Chemical agents, such as disulfonamide derivatives of fluorene, anthracene, xanthene, dibenzosuberone and acridine, and similar heterocyclic ring structures, including salts thereof, that act as anti-cancer and anti-tumor agents, especially where such agents modulate the activity of the Wnt/β-catenin signaling pathway, and serve to reduce β-catenin levels present in cells, such as cancer cells, or where the agents modulate levels of gene expression in cellular systems, including cancer cells, are disclosed, along with methods for preparing such agents, as well as pharmaceutical compositions containing such agents as active ingredients and methods of using these as therapeutic agents.