Arsenic-based drug shown to be effective in killing several types of cancer cells.

Arsenic trioxide is a chemical that is already approved as a second line treatment for one form of leukemia.  The compound was shown in this research to inhibit a critical signaling pathway.  The drug was able to kill Ewing sarcoma and meduloblasoma cells in the lab and in animals with these cancers.  The discovery means that this drug could be effective in a variety of cancers.