The CBX8 Knockout K-562 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population with targeted disruption of the human CBX8 gene. CBX8 encodes a chromobox protein that functions as a core component of Polycomb repressive complex 1 (PRC1). This product comprises a heterogeneous pool of edited cells, avoiding clone-specific artifacts and capturing a range of editing outcomes. The polyclonal format enables analysis of gene function within a population context.
The host K-562 cell line is derived from a female patient with chronic myelogenous leukemia in blast crisis and harbors the BCR-ABL fusion oncogene. K-562 cells serve as a model of multipotent hematopoietic progenitors, capable of lineage-appropriate differentiation. The BCR-ABL-positive background makes these cells particularly relevant for studying the interplay between oncogenic signaling and epigenetic regulation in leukemia.
CBX8 is a reader of H3K27me3, a histone modification deposited by PRC2. Through its chromodomain, CBX8 recruits PRC1 to chromatin, where it associates with RING1B and BMI1 to catalyze H2AK119ub, promoting chromatin compaction and transcriptional silencing. CBX8 activity is modulated by upstream regulators E2F1, MYC, and BCR-ABL signaling. Key downstream targets include the tumor suppressors CDKN2A and CDKN1A, as well as HOX genes and pro-apoptotic factors, linking CBX8 to cell cycle control and apoptosis.
In K-562 cells, BCR-ABL-driven proliferation may be sustained in part through CBX8-mediated repression of growth-restrictive genes. Knockout of CBX8 can disrupt this silencing, potentially derepressing CDKN2A and CDKN1A and impairing leukemic growth. This model thus enables dissection of how oncogenic signaling exploits Polycomb silencing to maintain an undifferentiated state, and provides a tool to study CBX8-dependent regulation of hematopoietic progenitor cell fate.
This knockout model supports a wide range of applications, from transcriptome-wide RNA-seq and targeted RT-qPCR to chromatin immunoprecipitation for H3K27me3 and H2AK119ub. Protein-level validation by Western blotting and functional assays such as flow cytometry for cell cycle and differentiation markers, colony formation, and drug sensitivity testing are readily performed. These cells facilitate research into Polycomb biology, cancer epigenetics, and leukemia therapeutic strategies. For detailed information, please contact Ascent Research.
