Inhibitory mechanism of pure curcumin on Wilms' tumor 1 (WT1) gene expression through the PKCα signaling pathway in leukemic K562 cells

► WT1 expression in K562 leukemic cells was suppressed by pure curcumin through disruption of a WT1 auto-regulatory loop. ► Pure curcumin remodeled the WT1 promoter, resulting in loss of WT1 transcription and decreased WT1 expression. ► Curcumin inhibition of WT1 was independent of protein and mRNA degradation pathways. ► The inhibitory effect of curcumin was mediated through inhibition of the PKCα signaling pathway. ► WT1 over-expression reversed pure curcumin-mediated growth inhibition of K562 cells.