The CCNB2 Knockout HAP1 Polyclonal Cells product is a CRISPR/Cas9-edited polyclonal population of HAP1 cells harboring targeted disruption of the CCNB2 gene. This heterogeneous pool of edited cells provides a robust loss-of-function model for investigating Cyclin B2 function in cell cycle regulation and cancer biology. The polyclonal format ensures representation of diverse gene disruption events, minimizing clonal selection artifacts and enabling broad phenotypic assessment.
The HAP1 cell line is a human near-haploid myeloid cell line derived from the KBM-7 chronic myeloid leukemia isolate. Haploid for all chromosomes except a portion of chromosome 8, HAP1 cells offer simplified genetic manipulation and clear genotype-phenotype correlations. This background is widely utilized in functional genomics, drug discovery, and cancer research due to its amenability to CRISPR editing and stable growth characteristics.
CCNB2 encodes Cyclin B2, the regulatory subunit of cyclin-dependent kinase 1 (CDK1), forming the M-phase-promoting factor (MPF) that governs G2/M transition. Cyclin B2 expression is transcriptionally activated by E2F1, FoxM1, and NF-Y, while p53-mediated repression links it to stress signaling. The Cyclin B2-CDK1 complex phosphorylates downstream substrates including nuclear lamins and condensin complexes, driving nuclear envelope breakdown and chromosome condensation. MPF activity is modulated by Wee1/Myt1 inhibitory kinases and Cdc25C phosphatase, and Cyclin B2 interacts with p21Cip1/Waf1 and 14-3-3 proteins for kinase regulation and cytoplasmic retention. The anaphase-promoting complex/cyclosome (APC/C) mediates its degradation. Disruption of CCNB2 impairs MPF assembly, leading to G2 arrest and mitotic defects.
In the HAP1 myeloid leukemia context, CCNB2 knockout provides a relevant model for studying mitotic vulnerabilities in hematologic malignancies. Cyclin B2 overexpression is frequent in acute myeloid leukemia and solid tumors, correlating with poor prognosis and chromosomal instability. The knockout cells enable assessment of proliferation dependency on Cyclin B2 and can uncover synthetic lethal interactions with other G2/M checkpoint components. The near-haploid nature of HAP1 also facilitates unbiased gene modifier screens.
Typical applications include dissecting G2/M regulatory mechanisms, evaluating cell cycle checkpoint fidelity, and examining mitotic catastrophe in cancer. Researchers can employ immunofluorescence for ??-tubulin and pericentrin to visualize spindle abnormalities, phospho-histone H3 Western blotting to assess mitotic entry, and propidium iodide flow cytometry for cell cycle profiling. Proliferation can be measured via BrdU/EdU incorporation, and phospho-CDK substrate antibodies detect kinase activity. This model further supports CDK1 inhibitor screening and synthetic lethality studies targeting Cyclin B2-deficient contexts. For additional details, please contact Ascent Research.
