Cancer Stem Cells And The Population Dynamics Of Tumors

According to the CSC hypothesis, tumor growth is driven by a small population of cancer stem cells which can self-renew and differentiate into cancer cells with a long but limited lifespan. The experimental challenges in the identification of CSCs are discussed in Section 5.1 where we review the relevant biological markers. In Section 5.2, we discuss the population dynamics within the tumor, composed by CSCs and other tumor cells. To this end, we introduce a mathematical model for the evolution of the populations and compare its results with experiments. In Section 5.3, we deal with the possibility that cancer cells can occasionally switch back to the CSC state, discussing relevant experiments and models. Section 5.4 is devoted to the issue of cell sorting. While one would like to define the CSC population in a sharp way, in practice the boundary is fuzzy, being based on the expression of biological markers which are by their nature imperfect. This opens an interesting issue about the interpretation of the experimental results.