The CCDC8 Knockout HAP1 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal cell population designed for targeted disruption of the CCDC8 gene in the HAP1 human cell line. This engineered pool of cells serves as a loss-of-function model to investigate the roles of the centrosomal protein CCDC8 in mitotic regulation and growth factor signaling. The polyclonal format provides a diverse cellular population, enabling robust phenotyping and screening applications without clonal selection. Through CRISPR/Cas9-mediated gene disruption, the CCDC8 locus is targeted to ablate protein expression, facilitating the study of its biological functions in a near-haploid background.
The HAP1 cell line is a near-haploid derivative of the KBM-7 chronic myeloid leukemia (CML) cell line, characterized by a single set of chromosomes except for a disomic region on chromosome 15. This haploid nature simplifies genetic manipulation and analysis, making it an invaluable tool for functional genomics, drug discovery, and cancer research. HAP1 cells retain key signaling pathways relevant to CML and growth factor responses, providing a relevant context for studying centrosome biology and ubiquitin ligase functions. Their adherent morphology and stable karyotype further support high-throughput imaging and quantitative cellular assays.
CCDC8 encodes a centrosomal protein that is a critical subunit of the CUL7-OBSL1-CCDC8 E3 ubiquitin ligase complex. This complex targets insulin receptor substrate-1 (IRS-1) for proteasomal degradation, thereby modulating insulin-like growth factor-1 (IGF-1) signaling downstream of IGF1R. CCDC8 localizes to the centrosome and is essential for proper mitotic spindle assembly, microtubule organization, and chromosome segregation. It interacts directly with CUL7, OBSL1, and FBXW8, and is regulated by upstream signals including IGF-1, growth hormone, and insulin. Through these interactions, CCDC8 integrates growth factor signaling with centrosome function, influencing cell cycle progression and proliferation.
In the HAP1 cellular context, loss of CCDC8 disrupts the coordination between centrosome dynamics and mitotic progression, potentially leading to aberrant spindle formation, delayed mitosis, and altered cell cycle distribution. The near-haploid background eliminates confounding effects from allelic variation, enabling clear attribution of phenotypes to CCDC8 deficiency. This model is particularly suited for studying the molecular pathogenesis of 3-M syndrome, a disorder characterized by severe growth retardation and skeletal abnormalities, where mutations in CCDC8, CUL7, or OBSL1 impair E3 ligase activity and centrosomal function. Additionally, the leukemic origin of HAP1 cells provides a platform to explore CCDC8??s role in hematological malignancies.
Research applications include immunofluorescence analysis of mitotic spindle organization, cell cycle profiling by flow cytometry, and proliferation assays in growth factor-supplemented media. Ubiquitination assays for IRS-1 assess CUL7-OBSL1-CCDC8 complex activity, while western blotting and RT-qPCR confirm CCDC8 knockout. These cells facilitate drug screening for growth signaling modulators or mitotic defect rescue in 3-M syndrome models. For additional information, please contact Ascent Research.
