TY - JOUR
T1 - Targeting the neurokinin-1 receptor compromises canonical Wnt signaling in hepatoblastoma
AU - Ilmer, Matthias
AU - Garnier, Agnés
AU - Vykoukal, Jody
AU - Alt, Eckhard
AU - Von Schweinitz, Dietrich
AU - Kappler, Roland
AU - Berger, Michael
N1 - Publisher Copyright:
© 2016 American Association for Cancer Research.
PY - 2015/12/1
Y1 - 2015/12/1
N2 - 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 b-catenin or extrinsic Wnt activation. Wnt inhibition seemed to be strengthened by disruption of the FOXM1-b-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.
AB - 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 b-catenin or extrinsic Wnt activation. Wnt inhibition seemed to be strengthened by disruption of the FOXM1-b-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.
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U2 - 10.1158/1535-7163.MCT-15-0206
DO - 10.1158/1535-7163.MCT-15-0206
M3 - Article
C2 - 26516161
AN - SCOPUS:84958211517
SN - 1535-7163
VL - 14
SP - 2712
EP - 2721
JO - Molecular cancer therapeutics
JF - Molecular cancer therapeutics
IS - 12
ER -