title: Prolactin Signaling Stimulates Invasion via Na(+)/H(+) Exchanger NHE1 in T47D Human Breast Cancer Cells.
abstract: Prolactin (PRL) and its receptor (PRLR) are implicated in breast cancer invasiveness, although their exact roles remain controversial. The Na(+)/H(+) exchanger (NHE1) plays essential roles in cancer cell motility and invasiveness, but the PRLR and NHE1 have not previously been linked. Here we show that in T47D human breast cancer cells, which express high levels of PRLR and NHE1, exposure to PRL led to the activation of Janus kinase-2 (JAK2)/signal transducer and activator of transcription-5 (STAT5), Akt, and ERK1/2 signaling and the rapid formation of peripheral membrane ruffles, known to be associated with cell motility. NHE1 was present in small ruffles prior to PRL treatment and was further recruited to the larger, more dynamic ruffles induced by PRL exposure. In PRL-induced ruffles, NHE1 colocalized with activated Akt, ERK1/2, and the ERK effector p90Ribosomal S kinase (p90RSK), known regulators of NHE1 activity. Stimulation of T47D cells with PRL augmented p90RSK activation, Ser703-phosphorylation of NHE1, NHE1-dependent intracellular pH recovery, pericellular acidification, and NHE1-dependent invasiveness. NHE1 activity and localization to ruffles were attenuated by the inhibition of Akt and/or ERK1/2. In contrast, noncancerous MCF10A breast epithelial cells expressed NHE1 and PRLR at lower levels than T47D cells, and their stimulation with PRL induced neither NHE1 activation nor NHE1-dependent invasiveness. In conclusion, we show for the first time that PRLR activation stimulates breast cancer cell invasiveness via the activation of NHE1. We propose that PRL-induced NHE1 activation and the resulting NHE1-dependent invasiveness may contribute to the metastatic behavior of human breast cancer cells.
authors.affiliation: Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Elena
authors.initials: E
authors.lastname: Pedraz-Cuesta
authors.affiliation: Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Jacob
authors.initials: J
authors.lastname: Fredsted
authors.affiliation: Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Helene H
authors.initials: HH
authors.lastname: Jensen
authors.affiliation: Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Annika
authors.initials: A
authors.lastname: Bornebusch
authors.affiliation: Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Lene N
authors.initials: LN
authors.lastname: Nejsum
authors.affiliation: Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Birthe B
authors.initials: BB
authors.lastname: Kragelund
authors.affiliation: Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Stine F
authors.initials: SF
authors.lastname: Pedersen
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects / Q000235:genetics; D011388:Prolactin / Q000494:pharmacology*; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000235:genetics / Q000378:metabolism; D050799:STAT5 Transcription Factor / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D000074082:Sodium-Hydrogen Exchanger 1 / Q000235:genetics / Q000378:metabolism*
chemical_list: C490998:SLC9A1 protein, human; D050799:STAT5 Transcription Factor; D000074082:Sodium-Hydrogen Exchanger 1; D011388:Prolactin; C507924:JAK2 protein, human; D053614:Janus Kinase 2; D051057:Proto-Oncogene Proteins c-akt; D038744:Ribosomal Protein S6 Kinases, 90-kDa; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3