Disruption of NANOG-driven epithelial-mesenchymal transition (EMT) and self-renewal restores drug sensitivity in colorectal cancer

Abstract

Aims: To investigate the regulatory role of NANOG in genes associated with stemness, symmetric division, and therapeutic resistance in colorectal cancer stem-like cells (CRC-SCs), with a focus on ERK/GSK-3β/β-catenin signalling and epithelial-mesenchymal transition (EMT), in order to evaluate the translational potential of targeting NANOG-associated signalling pathways.

Methods: Stemness, signalling activity, and cell division modes were analysed using 3D colonospheres enriched for CRC-SCs. Drug responses to the MEK inhibitor U0126 and the GSK-3β inhibitor TDZD-8 were assessed in CRC patient-derived organoids (PDOs), alongside molecular assays, immunohistochemistry with H-score quantification in xenograft models, and molecular dynamics simulations.

Results: NANOG overexpression enhanced the expression of stemness-associated genes, promoted symmetric cell division, and activated ERK/GSK-3β signalling, contributing to increased sphere formation. Inhibition of MEK and GSK-3β reduced EMT, cell proliferation, and symmetric division in CRC-SCs. NANOG-mediated dysregulation of ERK/GSK-3β altered β-catenin signalling and disrupted E-cadherin-dependent cell-cell adhesion. Molecular simulations and drug assays demonstrated that TDZD-8 and U0126 interfere with NANOG-DNA binding and β-catenin/E-cadherin interactions.

Conclusions: NANOG drives CRC-SC maintenance via ERK/GSK-3β/β-catenin signalling and EMT modulation. This study offers significant insights into the translational impact of targeting NANOG and its downstream pathways with small-molecule inhibitors U0126 and TDZD-8 and presents a promising strategy to reduce CRC-SCs stemness, functionality, and tumourigenicity.

Keywords: Colorectal cancer stem cells (CRC-SCs); DNA-binding inhibitors; ERK/GSK-3β/β-catenin signalling; Epithelial-mesenchymal transition (EMT); NANOG; Symmetrical and asymmetrical cell division.