E2F1 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population with targeted disruption of the E2F1 gene. This product provides a heterogeneous pool of HAP1 cells harboring diverse E2F1 gene disruptions, enabling robust functional studies while avoiding clonal artifacts. The polyclonal format preserves genetic diversity and ensures effective abrogation of E2F1 protein expression, making it a versatile tool for investigating E2F1-dependent processes and pooled genetic screens.
The host cell model, HAP1, is a near-haploid human chronic myeloid leukemia cell line with an adherent, fibroblast-like morphology, originally derived from the KBM-7 line. Owing to its stable haploid karyotype, HAP1 is widely employed in functional genomics and haploid genetic screening, as it facilitates unambiguous genotype?Cphenotype correlations and simplifies CRISPR-based knockout generation. Its well-characterized background and robust growth characteristics make it an ideal chassis for dissecting the roles of essential cell cycle regulators such as E2F1.
E2F1 is a transcription factor regulating G1/S transition. In quiescent cells, hypophosphorylated pRB binds and represses E2F1. Growth factor signaling activates CDK4/6?CCyclin D and CDK2?CCyclin E to phosphorylate pRB, releasing E2F1 to heterodimerize with DP-1 and transactivate genes essential for DNA replication, such as Cyclin E, Cdc25A, DHFR, and PCNA. Additionally, E2F1 integrates DNA damage responses: ATM/ATR-dependent stabilization of E2F1 promotes expression of pro-apoptotic factors (p73, Bim, Bax) and p14ARF, which inhibits MDM2 to stabilize p53. Thus, E2F1 exerts context-dependent control over proliferation, checkpoint arrest, and apoptosis, making it a central node in cell fate decisions.
In the haploid HAP1 background, E2F1 knockout yields an unambiguous loss-of-function phenotype, enabling clear dissection of E2F1-mediated cell cycle control, apoptosis, and DNA damage responses. The model facilitates investigation of CDK inhibitor sensitivity, synthetic lethal interactions, and the compensatory rewiring of gene expression following E2F1 ablation, with direct relevance to cancers harboring pRB pathway defects.
Typical applications include cell cycle profiling by flow cytometry and BrdU incorporation, apoptosis assessment via Annexin V staining, and growth analyses under various conditions. The cells are compatible with western blotting, RT-qPCR, E2F luciferase reporter assays, RNA-seq, and ChIP-qPCR to examine transcriptional outputs and chromatin occupancy. They can be challenged with CDK4/6 inhibitors such as palbociclib to evaluate drug sensitivity and resistance in a genetically defined context. This polyclonal knockout population is an essential tool for cancer biologists, cell cycle researchers, and drug discovery programs targeting the pRB/E2F axis. For further information or to order this product, please contact Ascent Research.
