title: Expression of the bitter receptor T2R38 in pancreatic cancer: localization in lipid droplets and activation by a bacteria-derived quorum-sensing molecule.
abstract: T2R38 belongs to the family of bitter receptors and was initially detected in cells of the oral cavity. We now describe expression of T2R38 in tumor cells in patients with pancreatic cancer and in tumor-derived cell lines. T2R38 is localized predominantly intracellular in association with lipid droplets, particularly with the lipid droplet membrane. The receptor can be activated by the bona fide ligand for T2R38, phenylthiourea (PTU), and by N-acetyl-dodecanoyl homoserine (AHL-12), a quorum sensing molecule of Pseudomonas aeruginosa, the latter is the only known natural ligand for T2R38. In response to PTU or AHL-12, key transcription factors are activated including phosphorylation of the MAP kinases p38 and ERK1/2, and upregulation of NFATc1. Moreover, we found increased expression of the multi-drug resistance protein 1 (also known as ABCB1), a transmembrane transporter molecule, participating in shuttling of a plethora of drugs, such as chemotherapeutics or antibiotics. In conclusion, our data indicate a new, additional function of the taste receptor T2R38 beyond sensing "bitter". Moreover, because T2R38 can be stimulated by a bacteria-derived signaling molecule the receptor could link microbiota and cancer.
authors: Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany.
authors: Matthias M
authors: MM
authors: Gaida
authors: Department for Gynecology and Obstetrics, University Hospital Heidelberg, Heidelberg, Germany.
authors: Christine
authors: C
authors: Mayer
authors: Department for Orthopedics, University Hospital Heidelberg, Heidelberg, Germany.
authors: Ulrike
authors: U
authors: Dapunt
authors: Institute of Immunology, University Heidelberg, Heidelberg, Germany.
authors: Sabine
authors: S
authors: Stegmaier
authors: Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany.
authors: Peter
authors: P
authors: Schirmacher
authors: Institute of Immunology, University Heidelberg, Heidelberg, Germany.
authors: Guido H
authors: GH
authors: Wabnitz
authors: Institute of Immunology, University Heidelberg, Heidelberg, Germany.
authors: G Maria
authors: GM
authors: Hänsch
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism / Q000494:pharmacology; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism*; D006801:Humans; D000070136:Lipid Droplet Associated Proteins / Q000378:metabolism; D066292:Lipid Droplets / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000378:metabolism*; D010670:Phenylthiourea / Q000494:pharmacology; D011550:Pseudomonas aeruginosa; D053038:Quorum Sensing; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D000098706:Taste Receptors, Type 2
chemical_list: D001426:Bacterial Proteins; D000070136:Lipid Droplet Associated Proteins; D043562:Receptors, G-Protein-Coupled; D000098706:Taste Receptors, Type 2; D010670:Phenylthiourea
keywords: ABCB1; bitter receptor; microbiome; pancreatic cancer