The BMI1 Knockout HeLa Polyclonal Cells product consists of a heterogeneous population of HeLa cells with CRISPR/Cas9-mediated disruption of the BMI1 gene, creating a polyclonal loss-of-function model. This format preserves biological variability and enables robust investigation of BMI1-dependent processes without clonal selection.
The host HeLa cell line is an epithelial line derived from human cervical adenocarcinoma and is positive for HPV-18. HeLa cells express viral oncoproteins E6 and E7, which inactivate the tumor suppressors p53 and Rb, respectively. This permissive genetic background facilitates the study of additional oncogenic events, including aberrant activation of Polycomb proteins such as BMI1. The HPV-positive, epithelial origin makes HeLa cells particularly relevant for examining gene regulatory mechanisms that cooperate with viral transformation.
BMI1 is a core subunit of Polycomb repressive complex 1 (PRC1), which together with RING1B catalyzes histone H2A monoubiquitination at lysine 119 (H2AK119ub1) to enforce transcriptional repression. BMI1 interacts with CBX proteins (e.g., CBX7, CBX8) and PHC proteins (PHC1/2) to target genomic loci such as CDKN2A, silencing the tumor suppressors p16INK4a and p14ARF. This repression promotes cell cycle progression and blocks senescence. Oncogenic signals from MYC, E2F1, GLI1, and ??-catenin/TCF stimulate BMI1 expression; BMI1 activity consequently impinges on the p53 and Rb pathways through p14ARF and p16INK4a, respectively. Additionally, BMI1 controls Hox gene expression and is essential for stem cell self-renewal, linking its function to both normal homeostasis and malignant transformation.
In HeLa cells, HPV oncoproteins E6 and E7 neutralize p53 and Rb, yet BMI1 further represses the CDKN2A locus, adding an additional layer of oncogenic support. Disruption of BMI1 in this context allows dissection of PRC1-mediated gene silencing independent of viral protein function. The polyclonal nature also permits study of heterogeneous responses to BMI1 loss, informing resistance mechanisms to therapeutic targeting. This model is valuable for exploring synthetic vulnerabilities and validating BMI1 as a drug target in cervical and other solid tumors.
These polyclonal knockout cells support a panel of assays: ChIP-qPCR for H2AK119ub1 profiling, Western blotting and RT-qPCR for BMI1 and p16INK4a expression, senescence-associated ??-galactosidase staining, flow cytometry for cell cycle and apoptosis, and RNA-seq for transcriptome-wide analyses. They are also suitable for small-molecule screening to identify compounds synthetically lethal with BMI1 loss. For further technical information, please contact Ascent Research.
