title: Genistein stimulates MCF-7 breast cancer cell growth by inducing acid ceramidase (ASAH1) gene expression.
abstract: Sphingolipid metabolites, such as ceramide (Cer), sphingosine (SPH), and sphingosine 1-phosphate (S1P), contribute to multiple aspects of carcinogenesis including cell proliferation, migration, angiogenesis, and tumor resistance. The cellular balance between Cer and S1P levels, for example, is an important determinant of cell fate, with the former inducing apoptosis and the later mitogenesis. Acid ceramidase (ASAH1) plays a pivotal role in regulating the intracellular concentration of these two metabolites by hydrolyzing Cer into SPH, which is rapidly phosphorylated to form S1P. Genistein is a phytoestrogen isoflavone that exerts agonist and antagonist effects on the proliferation of estrogen-dependent MCF-7 cells in a dose-dependent manner, primarily as a ligand for estrogen receptors. Genistein can also activate signaling through GPR30, a G-protein-coupled cell surface receptor. Based on the relationship between bioactive sphingolipids and tumorigenesis, we sought to determine the effect of genistein on ASAH1 transcription in MCF-7 breast cancer cells. We show herein that nanomolar concentrations of genistein induce ASAH1 transcription through a GPR30-dependent, pertussis toxin-sensitive pathway that requires the activation of c-Src and extracellular signal regulated kinase 1/2 (ERK1/2). Activation of this pathway promotes histone acetylation and recruitment of phospho-estrogen receptor α and specificity protein-1 to the ASAH1 promoter, ultimately culminating in increased ceramidase activity. Finally, we show that genistein stimulates cyclin B2 expression and cell proliferation in an ASAH1-dependent manner. Collectively, these data identify a mechanism through which genistein promotes sphingolipid metabolism and support a role for ASAH1 in breast cancer cell growth.
authors.affiliation: School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: Natasha C
authors.initials: NC
authors.lastname: Lucki
authors.forename: Marion B
authors.initials: MB
authors.lastname: Sewer
mesh_terms: D000107:Acetylation / Q000187:drug effects; D055573:Acid Ceramidase / Q000096:biosynthesis* / Q000235:genetics; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000201:enzymology* / Q000235:genetics; D000081247:CSK Tyrosine-Protein Kinase; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects* / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects* / Q000235:genetics; D019833:Genistein / Q000494:pharmacology*; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D011960:Receptors, Estrogen; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D013107:Sphingolipids / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects / Q000235:genetics; D019061:src-Family Kinases
chemical_list: D016588:Anticarcinogenic Agents; C109584:GPER1 protein, human; D006657:Histones; D011518:Proto-Oncogene Proteins; D011960:Receptors, Estrogen; D043562:Receptors, G-Protein-Coupled; D013107:Sphingolipids; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C000631346:CSK protein, human; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; C526693:ASAH1 protein, human; D055573:Acid Ceramidase