Ketoprofen-inhibited N-acetyltransferase activity and gene expression in human colon tumor cells.

The activation of ketoprofen, which inhibits the outgrowth of azoxymethane-induced aberrant crypt foci in the rat colon, on the inhibition of arylamine N-acetyltransferase (NAT) activity (N-acetylation of substrates), gene expression (mRNA NAT) and 2-aminofluorene (AF)-DNA adduct formation was studied in a human colon tumor (adenocarcinoma) cell line (colo 205). Cellular cytosols (9000 xg supernatant) and intact colon tumor cells were used. The NAT activity in colo 205 cells was inhibited by ketoprofen in a dose- and time -dependent manner in both examined systems.

Evidence for arylamine N-acetyltransferase activity in Klebsiella pneumoniae.

Arylamine N-acetyltransferase (NAT) enzymes have been found in laboratory animals, humans, microorganisms (fungi, bacteria and parasites), and in plants. But the characteristics of NAT from Klebsiella pneumoniae are not clear. NAT activities with p-aminobenzoic acid (PABA) and 2-aminofluorene (AF) as substrates were examined in the cytosol of K.