title: Targeting the Neurokinin-1 Receptor Compromises Canonical Wnt Signaling in Hepatoblastoma.
abstract: The substance P (SP)/NK-1 receptor (NK1R) complex represents an intriguing anticancer target for a variety of tumors, including hepatoblastoma (HB). Therefore, NK1R antagonists, such as the clinical drug aprepitant, recently have been proposed as potent anticancer agents. However, very little is known regarding the molecular basis of NK1R inhibition in cancer. Using reverse phase protein array, Western blot, Super TOP/FOP, confocal microscopy, and sphere formation ability (SFA) assays, we identified the AKT and Wnt signaling pathways as the key targets of aprepitant in three human HB cell lines (HepT1, HepG2, and HuH6). Following NK1R blockage, we observed decreased phosphorylation of p70S6K and 4E-BP1/2 and inhibition of the canonical Wnt pathway with subsequent decrease of HB cell growth. This effect was dependent of high baseline Wnt activity either by mutational status of β-catenin or extrinsic Wnt activation. Wnt inhibition seemed to be strengthened by disruption of the FOXM1-β-catenin complex. Furthermore, treatment of HB cells with aprepitant led to reduced expression of (liver) stemness markers (AFP, CD13, SOX2, NANOG, and OCT4) and SFA when grown under cancer stem cell conditions. Taken together, we show for the first time that targeting the SP/NK1R signaling cascade inhibits canonical Wnt signaling in HB cells. These findings reveal important insight into the molecular mechanisms of the SP/NK1R complex as a critical component in a model of pediatric liver cancer and may support the development of novel therapeutic interventions for HB and other Wnt-activated cancers.
authors.affiliation: Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Matthias
authors.initials: M
authors.lastname: Ilmer
authors.affiliation: Department of Pediatric Surgery, Research Laboratories, Dr. von Hauner Children's Hospital, Ludwig Maximilians University Munich, Munich, Germany.
authors.forename: Agnès
authors.initials: A
authors.lastname: Garnier
authors.affiliation: Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Jody
authors.initials: J
authors.lastname: Vykoukal
authors.affiliation: Department of Medicine, Tulane University Health Science Center, New Orleans, Louisiana.
authors.forename: Eckhard
authors.initials: E
authors.lastname: Alt
authors.affiliation: Department of Pediatric Surgery, Research Laboratories, Dr. von Hauner Children's Hospital, Ludwig Maximilians University Munich, Munich, Germany.
authors.forename: Dietrich
authors.initials: D
authors.lastname: von Schweinitz
authors.affiliation: Department of Pediatric Surgery, Research Laboratories, Dr. von Hauner Children's Hospital, Ludwig Maximilians University Munich, Munich, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Kappler
authors.affiliation: Department of Pediatric Surgery, Research Laboratories, Dr. von Hauner Children's Hospital, Ludwig Maximilians University Munich, Munich, Germany. michael.fabian.berger@gmail.com.
authors.forename: Michael
authors.initials: M
authors.lastname: Berger
mesh_terms: D000077608:Aprepitant; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002648:Child; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D056945:Hep G2 Cells; D018197:Hepatoblastoma / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D009025:Morpholines / Q000008:administration & dosage*; D051058:Oncogene Protein v-akt / Q000235:genetics; D018040:Receptors, Neurokinin-1 / Q000096:biosynthesis* / Q000235:genetics; D060449:Wnt Signaling Pathway / Q000187:drug effects; D051176:beta Catenin / Q000235:genetics
chemical_list: D009025:Morpholines; D018040:Receptors, Neurokinin-1; D051176:beta Catenin; D000077608:Aprepitant; D051058:Oncogene Protein v-akt