title: Novel effects of FTY720 on perinuclear reorganization of keratin network induced by sphingosylphosphorylcholine: Involvement of protein phosphatase 2A and G-protein-coupled receptor-12.
abstract: Sphingosylphosphorylcholine (SPC) evokes perinuclear reorganization of keratin 8 (K8) filaments and regulates the viscoelasticity of metastatic cancer cells leading to enhanced migration. Few studies have addressed the compounds modulating the viscoelasticity of metastatic cancer cells. We studied the effects of sphingosine (SPH), sphingosine 1-phosphate (S1P), FTY720 and FTY720-phosphate (FTY720P) on SPC-induced K8 phosphorylation and reorganization using Western blot and confocal microscopy, and also evaluated the elasticity of PANC-1 cells by atomic force microscopy. FTY720, FTY720P, SPH, and S1P concentration-dependently inhibited SPC-evoked phosphorylation and reorganization of K8, and migration of PANC-1 cells. SPC triggered reduction and narrow distribution of elastic constant K and conversely, FTY720 blocked them. A common upstream regulator of JNK and ERK, protein phosphatase 2A (PP2A) expression was reduced by SPC, but was restored by FTY720 and FTY72P. Butyryl forskolin, a PP2A activator, suppressed SPC-induced K8 phosphorylation and okadaic acid, a PP2A inhibitor, induced K8 phosphorylation. Gene silencing of PP2A also led to K8 phosphorylation, reorganization and migration. We also investigated the involvement of GPR12, a high-affinity SPC receptor, in SPC-evoked keratin phosphorylation and reorganization. GPR12 siRNA suppressed the SPC-triggered phosphorylation and reorganization of K8. GPR12 overexpression stimulated keratin phosphorylation and reorganization even without SPC. FTY720 and FTY720P suppressed the GPR12-induced phosphorylation and reorganization of K8. The collective data indicates that FTY720 and FTY720P suppress SPC-induced phosphorylation and reorganization of K8 in PANC-1 cells by restoring the expression of PP2A via GPR12. These findings might be helpful in the development of compounds that modulate the viscoelasticity of metastatic cancer cells and various SPC actions.
authors.affiliation: BK21PLUS R-FIND Team, College of Pharmacy, Dongguk University, Seoul 100-715, Republic of Korea.
authors.forename: Mi Kyung
authors.initials: MK
authors.lastname: Park
authors.affiliation: College of Pharmacy, Keimyung University, Daegu 704-701, Republic of Korea.
authors.forename: Soyeun
authors.initials: S
authors.lastname: Park
authors.affiliation: BK21PLUS R-FIND Team, College of Pharmacy, Dongguk University, Seoul 100-715, Republic of Korea.
authors.forename: Hyun Ji
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: BK21PLUS R-FIND Team, College of Pharmacy, Dongguk University, Seoul 100-715, Republic of Korea.
authors.forename: Eun Ji
authors.initials: EJ
authors.lastname: Kim
authors.affiliation: BK21PLUS R-FIND Team, College of Pharmacy, Dongguk University, Seoul 100-715, Republic of Korea.
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Kim
authors.affiliation: BK21PLUS R-FIND Team, College of Pharmacy, Dongguk University, Seoul 100-715, Republic of Korea.
authors.forename: Gyeoung Jin
authors.initials: GJ
authors.lastname: Kang
authors.affiliation: BK21PLUS R-FIND Team, College of Pharmacy, Dongguk University, Seoul 100-715, Republic of Korea.
authors.forename: Hyun Jung
authors.initials: HJ
authors.lastname: Byun
authors.affiliation: College of Pharmacy, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Sang Hee
authors.initials: SH
authors.lastname: Kim
authors.affiliation: National Cancer Center, Goyang 10408, Republic of Korea.
authors.forename: Ho
authors.initials: H
authors.lastname: Lee
authors.affiliation: BK21PLUS R-FIND Team, College of Pharmacy, Dongguk University, Seoul 100-715, Republic of Korea. Electronic address: uatheone@dongguk.edu.
authors.forename: Chang Hoon
authors.initials: CH
authors.lastname: Lee
mesh_terms: D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D000068876:Fingolimod Hydrochloride / Q000494:pharmacology*; D006801:Humans; D053533:Keratin-8 / Q000378:metabolism*; D010755:Organophosphates / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D010767:Phosphorylcholine / Q000031:analogs & derivatives* / Q000494:pharmacology; D054648:Protein Phosphatase 2 / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: C525008:FTY 720P; C097350:GPR12 protein, human; D053533:Keratin-8; D010755:Organophosphates; D034741:RNA, Small Interfering; D043562:Receptors, G-Protein-Coupled; C005356:sphingosine phosphorylcholine; D010767:Phosphorylcholine; D054648:Protein Phosphatase 2; D000068876:Fingolimod Hydrochloride; D013110:Sphingosine
keywords: Elastic constant; FTY720; GPR12; Keratin 8 reorganization; Protein phosphatase 2A; Sphingosylphosphorylcholine