Reactive oxygen species in signal transduction

reactive oxygen species (roS) are products of incomplete reduction of oxygen both nonradicals and radicals that function as mediators of redox signaling and oxidative stress depending on their levels in different subcellular compartments.up to date, a huge body of data are accumulated, which supports a role of roS as "second messengers" in intracellular signaling cascades that control cell growth, proliferation, apoptosis as well as migration and invasion.the current review summarizes data regarding roS-dependent regulation of signaling networks components including mAPk, PI3k/Akt, Pkc, NF-κB, Nrf2, Foxo and hIF-1α, and role of roS in tumorigenesis.k e y w o r d s: roS, redox-dependent signaling, carcinogenesis.