USP7 Knockout DU145 Cell Line

The USP7 Knockout DU145 Cell Line is a human prostate carcinoma cell model with CRISPR/Cas9-mediated disruption of the USP7 gene, generating a stable loss-of-function model for studying USP7-dependent pathways.

DU145 cells were originally derived from a brain metastasis of prostate adenocarcinoma and serve as an androgen-independent, AR-negative prostate carcinoma model. These cells harbor a mutant p53 gene, contributing to their tumorigenic properties and resistance to standard therapies.

USP7 is a deubiquitinase that critically regulates protein stability by removing ubiquitin moieties from substrates. Its primary target, MDM2, is stabilized via deubiquitination, which in turn promotes the ubiquitin-dependent degradation of p53. Additionally, USP7 modulates FOXO4 and PTEN levels, thereby linking its activity to WNT, Notch, and DNA damage response pathways. Upstream regulators such as DNA damage signals and CK2 kinase influence USP7, while USP7 interacts with factors including DAXX, GMPS, DNMT1, and UHRF1. Downstream, USP7-mediated control of MDM2 and p53 impacts key effectors like p21, BAX, and PUMA.

In DU145 cells, which express mutant p53, disruption of USP7 leads to destabilization of MDM2, resulting in reduced MDM2-mediated suppression of p53 and consequent activation of p53 transcriptional programs. This reactivates p53 target genes such as p21 and BAX, triggering cell cycle arrest and apoptosis. The model therefore provides a platform to study p53 reactivation strategies in a context of mutant p53, exploring how USP7 inhibition can bypass MDM2-mediated p53 suppression and induce tumor-suppressive effects.

This cell line is suitable for a range of investigations, including functional studies of p53 signaling, screening of MDM2 inhibitors, and analysis of prostate cancer drug resistance. Representative assays include Western blot analysis of p53 and MDM2 levels, RT-qPCR for downstream targets, apoptosis and cell cycle assays, colony formation tests, and xenograft tumor growth studies. The model also supports co-immunoprecipitation to examine USP7-containing complexes and drug sensitivity assays to evaluate therapeutic candidates. For additional information, please contact Ascent Research.