title: Sulfotransferase-1A1-dependent bioactivation of aristolochic acid I and N-hydroxyaristolactam I in human cells.
abstract: Aristolochic acids (AA) are implicated in the development of chronic renal disease and upper urinary tract carcinoma in humans. Using in vitro approaches, we demonstrated that N-hydroxyaristolactams, metabolites derived from partial nitroreduction of AA, require sulfotransferase (SULT)-catalyzed conjugation with a sulfonyl group to form aristolactam-DNA adducts. Following up on this observation, bioactivation of AA-I and N-hydroxyaristolactam I (AL-I-NOH) was studied in human kidney (HK-2) and skin fibroblast (GM00637) cell lines. Pentachlorophenol, a known SULT inhibitor, significantly reduced cell death and aristolactam-DNA adduct levels in HK-2 cells following exposure to AA-I and AL-I-NOH, suggesting a role for Phase II metabolism in AA activation. A gene knockdown, siRNA approach was employed to establish the involvement of selected SULTs and nitroreductases in AA-I bioactivation. Silencing of SULT1A1 and PAPSS2 led to a significant decrease in aristolactam-DNA levels in both cell lines following exposure to AA-I, indicating the critical role for sulfonation in the activation of AA-I in vivo Since HK-2 cells proved relatively resistant to knockdown with siRNAs, gene silencing of xanthine oxidoreductase, cytochrome P450 oxidoreductase and NADPH:quinone oxidoreductase was conducted in GM00637 cells, showing a significant increase, decrease and no effect on aristolactam-DNA levels, respectively. In GM00637 cells exposed to AL-I-NOH, suppressing the SULT pathway led to a significant decrease in aristolactam-DNA formation, mirroring data obtained for AA-I. We conclude from these studies that SULT1A1 is involved in the bioactivation of AA-I through the sulfonation of AL-I-NOH, contributing significantly to the toxicities of AA observed in vivo.
authors.affiliation: Department of Pharmacological Sciences.
authors.forename: Keiji
authors.initials: K
authors.lastname: Hashimoto
authors.affiliation: Department of Pharmacological Sciences.
authors.forename: Irina N
authors.initials: IN
authors.lastname: Zaitseva
authors.affiliation: Department of Pharmacological Sciences.
authors.forename: Radha
authors.initials: R
authors.lastname: Bonala
authors.affiliation: Department of Pharmacological Sciences.
authors.forename: Sivaprasad
authors.initials: S
authors.lastname: Attaluri
authors.affiliation: Department of Pharmacological Sciences.
authors.forename: Katherine
authors.initials: K
authors.lastname: Ozga
authors.affiliation: Department of Pharmacological Sciences.
authors.forename: Charles R
authors.initials: CR
authors.lastname: Iden
authors.affiliation: Department of Pharmacological Sciences.|Department of Chemistry and.
authors.forename: Francis
authors.initials: F
authors.lastname: Johnson
authors.affiliation: Department of Pharmacological Sciences.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Moriya
authors.affiliation: Department of Pharmacological Sciences.|Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA.
authors.forename: Arthur P
authors.initials: AP
authors.lastname: Grollman
authors.affiliation: Department of Pharmacological Sciences.
authors.forename: Viktoriya S
authors.initials: VS
authors.lastname: Sidorenko
mesh_terms: D034341:Aristolochic Acids / Q000378:metabolism*; D015239:Arylsulfotransferase / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D002273:Carcinogens / Q000378:metabolism / Q000633:toxicity; D004247:DNA / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D055785:Gene Knockdown Techniques; D006801:Humans; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D009097:Multienzyme Complexes / Q000235:genetics* / Q000378:metabolism; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D010416:Pentachlorophenol / Q000494:pharmacology; D034741:RNA, Small Interfering; D013430:Sulfate Adenylyltransferase / Q000235:genetics* / Q000378:metabolism; D014968:Xanthine Dehydrogenase / Q000378:metabolism
chemical_list: D034341:Aristolochic Acids; D002273:Carcinogens; D009097:Multienzyme Complexes; D034741:RNA, Small Interfering; C121135:aristolactam I; D004247:DNA; C000228:aristolochic acid I; D010416:Pentachlorophenol; D014968:Xanthine Dehydrogenase; D009251:NADPH-Ferrihemoprotein Reductase; C022322:PAPS synthetase; D013430:Sulfate Adenylyltransferase; D015239:Arylsulfotransferase; C117544:SULT1A1 protein, human