AMP-activated protein kinase (AMPK) is a critical monitor of cellular energy status and also controls processes related to tumor development, including cell cycle progression, protein synthesis, cell growth and survival. Therefore AMPK as an anti-cancer target has received intensive attention recently. It has been reported that the anti-diabetic drug metformin and some natural compounds, such as quercetin, genistein, capsaicin and green tea polyphenol epigallocatechin gallate (EGCG), can activate AMPK and inhibit cancer cell growth. Indeed, natural products have been the most productive source of leads for the development of anti-cancer drugs but perceived disadvantages, such as low bioavailability and week potency, have limited their development and use in the clinic. In this study we demonstrated that synthetic EGCG analogs 4 and 6 were more potent AMPK activators than metformin and EGCG. Activation of AMPK by these EGCG analogs resulted in inhibition of cell proliferation, up-regulation of the cyclin-dependent kinase inhibitor p21, down-regulation of mTOR pathway, and suppression of stem cell population in human breast cancer cells. Our findings suggest that novel potent and specific AMPK activators can be discovered from natural and synthetic sources that have potential to be used for anti-cancer therapy in the clinic.

A modular approach to explore the macrocyclic chemical space around an aminoindoline scaffold is developed. This is achieved by incorporating an amino acid moiety and subsequent “stitching technology”. Through screening of a zebrafish assay, several antiangiogenesis agents are identified.

EGCG analogs 6 and 8 with 1,3-benzenediol, but not 2 and 4 with a 1,2-benzenediol structure, can enhance the anti-cancer effects of bortezomib (BZM) on human multiple myeloma cells.