Journal: Acta Pharmacologica Sinica
Article Title: 3-Deoxy-2β,16-dihydroxynagilactone E, a natural compound from Podocarpus nagi , preferentially inhibits JAK2/STAT3 signaling by allosterically interacting with the regulatory domain of JAK2 and induces apoptosis of cancer cells
doi: 10.1038/s41401-019-0254-4
Figure Lengend Snippet: B6 preferentially inhibited the cytokine-induced phosphorylation of STAT3. a Chemical structure of 3-deoxy-2β, 16-dihydroxynagilactone E (B6). b , c Effects of B6 on the luciferase activities of the HepG2/STAT3-luciferase or HepG2/STAT1-luciferase reporter gene-containing cells. The luciferase reporter gene-containing cells were treated with B6 at the indicated concentrations for 1 h, followed by stimulation with IL-6 (10 ng/mL) or IFN-γ (10 ng/mL) for 4 h, and then the luciferase activities were measured. These experiments were performed in triplicates. Data shown are mean ± SD ( n = 3). ns, not significant, ** P < 0.01 and *** P < 0.001 versus the control group without B6 but with cytokine stimulation. Best-fit curve was determined using Prism software and was used to calculate the IC 50 value. d – f Effects of B6 on the phosphorylation of STAT1 and STAT3. HeLa cells were pretreated with B6 at indicated concentrations for 1 h before stimulation with IL-6 (10 ng/mL), IFN-γ (10 ng/mL), or IFN-α (1000 U) for 15 min. The cells were then lysed and analyzed by Western blotting using antibodies as indicated. Densitometric quantification of phospho-proteins normalized to total proteins was graphed below the corresponding Western blots. WB band density was quantified three times. Data shown are mean ± SD ( n = 3). ns, not significant, ** P < 0.01, *** P < 0.001
Article Snippet: B6 (purity: ≥98%), isolated from P. nagi , was provided by Dr. Yang Ye (Shanghai Institute of Materia Medica, Chinese Academy of Sciences); 17-hydroxy-jolkinolide B (HJB) (purity: ≥98%) was isolated from Euphorbia fischeriana , as reported previously [ ]; DTT (purity: ≥99%) and MTT (purity: ≥99%) were purchased from Genebase (Shanghai, China); GSH (purity: ≥99%) was obtained from Sibas Bioscience (Shanghai, China); IL-6 (#200-02), IFN-γ (#300-02), and IFN-α (human recombinant interferon-alpha 2A) (#300-02BC) were purchased from Peprotech (Saint Paul, MN, USA); and AZD1480 (#S2162, purity: ≥99%) was purchased from Selleckchem (Shanghai, China).
Techniques: Luciferase, Software, Western Blot
