The BRCC3 Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population generated from the HT29 human colorectal adenocarcinoma cell line, featuring targeted disruption of the BRCC3 gene. This polyclonal pool provides a loss-of-function model for studying BRCC3-dependent processes without clonal selection, preserving genetic heterogeneity while eliminating functional BRCC3 protein expression. The cells enable investigation of DNA damage repair, cell cycle regulation, and innate immune signaling pathways governed by this K63-specific deubiquitinase.
HT29 cells are an epithelial cell line derived from a primary colon adenocarcinoma, widely utilized as a model for colorectal cancer research. Their adherent growth and well-characterized signaling pathways make them a suitable host for CRISPR-based gene editing to probe oncogenic mechanisms and drug responses. As a representative of colorectal tumor epithelium, HT29 cells express key DNA repair and inflammatory pathway components, providing a relevant context for assessing BRCC3 function.
BRCC3 encodes a JAMM/MPN+ domain-containing metalloprotease that specifically cleaves K63-linked polyubiquitin chains. It is a core subunit of the BRCA1-A complex, alongside BARD1, MERIT40, RAP80, and BRCC45, which is recruited to DNA double-strand breaks by ATM/ATR-dependent phosphorylation and RAP80-mediated recognition of K63-ubiquitinated histones. BRCC3 deubiquitinates ??H2AX and other substrates at damage sites, promoting non-homologous end joining and restricting CtIP-dependent end resection. Beyond DNA repair, BRCC3 negatively regulates innate immune signaling by deubiquitinating the adaptors RIG-I, NLRP3, and STING, thereby suppressing type I interferon and inflammatory cytokine production. Thus, BRCC3 acts as a molecular switch balancing genomic stability and immune activation.
In the colorectal adenocarcinoma context, disruption of BRCC3 in HT29 cells impairs the BRCA1-A complex??s ability to resolve DNA damage, potentially sensitizing cells to genotoxic agents and PARP inhibitors??a phenotype relevant to synthetic lethality strategies. Concurrently, loss of BRCC3 may elevate basal inflammatory signaling through unchecked activation of RIG-I, NLRP3, or STING pathways, linking DNA repair deficiency to tumor microenvironment modulation. This dual role makes the knockout model particularly valuable for dissecting cross-talk between genome maintenance and immune surveillance in colon cancer.
Researchers can employ these polyclonal knockout cells in a variety of assays, including western blotting for phospho-H2AX to monitor DNA damage, immunofluorescence to quantify DNA repair foci, co-immunoprecipitation to assess BRCA1-A complex integrity, and flow cytometry for cell cycle or apoptosis analyses after genotoxic challenge. Additional applications include RT-qPCR profiling of inflammatory gene expression and PARP inhibitor sensitivity assays to explore therapeutic vulnerabilities. For further technical details or to request a quote, please contact Ascent Research.
