Withaferin A combined with ricolinostat: a potent synergistic therapy for cervical cancer through regulating p53 ubiquitination and acetylation
As a classic tumor suppressor gene, p53 has been extensively studied since its discovery in the mid-1980s. Research findings have revealed that p53 protein expression is suppressed in various cancers [1]. For example, in cervical cancer, p53 predominantly exists in a wild-type form to maintain its biological function [2]. Nevertheless, its tumor-suppressive activity is significantly impaired because of rapid protein degradation, short half-life, and low levels. Post-translational modifications (PTMs) of p53, such as ubiquitination, acetylation, phosphorylation and methylation, are critical regulators of its stability, activity, conformation, localization, and interactions with cofactors [3]. Among these, ubiquitination and acetylation play central roles in controlling p53 protein stability and activity [4]. Therefore, targeting p53 PTMs to modulate its ubiquitination and acetylation levels represents an effective strategy to increase its stability and tumor-suppressive function, offering a promising avenue for cervical cancer drug development. In 99% of cervical cancers (high-risk human papillomavirus-positive), E3 ubiquitin ligase E6-associated protein (E6AP) mediates the ubiquitination degradation of p53 [5], whereas histone deacetylase 6 (HDAC6) deacetylates p53. In this study, we explored the possibility of combining the natural product withferin A (WA) with the HDAC6 inhibitor ricolinostat (RIC) to treat cervical cancer cells, with a focus on the ubiquitination and acetylation of p53 and the consequences for its stability. These results suggested that the combination of WA and RIC is more effective than either treatment alone in inhibiting the degradation and increasing the stability of p53, thereby synergistically slowing the onset and progression of cervical cancer.