title: N-hydroxy-N'-(3,4,5-trimethoxyphenyl)-3,4,5-trimethoxy-benzamidine, a novel resveratrol analog, inhibits ribonucleotide reductase in HL-60 human promyelocytic leukemia cells: synergistic antitumor activity with arabinofuranosylcytosine.
abstract: Resveratrol (3,4',5,-trihydroxystilbene, RV), an ingredient of wine, exhibits a broad spectrum of antiproliferative effects against human cancer cells. In order to develop a derivative with comparable effects, we modified the molecule by introducing additional methoxyl groups. The resulting novel RV analog, N-hydroxy-N'-(3,4,5-trimethoxyphenyl)-3,4,5-trimethoxybenzamidine (KITC), was investigated in HL-60 human promyelocytic leukemia cells. The induction of apoptosis was determined employing a specific Hoechst/propidium iodide double staining method and cell cycle distribution was evaluated by FACS. KITC's influence on the concentration of deoxyribonucleoside triphosphates, the products of ribonucleotide reductase (RR), was determined using the HPLC method. In addition, we analyzed the effects of KITC treatment on the incorporation of 14C-cytidine into the DNA of tumor cells in order to quantify the loss of RR in situ activity. To reveal a potential value of KITC for supporting conventional chemotherapy, we also examined whether a combination of KITC with arabinofuranosylcytosine (Ara-C) could yield synergistic growth inhibitory effects. KITC caused a dose-dependent induction of apoptosis, whereas no remarkable changes of the cell cycle distribution were observed. Incubation with KITC resulted in a significant depletion of intracellular dTTP and dATP pools and was also found to remarkably reduce the in situ activity of RR, the key enzyme of de novo DNA synthesis. In addition, KITC exhibited synergistic combination effects when applied sequentially with Ara-C. Due to these promising results, KITC deserves further preclinical and in vivo testing.
authors.affiliation: Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, General Hospital of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
authors.forename: Philipp
authors.initials: P
authors.lastname: Saiko
authors.forename: Maria
authors.initials: M
authors.lastname: Ozsvar-Kozma
authors.forename: Astrid
authors.initials: A
authors.lastname: Bernhaus
authors.forename: Margit
authors.initials: M
authors.lastname: Jaschke
authors.forename: Geraldine
authors.initials: G
authors.lastname: Graser
authors.forename: Andreas
authors.initials: A
authors.lastname: Lackner
authors.forename: Michael
authors.initials: M
authors.lastname: Grusch
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Horvath
authors.forename: Sibylle
authors.initials: S
authors.lastname: Madlener
authors.forename: Georg
authors.initials: G
authors.lastname: Krupitza
authors.forename: Norbert
authors.initials: N
authors.lastname: Handler
authors.forename: Thomas
authors.initials: T
authors.lastname: Erker
authors.forename: Walter
authors.initials: W
authors.lastname: Jaeger
authors.forename: Monika
authors.initials: M
authors.lastname: Fritzer-Szekeres
authors.forename: Thomas
authors.initials: T
authors.lastname: Szekeres
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D003561:Cytarabine / Q000494:pharmacology*; D003562:Cytidine / Q000378:metabolism; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D018922:HL-60 Cells; D006801:Humans; D000077185:Resveratrol; D012264:Ribonucleotide Reductases / Q000037:antagonists & inhibitors*; D013267:Stilbenes / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D004791:Enzyme Inhibitors; C525082:N-hydroxy-N'-(3,4,5-trimethoxyphenyl)-3,4,5-trimethoxy-benzamidine; D013267:Stilbenes; D003561:Cytarabine; D003562:Cytidine; D012264:Ribonucleotide Reductases; D000077185:Resveratrol