Culture conditions to grow human leukemia stem cells in the lab are described in a paper published online this week in Nature Methods. The ability to grow these cancer stem cells outside of the body will promote basic studies of their self-renewal mechanisms as well as screens for drugs that can block the cells’ ability to grow.
Leukemic stem cells are thought to be particularly difficult to target with drugs and are a potential culprit in cancer relapse. A major bottleneck in studying these cells is the fact that they cannot be grown and expanded in vitro, as the cells rapidly lose their ability to function as cancer stem cells and to cause disease, when they are cultured.
Guy Sauvageau and colleagues identify two small molecules that, when added to the culture medium, can improve expansion of functional human leukemia stem cells over seven days in vitro. The effects of the two drugs are additive, a result suggesting that they affect independent pathways. The drugs function to block differentiation of the cells that otherwise occurs when they are grown in vitro.