BBX Knockout HT29 Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout cell population derived from the HT29 human colorectal adenocarcinoma cell line. This product provides a loss-of-function model for the BBX gene, encoding an HMG-box transcription factor with established roles in cell cycle control. The polyclonal format encompasses a heterogeneous pool of edited alleles, enabling population-level functional analyses without clonal bias.
The parental HT29 line is a widely employed epithelial model isolated from a primary colorectal adenocarcinoma. HT29 cells harbor a well-characterized hotspot mutation in TP53 (commonly R273H), resulting in a mutant p53 protein that retains some transcriptional activity. This cell line serves as a standard platform for colorectal cancer research, intestinal epithelial biology, and studies on p53 pathway dysfunction. HT29 cells form adherent cultures with epithelial morphology, making them amenable to standard cell-based assays.
BBX functions as a transcriptional repressor, primarily targeting the CDKN1A promoter to suppress expression of the cyclin-dependent kinase inhibitor p21. This activity promotes cell cycle progression through G1/S and G2/M transitions. Upstream regulators of BBX include TP53, DNA damage signaling cascades, and E2F transcription factors. Key downstream targets comprise CDKN1A, CCNA2, CCNB1, GADD45A, and apoptosis-related genes such as BAX. BBX physically interacts with TP53, histone deacetylases HDAC1 and HDAC2, and the acetyltransferase EP300, forming transcriptional regulatory complexes. Within the p53/p21 signaling axis, BBX repression of CDKN1A provides a critical rheostat for cell proliferation and checkpoint control.
In the HT29 context with mutant TP53, CRISPR-mediated disruption of BBX is anticipated to derepress CDKN1A, leading to p21 accumulation and activation of p53-dependent cell cycle arrest mechanisms. The resulting phenotype may include growth inhibition and senescence, revealing the functional interplay between BBX and p53 in colorectal cancer biology. The polyclonal knockout population is particularly suited for experiments that demand phenotypic assessment across multiple genetic backgrounds within the same population, reducing artifacts seen in single clones. This model enables exploration of how BBX loss modulates differentiation potential and tumorigenic properties in a colorectal cancer-relevant setting.
Typical research applications include Western blotting for p21 and p53, RT-qPCR for BBX and target genes, and flow cytometry for cell cycle analysis. Functional assays encompass MTT or BrdU proliferation, colony formation, and senescence-associated ??-galactosidase staining. Co-immunoprecipitation confirms BBX-p53 interactions, while ChIP-qPCR quantifies BBX occupancy at the CDKN1A promoter. These cells support drug sensitivity screening with cell cycle inhibitors and transcription factor network dissection. For further technical details, please contact Ascent Research.
