5-FU promotes stemness of colorectal cancer via p53-mediated WNT/\u03b2-catenin pathway activation

Yong-Hee Cho,Tomohiro Mizutani,Jeong-Su Yoon,Eun Ji Ro,Jong-Chan Park,Hans Clevers,Kang-Yell Choi,Tae Il Kim,Dong-Woo Kang

doi:10.1038/s41467-020-19173-2

Abstract

5-Fluorouracil (5-FU) remains the first-line treatment for colorectal cancer (CRC). Although 5-FU initially de-bulks the tumor mass, recurrence after chemotherapy is the barrier to effective clinical outcomes for CRC patients. Here, we demonstrate that p53 promotes WNT3 transcription, leading to activation of the WNT/β-catenin pathway in ApcMin/+/Lgr5EGFP mice, CRC patient-derived tumor organoids (PDTOs) and patient-derived tumor cells (PDCs). Through this regulation, 5-FU induces activation and enrichment of cancer stem cells (CSCs) in the residual tumors, contributing to recurrence after treatment. Combinatorial treatment of a WNT inhibitor and 5-FU effectively suppresses the CSCs and reduces tumor regrowth after discontinuation of treatment. These findings indicate p53 as a critical mediator of 5-FU-induced CSC activation via the WNT/β-catenin signaling pathway and highlight the significance of combinatorial treatment of WNT inhibitor and 5-FU as a compelling therapeutic strategy to improve the poor outcomes of current 5-FU-based therapies for CRC patients.

Highlights

5-Fluorouracil (5-FU) remains the first-line treatment for colorectal cancer (CRC)
We demonstrate that 5-FU activates cancer stem cells (CSCs) via p53-induced WNT3 transcription, which is followed by activation of the WNT/β-catenin pathway in CRC cell lines and xenograft tumors as well as patient avatar models, such as patient-derived tumor organoids (PDTOs) and patient-derived cells (PDCs)
Given that CSCs share characteristics with intestinal stem cells (ISCs), we investigated whether the most essential niche factors WNT3 and R-spondin[1] for maintaining the activation of the WNT/β-catenin pathway of ISCs were involved in the p53-mediated activation of the WNT/β-catenin pathway and CSC activation in 5-FU-treated CRC

Summary

Discussion

Since the 1950s, 5-FU-based chemotherapy has remained the mainstay of therapy for patients with CRC. Upon treatment with 5-FU, p53 activated the WNT/β-catenin signaling pathway via transcriptional induction of WNT3, leading to activation and enrichment of CSCs in the tumor. Our findings reveal that p53 may contribute to clinical outcomes of 5-FU treatment in CRC harboring wild-type p53 via its dual roles in anti-cancer effects and CSC-inducing effects. Combinatory treatment of the 5FU-based therapy with a WNT/β-catenin signaling inhibitor may be beneficial for suppression of CSCs and minimization of recurrence in CRC. The details of the involvement of wildtype and mutant APC and functional redundancy of APC2 in the responsiveness of downstream signaling to WNT ligand in CRCs harboring APC loss of function remain unknown, our findings revealed a critical role for WNT ligand in the activation and enrichment of CSCs in the 5-FUtreated CRC tumors. It is possible that inhibitors of WNT/β-catenin signaling, though probably not LGK-974 but rather cell-intrinsic inhibitors, such as the downstream WNT/β-catenin signaling inhibitors that showed effectiveness in CSC suppression such as KYA1797K41, might be beneficial to mutant p53 harboring colorectal cancer patients, while both WNT ligand and downstream WNT/β-catenin signaling inhibitors may be useful to prevent relapse after 5-FU treatment in WT p53 harboring patients

Methods

Findings

Code availability