Gambogic acid inhibits proliferation and induces apoptosis of human acute T­cell leukemia cells by inducing autophagy and downregulating ß­catenin signaling pathway: Mechanisms underlying the effect of Gambogic acid on T­ALL cells.

The main active compound of Garcinia hanburyi (referred to as gamboge) is gambogic acid (GA), which has long been a Chinese herbal medicine for treating several types of cancer. However, the potential therapeutic role and mechanisms of GA in T­cell acute lymphoblastic leukemia (T­ALL) remain unclear. In the present study, the effects of GA on proliferation, cell cycle, apoptosis, and autophagy in T­ALL cell lines were investigated. The possible mechanisms underlying GA activity were also examined. The results showed that GA inhibited proliferation, induced apoptosis, and activated autophagy in T­ALL cell lines (Jurkat and Molt­4 cells). Findings confirmed that GA has an antileukemia effect against peripheral blood lymphocyte cells in patients with ALL. GA inhibited phospho­GSK3ß S9 (p­GSK3ß S9) protein levels to inactivate Wnt signaling and suppress ß­catenin protein levels. In addition, the inhibitory effect of GA on T­ALL was reversed by overexpression of ß­catenin. Thus, GA can inhibit the growth and survival of T­ALL cells. GA also had antileukemic activity, at least in part, through the downregulation of the Wnt/ß­catenin signaling pathway.