Role of Oxidative Stress in Modulating Unfolded Protein Response Activity in Chronic Myeloid Leukemia Cell Line

Recently, it has been revealed that tyrosine kinase inhibitors (TKIs) act through inducing both oxidative and endoplasmic reticulum (ER) stress in chronic myeloid leukemia cells. However, ER stress signaling triggers both apoptotic and survival processes within cells. Nevertheless, mechanisms by which TKIs avoid the pro-survival effects are not clear. The aim of this study was to evaluate the potential role of oxidative stress in activity of unfolded protein response (UPR) survival pathway within K562 cell line. The expression of UPR survival target genes, Xbp1, and Grp94 (glucose requiring protein 94) was studied in single and combined exposure to oxidative and ER stress in K562 cell line by quantitative and qualitative PCR. The expression of UPR-related survival gene Grp94 was hampered by exposing to oxidative stress in cell induced with ER stress. Interaction of oxidative and ER stress may role as a mediator influencing UPR signaling activity.