A therapeutic compound having intrinsic anti-mitochondrial properties may be chemically modified to target the compound to mitochondria, and the resulting "repurposcins" may have enhanced anti-cancer properties, among other advantageous properties. For example, a repurposcin may be used to treat and/or prevent tumor recurrence, metastasis, drug resistance, and/or radiotherapy resistance. Described herein are repurposcin compounds and pharmaceutical compositions that have been developed according to the present approach. Also described are methods for identifying and developing repurposcins, methods of using repurposcins to target cancer stem cells, and compositions for treating cancer containing one or more repurposcins as the active ingredient.
