Depleting Cancer Stem Cells by Blocking Hedgehog

Baltimore, MD -

It is believed that tumor stem cells share various characteristics with their non-malignant counterparts, such as expression of CD133. In a recent study (Bar et al. Cyclopamine-Mediated Hedgehog Pathway Inhibition Depletes Stem-Like Cancer Cells in Glioblastoma. Stem Cells. 2007 Jul 12) glioblastoma cells were shown to express the hedgehog protein Gli1, which is also found in stem cells.

Inhibition of this protein with the chemical agent cyclopamine not only depleted clonogenic cells in vitro, but also blocked ability of primary tumor cells to form tumors in immune compromised animals. Interestingly, treating tumors with radiation did not deplete clonogenic precursors but actually enhanced them.

This is a great paper demonstrating the importance of depleting tumor stem cells as opposed to more differentiated tumor cells.