Reactive Oxygen Species in Cancer Biology and Anticancer Therapy

The relevance of Nrf2 pathway and autophagy in pancreatic cancer cells upon stimulation of reactive oxygen species

“…Low level of ROS could promote the antioxidant production and the tumor growth in cancer cells, but further increased production of ROS and/or decrease in antioxidant capacity would lead to the imbalance in oxidant-antioxidant system of cancer cells, resulting in cell death [39]. Some evidence indicated that Nrf2 has the ability to lower intracellular ROS by its antioxidant program [31].…”

Indicators of oxidative and nitrosative stress and activity of enzymes of nitric oxide metabolism in rats treated with 4-thiazolidinone derivatives possessing antineoplastic activity

“…eneration of the reactive oxygen species (ROS) and reactive nitrogen species (RNS) by cells of tissues and organs is an important mechanism in pathogenesis and in defense of the organism against various pathological agents [1][2][3]. Several toxic substances induce the development of the oxidative and/or nitrosative stress that are charac terized by a shift of the intracellular redox balance to higher levels of free radical oxidation (FRO) [4,5].…”

“…Several toxic substances induce the development of the oxidative and/or nitrosative stress that are charac terized by a shift of the intracellular redox balance to higher levels of free radical oxidation (FRO) [4,5]. The mammalian cells produce free radi cal metabolites of oxygen and nitrogen that might be involved in transferring the regulatory signals in targeted cells [1,4,6]. The relevant signaling molecules affect cellular metabolism and play a key role in non-specific immune defense against the pathogenic factors, including those appearing at cancer development [5][6][7].…”

“…ROS and RNS are molecules containing unpaired electrons, that makes them exceptionally reactive to DNA, proteins and lipids [1,4,7]. The superoxide radical is formed as a by-product of different enzymatic reactions, including cellular respiration, and it is converted into the hydroxyl radical in Fenton reaction catalyzed by the ions of transition metals such as copper and iron.…”

“…Both the pro-and anti-apoptotic factors use FRO-modulated pro-and anti-oxidant mechanisms for killing both normal and tumor cells [11,12]. New antineoplastic strategy based on differential induction of FROdependent mechanisms in normal and tumor cells has been proposed [1,11,13]. It should be noted that the use of most existing therapies in oncology is accompanied by the development of harmful effects of FRO on the cells of normal tissues and organs [1,5,6,[11][12][13].…”