title: Ceramide synthases CerS4 and CerS5 are upregulated by 17β-estradiol and GPER1 via AP-1 in human breast cancer cells.
abstract: Ceramide synthases (CerS) are important enzymes of the sphingolipid pathway, responsible for the production of ceramides with distinct chain lengths. In human breast cancer tissue, we detected a significant increase in CerS4 and CerS6 mRNA in estrogen receptor positive (ER+) cancer tissue. To clarify the molecular mechanism of this upregulation, we cloned CerS2, -4, -5 and CerS6 promoter and 3'-UTR fragments into luciferase reporter gene plasmids and determined luciferase activity in MCF-7 (ERα/β) and MDA-MB-231 (ERβ) cells after 17β-estradiol treatment. Only the activities of CerS4 and CerS5 promoter Luc constructs, as well as CerS2- and CerS5-3'-UTR Luc constructs increased after estradiol treatment in MCF-7 cells, and this could be inhibited by the anti-estrogen fulvestrant. Co-transfection with the G protein-coupled estrogen receptor 1 (GPER1) also enhanced CerS2, CerS4 and CerS6 promoter activity whereas CerS5 promoter activity was inhibited in both cell lines. Promoter deletion and mutation constructs from CerS4 and CerS5 promoters revealed that estradiol and GPER1 mediate their effects on both promoters by activating AP-1, most likely through dimerization of c-Jun and c-Fos. At least we could show, that cell proliferation induced by estradiol could be blocked by co-treatment with Fumonisin B1, indicating that upregulation of CerS in breast cancer cells by estrogen is important for cell proliferation and possibly tumor development. In conclusion, our data highlight transcriptional and posttranscriptional mechanisms regulating CerS expression in human cells which provide the basis for further studies investigating the regulation of CerS expression and ceramide synthesis after diverse stimuli in physiological and pathophysiological processess.
authors.affiliation: pharmazentrum frankfurt/ZAFES, Institute for Clinical Pharmacology, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany.
authors.forename: Marthe-Susanna
authors.initials: MS
authors.lastname: Wegner
authors.affiliation: pharmazentrum frankfurt/ZAFES, Institute for Clinical Pharmacology, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany.
authors.forename: Ruth Anna
authors.initials: RA
authors.lastname: Wanger
authors.affiliation: pharmazentrum frankfurt/ZAFES, Institute for Clinical Pharmacology, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Oertel
authors.affiliation: pharmazentrum frankfurt/ZAFES, Institute for Clinical Pharmacology, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Brachtendorf
authors.affiliation: pharmazentrum frankfurt/ZAFES, Institute for Clinical Pharmacology, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Hartmann
authors.affiliation: Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Project Group Translational Medicine and Pharmacology (TMP), Theodor-Stern-Kai 7, 60596 Frankfurt am Main, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Schiffmann
authors.affiliation: Institute for Pharmaceutical Biology, Biozentrum, Max-von-Laue-Str. 9, 60438 Frankfurt/Main, Germany.
authors.forename: Rolf
authors.initials: R
authors.lastname: Marschalek
authors.affiliation: pharmazentrum frankfurt/ZAFES, Institute for Clinical Pharmacology, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Schreiber
authors.affiliation: pharmazentrum frankfurt/ZAFES, Institute for Clinical Pharmacology, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany.
authors.forename: Nerea
authors.initials: N
authors.lastname: Ferreirós
authors.affiliation: pharmazentrum frankfurt/ZAFES, Institute for Clinical Pharmacology, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Geisslinger
authors.affiliation: pharmazentrum frankfurt/ZAFES, Institute for Clinical Pharmacology, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany. Electronic address: groesch@em.uni-frankfurt.de.
authors.forename: Sabine
authors.initials: S
authors.lastname: Grösch
mesh_terms: D001483:Base Sequence; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D017931:DNA Primers; D004958:Estradiol / Q000494:pharmacology*; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012323:RNA Processing, Post-Transcriptional; D060888:Real-Time Polymerase Chain Reaction; D011960:Receptors, Estrogen / Q000378:metabolism / Q000502:physiology; D043562:Receptors, G-Protein-Coupled / Q000502:physiology; D015854:Up-Regulation / Q000187:drug effects*
chemical_list: D017931:DNA Primers; C109584:GPER1 protein, human; D007527:Isoenzymes; D011960:Receptors, Estrogen; D043562:Receptors, G-Protein-Coupled; D004958:Estradiol; D010088:Oxidoreductases; C108138:dihydroceramide desaturase
keywords: Cancer; Ceramide; Hormones; Sphingolipids; Transcription