Using X-ray absorption spectroscopy and microprobe synchrotron radiation-X-ray fluorescence imaging for understanding the mode of action of arsenic anti-leukaemia agents

Paradoxically, Arsenic (As) is a potent human carcinogen and also a highly effective anti-leukaemia agent (Cui et al. 2008). Arsenic trioxide (As2O3), marketed as Trisenox™, was approved by the FDA for the treatment of relapsed acute promyelocytic leukaemia in 2000 (Rojewski et al. 2004). Since this time it has been shown to be effective against several other types of cancer and a renewed interest in the use of As as a therapeutic agent has emerged. As such several new As-based anti-cancer agents have entered clinical trials.