Angelica gigas Nakai and Decursin Downregulate Myc Expression to Promote Cell Death in B-cell Lymphoma

Angelica gigas Nakai (AGN) is an oriental traditional medicine to treat anemia, dysmenorrhea, and migraine. However, its anti-lymphoma effect is yet to be tested. Here, we demonstrated that AGN and its major component decursin target Myc to suppress lymphomagenesis in vitro and in vivo. AGN inhibited cell viability in multiple B lymphoma cells, while sparing normal splenocytes and bone marrow cells. Increased cleaved PARP level and caspase 3/7 activity and the repression of survival-promoting AKT/mTOR and MAPK pathways downstream of BCR, were responsible for the pro-apoptotic effects of AGN. We found that Myc, a prominent downstream target of these signaling pathways, contributes to AGN-induced cell death. Moreover, co-treatment with AGN and a Myc inhibitor, JQ1 or 10058-F4 yielded synergistic cytotoxic activities against cancer cells with markedly reduced Myc expression. AGN downregulated Myc expression and suppressed tumorigenesis in E mu-myc transgenic mice. The proapoptotic activities of AGN were recapitulated by decursin, indicating that the anti-tumor effect of AGN was mainly caused by decursin. These findings suggest that AGN and decursin possess potent anti-lymphoma activity, and combination therapies with AGN/decursin and a Myc inhibitor to target Myc more efficiently could be a valuable avenue to explore in the treatment of B-cell lymphoma.