The CCNG1 Knockout HAP1 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt expression of the CCNG1 gene in the HAP1 cell line. This product provides a heterogeneous pool of knockout cells, ideal for functional studies where clonal variability is not a primary concern, and enables researchers to investigate the role of cyclin G1 in p53-mediated tumor suppression and cell cycle regulation to gain insights into oncogenic processes.
The HAP1 host cell line is a near-haploid, chronic myeloid leukemia (CML)-derived model originally generated from the KBM-7 parental line. HAP1 cells are adherent upon differentiation and retain the capacity for haploid genetic screens, making them a powerful tool for loss-of-function analyses. Their haploid state simplifies knockout generation and interpretation of phenotypic effects, particularly in pathways associated with hematological malignancies.
CCNG1 encodes cyclin G1, a transcriptional target of TP53 that functions in a negative feedback loop controlling p53 stability. Upon activation by DNA damage, p53 induces CCNG1 expression. CCNG1 then recruits the PP2A phosphatase via its PPP2R5 B regulatory subunit to dephosphorylate MDM2, thereby promoting MDM2-mediated ubiquitylation and proteasomal degradation of p53. This feedback limits the accumulation of p53 and attenuates the transcription of its downstream effectors, including CDKN1A (p21) and BAX, which are critical for cell cycle arrest and apoptosis. Disruption of CCNG1 by CRISPR/Cas9 editing releases this brake, leading to heightened p53 activity, increased expression of pro-apoptotic and anti-proliferative genes, and enhanced sensitivity to genotoxic stress.
In the HAP1 CML background, loss of CCNG1 uncouples the p53?CMDM2 feedback loop, providing a sensitized genetic context for dissecting p53-dependent signaling. Since HAP1 cells retain a functional p53 pathway, this knockout model is particularly relevant for examining how cyclin G1 fine-tunes the balance between survival and death in myeloid leukemia cells. The model is valuable for studying responses to chemotherapeutics such as doxorubicin and MDM2 inhibitors like Nutlin-3, and for investigating the interplay between DNA damage signaling kinases (ATM/ATR) and p53-mediated cell fate decisions.
Researchers can employ this polyclonal knockout pool in diverse assays. Western blotting and RT-qPCR can confirm reduced CCNG1 protein and altered expression of p53 target genes. RNA-seq analysis reveals transcriptome-wide consequences of CCNG1 loss. Functional phenotyping through Annexin V staining and flow cytometry assesses apoptosis induction and cell cycle distribution changes. Drug sensitivity studies with genotoxic agents or targeted MDM2 antagonists explore therapeutic vulnerabilities. Co-immunoprecipitation can probe the integrity of the PP2A?CMDM2 interaction. This model supports applications in cancer biology, functional genomics, and pharmacological screening. For more information, please contact Ascent Research.
