LGR4 cooperates with PrPc to endow the stemness of colorectal cancer stem cells contributing to tumorigenesis and liver metastasis

Abstract

Cancer stem cells (CSCs) are a subpopulation of cancer cells that drive tumour progression and metastasis. Anti-CSC strategies represent new targets for cancer therapies. However, CSCs are highly plastic and heterogeneous, making validation and targeting difficult without bona fide markers that define their identity, especially in a clinical setting. Here, we report that a leucine-rich repeat containing G protein-coupled receptor 4 (LGR4) cooperates with CD44 and PrPc; the latter contributes significantly to metastatic capacity and defines the stemness characteristics of colorectal CSCs. CD44⁺PrPc⁺LGR4⁺ cells effectively developed into organoids and, when transplanted, generated orthotopic and metastatic tumours. Importantly, targeting LGR4 and PrPc with lentiviral shRNAs inhibited organoid development and the growth of orthotopic tumours by inhibiting Wnt/β-catenin signalling. Thus, our study offers a novel therapeutic strategy that simultaneously targets CSC stemness and metastatic properties.

Keywords: Cancer stem cell; Colorectal cancer; LGR4; PrPc; Tumour organoid.