The seed of life is a fertilized ovum, which is also the ultimate stem cell. Stem cells are needed during growth and tissue repair. Similarly, the seed of cancer is the cancer initiating stem cell. Cancer stem cells are needed to maintain tumor growth and metastasis. Most current studies on leukemia, brain, breast and lung cancers suggest that the cancer cells have heterogeneous proliferative and self-renewal capacities. The cancer cells in these malignancies are organized as a hierarchy that originates from rare cancer initiating stem cells. This discovery of cells possessing stem cell like properties in cancers has changed our view of how cancer develops. Although chemotherapy kills most cells in cancer, it is believed to leave the stem cells behind, which might explain the mechanism for chemo-resistance. Normal and cancer stem cells share common characteristics. They can both self renew and differentiate. They both have the capacity for long lifespan and relative quiescence and the resistance to drugs and toxins through expression of several ATP-binding cassette (ABC) transporter proteins. Finally, they both have an efficient DNA-repair capacity and resistance to apoptosis.
Our laboratory seeks to identify and characterize normal and cancer stem cells using immuno-phenotyping, molecular and cell culture techniques. Characterization of cancer stem cells will allow better insight into the mechanism of stem cell resistance to chemotherapy and might therefore lead to identification of new therapeutic targets, more effective anti-cancer therapies and chemoprevention.