Descrição
The use of cancer biomarkers to anticipate the outlines of
disease has been an emerging issue, especially as cancer
treatment has made such positive steps in the last few years.
Progress in the development of consistent malignancy
markers is imminent because advances in genomics and
bioinformatics have allowed the examination of immense
amounts of data. Osteopontin is a phosphorylated glycoprotein
secreted by activated macrophages, leukocytes, and
activated T lymphocytes, and is present in extracellular fluids,
at sites of inflammation, and in the extracellular matrix of
mineralized tissues. Several physiologic roles have been
attributed to osteopontin, i.e., in inflammation and immune
function, in mineralized tissues, in vascular tissue, and in
kidney. Osteopontin interacts with a variety of cell surface
receptors, including several integrins and CD44. Binding of
osteopontin to these cell surface receptors stimulates cell adhesion, migration, and specific signaling functions. Overexpression
of osteopontin has been found in a variety of
cancers, including breast cancer, lung cancer, colorectal cancer,
stomach cancer, ovarian cancer, and melanoma. Moreover,
osteopontin is present in elevated levels in the blood and
plasma of some patients with metastatic cancers. Therefore,
suppression of the action of osteopontin may confer significant
therapeutic activity, and several strategies for bringing
about this suppression have been identified. This review
looks at the recent advances in understanding the possible
mechanisms by which osteopontin may contribute functionally
to malignancy, particularly in breast cancer. Furthermore,
the measurement of osteopontin in the blood or tumors of
patients with cancer, as a way of providing valuable prognostic
information, will be discussed based on emerging clinical
data.
; Teixeira, J. A. 
