Concurrent inhibition of enzymatic activity and NF-Y-mediated transcription of Topoisomerase-IIα by bis-DemethoxyCurcumin in cancer cells

Abstract

Topoisomerases-IIα (TOP2A) enzyme is essential for cell viability due to its fundamental role in DNA metabolism and in chromatin organization during interphase and mitosis. TOP2A expression is finely regulated at the transcriptional level through the binding of the CCAAT-transcription factor NF-Y to its promoter. Overexpression and/or amplification of TOP2A have been observed in many types of cancers. For this reason, TOP2A is the target of the most widely successful drugs in cancer chemotherapy, such as TOP2A poisons, which stabilize TOP2A-DNA cleavage complexes and create DSBs, leading to chromosome damage and cell death. We previously reported that the Curcumin-derivative bis-DemethoxyCurcumin (bDMC) is an anti-proliferative agent that inhibits cell growth by concomitant G1/S and G2/M arrest. Here we showed that bDMC irreversibly induces DSBs in cancer cells, but not in normal cells, by targeting TOP2A activity and expression. TOP2A ablation by siRNA corroborates its contribution to apoptosis induced by bDMC. Short-term exposure to bDMC induces retention of TOP2A-DNA intermediates, while longer exposure inhibits TOP2A transcription by affecting expression and sub-cellular localization of NF-Y subunits. ChIP analysis highlighted reduced recruitment of NF-Y to TOP2A regulatory regions, concomitantly to histone deacetylation and decreased gene transcription. Our findings suggest that the dual activity of bDMC on TOP2A represents a novel therapeutic strategy to induce persistent apoptosis in cancer cells and identify NF-Y regulation as a promising approach in anti-cancer therapy.

Bioinformatics analysis to identify possible mechanisms of action of curcumin against tea geometrid

“…While we are unaware of reports examining whether our candidate proteins in tea geometrid (TOP2B, TP53 (Bhullar, Jha, & Rupasinghe, 2015). Curcumin also irreversibly induces double-strand breaks in cancer cells, but not normal cells, by affecting TOP2A activity and expression (Belluti et al, 2013).…”

NF-Y loss triggers p53 stabilization and apoptosis in HPV18-positive cells by affecting E6 transcription

“…For the determination of cell cycle progression, cells were stained with Propidium Iodide (PI), as previously described [57]. Apoptotic cells were detected by FACS using Annexin V-PE conjugate (BD Biosciences, Becton Dickinson Italia, Milan, Italy), following the protocol of the manufacturer.…”

The 1,10-Phenanthroline Ligand Enhances the Antiproliferative Activity of DNA-Intercalating Thiourea-Pd(II) and -Pt(II) Complexes Against Cisplatin-Sensitive and -Resistant Human Ovarian Cancer Cell Lines

“…TG1001, TopoGEN Inc., Port Orange, FL, USA), following the instructions of the manufacturer. Nuclear extracts containing TOPO-II activity were obtained from cells and the ability to decatenate kDNA was analysed in the presence of DMSO and of the tested complexes, as previously shown [53]. Briefly, decatenation assay was performed with 50 ng kDNA in a 10 mL reaction mixture containing 50 mM Tris-HCl (pH 8.0); 150 mM NaCl; 10 mM MgCl 2 ; 0.5 mM dithiothreitol; 2 mM ATP; 30 mg/mL BSA with DMSO; or 5, 15, 30 µM of compounds and 0.5 mg of cell nuclear extract.…”