Abnormal vasculature, termed
tumor vessels, is a hallmark of solid
tumors. The degree of angiogenesis is associated with
tumor aggressiveness and clinical outcome. Therefore, exact quantification of
tumor vessels is useful to evaluate prognosis. Furthermore, selective detection of newly formed
tumor vessels within
cancer tissues using specific markers raises the possibility of
molecular targeted therapy via the inhibition of
tumor angiogenesis.
Nestin, an intermediate filament
protein, is reportedly expressed in repair processes, various
neoplasms, and proliferating vascular endothelial cells.
Nestin expression is detected in endothelial cells of embryonic capillaries, capillaries of the corpus luteum, which replenishes itself by angiogenesis, and proliferating endothelial progenitor cells, but not in mature endothelial cells. Therefore, expression of
nestin is relatively limited to proliferating vascular endothelial cells and endothelial progenitor cells.
Nestin expression is also reported in blood vessels within
glioblastoma,
prostate cancer,
colorectal cancer, and
pancreatic cancer, and its expression is more specific for newly formed blood vessels than other endothelial cell markers.
Nestin-positive blood vessels form smaller vessels with high proliferation activity in
tumors. Knockdown of
nestin in vascular endothelial cells suppresses endothelial cell growth and
tumor formation ability of
pancreatic cancers in vivo. Using
nestin to more accurately evaluate microvessel density in
cancer specimens may be a novel prognostic
indicator. Furthermore,
nestin-targeted
therapy may suppress
tumor proliferation via inhibition of angiogenesis in numerous
malignancies, including
pancreatic cancer. In this review article, we focus on
nestin as a novel angiogenesis marker and possible therapeutic target via inhibition of
tumor angiogenesis.