RT Journal Article SR Electronic T1 N-Acetyltransferase is Involved in Baicalein-induced N-Acetylation of 2-Aminofluorene and DNA-2-Aminofluorene Adduct Formation in Human Leukemia HL-60 Cells JF In Vivo JO In Vivo FD International Institute of Anticancer Research SP 399 OP 405 VO 19 IS 2 A1 YU-CHING LI A1 YU-SHENG TYAN A1 YIH-MIN LEE A1 TANG-YI TSAO A1 JING-YUAN CHUANG A1 HSIU-MAAN KUO A1 TE-CHUN HSIA A1 JEN-HUNG YANG A1 JING-GUNG CHUNG YR 2005 UL http://iv.iiarjournals.org/content/19/2/399.abstract AB Many arylamine and hydrazine drugs are acetylated by cytosolic N-acetyltransferase (NAT). The human promyelocytic leukemia cell line (HL-60) has been shown to acetylate arylamine and contain NAT activity. The purpose of this study was to determine whether or not baicalein could affect N-acetylation of 2-aminofluorene (AF) in HL-60 cells. Acetylated and nonacetylated AF were determined by using high performance liquid chromatography. Baicalein displayed a dose-dependent inhibition of cytosolic and intact cells' NAT activity and reduced the number of viable cells. Time-course experiments showed that N-acetylation of AF, measured from intact HL-60 cells, was inhibited by baicalein for up to 48 h. Baicalein also decreased AF-DNA adduct formation in the examined cells. The effects of baicalein on NAT were examined by flow cytometry and NAT gene expression was examined by polymerase chain reaction. The results demonstrated that baicalein inhibited NAT1 mRNA gene expression and reduced the level of NAT in HL-60 cells. These results show that baicalein can affect the NAT activity of human leukemia cells in vitro.