresses, cells intravasate, either as
individual cells or a cluster of cells, and enter the circulation. At a distant site, the tumor cell(s)
adheres to the endothelium and extravasates, migrating into the tissue, where it can now proliferate,
creating a metastatic tumor.
