Targeting the Untargetable: Oncolytic Virotherapy for the Cancer Stem Cell

Abstract

The biological and therapeutic importance of cancer stem cells has become increasingly clear over the past several years.1 The success or failure of cancer treatment approaches may be influenced greatly by the presence and treatment sensitivity of these cells. Cancer cures may therefore require effective targeting and destruction of the cancer stem cell population. For therapeutics to be effective against such cells, they must be effective against quiescent, apoptosis-resistant, and drug transporter–overexpressing cells. Further complicating this challenge, normal stem cells share many of these same features, to the extent that selectively targeting the cancer stem cell while leaving the normal stem cells unharmed is a difficult proposition. In this issue of Molecular Therapy, Eriksson and colleagues report proof-of-concept studies for the efficacy of oncolytic virotherapy against cancer stem cells.2