title: Novel participation of transglutaminase-2 through c-Jun N-terminal kinase activation in sphingosylphosphorylcholine-induced keratin reorganization of PANC-1 cells.
abstract: Sphingosylphosphorylcholine (SPC) is found at increased levels in the malignant ascites of tumor patients and induces perinuclear reorganization of keratin 8 (K8) filaments that contribute to the viscoelasticity of metastatic cancer cells. In this study, we investigated the role and molecular mechanisms of Tgase-2 in SPC-induced K8 phosphorylation and perinuclear reorganization in PANC-1 cells (PAN(WT)), and in PANC-1 cells that stably expressed shTgase-2 or Tgase-2 (PAN(shTg2) and PAN(Tg2)). SPC induces the expression of Tgase-2 in a time- and dose-dependent manner. Gene silencing of Tgase-2 or cystamine suppressed the SPC-induced phosphorylation and perinuclear reorganization of K8 and suppressed the SPC-induced migration of PANC-1 cells. An inhibitor of c-Jun N-terminal kinase (JNK), SP600125, suppressed the SPC-induced phosphorylation of serine 431 in K8 and keratin reorganization. Next, we examined the effect of Tgase-2 on JNK activation of serine 431 phosphorylation in K8. Tgase-2 gene silencing suppressed the expression of active form JNK (pJNK). Constitutive or tetracyclin-induced conditional expression of Tgase-2 increased the levels of pJNK. Tgase-2 was coimmunoprecipitated with K8 and JNK. In addition, K8 was coimmunoprecipitated with Tgase-2 and JNK. JNK was also coimmunoprecipitated with K8 and Tgase-2. Overall, these results suggest that Tgase-2 is involved in SPC-induced phosphorylation and perinuclear reorganization of K8 by activating JNK and forming a triple complex with K8 and JNK. Therefore, SPC-induced Tgase-2 might be a new target for modulating keratin reorganization, metastasis of cancer cells and JNK activation.
authors.affiliation: College of Pharmacy, Dongguk University, Seoul, Korea.
authors.forename: Mi Kyung
authors.initials: MK
authors.lastname: Park
authors.forename: Hye Ja
authors.initials: HJ
authors.lastname: Lee
authors.forename: Jennifer
authors.initials: J
authors.lastname: Shin
authors.forename: Minsoo
authors.initials: M
authors.lastname: Noh
authors.forename: Soo Youl
authors.initials: SY
authors.lastname: Kim
authors.forename: Chang Hoon
authors.initials: CH
authors.lastname: Lee
mesh_terms: D000873:Anthracenes / Q000494:pharmacology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D003538:Cystamine / Q000494:pharmacology; D003599:Cytoskeleton / Q000235:genetics / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000172:deficiency / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D020868:Gene Silencing; D006801:Humans; D047468:Immunoprecipitation; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D053533:Keratin-8 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000235:genetics*; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D010767:Phosphorylcholine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000378:metabolism; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D012694:Serine / Q000235:genetics / Q000378:metabolism; D013110:Sphingosine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000378:metabolism; D011503:Transglutaminases / Q000172:deficiency / Q000235:genetics
chemical_list: D000873:Anthracenes; D053533:Keratin-8; D047428:Protein Kinase Inhibitors; D034741:RNA, Small Interfering; C005356:sphingosine phosphorylcholine; D010767:Phosphorylcholine; C432165:pyrazolanthrone; D012694:Serine; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D048031:JNK Mitogen-Activated Protein Kinases; D019204:GTP-Binding Proteins; D013110:Sphingosine; D003538:Cystamine