title: Luteolin sensitizes the antiproliferative effect of interferon α/β by activation of Janus kinase/signal transducer and activator of transcription pathway signaling through protein kinase A-mediated inhibition of protein tyrosine phosphatase SHP-2 in cancer cells.
abstract: New negative regulators of interferon (IFN) signaling, preferably with tissue specificity, are needed to develop therapeutic means to enhance the efficacy of type I IFNs (IFN-α/β) and reduce their side effects. We conducted cell-based screening for IFN signaling enhancer and discovered that luteolin, a natural flavonoid, sensitized the antiproliferative effect of IFN-α in hepatoma HepG2 cells and cervical carcinoma HeLa cells. Luteolin promoted IFN-β-induced Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway activation by enhancing the phosphorylation of Jak1, Tyk2, and STAT1/2, thereby promoting STAT1 accumulation in the nucleus and endogenous IFN-α-regulated gene expression. Of interest, inhibition of phosphodiesterase (PDE) abolished the effect of IFN-β and luteolin on STAT1 phosphorylation. Luteolin also increased the cAMP-degrading activity of PDE bound with type I interferon receptor 2 (IFNAR2) and decreased the intracellular cAMP level, indicating that luteolin may act on the JAK/STAT pathway via PDE. Protein kinase A (PKA) was found to negatively regulate IFN-β-induced JAK/STAT signaling, and its inhibitory effect was counteracted by luteolin. Pull-down and immunoprecipitation assays revealed that type II PKA interacted with IFNAR2 via the receptor for activated C-kinase 1 (RACK-1), and such interaction was inhibited by luteolin. Src homology domain 2 containing tyrosine phosphatase-2 (SHP-2) was further found to mediate the inhibitory effect of PKA on the JAK/STAT pathway. These data suggest that PKA/PDE-mediated cAMP signaling, integrated by RACK-1 to IFNAR2, may negatively regulate IFN signaling through SHP-2. Inhibition of this signaling may provide a new way to sensitize the efficacy of IFN-α/β.
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.
authors: Zhengfu
authors: Z
authors: Tai
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China; Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, China.
authors: Yuan
authors: Y
authors: Lin
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.
authors: Yujiao
authors: Y
authors: He
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.
authors: Junmei
authors: J
authors: Huang
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.
authors: Jiajia
authors: J
authors: Guo
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.
authors: Lijuan
authors: L
authors: Yang
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China; Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China. Electronic address: zhanggl@cib.ac.cn.
authors: Guolin
authors: G
authors: Zhang
authors: Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China; Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China. Electronic address: wangfei@cib.ac.cn.
authors: Fei
authors: F
authors: Wang
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000906:Antibodies / Q000276:immunology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry; D019204:GTP-Binding Proteins; D057809:HEK293 Cells; D006367:HeLa Cells; D056945:Hep G2 Cells; D006801:Humans; D007155:Immunologic Factors / Q000494:pharmacology; D016898:Interferon-alpha / Q000494:pharmacology*; D016899:Interferon-beta / Q000494:pharmacology*; D053613:Janus Kinase 1 / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*; D047311:Luteolin / Q000494:pharmacology*; D009363:Neoplasm Proteins; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11 / Q000037:antagonists & inhibitors*; D053633:Receptor, Interferon alpha-beta / Q000737:chemistry / Q000378:metabolism; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface; D050794:STAT1 Transcription Factor / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D050795:STAT2 Transcription Factor / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D053634:TYK2 Kinase / Q000276:immunology / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; D000906:Antibodies; C508033:IFNAR2 protein, human; D007155:Immunologic Factors; D016898:Interferon-alpha; D009363:Neoplasm Proteins; D010726:Phosphodiesterase Inhibitors; C419368:RACK1 protein, human; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface; D050794:STAT1 Transcription Factor; D050795:STAT2 Transcription Factor; D053633:Receptor, Interferon alpha-beta; D005576:Colforsin; D016899:Interferon-beta; D000242:Cyclic AMP; C507904:JAK1 protein, human; D053613:Janus Kinase 1; D053634:TYK2 Kinase; C070139:TYK2 protein, human; D017868:Cyclic AMP-Dependent Protein Kinases; C516724:PTPN11 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D010727:Phosphoric Diester Hydrolases; D019204:GTP-Binding Proteins; D047311:Luteolin
keywords: 2′5′-OAS1; 2′5′-oligoadenylate synthetase 1; 3-isobutyl-1-methylxanthine; 3′,4′,5,7-tetrahydroxyflavone; A-kinase anchoring protein; AKAP; CRE; DMSO; ERK; GADPH; GST; IBMX; IFN; IFNAR; ISRE; Interferon; JAK; Janus kinase; Luteolin; MS; Na(3)VO(4); PDE; PKA; PKA RIIα; PKC; PKR; Phosphodiesterase; RACK-1; SHP; SHP-2; STAT; Src homology domain 2 containing phosphotyrosine phosphatase; cAMP; cAMP responsive element; cAMP-dependent protein kinase A; cyclic adenosine 3′,5′-monophosphate; dimethyl sulfoxide; extracellular signal-regulated kinase; glutathione S-transferase; glyceraldehyde-3-phosphate dehydrogenase; interferon; interferon α-stimulated response element; interferon-induced, double-stranded RNA-activated protein kinase; luteolin; multiple sclerosis; phosphodiesterase; protein kinase C; receptor for activated C-kinase 1; signal transducer and activator of transcription; sodium orthovanadate; type I interferon receptor; type II PKA regulatory subunit α