The ATM Knockout Hep-G2 Polyclonal Cells are a polyclonal knockout population of Hep-G2 cells (Homo sapiens, hepatocellular carcinoma) generated via CRISPR/Cas9-mediated disruption of the ATM gene. This loss-of-function model abrogates ATM kinase activity without clonal selection, providing a heterogeneous cell pool that reduces clonal artifacts. The polyclonal format is ideal for experiments requiring broad population-level responses.
The parental Hep-G2 line was derived from a hepatocellular carcinoma of a 15-year-old Caucasian male and displays epithelial morphology. Widely used as a liver cancer model, Hep-G2 cells retain drug-metabolizing enzyme activities and express wild-type p53, a critical ATM substrate. This combination of hepatic characteristics and intact downstream signaling makes the line particularly valuable for studying ATM-mediated DNA damage responses in a liver-relevant setting.
ATM is a master serine/threonine kinase responding to DNA double-strand breaks. Upon damage, the MRE11-RAD50-NBS1 (MRN) complex recruits and activates ATM. Activated ATM phosphorylates downstream effectors including CHK2, p53, and H2AX (??-H2AX), which initiate cell cycle arrest and coordinate DNA repair via homologous recombination and non-homologous end joining. ATM also interacts with Tip60, PP2A, DNA-PKcs, and ATR, and phosphorylates substrates such as BRCA1, NBS1, SMC1, KAP1, and MDM2. The canonical MRN??ATM??CHK2/p53 signaling axis enforces checkpoints, while ??-H2AX foci formation marks damage sites for repair complex assembly.
Disruption of ATM in Hep-G2 cells creates a model of DNA repair deficiency in a hepatocellular carcinoma background. ATM loss promotes genomic instability and is associated with cancer predisposition syndromes and chemoresistance. This knockout model enables dissection of how ATM-mediated checkpoint and repair functions influence hepatocarcinogenesis. It permits evaluation of altered cell cycle regulation, apoptosis, and sensitivity to DNA-damaging therapeutics such as doxorubicin and ionizing radiation, addressing key questions in liver cancer biology.
These polyclonal knockout cells are validated for standard DNA damage assays, including Western blotting of ATM, phospho-ATM (S1981), ??-H2AX, CHK2, and p53; immunofluorescence for ??-H2AX foci; and flow cytometry for cell cycle and Annexin V apoptosis. Complementary techniques such as comet assays, clonogenic survival, and RT-qPCR for p21 and BAX are also supported. Research applications include drug sensitivity screening, DNA repair pathway analysis, and investigation of ATM-p53 signaling dynamics. For detailed protocols or technical inquiries, contact Ascent Research.
