Preclinical study reveals that YAP and RAR-RXR coactivation drives stemness and 5-FU resistance in colorectal cancer cells, indicating potential targets for combination therapy.
Key Points
To elucidate the mechanisms through which the Hippo pathway effector YAP regulates cancer cell stemness and resistance to 5-fluorouracil in colorectal cancer.
Assessed 5-FU–sensitive and 5-FU–resistant HT29 colorectal cancer cell models under conditions of experimental YAP activation, YAP silencing, pan-RAR antagonism with BMS493, and vitamin A depletion.
Performed proximity-dependent labeling, nuclear YAP pulldown coupled with mass spectrometry, and ChIP/re-ChIP assays to evaluate physical interactions and chromatin co-occupancy.
Constitutive YAP activation enhanced nuclear YAP accumulation and upregulated expression of stemness biomarkers ALDH1A3, LGR5, and OCT4 via retinoic acid response elements.
YAP physically colocalized and interacted with RARγ and RXRs, exhibiting combined genomic co-occupancy at proximal promoter regions of LGR5 and ALDH1A3 to drive an active retinoic acid self-activation loop.
Inhibition of the pathway via YAP knockdown, BMS493 treatment, or vitamin A depletion reversed stemness characteristics and self-renewal capacity in resistant cells.