Synthesis and cytotoxic activity of 2-acyl-1H-indole-4,7-diones on human cancer cell lines

Synthesis and cytotoxic activity of a series of 2-acyl-1H-indole-4,7-diones on human cancer cell lines are described. Due to close structural relationship to 2-acylindoles, potent inhibitors of tubulin polymerization, the mode of action of these novel compounds has been investigated. Cytotoxicity, the influence on tubulin polymerization, and cell cycle dependent cytotoxicity on colon carcinoma cells by investigation of RKO exo p27 versus RKO p27(kip1) cells are described. IC50 values of arrested versus proliferating cells differ only in a range of two to fourfold and therefore cellular targets, predominantly relevant for mitotic progression, are excluded. As shown by the significant difference in the IC90 values on different tumor cell lines, the investigated compounds seem to act selectively on mammary and renal cancer cells.