TY  - JOUR
A1  - Wohlfarth, Carolin
A1  - Schmitteckert, Stefanie
A1  - Härtle, Janina D.
A1  - Houghton, Lesley A.
A1  - Dweep, Harsh
A1  - Fortea, Marina
A1  - Assadi, Ghazaleh
A1  - Braun, Alexander
A1  - Mederer, Tanja
A1  - Pöhner, Sarina
A1  - Becker, Philip P.
A1  - Fischer, Christine
A1  - Granzow, Martin
A1  - Mönnikes, Hubert
A1  - Mayer, Emeran A.
A1  - Sayuk, Gregory
A1  - Boeckxstaens, Guy
A1  - Wouters, Mira M.
A1  - Simrén, Magnus
A1  - Lindberg, Greger
A1  - Ohlsson, Bodil
A1  - Schmidt, Peter Thelin
A1  - Dlugosz, Aldona
A1  - Agreus, Lars
A1  - Andreasson, Anna
A1  - D'Amato, Mauro
A1  - Burwinkel, Barbara
A1  - Bermejo, Justo Lorenzo
A1  - Röth, Ralph
A1  - Lasitschka, Felix
A1  - Vicario, Maria
A1  - Metzger, Marco
A1  - Santos, Javier
A1  - Rappold, Gudrun A.
A1  - Martinez, Cristina
A1  - Niesler, Beate
T1  - miR-16 and miR-103 impact 5-HT4 receptor signalling and correlate with symptom profile in irritable bowel syndrome
JF  - Scientific Reports
N2  - Irritable bowel syndrome (IBS) is a gut-brain disorder involving alterations in intestinal sensitivity and motility. Serotonin 5-HT4 receptors are promising candidates in IBS pathophysiology since they regulate gut motor function and stool consistency, and targeted 5-HT4R selective drug intervention has been proven beneficial in subgroups of patients. We identified a single nucleotide polymorphism (SNP) (rs201253747) c.*61 T > C within the 5-HT4 receptor gene \(HTR4\) to be predominantly present in diarrhoea-IBS patients (IBS-D). It affects a binding site for the miR-16 family and miR-103/miR-107 within the isoforms \({HTR4b/i}\) and putatively impairs \(HTR4\) expression. Subsequent miRNA profiling revealed downregulation of miR-16 and miR-103 in the jejunum of IBS-D patients correlating with symptoms. \(In\) \(vitro\) assays confirmed expression regulation via three 3′UTR binding sites. The novel isoform \(HTR4b\_2\) lacking two of the three miRNA binding sites escapes miR-16/103/107 regulationin SNP carriers. We provide the first evidence that \(HTR4\) expression is fine-tuned by miRNAs, and that this regulation is impaired either by the SNP c.*61 T > C or bydiminished levels of miR-16 and miR-103 suggesting that \(HTR4\) might be involved in the development of IBS-D.
KW  - Medicine
KW  - Gene regulation
KW  - Irritable bowel syndrome
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-173478
VL  - 7
ER  - 
TY  - JOUR
A1  - Weich, Alexander
A1  - Rogoll, Dorothee
A1  - Gawlas, Sophia
A1  - Mayer, Lars
A1  - Weich, Wolfgang
A1  - Pongracz, Judit
A1  - Kudlich, Theodor
A1  - Meining, Alexander
A1  - Scheurlen, Michael
T1  - Wnt/β-catenin signaling regulates CXCR4 expression and [\(^{68}\)Ga] Pentixafor internalization in neuroendocrine tumor cells
JF  - Diagnostics
N2  - Loss of Somatostatin Receptor 2 (SSTR2) expression and rising CXC Chemokine Receptor Type 4 (CXCR4) expression are associated with dedifferentiation in neuroendocrine tumors (NET). In NET, CXCR4 expression is associated with enhanced metastatic and invasive potential and worse prognosis but might be a theragnostic target. Likewise, activation of Wnt/β-catenin signaling may promote a more aggressive phenotype in NET. We hypothesized an interaction of the Wnt/β-catenin pathway with CXCR4 expression and function in NET. The NET cell lines BON-1, QGP-1, and MS-18 were exposed to Wnt inhibitors (5-aza-CdR, quercetin, and niclosamide) or the Wnt activator LiCl. The expressions of Wnt pathway genes and of CXCR4 were studied by qRT-PCR, Western blot, and immunohistochemistry. The effects of Wnt modulators on uptake of the CXCR4 ligand [\(^{68}\)Ga] Pentixafor were measured. The Wnt activator LiCl induced upregulation of CXCR4 and Wnt target gene expression. Treatment with the Wnt inhibitors had opposite effects. LiCl significantly increased [\(^{68}\)Ga] Pentixafor uptake, while treatment with Wnt inhibitors decreased radiopeptide uptake. Wnt pathway modulation influences CXCR4 expression and function in NET cell lines. Wnt modulation might be a tool to enhance the efficacy of CXCR4-directed therapies in NET or to inhibit CXCR4-dependent proliferative signaling. The underlying mechanisms for the interaction of the Wnt pathway with CXCR4 expression and function have yet to be clarified.
KW  - neuroendocrine tumor
KW  - NET
KW  - Wnt
KW  - β-catenin
KW  - CXCR4
KW  - [\(^{68}\)Ga] Pentixafor
KW  - BON-1
KW  - QGP-1
KW  - MS-18
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228914
SN  - 2075-4418
VL  - 11
IS  - 2
ER  -