Negative-feedback loop between Nrf2/KEAP1 axis and xCT-GSH axis in PEL cells Go Yoshida, Tokyo Medical and Dental University 25 July 2014 The authors investigated the role of xCT transporter in primary effusion lymphoma (PEL). The treatment of KSHV-infected PEL cells with monosodium glutamate (MSG) and sulfasalazine (SASP) disrupted the synthesis of glutathione (GSH), thereby activating Rac1/p22phox/Nox1/Nox2 axis. Ishii T et al. have recently reviewed that Nrf2 signal pathway contributes to the expression of xCT (Redox Biol. 2014 Apr 18;2:786-794). Thus, it is likely that negative-feedback loop between Nrf2/KEAP1 axis and xCT-GSH axis might exist, resulting in keeping the ROS level in the intermediated level preferential for cellular survival and proliferation but inducing neither cell-cycle arrest nor apoptosis. Competing interests No Competing Interests Exist.