Pentagalloyl glucose targets the JAK1/JAK3-STAT3 pathway to inhibit cancer stem cells and epithelial-mesenchymal transition in 5-fluorouracil-resistant colorectal cancer

Abstract

Background: Colorectal cancer (CRC) resistance to 5-fluorouracil (5-FU), primarily driven by cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT), remains a major clinical challenge, necessitating novel therapeutic strategies.

Purpose: This study aims to evaluate the therapeutic potential of pentagalloyl glucose (PGG), a bioactive compound derived from Bouea macrophylla seeds, in overcoming 5-FU resistance in CRC.

Method: Anti-tumor effects of PGG were investigated using two- and three-dimensional (2D and 3D) cell culture models and subcutaneous xenograft and metastatic mouse models. Transcriptome sequencing, western blotting, and pharmacological inhibitors were employed to elucidate the underlying molecular mechanisms.

Results: PGG demonstrated potent anti-CSC activity; suppressed EMT-driven invasion and metastasis; and induced apoptosis in 2D monolayers, 3D spheroid models, and xenograft tumor models. Mechanistically, PGG selectively inhibited the JAK1/JAK3-STAT3 signaling pathway, considerably reducing STAT3 phosphorylation. This disruption downregulated the expression of CSC markers (CD133 and CD44), EMT regulators (N-cadherin and vimentin), and anti-apoptotic proteins (Bcl-2), effectively sensitizing 5-FU-resistant CRC to therapy.

Conclusion: PGG inhibit dual-target of CSCs and EMT via JAK1/JAK3-STAT3 signaling pathway in 5-FU-resistant CRC, providing a novel therapeutic approach to overcome chemoresistance.

Keywords: 5-fluorouracil; Cancer stem cell; Colorectal cancer; Drug resistance; Epithelial‒mesenchymal transition; Pentagalloyl glucose.