The BRCC3 Knockout HCT 116 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal cell population derived from the HCT 116 human colorectal carcinoma line, engineered to disrupt the BRCC3 gene. This polyclonal knockout model provides a mixed population of cells with targeted disruption of the BRCC3 locus, enabling robust loss-of-function studies without clonal selection artifacts. The product is designed for advanced research into DNA damage response, ubiquitin signaling, and cancer therapy.
HCT 116 is a widely used human epithelial colorectal carcinoma cell line characterized by microsatellite instability (MSI) and a homozygous KRAS mutation (G13D). The MSI phenotype results from defective DNA mismatch repair, while the activating KRAS mutation drives constitutive mitogenic signaling. These features make HCT 116 an excellent model for studying genomic instability and oncogenic signaling in colorectal cancer, and for evaluating sensitivity to DNA-damaging agents and targeted therapies.
BRCC3 encodes a deubiquitinating enzyme (DUB) that specifically cleaves K63-linked polyubiquitin chains and is a core component of the BRCA1-A complex. Following DNA double-strand breaks, ATM kinase phosphorylates H2AX, recruiting MDC1, RNF8, and RNF168 to ubiquitinate histones. BRCC3, together with BRCA1, RAP80, ABRAXAS, BABAM1, BRE, BARD1, and UIMC1, reverses this histone ubiquitination, removing K63-linked ubiquitin from H2A/H2AX to promote BRCA1 retention and facilitate homologous recombination repair. Loss of BRCC3 impairs deubiquitination, leading to defective BRCA1 focus formation, reduced homologous recombination efficiency, and increased reliance on error-prone non-homologous end joining, resulting in heightened genomic instability.
In the HCT 116 background, BRCC3 disruption exacerbates the existing DNA repair deficiencies caused by MSI. The combination of mismatch repair defects and impaired homologous recombination creates a synthetic lethal context that can be exploited for therapeutic targeting, particularly with PARP inhibitors or DNA-damaging chemotherapies. This model is highly relevant for studying the role of the BRCA1-A complex in colorectal carcinomas and for identifying novel vulnerabilities in MSI-high cancers.
The BRCC3 Knockout HCT 116 Polyclonal Cells are suitable for DNA damage signaling studies using Western blotting for ??H2AX and immunofluorescence for BRCA1 foci; clonogenic survival assays following ionizing radiation or chemotherapy; comet assays to measure DNA break accumulation; and homologous recombination reporter assays to quantify repair pathway usage. The cells support drug discovery, chemosensitivity testing, and synthetic lethality screening, particularly in contexts related to breast and ovarian cancer mechanisms. For additional information or technical support, please contact Ascent Research.
