Research On Imperatorin Inhibiting HIF-1? Signaling Pathway And ZFP91 Promoting Interleukin-1? Secretion

Background:There is a close relationship between inflammation and cancer.It is reported that HIF-la is an important regulatory factor in cancer.IL-1? is an important marker in inflammation.Angelica dahurica is a commonly used traditional Chinese medicine to treat migraine headache,toothache and cancer.Imperatorin is an active natural furocoumarin component originating from Angelica dahurica and has been shown to exhibit multiple bioeffector functions,including anti-cancer activity.However,the mechanism by which imperatorin inhibits tumor growth is not fully understood.Interleukin-1?(IL-1?)is a cytokine of critical importance in inflammatory,infectious and autoimmune diseases.It is reported that zinc finger protein 91 participates in a variety of biological processes.Our study shows that ZFP91 can promote the production of pro-IL-1? and the secretion of IL-1? for the first time.However,how IL-1? expression is regulated by ZFP91 remains largely unknown.Aim of the study:(1)The aim of this study was to investigate the effectiveness of imperatorin as a treatment of cancer and to identify the underlying mechanisms of its anticancer activity.(2)The aim of this study was to investigate the underlying mechanism of ZFP91 activation in promoting pro-IL-1? production and IL-1?secretion.Materials and methods:(1)Major assays were promoter-reporter gene assay,MTT,western blot analysis,immunofluorescence assay,reverse transcription-PCR(RT-PCR),flow cytometric analysis,clonogenic assay,EdU labeling and immunofluorescence,xenografted assay,immunohistochemistry and ELISA.(2)The major experimental methods are were western blot analysis,immunofluorescence assay,reverse transcription-PCR(RT-PCR),immunoprecipitation,ELISA,in vivo peritonitis,DSS-induced colitis and immunohistochemistry.Results:(1)We here demonstrated the effect of imperatorin on hypoxia-inducible factor-1(HIF-1)activation.Imperatorin showed a potent inhibitory activity against HIF-1 activation induced by hypoxia in various human cancer cell lines.This compound markedly decreased the hypoxia-induced accumulation of HIF-1? protein dose-dependently,whereas it did not affect the expressions of HIF-1?and Topo-I.Further analysis revealed that imperatorin inhibited HIF-la protein synthesis,without affecting the expression level of HIF-1? mRNA or degradation of HIF-1? protein.Moreover,the phosphorylation levels of mammalian target of rapamycin(mTOR),ribosomal protein S6 kinase(p70S6K),eIF4E binding protein-1(4E-BP1),eukaryotic initiation factor 4E(eIF4E),extracellular signal-regulated kinase-1/2(ERK1/2),SAPK/JNK and p38 were significantly suppressed by imperatorin.Furthermore,imperatorin prevented hypoxia-induced expression of HIF-1 target genes and flow cytometric analysis indicated that imperatorin induced G1 phase arrest in human colon cancer cell(HCT116),We found that imperatorin administration inhibits tumor growth and blocks tumor angiogenesis in a xenograft tumor model.(2)In this study,we found that ZFP91 up-regulates the production and activation of pro-IL-1? in LPS-stimulated THP-1 cells and BMDM cells.ZFP91 enhances the expression of non-canonical caspase-8 inflammasome components,and facilitates non-canonical caspase-8 inflammasome complex assembly in LPS-stimulated macrophages.Moreover,ZFP91 enhances the activation of extracellular signal-regulated kinase-1/2(ERK1/2),SAPK/JNK and p38 in LPS-stimulated cells.The synthesis of pro-IL-1? is dependent on activation of MAPKs signaling pathways in LPS-stimulated THP-1 cells.In vivo experiments,ZFP91 deficiency ameliorates the symptoms and colon inflammation in DSS-induced colitis mice.ZFP91 deficiency reduces alum-induced peritonitis.Conclusions:(1)These results indicate that imperatorin inhibited the synthesis of HIF-la protein via modulating the mTOR/p70S6K/4E-BP1 and MAPKs pathways.These conclusions suggest that imperatorin is a potent HIF-1 inhibitor and provide new perspectives for anti-cancer activity mechanism.(2)Our research describes the mechanism by which ZFP91 limits production of IL-1(3 under physiological conditions and suggests that ZFP91 may be a promising therapeutic target for the intervention of inflammatory,infectious and autoimmune diseases related diseases.