Selective degradation of the p53‐R175H oncogenic hotspot mutant by an RNA aptamer‐based PROTAC

作者：Lingping Kong, Fanlu Meng, Sijin Wu, Ping Zhou, Ruixin Ge, Min Liu, Linlin Zhang, Jun Zhou, Diansheng Zhong, Songbo Xie · 发表于：Clinical and Translational Medicine · 年份：2023 · DOI：10.1002/ctm2.1191 · 被引用次数：38 · 研究领域：Protein Degradation and Inhibitors、Peptidase Inhibition and Analysis、Chromatin Remodeling and Cancer

To the Editor: TP53 encodes the tumour suppressor protein p53, a master regulator of genomic integrity and cell survival, and is the most frequently mutated gene.1 p53 mutant proteins are stabilised and can acquire dominant-negative or oncogenic gain-of-function activities, thereby promoting malignant transformation, metastasis and chemoresistance.2, 3 Proteolysis targeting chimeras (PROTACs) that hijack cellular ubiquitin-proteasome machinery for targeted protein degradation have shown considerable promise in targeting previously undruggable proteins.4, 5 However, PROTACs targeting p53 mutants have not yet been reported, probably due to difficulty in identifying a suitable binder for these mutants. Some recent studies have revealed that aptamers can be exploited as ligands in place of standard peptides or small molecules for PROTACs.6-8 Here, using an aptamer-based strategy, we developed the first selective hotspot p53 mutant PROTAC. p53-R175H is the most common p53 hotspot mutation.9 In this study, we used an RNA aptamer10 (hereafter named p53m-RA) that selectively targets p53-R175H as a binder for PROTAC development. First, we used streptavidin pulldown assays to confirm its binding specificity. Both p53m-RA and N3-p53m-RA competitively abolished p53-R175H pulldown from cell lysates with N3-p53m-RA-biotin. By contrast, there was almost no pulldown of wild-type p53 (p53-WT) (Figure 1A). Structural analysis revealed that p53-R175H displays a much narrower binding area for th...