Antitumor derivatives for differentiation therapy

A method of treating cancer in a subject in need thereof by administering a therapeutically effective amount of a compound of Formula I:

• wherein X is selected from CH, N, S, and O, Y is selected from S, CO, NH, NO, and O,
• R1 and optional R2 are independently selected from unsubstituted C4-C6 alkyl, unsubstituted C4-C6 cycloalkyl or cycloheteroalkyl, and aryl;
• R3 is selected from H, OH, substituted or unsubstituted C1-C6 alkyl, and optional Z is selected from OH, NH2, NH(CO)R4, NH(SO2)R4, guanidine, alkylguanidine, and fluoroguanidine, R4 is polyethylene glycol or substituted or unsubstituted C1-C6 alkyl, and pharmaceutically acceptable salt thereof, and wherein the cancer is bladder cancer, prostate cancer, liver cancer, breast cancer, colon cancer, or leukemia.