WT1 promoter G-quadruplex DNA targeted by Idarubicin as an antileukemic drug

Idarubicin was eight 5-8 times more potent than daunorubicin in acute myeloid leukemia (AML) treatment and have a similar mechanism of action with it. Wilms tumor 1 (WT1) has long been overexpressed in AML. Lately, the formation of G-quadruplexes in oncogenic promoters like WT1 has been widely investigated since stabilization these structures leads to transcriptional inhibition of the oncogene. The aim of this study was to understand the effect of Idarubicin on formation of Gquadruplex motifs in WT1 promoter oligonucleotides. Differential pulse voltammetry (DPV), circular dichroism (CD), polyacrylamide gel electrophoresis, electrophoretic mobility shifts assay (EMSA) and polymerase chain reaction (PCR) stop assays were performed in order to study the nature of interactions between idarubicin and WT1 promoter region. Electrochemical characterizations of WT1 promoter motif showed that with increased drug concentration, secondary structures formation in WT1 synthetic oligomer. CD measurements revealed parallel Gquadruplex structure with a major positive signal at 260 nm and a minor negative signal at 240 nm. EMSA assay showed that the high-mobility bands were identified as compact intramolecular G-quadruplex structures. PCR stop assay were performed to further demonstrate that inhibition of PCR induced due to G-quadruplex stabilization in the oligomer by idarubicin. Data clearly revealed that idarubicin had potential to stabilize Gquadruplexes in WT21 oligomer. Accordingly, the WT1 promoter can form stable intramolecular parallel Gquadruplexes. Consequently, we hypothesized ligandmediated stabilization of G-quadruplexes within the WT1 promoter could have silencing effect on WT1 expression

کلیدواژه ها:

Idarubicin ، Promoter G-quadruplex structure ، Targeted leukemia therapy ، WT1