TY - JOUR T1 - Ursolic Acid Inhibits the Growth of Colon Cancer-initiating Cells by Targeting STAT3 JF - Anticancer Research JO - Anticancer Res SP - 4279 LP - 4284 VL - 33 IS - 10 AU - WENLONG WANG AU - CHONGQIANG ZHAO AU - DAVID JOU AU - JIAGAO LÜ AU - CUNTAI ZHANG AU - LI LIN AU - JIAYUH LIN Y1 - 2013/10/01 UR - http://ar.iiarjournals.org/content/33/10/4279.abstract N2 - Background: We have previously reported Signal Transducer and Activator of Transcription 3 (STAT3) to be constitutively activated in aldehyde dehydrogenase (ALDH)+/cluster of differentiation-133 (CD133)+ colon cancer-initiating cells. In the present study we tested the efficacy of inhibiting STAT3 signaling in human colon cancer-initiating cells by ursolic acid (UA), which exists widely in fruits and herbs. Results: Our data demonstrated that UA inhibited STAT3 phosphorylation, and induced caspase-3 cleavage of ALDH+/CD133+ colon cancer-initiating cells. UA also reduced cell viability and inhibited tumor sphere formation of colon cancer-initiating cells, more potently than two other natural compounds, resveratrol and capsaicin. UA also inhibited the activation of STAT3 induced by interleukin-6 in DLD-1 colon cancer cells. Furthermore, daily administration of UA suppressed HCT116 tumor growth in mice in vivo. Conclusion: Our results suggest STAT3 to be a target for colon cancer prevention. UA, a dietary agent, might offer an effective approach for colorectal carcinoma prevention by inhibiting persistently activated STAT3 in cancer stem cells. ER -