The role of peroxiredoxin II in chemoresistance of breast cancer cells.

Peroxiredoxin (Prx)II belongs to a family of redox-active proteins that use redox-sensitive cysteine in the active site to reduce peroxides. PrxII is induced by various oxidative stimuli and plays an important protective role against oxidative radical damage by reactive oxygen species. PrxII expression levels are correlated with resistance to radiation therapy or certain anti-cancer drugs in radioresistant breast cancer cells, glioblastomas, and head and neck cancer cells as well as in tissue isolated from head and neck patients who do not respond to radiation therapy. Small interfering RNA (siRNA) that inhibits the PrxII gene expression has been shown to partially reverse the radioresistant phenotype in radiation resistant breast cancer cells and sensitizes glioma cells to oxidative stress, highlighting the potential clinical importance of PrxII in radiation resistance in cancer. This article focuses on the role that PrxII may play in chemoresistant breast cancer cells.