title: PCR and flow cytometric analysis of paclitaxel-inhibited arylamine N-acetyltransferase activity and gene expression in human osteogenic sarcoma cells (U-2 OS).
abstract: Human epidemiological studies suggest an association between N-acetyltransferase (NAT) activity and the incidence of bladder and colorectal cancers. In this study, paclitaxel was selected to examine the inhibition of arylamine NAT activity, gene expression and 2-aminofluorene-DNA adduct formation in a human osteogenic sarcoma cell line (U-2 OS). The activity of NAT was determined by high performance liquid chromatography (HPLC) assay for the amounts of acetylated 2-aminofluorene (AF) and p-aminobenzoic acid (PABA) and nonacetylated AF and PABA. Human osteogenic sarcoma cell cytosols and intact cells were used to examine the NAT activity, gene expression and AF-DNA adduct formation. The results demonstrated that NAT activity percent of NAT in examined cells, gene expression (NAT1 mRNA) and AF-DNA adduct formation in human osteogenic sarcoma cells were inhibited and decreased by paclitaxel in a dose-dependent manner. The results also demonstrated that paclitaxel decreased the apparent values of Km and Vmax from intact human osteogenic sarcoma cells (U-2 OS). Thus, paclitaxel is an uncompetitive inhibitor of the NAT enzyme.
authors.affiliation: Department of Orthopaedic Surgery, Chung Shan Medical University Hospital, Taichung, Taiwan, Republic of China.
authors.forename: Ko-Hsiu
authors.initials: KH
authors.lastname: Lu
authors.forename: Der-Yean
authors.initials: DY
authors.lastname: Wang
authors.forename: Ko-Huang
authors.initials: KH
authors.lastname: Lue
authors.forename: Yie-Ming
authors.initials: YM
authors.lastname: Hsiao
authors.forename: Ming-Chih
authors.initials: MC
authors.lastname: Chou
authors.forename: Yi-Shuan
authors.initials: YS
authors.lastname: Chen
authors.forename: Jing-Gung
authors.initials: JG
authors.lastname: Chung
mesh_terms: D015073:2-Acetylaminofluorene / Q000031:analogs & derivatives* / Q000378:metabolism; D010129:4-Aminobenzoic Acid / Q000378:metabolism; D000293:Adolescent; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D001191:Arylamine N-Acetyltransferase / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D001859:Bone Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000235:genetics; D045744:Cell Line, Tumor; D003600:Cytosol / Q000201:enzymology; D018736:DNA Adducts / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D005260:Female; D005434:Flow Cytometry; D005449:Fluorenes / Q000037:antagonists & inhibitors*; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D012516:Osteosarcoma / Q000188:drug therapy / Q000201:enzymology* / Q000235:genetics; D017239:Paclitaxel / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D062366:para-Aminobenzoates
chemical_list: C052668:2-aminofluorene-DNA complex; D000972:Antineoplastic Agents, Phytogenic; D018736:DNA Adducts; D005449:Fluorenes; D012333:RNA, Messenger; D062366:para-Aminobenzoates; C023730:Acedoben; D015073:2-Acetylaminofluorene; D001191:Arylamine N-Acetyltransferase; D017239:Paclitaxel; D010129:4-Aminobenzoic Acid