Scientists at the Johns Hopkins Kimmel Cancer Center, working with Danish researchers, have developed a novel anticancer drug designed to travel -- undetected by normal cells -- through the bloodstream until activated by specific cancer proteins. The drug, made from a weedlike plant, has been shown to destroy cancers and their direct blood supplies, acting like a “molecular grenade,” and sparing healthy blood vessels and tissues

...But according to Prof Hugo Snippert of the University Medical Centre in Utrecht, who led the study into intestinal tumours, the confirmation that these cells exist is an important step in future cancer research.

"Many argued that these cells did not exist. But we have shown for the first time there is such a thing as a cancer stem cell and that tumours are maintained by them," he said.

Prof Luis Parada of the University of Texas, who led research that identified stem cells in brain tumours in mice, said he believed there would now be a new approach to developing new treatments for solid tumour cancers.

"Cancer stem cells change the paradigm. The goal of shrinking tumours may well turn out to be less important than targeting the cancer cells in that tumour."

Dr Michaela Frye, a Cancer Research UK scientist based at the University of Cambridge, said: "These results add even more weight to the theory that cancers are driven by a distinct group of cells called cancer stem cells. Because cancers are proving to be so complex, we don't yet know how relevant this research in mice is to humans, but it gives us new insights into how cancers might develop and why they can sometimes grow back after therapy."