Rasfonin (A304) is a fungal
natural product isolated from the fermentation substrate of Talaromyces sp. 3656-A1, which was named according to its activity against the
small G-protein Ras. In a former study, we demonstrated that it induced autophagy and apoptosis; however, whether
rasfonin activated necroptosis remained unknown. Moreover, the interplay among different cell death processes induced by
rasfonin was unexplored. In the present study, we revealed that, in addition of promoting autophagy and caspase-dependent apoptosis,
rasfonin also activated necroptosis. Nectrostatin-1 (Nec-1), an inhibitor of necroptosis, affected
rasfonin-induced autophagy in a time-dependent manner concurring with an increased caspase-dependent apoptosis. The aforementioned results were confirmed by knockdown of receptor-interacting
protein 1 (RIP1), a crucial necrostatin-1-targeted adaptor
kinase mediating cell death and survival. Taken together, the data presented indicate that
rasfonin activates various cell death pathways, and RIP1 plays a critical role in
rasfonin-induced autophagy and apoptosis.