title: Anticancer effects of the metabolic products of the resveratrol analogue, DMU-212: structural requirements for potency.
abstract: The methoxylated trans-stilbene resveratrol analogue, (E)-3,4,5,4'-tetramethoxystilbene (1), has shown promising antiproliferative activity in in vitro cell line and in vivo models. In vivo 1 gives rise to several metabolic products through demethylation or hydroxylation reactions at the stilbene moiety. In the present study we examined the anticancer activity of 1 and the metabolites (E)-3'-hydroxy-3,4,5,4'-tetramethoxystilbene (2), (E)-4'-hydroxy-3,4,5-trimethoxystilbene (3), (E)-4-hydroxy-3,5,4'-trimethoxystilbene (4) and (E)-3-hydroxy-4,5,4'-trimethoxystilbene (5) by means of cell viability testing, cell cycle analysis, immunostaining and Western blotting. Compounds 1 and 2 exhibited submicromolar toxicity in MCF-7 breast adenocarcinoma and HepG2 hepatoma cells, whereas 3, 4 and 5 were inactive in terms of inhibition of cellular proliferation. Incubation with 1 or 2 at 10 μM for 24h induced apoptosis and G2/M cell cycle arrest in MCF-7 and HepG2 cells. Immunostaining of MCF-7 cells for β-tubulin in the presence of either 1 or 2 revealed shorter localization of the protein around the nucleus, as compared to control cells. Western blot analyses further demonstrated that treatment with either 1 or 2 at concentrations between 30 and 50 μM for 24 h caused a downregulation in the levels of β-tubulin and cyclin D1 expression and an upregulation in the levels of p53 expression in MCF-7 and HepG2 cells. 2 further increased the ratio of mRNA levels of the apoptosis-related genes Bax/Bcl-xL in both MCF-7 and HepG2 cells in a dose-dependent manner. We conclude that 2 inhibits HepG2 and MCF-7 cellular proliferation by inducing apoptosis and G2/M arrest through p53 and Bax/Bcl-xL upregulation. Our findings further demonstrate that trimethoxy substitutions along with the presence of a methoxy group at position 4' are necessary for retaining the activity of 1.
authors.affiliation: Laboratory of Clinical Virology, University of Crete, Medical School, Voutes, 71003 Heraklion, Crete, Greece. vandrou@med.uoc.gr
authors.forename: Vasilis P
authors.initials: VP
authors.lastname: Androutsopoulos
authors.forename: Ketan C
authors.initials: KC
authors.lastname: Ruparelia
authors.forename: Athanasios
authors.initials: A
authors.lastname: Papakyriakou
authors.forename: Harilaos
authors.initials: H
authors.lastname: Filippakis
authors.forename: Aristeidis M
authors.initials: AM
authors.lastname: Tsatsakis
authors.forename: Demetrios A
authors.initials: DA
authors.lastname: Spandidos
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D019295:Computational Biology; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D056945:Hep G2 Cells; D006801:Humans; D008958:Models, Molecular; D015394:Molecular Structure; D013237:Stereoisomerism; D013267:Stilbenes / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
chemical_list: C482492:3,4,5,4'-tetramethoxystilbene; D000970:Antineoplastic Agents; D013267:Stilbenes