Nrf2 represses ER stress-related ferroptosis in renal carcinoma cells via HO-1

Selective-induction of regulated cell death is considered as a useful strategy for developing effective therapies against renal cell carcinoma (RCC). In this study, the role of nuclear factor-E2-related factor 2 (Nrf2) and its downstream genes in erastin-induced ferroptosis of renal carcinoma cells was investigated. Erastin induced endoplasmic reticulum (ER) stress and ferroptosis in renal carcinoma cells (786-0 and Caki-1), which was confirmed by morphological changes, increased lipid oxidation and ferroptosis inhibition. Data obtained from TCGA dataset showed that Nrf2 and heme oxygenase-1 (HO-1) were not only significantly differentially expressed between RCC and normal samples, but also associated with better survival in RCC patients. Moreover, the process of ferroptosis induced by erastin in renal carcinoma cells was accompanied by increased expression of Nrf2 and HO-1. Inhibition of Nrf2 or HO-1 expression enhanced lipid ROS accumulation and ferroptosis. Furthermore, pharmacological activation of HO-1 reversed ferroptosis-sensitizing effect of Nrf2 silencing, thereby clarifying the key role of Nrf2/HO-1 pathway in erastin-induced ferroptosis in renal carcinoma cells. In summary, we identified the role of Nrf2/HO-1 signaling pathway in the protection of renal carcinoma cells from ER stress-related ferroptosis, which indicated that targeting of Nrf2/HO-1 pathway as a viable treatment strategy for RCC. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=151 SRC="FIGDIR/small/977769v1_ufig1.gif" ALT="Figure 1"> View larger version (60K): org.highwire.dtl.DTLVardef@1068dacorg.highwire.dtl.DTLVardef@13f388eorg.highwire.dtl.DTLVardef@199fd87org.highwire.dtl.DTLVardef@d3e03a_HPS_FORMAT_FIGEXP M_FIG Graphical abstract (supplementary figure): Nrf2 protects against ER stress-related ferroptosis via HO-1 in renal cancer cells. Cystine/glutamate antiporter (SLC7A11) abbreviated as xCT. Mitochondria abbreviated as Mito. C_FIG