Cancer Stem Cells and Tumor Maintenance

Most cancers contain a non-uniformly distributed and genetically distinct subpopulation of tumor cells.

Some of these cells, called cancer stem cells, possess the characteristics associated with both cancer cells and stem cells. This means that as well as participating in tumor propagation, such cells can self-renew and differentiate into multiple lineages.

A cancer stem cell, or CSC, can undergo asymmetric cell division - where one set of daughter cells retain the stem-cell potential and can divide indefinitely, while the other can undergo only a few rounds of division before terminally differentiating and eventually dying.

A CSC can also secrete elevated levels of vascular endothelial growth factors within a tumor and generate new blood and lymphatic vessels that maintain a continuous supply of nutrients to the growing tumor.

Additionally, cancer stem cells can attain properties such as increased invasiveness and migration ability, which may aid them in establishment of secondary metastatic sites in the body.

Even though cancer stem cells carry the potential to seed new tumors and drive their growth, it is the rapidly dividing non-stem cells that form major components of the tumo