A Possible Anticancer Agent, Type III Interferon, Activates Cell Death Pathways and Produces Antitumor Effects

Figure 1

Signaling pathways mediated by type I and type III IFNs. Type I IFNs binding to the receptor complex induces JAK1 and TYK2 activation and phosphorylation of STAT1 and STAT2. The phosphorylated STAT1/STAT2 complex with IRF-9 forms ISGF3, which binds ISRE and initiates a number of transcriptions. Type I IFNs also activate STATs without forming ISGF3 and transactivate IFN-inducible genes through GAS elements. Additionally, type I IFNs activate the PI3K and p38 pathways to stimulate transcription of relevant genes through a number of transcription factors such as AP-1. Similarly, type III IFNs induce the JAK-STATs pathways; however, it is currently unknown whether type III IFNs activate the PI3K and p38 pathways.