The ATM Knockout HeLa Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt the ATM gene in HeLa cells. This heterogeneous loss-of-function model is generated without single-cell cloning, preserving genetic diversity and enabling robust representation of knockout phenotypes. It is well-suited for large-scale functional genomics, biochemical assays, and investigations where polyclonality mitigates clonal artifacts.
HeLa is an immortalized human cervical epithelial adenocarcinoma line, a classic cancer model known for its aggressive growth, genomic instability, and HPV E6-mediated p53 degradation. This p53 deficiency makes it particularly useful for probing DNA damage responses independent of the canonical p53 tumor suppressor axis, as well as for studying oncogenic signaling in a high-grade cancer context.
ATM encodes a serine/threonine kinase that acts as a master regulator of the DNA damage response. At double-strand breaks, the MRN complex (MRE11-RAD50-NBS1) recruits and activates ATM, leading to autophosphorylation and subsequent phosphorylation of critical substrates including histone H2AX (forming ??-H2AX foci), checkpoint kinase CHK2, and p53. These phosphorylation events propagate signals that enforce G1/S and G2/M cell cycle checkpoints, promote DNA repair via homologous recombination and non-homologous end joining, and induce apoptosis if damage is irreparable. ATM also targets BRCA1, MDC1, 53BP1, and other effectors to coordinate repair complex assembly and chromatin remodeling. Additionally, ATM responds to oxidative stress and integrates multiple upstream inputs to safeguard genome integrity.
In the HeLa background, loss of ATM ablates a central DDR kinase in a cell system already deficient in p53-dependent apoptotic and checkpoint responses. This allows detailed investigation of ATM??CHK2 signaling and its role in G2/M arrest, DNA repair modulation, and cell survival after genotoxic insult. The model exhibits heightened sensitivity to PARP inhibitors and ionizing radiation, making it valuable for synthetic lethality studies and radiosensitizer screening. Moreover, the polyclonal composition captures heterogeneous responses to DNA damage, facilitating research on clonal evolution of resistance mechanisms and stochastic fate decisions under therapeutic pressure.
Typical applications include Western blotting for phospho-ATM, phospho-CHK2, or phospho-p53; immunofluorescence microscopy of ??-H2AX foci to quantify DNA double-strand breaks; comet assays to measure DNA fragmentation; flow cytometry for cell cycle distribution; and clonogenic survival assays to assess radiosensitivity or drug sensitivity. The cells also support high-throughput screens for novel DNA damage response inhibitors. For additional product information, please contact Ascent Research.
