title: Estradiol induces export of sphingosine 1-phosphate from breast cancer cells via ABCC1 and ABCG2.
abstract: Sphingosine 1-phosphate (S1P), a potent sphingolipid mediator produced by sphingosine kinase isoenzymes (SphK1 and SphK2), regulates diverse cellular processes important for breast cancer progression acting in an autocrine and/or paracrine manner. Here we show that SphK1, but not SphK2, increased S1P export from MCF-7 cells. Whereas for both estradiol (E(2)) and epidermal growth factor-activated SphK1 and production of S1P, only E(2) stimulated rapid release of S1P and dihydro-S1P from MCF-7 cells. E(2)-induced S1P and dihydro-S1P export required estrogen receptor-alpha, not GPR30, and was suppressed either by pharmacological inhibitors or gene silencing of ABCC1 (multidrug resistant protein 1) or ABCG2 (breast cancer resistance protein). Inhibiting these transporters also blocked E(2)-induced activation of ERK1/2, indicating that E(2) activates ERK via downstream signaling of S1P. Taken together, our findings suggest that E(2)-induced export of S1P mediated by ABCC1 and ABCG2 transporters and consequent activation of S1P receptors may contribute to nongenomic signaling of E(2) important for breast cancer pathophysiology.
authors.affiliation: From the Division of Surgical Oncology, Massey Cancer Center, Virginia Commonwealth University School ofMedicine, Richmond, Virginia 23298, USA.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Takabe
authors.forename: Roger H
authors.initials: RH
authors.lastname: Kim
authors.forename: Jeremy C
authors.initials: JC
authors.lastname: Allegood
authors.forename: Poulami
authors.initials: P
authors.lastname: Mitra
authors.forename: Subramaniam
authors.initials: S
authors.lastname: Ramachandran
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nagahashi
authors.forename: Kuzhuvelil B
authors.initials: KB
authors.lastname: Harikumar
authors.forename: Nitai C
authors.initials: NC
authors.lastname: Hait
authors.forename: Sheldon
authors.initials: S
authors.lastname: Milstien
authors.forename: Sarah
authors.initials: S
authors.lastname: Spiegel
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D004967:Estrogens / Q000494:pharmacology*; D006801:Humans; D008246:Lysophospholipids / Q000378:metabolism*; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D021241:Spectrometry, Mass, Electrospray Ionization; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000378:metabolism; D000099157:Sphingosine Kinase
chemical_list: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D004958:Estradiol; D004967:Estrogens; D008246:Lysophospholipids; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins; D017853:Phosphotransferases (Alcohol Group Acceptor); D012333:RNA, Messenger; D013110:Sphingosine; D000099157:Sphingosine Kinase; C116614:ABCG2 protein, human; C060506:sphingosine 1-phosphate; C421109:multidrug resistance-associated protein 1