Daphnoretin targeted binding to HSP90AA1 to promote P53 UFMylation and stability thereby inducing apoptosis in colorectal cancer.

BACKGROUND

Daphnoretin (DAP), the principal bioactive constituent isolated from the traditional Chinese medicinal herb Wikstroemia indica rasix (WIR), exhibits well-documented pharmacological properties-including anti-inflammatory, antioxidant, immunomodulatory, and antitumor activities. Nevertheless, its molecular mechanism of action in colorectal cancer (CRC) remains incompletely elucidated.

METHODS

The anti-tumor effect of DAP was verified through in vivo and in vitro models. The potential mechanism of DAP's influence on CRC was explored through network pharmacology analysis. Key targets were screened and the molecular mechanism of DAP's action was verified in vivo and in vitro models. The clinical value of DAP in combination with 5-FU was evaluated in cell models.

RESULTS

DAP treatment potently suppressed proliferation (240 μg/ml, decreased by 96.6.6%) and migration (240 μg/ml, decreased by 65.6%) of CRC cells in vitro, and significantly inhibited both subcutaneous xenograft tumor growth nude mice (decreased by 58.3%) and colonic tumorigenesis in the azoxymethane/dextran sulfate sodium (AOM/DSS)-induced murine CRC model. Network pharmacology analysis screened out 7 key targets, among which HSP90AA1 was confirmed as a key target. Mechanistically, DAP enhances the ubiquitination level of P53 by targeting HSP90AA1, thereby inhibiting its ubiquitination degradation and promoting apoptosis. Additionally, the combination of DAP and 5-fluorouracil (5-FU) can inhibit tumor growth and reduce tumor number.

CONCLUSION

This study identifies, for the first time, DAP as a functional modulator of the HSP90AA1-P53 axis, thereby elucidating a novel molecular mechanism underlying its anti-colorectal cancer activity. These findings provide a mechanistically grounded rationale for the synergistic combination of DAP-a natural bioactive compound derived from traditional Chinese medicine-with standard chemotherapeutic agents, and underscore its strong translational potential in oncology.