title: Aryl hydrocarbon receptor activation by aminoflavone: new molecular target for renal cancer treatment.
abstract: Aminoflavone (AF; NSC 686288, AFP464, NSC710464) is a new anticancer drug that has recently entered phase II clinical trials. It has demonstrated antiproliferative effects in MCF-7 human breast cancer cells mediated by the aryl hydrocarbon receptor (AhR). AF also exhibits noteworthy evidence of antitumor activity in vitro and in vivo against neoplastic cells of renal origin. AF treatment of sensitive renal cells, in contrast to resistant cells, promotes the induction of CYP1A1, the covalent binding of AF-reactive intermediates and apoptosis. Based on this evidence, the aim of this study was to evaluate the role of AhR, the main transcriptional regulator of CYP1A1, in the antiproliferative effects of AF in human renal cancer cells. AF-cytoxicity in human renal cell lines and a renal cancer cell strain was assessed by MTS assay in the presence or absence of an Ahr inhibitor. Drug-induced AhR nuclear translocation was evaluated by western blotting of AhR in cytosolic and nuclear fractions and by measuring xenobiotic response element-driven luciferase activity. Apoptosis induced by the drug was evaluated by 4,6-diamidino-2-phenylindole and acridine orange/ethidium bromide staining and by measuring phosphorylated P53 (p-P53) and P21 levels, caspase 3 activation and poly(ADP-ribose) polymerase cleavage. AF inhibited cell growth in a dose-dependent manner in TK-10, Caki-1, SN12-C and A498 human renal cells but not in ACHN cells. The antiproliferative effect of AF was abrogated by pre-incubation of TK-10, Caki-1 and SN12-C cells with the AhR antagonist, α-naphthoflavone. AF treatment also induced apoptosis in TK-10, Caki-1 and SN12-C cells, which was not observed in ACHN cells. AF induced time-dependent AhR nuclear translocation and AhR transcriptional activity in sensitive renal cancer cell lines. A renal cell strain derived from a human papillary tumor also showed sensitivity to AF, as well as AhR pathway activation and drug-induced apoptosis. AhR translocation could be included as a marker of sensitivity to AF in sensitive renal tumor cells of different histological origin, in ongoing phase II clinical trials.
authors.affiliation: Research Area, Institute of Oncology Ángel H Roffo, University of Buenos Aires, Ciudad de Buenos Aires, Argentina.
authors.forename: Mariana A
authors.initials: MA
authors.lastname: Callero
authors.forename: Guadalupe V
authors.initials: GV
authors.lastname: Suárez
authors.forename: Gabriela
authors.initials: G
authors.lastname: Luzzani
authors.forename: Boris
authors.initials: B
authors.lastname: Itkin
authors.forename: Binh
authors.initials: B
authors.lastname: Nguyen
authors.forename: Andrea I
authors.initials: AI
authors.lastname: Loaiza-Perez
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics; D002291:Carcinoma, Papillary / Q000188:drug therapy* / Q000473:pathology; D002292:Carcinoma, Renal Cell / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics; D065633:Cytochrome P-450 CYP1B1; D005419:Flavonoids / Q000494:pharmacology*; D017930:Genes, Reporter; D006801:Humans; D007680:Kidney Neoplasms / Q000188:drug therapy* / Q000473:pathology; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D058990:Molecular Targeted Therapy; D011401:Promoter Regions, Genetic; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism*; D015533:Transcriptional Activation / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; D005419:Flavonoids; D018336:Receptors, Aryl Hydrocarbon; C413760:aminoflavone; D008156:Luciferases; D001189:Aryl Hydrocarbon Hydroxylases; C569463:CYP1A1 protein, human; C585496:CYP1B1 protein, human; D019363:Cytochrome P-450 CYP1A1; D065633:Cytochrome P-450 CYP1B1