H-Prune through GSK-3β interaction sustains canonical WNT/β-catenin signaling enhancing cancer progression in NSCLC

Abstract

H-Prune hydrolyzes short-chain polyphosphates (PPase activity) together with an hitherto cAMP-phosphodiesterase (PDE), the latest influencing different human cancers by its overexpression. H-Prune promotes cell migration in cooperation with glycogen synthase kinase-3 (Gsk-3β). Gsk-3β is a negative regulator of canonical WNT/β-catenin signaling. Here, we investigate the role of Gsk-3β/h-Prune complex in the regulation of WNT/β-catenin signaling, demonstrating the h-Prune capability to activate WNT signaling also in a paracrine manner, through Wnt3a secretion. In vivo study demonstrates that h-Prune silencing inhibits lung metastasis formation, increasing mouse survival. We assessed h-Prune levels in peripheral blood of lung cancer patients using ELISA assay, showing that h-Prune is an early diagnostic marker for lung cancer. Our study dissects out the mechanism of action of h-Prune in tumorigenic cells and also sheds light on the identification of a new therapeutic target in non-small-cell lung cancer.

Epac1 links prostaglandin E2 to β-catenin-dependent transcription during epithelial-to-mesenchymal transition

“…In NSCLC cells, PGE 2 has been shown to increase expression of the EMT regulator ZEB1 [4, 5]. In a recent study, inhibition of β-catenin-dependent transcription renders NSCLC cells unable to migrate [47]. Our observations confirm that expression of ZEB1 is increased by PGE 2 and coincides with nuclear translocation of β-catenin and activation of β-catenin-dependent transcription.…”

PRUNE is crucial for normal brain development and mutated in microcephaly with neurodevelopmental impairment

“…2A). In parallel with this we also assessed another known property of PRUNE in enhancing cell migration using HEK293 cells, which display negligible levels of endogenous PRUNE expression (Carotenuto et al , 2014), with expression levels assessed by western blotting (Supplementary Fig. 3E).…”

“…Data are presented as mean ± standard error of two replicate experiments. Absence of endogenous expression of PRUNE in HEK293 cells and reduction of levels of expression of PRUNE after adenovirus infection of SHSY5Y cells was confirmed by western blotting as described previously (Carotenuto et al , 2014). Immunoblotting for the immunoprepicipitation and co-sedimentation assays were performed using the following antibodies: anti-β-Tubulin (1 µg/ml; Abcam, ab15568), anti-alpha Tubulin (1 µg/ml; Abcam, ab15246), anti-Flag (1 µg/ml; Sigma, F3165), anti-Kinesin (1 µg/ml; Abcam, ab62105) and anti-GAPDH (1 µg/ml; Abcam, ab37168).…”

“…Subsequent studies indicated that PRUNE cAMP-phosphodiesterase activity is important for cell motility (D’Angelo et al , 2004) with a prominent exopolyphosphatase activity, and that PRUNE-interacts with glycogen synthase kinase-3 (GSK-3β), a negative regulator of canonical WNT/β-catenin signalling (Diana et al , 2013; Carotenuto et al , 2014). Consistent with this role PRUNE overexpression has also been shown to correlate with the staging of colorectal cancer liver metastases (Hashimoto et al , 2016), and PRUNE expression is an independent predictor of survival of patients with gastric cancer (Oue et al , 2007).…”

Janus-faces of NME–oncoprotein interactions

“…In addition to phospho-diesterase activity, studies have identified that human PRUNE encodes a polyphosphatase activity (Tammenkoski et al 2008), whilst still more recent studies have also implicated PRUNE in WNT/β-catenin signalling via regulation of GSK-3β (Carotenuto et al 2014b). Whilst these are significant observations, it remains unclear what role the interaction with NME proteins may have on these processes, and clearly this requires further investigation.…”