Validation and application a cell-based screening model for IL-6/JAK/STAT3 inhibitor / 药学学报

ABSTRACT

Interleukin-6 (IL-6)/janus kinase (JAK)/signal transducers and activators of transcription 3 (STAT3) is a pivotal signaling pathway in the regulation of cell proliferation, survival, differentiation and T cell activation. Aberration of this pathway is involved in multiple autoimmunity diseases and cancers, therefore the pathway is considered as a hot target for drug development. In our study, we validated a cell-based model of IL-6/JAK/STAT3 and used it in screening of its inhibitors. HEK-Blue IL-6 cells of Invivogen Inc. were used to stably express IL-6 receptor and STAT3-induced secreted embryonic alkaline phosphatase (SEAP) report gene. After stimulation by IL-6, SEAP was secreted from cells and reacted with QUANTI-Blue. The product can be detected at 655 nm. The inhibitory effect of compounds on STAT3 signaling showed as IC50 was calculated by OD value. The results shown that IL-6 specifically activated the cells, which could be applied to screen the inhibitors for IL-6/JAK/STAT3 signaling pathway. The optimized screening conditions were described as below50 000 cells/well, 1 ng·mL-1 IL-6 incubation for 20 h and reaction with QUANTI-Blue for 1 h. Based on this condition, we screened 14 natural products based on this cell model and arctigenin, cryptotanshinone and curcumin showed potential inhibitory activities on STAT3 signaling pathway with IC50 of 1.28, 2.96 and 6.61 μmol·L-1. Our study suggests that HEK-Blue IL-6 cells were suitable for screening inhibitors for the IL-6/JAK/STAT3 signaling pathway.