Slow-Cycling Cancer Stem Cells Regulate Progression and Chemoresistance in Colon Cancer

Area of Science:

• Oncology
• Cancer Stem Cell Biology
• Molecular Oncology

Background:

• Cancer chemoresistance is often linked to cancer stem cells (CSCs), but their specific chemoresistance levels are not fully understood.
• Previous research identified a tumorigenic subpopulation of LGR5 CSC-like cells in colon tumors, driven by the transcription factor TCF1 (TCF7).

Purpose of the Study:

• To investigate the characteristics of tumorigenic CSCs in colon cancer, specifically their cell-cycling state and chemoresistance mechanisms.
• To identify molecular signatures associated with slow-cycling CSCs and evaluate their therapeutic potential.

Main Methods:

• Analysis of LGR5+ cells in mouse and xenografted human colon tumors to identify slow-cycling subpopulations.
• Development and validation of a 22-gene signature for slow-cycling CSCs.
• Investigation of the role of Wnt target genes, including PROX1, in maintaining the slow-cycling state and chemoresistance.

Main Results:

• A tumorigenic subpopulation of LGR5+ colon CSCs was identified in a slow-cycling state.
• A unique 22-gene signature was established for these slow-cycling CSCs, with seven genes upregulated in human colon cancer specimens.
• The TCF1-PROX1-CDKN1C pathway was found to maintain the slow-cycling state, and PROX1 was crucial for tumor regrowth after chemotherapy.

Conclusions:

• Slow-cycling CSCs represent a critical driver of colon cancer development and chemoresistance.
• The identified gene signatures and the TCF1-PROX1-CDKN1C pathway present potential therapeutic targets for overcoming chemoresistance in colon cancer.
• Targeting this pathway in combination with chemotherapy may offer an effective strategy against refractory colon cancer.