title: Sphingosine 1-phosphate receptor 4 uses HER2 (ERBB2) to regulate extracellular signal regulated kinase-1/2 in MDA-MB-453 breast cancer cells.
abstract: We demonstrate here that the bioactive lipid sphingosine 1-phosphate (S1P) uses sphingosine 1-phosphate receptor 4 (S1P(4)) and human epidermal growth factor receptor 2 (HER2) to stimulate the extracellular signal regulated protein kinase 1/2 (ERK-1/2) pathway in MDA-MB-453 cells. This was based on several lines of evidence. First, the S1P stimulation of ERK-1/2 was abolished by JTE013, which we show here is an S1P(2/4) antagonist and reduced by siRNA knockdown of S1P(4). Second, the S1P-stimulated activation of ERK-1/2 was almost completely abolished by a HER2 inhibitor (ErbB2 inhibitor II) and reduced by siRNA knockdown of HER2 expression. Third, phyto-S1P, which is an S1P(4) agonist, stimulated ERK-1/2 activation in an S1P(4)- and HER2-dependent manner. Fourth, FTY720 phosphate, which is an agonist at S1P(1,3,4,5) but not S1P(2) stimulated activation of ERK-1/2. Fifth, S1P stimulated the tyrosine phosphorylation of HER2, which was reduced by JTE013. HER2 which is an orphan receptor tyrosine kinase is the preferred dimerization partner of the EGF receptor. However, EGF-stimulated activation of ERK-1/2 was not affected by siRNA knockdown of HER2 or by ErbB2 (epidermal growth factor receptor 2 (or HER2)) inhibitor II in MDA-MB-453 cells. Moreover, S1P-stimulated activation of ERK-1/2 does not require an EGF receptor. Thus, S1P and EGF function in a mutually exclusive manner. In conclusion, the magnitude of the signaling gain on the ERK-1/2 pathway produced in response to S1P can be increased by HER2 in MDA-MB-453 cells. The linkage of S1P with an oncogene suggests that S1P and specifically S1P(4) may have an important role in breast cancer progression.
authors.affiliation: Cell Biology Group, Strathclyde Institute of Pharmacy and Biomedical Science, Univesity of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, Scotland, United Kingdom.
authors.forename: Jaclyn S
authors.initials: JS
authors.lastname: Long
authors.forename: Yuko
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: Joanne
authors.initials: J
authors.lastname: Edwards
authors.forename: Claire L
authors.initials: CL
authors.lastname: Tannahill
authors.forename: Gabor
authors.initials: G
authors.lastname: Tigyi
authors.forename: Susan
authors.initials: S
authors.lastname: Pyne
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Pyne
mesh_terms: D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005260:Female; D000068876:Fingolimod Hydrochloride; D057809:HEK293 Cells; D006801:Humans; D008246:Lysophospholipids / Q000494:pharmacology; 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; D011409:Propylene Glycols / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D034622:RNA Interference; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D049349:Receptors, Lysosphingolipid / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D004815:Epidermal Growth Factor; D000068876:Fingolimod Hydrochloride; D008246:Lysophospholipids; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D011409:Propylene Glycols; D011720:Pyrazoles; D011725:Pyridines; D018719:Erb-b2 Receptor Tyrosine Kinases; D049349:Receptors, Lysosphingolipid; D013110:Sphingosine; C471998:JTE 013; C060506:sphingosine 1-phosphate; C535150:MAPK1 protein, human