Nestin expression in human tumors and tumor cell lines.

The aim of this review is to summarize current knowledge on nestin expression in human tumors and corresponding tumor cell lines. Nestin belongs to class VI of the intermediate filaments and it is expressed primarily in mammalian nervous tissue during embryonic development. In adults, nestin occurs only in a small subset of cells and tissues. This protein has been observed in the subventricular zone of the adult mammalian brain, where neurogenesis is localized. Nestin expression has also been detected in various types of human solid tumors, as well as in the corresponding established cell lines. This article provides an up-to-date overview of tumors in which nestin has been found. Another aim of this review is to summarize recent findings on the intracellular localization of nestin in human tumor cells, especially with regard to the possible correlation between nestin expression and the malignant phenotype of transformed cells. Nestin expression in vascular endothelial cells during angiogenesis is also reviewed. Special attention is paid to the detection of nestin in cancer stem cells because this protein, together with the CD133 surface molecule, is considered to be a possible marker of cancer stem cells, especially in tumors of neuroectodermal origin.