PRL-3 disrupts epithelial architecture by altering the post-mitotic midbody position

Abstract

Disruption of epithelial architecture is a fundamental event during epithelial tumorigenesis. We show that the expression of the cancer-promoting phosphatase PRL-3 (PTP4A3), which is overexpressed in several epithelial cancers, in polarized epithelial MDCK and Caco2 cells leads to invasion and the formation of multiple ectopic, fully polarized lumens in cysts. Both processes disrupt epithelial architecture and are hallmarks of cancer. The pathological relevance of these findings is supported by the knockdown of endogenous PRL-3 in MCF-7 breast cancer cells grown in three-dimensional branched structures, showing the rescue from multiple-lumen- to single-lumen-containing branch ends. Mechanistically, it has been previously shown that ectopic lumens can arise from midbodies that have been mislocalized through the loss of mitotic spindle orientation or through the loss of asymmetric abscission. Here, we show that PRL-3 triggers ectopic lumen formation through midbody mispositioning without altering the spindle orientation or asymmetric abscission, instead, PRL-3 accelerates cytokinesis, suggesting that this process is an alternative new mechanism for ectopic lumen formation in MDCK cysts. The disruption of epithelial architecture by PRL-3 revealed here is a newly recognized mechanism for PRL-3-promoted cancer progression.

Physiological and oncogenic roles of the PRL phosphatases

“…In agreement with these findings, integrin a1, the heterologous binding partner of integrin b1, was proposed as the PRL-3-interacting protein that causes a decrease in tyrosine phosphorylation of integrin b1 [164]. Of note, in polarized cells, PRL-3 does not colocalize with integrins [83]. During cell migration, PRL-3 showed enhanced interaction and colocalization with the ADP-ribosylation factor 1 in endosomal compartments, favoring the recycling of integrin a5 [165].…”

Activated ezrin controls MISP levels to ensure correct NuMA polarization and spindle orientation

“…In comparison to what is seen in single-cell models, studies in polarized cells reflect a more physiological context by recapitulating many aspects and characteristics of epithelial cells as for example cell-cell contacts and spindle orientation (Debnath and Brugge, 2005;McCaffrey and Macara, 2011). For studies in polarized cells, we used Caco-2 BBe cells in an 'on-top' of Matrigel approach to create polarized spherical cysts (Ivanov et al, 2008;Lujan et al, 2016). It has been previously shown that these cysts are characterized by a central lumen surrounded by a monolayer of polarized cells with basolateral and apical sides (O'Brien et al, 2002;Debnath and Brugge, 2005).…”

“…HeLa (ATCC CCL-2), HeLa Flp-In-T-Rex (Marius Lemberg, ZMBH, Heidelberg, Germany), HeLa EGFP-CenpA Tomato-EB3 (Andrew McAinsh, Warwick Medical School, Warwick, UK) and HEK293T (ACC 635, DSMZ, Braunschweig, Germany) cells were cultured in DMEM containing 1 g/l and 4.5 g/l glucose, respectively, supplemented with 10% (v/v) fetal bovine serum (FBS; Sigma-Aldrich), 1% (v/v) PenStrep (Sigma-Aldrich) (complete medium for for HeLa and HEK293Tcells) at 37°C in 5% CO 2 . Caco-2 BBe (C2BBe1) cells (Maja Köhn, EMBL, Heidelberg, Germany) (Lujan et al, 2016) were cultured in 4.5 g/l glucose Dulbecco's modified Eagle's medium (DMEM) containing 10% (v/v) FBS, 1% (v/v) PenStrep and 0.01 mg/ml holo-transferrin (AppliChem) (complete medium for Caco-2 BBe cells). By using the T-Rex system, a HeLa Flp-In-T-Rex GFP-MISP and HeLa Flp-In-T-Rex MISP-BirA* stable cell lines were generated according to the manufacturer's instructions (Life Technologies).…”

Cytokinetic furrowing and abscission dynamics during brain development revealed by live imaging

“…Post-abscission midbody remnants (MBRs) have been shown to adhere to plasma membranes of daughter or neighbor cells, and may influence cell polarity or proliferation (22,24,32,33). We wanted to ask whether MBRs of cortical NSCs remain on the apical membrane after abscission, and whether this changes across development.…”