CBX5 Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the HT29 human colorectal adenocarcinoma cell line. This product provides a genetically mixed pool of cells with targeted disruption of the CBX5 gene, enabling functional studies of heterochromatin protein 1 alpha (HP1??) without clonal selection artifacts. The polyclonal format preserves genetic heterogeneity and is suitable for bulk phenotypic assays and screening.
The HT29 cell line is an established human epithelial model derived from a primary colon adenocarcinoma of a 44-year-old Caucasian female. Widely employed in colorectal cancer research, HT29 cells retain key features of intestinal epithelial biology, including the ability to differentiate under specific conditions. They are extensively used to study oncogenic signaling, drug responses, and tumor microenvironment interactions, making them a relevant host for dissecting epigenetic mechanisms in colorectal carcinogenesis.
CBX5 (HP1??) is a core heterochromatin component that recognizes histone H3K9me2/3 marks through its chromodomain, promoting chromatin compaction and gene silencing. Its activity is regulated upstream by methyltransferases SUV39H1/2 and SETDB1 and modulated by ATM/ATR and CDK kinases. Upon binding, CBX5 recruits partners including TRIM28/KAP1, DNMT1, and CAF-1, reinforcing repressive chromatin. Downstream, it silences targets such as CDKN1A (p21) and matrix metalloproteinases, linking heterochromatin to cell cycle control, senescence, and invasion.
In HT29 colorectal cancer cells, CBX5 disruption destabilizes heterochromatin, derepressing tumor suppressors like CDKN1A, which encodes p21. This loss of silencing can trigger cell cycle arrest, senescence, or apoptosis, while impairing p53- and ATM/ATR-dependent DNA damage repair. Altered matrix metalloproteinase expression may affect invasive properties. These changes make the CBX5 knockout HT29 model valuable for investigating epigenetic dysregulation in solid tumors and testing epigenetic therapies.
This knockout population supports functional genomics of heterochromatin biology, mechanism-of-action studies of epigenetic drugs, and biomarker discovery. Assays include western blotting and immunofluorescence for CBX5 and heterochromatin foci, RT-qPCR and ChIP-qPCR for gene reactivation and histone marks, flow cytometry and BrdU for cell cycle, transwell assays for invasion, senescence-associated ??-galactosidase staining, and RNA-seq transcriptomics. For further information, please contact Ascent Research.
