Impact of Wnt signalling on somatostatin receptor (SSTR) expression and function

#3222

Introduction: Somatostatin receptors (SSTR) are expressed by most differentiated neuroendocrine tumors (NET) and are important treatment targets. Loss of SSTR expression is associated with a worse prognosis. Deregulation of Wnt/β-catenin signalling has been demonstrated in NET. Treatment with the Wnt inhibitor 5-aza-2'-deoxycytidine (5-aza-CdR) led to growth inhibition in a NET tumor cell line. Other data show an increase in SSTR2 mRNA expression and cellular uptake of radiolabelled octreotide in NET cell lines after incubation with 5-aza-CdR.

Aim(s): We aimed to demonstrate an interaction of the Wnt/β-catenin pathway with SSTR expression and function in NET. An inhibition of Wnt signalling might lead to an increase in SSTR expression and function, while Wnt stimulation would have opposite effects.

Materials and methods: The NET cell lines BON-1 and QGP-1 were exposed to Wnt inhibitors (5-aza-CdR Quercetine, Niclosamide) or the Wnt activator LiCl. Expression changes of Wnt pathway genes and SSTR 1, 2 and 5 were studied by qRT-PCR, Western Blot and immunohistochemistry. The influence of Wnt modulators on [125I-Tyr3] octreotide uptake was measured.

Conference: 18th Annual ENETS Concerence (2021)

Presenting Author: Weich A

Authors: Weich A, Rogoll D, Mayer L, Peschka M, Meining A,

Keywords: NET, Wnt Signalling, somatostatin receptor, BON-1, QGP-1, SSTR,