title: Recepteur d'origine nantais tyrosine kinase is a direct target of hypoxia-inducible factor-1alpha-mediated invasion of breast carcinoma cells.
abstract: Hypoxia-inducible factor-1alpha (HIF-1alpha) overexpression was shown to be associated with invasion and metastasis of tumors and tumor cell lines. The identification of molecular targets that contribute to HIF-1alpha-mediated invasion is under intensive investigation. We have analyzed the role of recepteur d'origine nantais (RON), a tyrosine kinase receptor for macrophage-stimulating protein (MSP) that plays a role in breast cancer cell invasion as one of the molecular targets of HIF-1alpha. Analysis of a panel of breast cancer cell lines indicated a correlation between HIF-1alpha and RON expression. Treatment of HIF-1alpha- and RON-positive breast cancer cells with HIF-1alpha inhibitor, echinomycin, led to the inhibition of HIF-1alpha activity and RON expression. We have identified HIF-1alpha binding site on the RON promoter. Chromatin immunoprecipitation analysis and site-directed mutagenesis of the RON promoter confirmed the binding of HIF-1alpha to RON promoter. HIF-1alpha inhibitor-, echinomycin-, or short hairpin RNA-mediated selective knockdown of HIF-1alpha or HIF-1alpha target RON tyrosine kinase abrogated RON gene expression, and the RON ligand macrophage-stimulating protein mediated invasion of breast cancer cells. Consequently, the data presented herein demonstrated RON as a novel molecular target of HIF-1alpha and suggest a potential therapeutic role for HIF-1alpha or RON tyrosine kinase inhibitors in the blockade of RON tyrosine kinase-mediated invasion of carcinoma cells.
authors.affiliation: Department of Medicine, Division of Hematology and Medical Oncology, and Cancer Therapy & Research Center, University of Texas Health Science Center, San Antonio, Texas 78229.
authors.forename: Amalraj
authors.initials: A
authors.lastname: Thangasamy
authors.forename: Jessica
authors.initials: J
authors.lastname: Rogge
authors.forename: Sudhakar
authors.initials: S
authors.lastname: Ammanamanchi
mesh_terms: D001943:Breast Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*; D002457:Cell Extracts; D045744:Cell Line, Tumor; D004448:Echinomycin / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D055785:Gene Knockdown Techniques; D017228:Hepatocyte Growth Factor / Q000378:metabolism; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011401:Promoter Regions, Genetic / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D002457:Cell Extracts; D004448:Echinomycin; D048049:Extracellular Signal-Regulated MAP Kinases; D017228:Hepatocyte Growth Factor; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; D020794:Receptor Protein-Tyrosine Kinases; C497442:HIF1A protein, human; C082332:macrophage stimulating protein; C080835:RON protein