Endothelin-converting enzyme-1c promotes stem cell traits and aggressiveness in colorectal cancer cells
Cargando...
Archivos
Fecha
2020-02
Profesor/a Guía
Facultad/escuela
Idioma
en
Título de la revista
ISSN de la revista
Título del volumen
Editor
John Wiley and Sons Ltd.
Nombre de Curso
Licencia CC
Licencia CC
Resumen
Endothelin-1 is a mitogenic peptide that activates several proliferation, survival, and invasiveness pathways. The effects of endothelin-1 rely on its activation by endothelin-converting enzyme-1 (ECE1), which is expressed as four isoforms with different cytoplasmic N termini. Recently, isoform ECE1c has been suggested to have a role in cancer aggressiveness. The N terminus of ECE1c is phosphorylated by protein kinase CK2 (also known as casein kinase 2), and this enhances its stability and promotes invasiveness in colorectal cancer cells. However, it is not known how phosphorylation improves stability and why this is correlated with increased aggressiveness. We hypothesized that CK2 phosphorylation protects ECE1c from N-terminal ubiquitination and, consequently, from proteasomal degradation. Here, we show that lysine 6 is the bona fide residue involved in ubiquitination of ECE1c and its mutation to arginine (ECE1cK6R) significantly impairs proteasomal degradation, thereby augmenting ECE1c stability, even in the presence of the CK2 inhibitor silmitasertib. Furthermore, colorectal cancer cells overexpressing ECE1cK6R displayed enhanced cancer stem cell (CSC) traits, including increased stemness gene expression, chemoresistance, self-renewal, and colony formation and spheroid formation in vitro, as well as enhanced tumor growth and metastasis in vivo. These findings suggest that CK2-dependent phosphorylation enhances ECE1c stability, promoting an increase in CSC-like traits. Therefore, phospho-ECE1c may be a biomarker of poor prognosis and a potential therapeutic target for colorectal cancer. © 2019 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.
Notas
Palabras clave
aggressiveness; cancer stem cell; CK2; endothelin-1; endothelin-converting enzyme; phosphorylation
Citación
Molecular OncologyOpen AccessVolume 14, Issue 2, Pages 347 - 3621 February 2020