The CBX5 Knockout DLD-1 Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout cell population designed for targeted disruption of the CBX5 gene in a colorectal adenocarcinoma background. This polyclonal model provides a heterogeneous pool of edited cells, enabling researchers to study loss-of-function effects of the heterochromatin protein 1 alpha (HP1??) without clonal selection. The CRISPR/Cas9 system introduces gene disruptions across the cell population, creating a versatile tool for investigating CBX5-dependent processes.
The host cell line, DLD-1, is an epithelial cell line originally derived from a Duke??s type C colorectal adenocarcinoma. It harbors well-characterized oncogenic mutations including KRAS G13D, APC, and TP53, and displays microsatellite instability (MSI). These genetic features make DLD-1 a representative model for studying colorectal cancer biology, particularly the interplay between genetic mutations and epigenetic alterations. The adherent nature of these cells facilitates a wide range of cell-based assays.
CBX5, encoding HP1??, is a central component of heterochromatin organization and gene silencing. It specifically recognizes and binds to trimethylated histone H3 at lysine 9 (H3K9me3), a modification deposited primarily by the methyltransferase SUV39H1. CBX5 functions as a scaffold, recruiting diverse factors such as G9a, CAF-1, DNMT1, UHRF1, and KAP1 to maintain repressive chromatin states. It is regulated by upstream kinases including Aurora B and CDK1, and its activity is modulated by microRNAs such as miR-29 and miR-124. Downstream, CBX5 mediates transcriptional repression of critical target genes, including the cyclin-dependent kinase inhibitor CDKN1A (p21), the cell adhesion molecule CDH1 (E-cadherin), and the telomerase reverse transcriptase TERT, thus linking heterochromatin to cell cycle control, cellular adhesion, and immortalization.
In the DLD-1 context, loss of CBX5 disrupts heterochromatin integrity, leading to derepression of silenced genes and potential genomic instability. Given the mutant KRAS and APC background, CBX5 knockout may exacerbate oncogenic signaling or relieve tumor suppressor constraints, providing a platform to dissect epigenetic contributions to colorectal tumorigenesis and metastasis. This model is particularly relevant for investigating how heterochromatin dysregulation cooperates with established colorectal cancer driver mutations.
The CBX5 Knockout DLD-1 Polyclonal Cells are suited for a variety of applications, including chromatin immunoprecipitation (ChIP-qPCR) to map H3K9me3 and HP1?? occupancy, immunofluorescence to visualize subcellular localization, and RNA-sequencing to profile global transcriptional changes upon loss of heterochromatin. Functional assays such as colony formation, cell proliferation, migration, and senescence-associated ??-galactosidase staining can assess phenotypic outcomes, while DNA damage foci analysis (??-H2AX) provides insight into genomic instability. This product supports studies in cancer epigenetics, tumor suppressor gene regulation, and drug target validation. For further technical information, please contact Ascent Research.
