Cancer Stem Cell Markers: Classification and Their Significance in Cancer Stem Cells

Abstract

This review is dealing with identification of cancer stem cell markers, their latest classification, func-tion in normal and cancer stem cells (CSCs), and their use in development of novel targeted antitumor therapy. It was difficult to prove the CSC s existence, unless the in vivo and in vitro experiments have been done supporting the theory that they have common clonogenic origin and perpetuate always the same phenotypic marker(s) on their surface, being also able to induce production of original tumor in transplanted NOD/SCID mice. The cancer stem cells so far have been found in most of human tissues and checked as well, in agar, for anchorage growth. Their tumorigenicity is high, while other cancer cells either do not express it or with a very low inten-sity. That is why idea of targeted antitumor therapy now has as a goal to target CSCs since in that case the cancer would have been removed forever. Re-occurrence is due to omitting the correct target (CSCs) and targeting other tumor cell and normal tissues. The research in this field is very extensive and requires more knowledge on cellular, molecular and supramolecular levels.