N-Aryl benzenesulfonamide inhibitors of [3H]-thymidine incorporation and β-catenin signaling in human hepatocyte-derived Huh-7 carcinoma cells.

Structure-activity relationships (SAR) in 2,5-dichloro-N-(2-methyl-4-nitrophenyl)benzenesulfonamide (FH535) were examined as part of a program to identify agents that inhibit the Wnt/β-catenin signaling pathway that is frequently upregulated in hepatocellular carcinoma (HCC). FH535 was reported as an inhibitor of both β-catenin in the Wnt signaling pathway and the peroxisome proliferator-activated receptor (PPAR). A β-catenin/T-cell factor (TCF)/Lymphoid-enhancer factor (LEF)-dependent assay (i.e., luciferase-based TOPFlash assay) as well as a [(3)H]-thymidine incorporation assay were used to explore SAR modifications of FH535. Although replacing the 2,5-dichlorophenylsulfonyl substituent in FH535 with a 2,6-dihalogenation pattern generally produced more biologically active analogs than FH535, other SAR modifications led only to FH535 analogs with comparable or slightly improved activity in these two assays. The absence of a clear SAR pattern in activity suggested a multiplicity of target effectors for N-aryl benzenesulfonamides.