UP12, a novel ursolic acid derivative with potential for targeting multiple signaling pathways in hepatocellular carcinoma.

Targeting cancer cell glucose metabolism is a promising strategy for cancer therapy. In past approaches to cancer drug discovery, ursolic acid (UA) has been chemically modified to improve its antitumor activities and bioavailability. Here, a novel ursolic acid (UA) derivative UP12 was developed via computer-aided drug design to explore potent anti-cancer agents and to examine possible mechanisms. The structural docking analyses suggested that UP12 could bind to the active sites of glucokinase (GK), glucose transporter 1 (GLUT1) and ATPase, which are the main enzymes involved in cancer glucose metabolism. We further investigated the synergistic effect between UP12 and glycolysis inhibitor 2-deoxy-d-glucose (2-DG) in inhibiting glucose metabolism of cancer cells. The pharmacological results showed that the combination enhanced depletion of intracellular ATP and decrease in lactate production, and pushed more cancer cells arrested in the S and G2/M cycle phases. The combination selectively down-regulated the expression of Bcl-2 and HKII proteins, up-regulated the expression of Bax and p53, and collectively resulted in enhanced apoptosis related to caspase-3, -8, and -9 activities, in addition to inhibition on the cell mitochondrial membrane potential. The animal studies further demonstrated that the combination exhibited significant antitumor activity without obvious toxicity. In summary, UP12 can interfere cancer cell metabolism pathway and further enhance the therapeutic effects of 2-DG likely through synergistic suppression of cancer cell glucose metabolism, making UP12 a likely new candidate for anti-cancer drug development.