Identification of a dual inhibitor of Janus Kinase 2 (JAK2) and p70 Ribosomal S6 Kinase1 (S6K1) pathways

Bioactive phytochemicals can suppress the growth of malignant cells, and investigation of the mechanisms responsible can assist in the identification of novel therapeutic strategies for cancer therapy. Ginger has been reported to exhibit potent anticancer effects, although previous reports have often focusedona narrow range of specific compounds. Through a direct comparison of various ginger compounds, we determined that gingerenone A selectively kills cancer cells while exhibiting minimal toxicity toward normal cells. Kinase array screening revealed JAK2 and S6K1 as the molecular targets primarily responsible for gingerenone A-induced cancer cell death. The effect of gingerenone A was strongly associated with relative phosphorylation levels of JAK2 and S6K1, and administration of gingerenone A significantly suppressed tumor growth in vivo. More importantly, the combined inhibition of JAK2 and S6K1 by commercial inhibitors selectively induced apoptosis in cancer cells, whereas treatment with either agent alone did not. These findings provide rationale for dual targeting of JAK2 and S6K1 in cancer for a combinatorial therapeutic approach.