Effect of inhibition of aloe-emodin on N-acetyltransferase activity and gene expression in human malignant melanoma cells (A375.S2).
Arylamine carcinogens and drugs are N-acetylated by cytosolic N-acetyltransferase (NAT), which uses acetyl-coenzyme A as a cofactor. NAT plays an initial role in the metabolism of these arylamine compounds. 2-Aminofluorene is one of the arylamine carcinogens which have been demonstrated to undergo N-acetylation in laboratory animals and humans. Our previous study showed that human cancer cell lines (colon cancer, colo 205; liver cancer, Hep G2; bladder cancer, T24; leukemia, HL-60; prostate cancer, LNCaP; osteogenic sarcoma, U-2 OS; malignant melanoma, A375.S2) displayed NAT activity, which was affected by aloe-emodin in human leukemia cells. The purpose of this study was to determine whether aloe-emodin could affect the enzyme activity and gene expression of NAT at the mRNA and protein levels in malignant human melanoma A375.S2 cells. The results showed that aloe-emodin inhibited NAT1 activity (decreased N-acetylation of 2-aminofluorene) in intact cells in a dose-dependent manner. The effect of aloe-emodin on NAT1 at the protein level was determined by Western blotting and the mRNA levels were examined by polymerase chain reaction (PCR) and cDNA microarray. These results clearly indicate that aloe-emodin inhibits the mRNA expression and enzyme activity of NAT1 in A375.S2 cells.
Lin
Shuw-Yuan
SY
Department of Food and Nutrition, Hung-Kuang University, Taichung, Taiwan.
Yang
Jen-Hung
JH
Hsia
Te-Chun
TC
Lee
Jau-Hong
JH
Chiu
Tsan-Hung
TH
Wei
Yau-Huei
YH
Chung
Jing-Gung
JG
D015073:2-Acetylaminofluorene / Q000378:metabolism; D000880:Anthraquinones; D001191:Arylamine N-Acetyltransferase / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D004642:Emodin / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005449:Fluorenes / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D008545:Melanoma / Q000201:enzymology* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000880:Anthraquinones; D004791:Enzyme Inhibitors; D005449:Fluorenes; D007527:Isoenzymes; D012333:RNA, Messenger; C012177:2-aminofluorene; D015073:2-Acetylaminofluorene; C518327:aloe emodin; D001191:Arylamine N-Acetyltransferase; C089384:N-acetyltransferase 1; D004642:Emodin