(z)-5-(2--hydroxybenzylidene)-2-thioxothiazolidin-4-one and Breast-Neoplasms

Arylamine N-acetyltransferase 1 is a phase II metabolizing enzyme that has been associated with certain breast cancer subtypes. While it has been linked to breast cancer risk because of its role in the metabolic activation and detoxification of carcinogens, recent studies have suggested it may be important in cell growth and survival. To address the possible importance of NAT1 in breast cancer, we have used a novel small molecule inhibitor (Rhod-o-hp) of the enzyme to examine growth and invasion of the breast adenocarcinoma line MDA-MB-231. The inhibitor significantly reduced cell growth by increasing the percent of cells in G2/M phase of the cell cycle. Rhod-o-hp also reduced the ability of the MDA-MB-231 cells to grow in soft agar. Using an in vitro invasion assay, the inhibitor significantly reduced the invasiveness of the cells. To test whether this effect was due to inhibition of NAT1, the enzyme was knocked down using a lentivirus-based shRNA approach and invasion potential was significantly reduced. Taken together, the results of this study demonstrate that NAT1 activity may be important in breast cancer growth and metastasis. The study suggests that NAT1 is a novel target for breast cancer treatment.

Topics: Adenocarcinoma; Arylamine N-Acetyltransferase; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Enzyme Inhibitors; Female; Humans; Isoenzymes; Neoplasm Invasiveness; Neoplasm Metastasis; Rhodanine

The identification, synthesis and evaluation of a series of rhodanine and thiazolidin-2,4-dione derivatives as selective inhibitors of human arylamine N-acetyltransferase 1 and mouse arylamine N-acetyltransferase 2 is described. The most potent inhibitors identified have submicromolar activity and inhibit both the recombinant proteins and human NAT1 in ZR-75 cell lysates in a competitive manner. (1)H NMR studies on purified mouse Nat2 demonstrate that the inhibitors bind within the putative active site of the enzyme.

Topics: Animals; Arylamine N-Acetyltransferase; Binding Sites; Biomarkers, Tumor; Breast Neoplasms; Enzyme Inhibitors; Female; Humans; Isoenzymes; Mice; Rhodanine; Thiazolidinediones