The USP7 Knockout HeLa Cell Line is a CRISPR/Cas9-edited knockout cell line derived from the widely used HeLa human cervical adenocarcinoma epithelial cell line. This product provides a stable loss-of-function model for investigating the biological roles of the USP7 gene, which encodes a critical deubiquitinase enzyme. Through CRISPR/Cas9-mediated gene disruption, the cell line enables researchers to dissect USP7-dependent signaling mechanisms, protein stability regulation, and cellular responses to stress. It is intended for advanced applications in cancer biology, DNA damage repair, and viral oncogenesis research, offering a defined genetic background for functional studies.
The host HeLa cell line is an immortalized epithelial cell line originally isolated from a human cervical adenocarcinoma. HeLa cells are HPV-18 positive and show high levels of E6 and E7 oncoprotein expression, which drive p53 degradation and retinoblastoma protein inactivation. This characteristic renders HeLa cells a unique model system in which wild-type p53 function is largely abrogated, thereby shifting cellular dependencies toward alternative survival and proliferation pathways. HeLa cells are extensively characterized, easy to manipulate, and serve as a standard platform for gene-editing studies in cancer research.
USP7 (ubiquitin-specific peptidase 7) is a deubiquitinase that controls the proteasomal turnover of numerous substrates, thereby governing protein stability and signal transduction. Mechanistically, USP7 deubiquitinates and stabilizes MDM2, promoting p53 ubiquitination and degradation under non-stressed conditions. Conversely, upon genotoxic stress, USP7 can deubiquitinate p53 directly, enhancing its stability. USP7 also targets PTEN, FOXO4, CHFR, and histone H2B, indicating broad roles in tumor suppression, cell cycle control, and chromatin dynamics. Upstream regulators include ATM kinase, HDACs, CK2, and the viral protein EBNA1, while interacting partners encompass DAXX and the USP7 homodimer. This positions USP7 at a nexus of the p53 signaling, DNA damage repair, NF-??B, Wnt, and viral carcinogenesis pathways, with particular relevance to the USP7-MDM2-p53 axis, USP7-PTEN-AKT pathway, and USP7-FOXO4 stress responses.
In the HeLa cellular context, HPV18 E6-mediated degradation of p53 significantly alters the canonical USP7-p53 regulatory loop. As p53 is constitutively targeted for destruction, USP7’s role in p53 stabilization is diminished, highlighting its p53-independent functions. Consequently, this knockout model becomes a powerful tool for examining USP7’s direct deubiquitination of substrates such as MDM2, PTEN, FOXO4, and histone H2B, as well as its influence on viral protein stability and carcinogenesis. The USP7 Knockout HeLa Cell Line thus facilitates dissection of both p53-dependent and -independent mechanisms, offering insights into how HPV-driven cancers exploit deubiquitinase networks to sustain malignancy.
Researchers can employ this knockout line in diverse experimental workflows. Western blotting can be used to confirm USP7 ablation and assess expression changes of MDM2, p53, and downstream targets. Co-immunoprecipitation assays are suitable for mapping USP7 interaction networks with factors such as DAXX and FOXO4. Immunofluorescence allows subcellular localization studies, while apoptosis assays (Annexin V) and cell viability assays (MTT) reveal functional consequences of USP7 loss. qRT-PCR can quantify transcriptional changes in downstream effectors, and chemosensitivity assays with agents like cisplatin enable exploration of USP7’s role in drug response. This versatile product serves as a valuable resource for target validation and mechanistic studies. For additional information or customization inquiries, please contact Ascent Research.
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