The ATM Knockout HCT 116 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population in which the ATM gene has been disrupted to create a loss-of-function model. This polyclonal cell pool provides a genetically heterogeneous population suitable for studying ATM-dependent signaling without the need for single-cell cloning, enabling robust and reproducible experiments in DNA damage response research.
The host cell line, HCT 116, is a well-characterized human epithelial colorectal carcinoma line with near-diploid karyotype, microsatellite instability (MSI), and a KRAS G13D mutation. These features make it a widely used model for colon cancer biology, particularly in studies of genome maintenance and drug sensitivity. The epithelial origin and tumorigenic properties provide a physiologically relevant context for investigating ATM function.
ATM encodes a serine/threonine kinase that serves as a central sensor of DNA double-strand breaks (DSBs). Upon DSB induction by ionizing radiation, oxidative stress, or chromatin alterations, ATM is recruited to damage sites by the MRN complex (MRE11-RAD50-NBS1) and undergoes autophosphorylation. Activated ATM phosphorylates a network of downstream targets including p53, CHK2, BRCA1, H2AX (forming ??H2AX), and SMC1, thereby coordinating cell cycle checkpoints, DNA repair, and apoptosis. ATM also interacts with ATR, DNA-PKcs, and 53BP1, integrating signals within the broader DNA damage response. The kinase functions upstream of p53 and CHK2 to promote G1/S arrest and G2/M checkpoint activation, while phosphorylation of ??H2AX serves as a platform for repair factor assembly.
In the HCT 116 background, disruption of ATM provides a powerful tool to dissect ATM-dependent pathways in a colorectal cancer model with defective mismatch repair and activated KRAS signaling. Loss of ATM function impairs the G1/S checkpoint, leading to genomic instability and increased sensitivity to DNA-damaging chemotherapeutics and ionizing radiation. This polyclonal knockout population recapitulates key aspects of ATM deficiency, facilitating investigation of synthetic lethal interactions and resistance mechanisms relevant to cancers with ATM loss-of-function mutations.
This product is ideal for a range of applications including DNA damage response studies, cancer drug screening, genome instability research, and radiosensitivity assays. Researchers can employ western blotting to confirm loss of ATM protein and monitor phosphorylation of substrates such as CHK2 and p53. Immunofluorescence for ??H2AX foci allows visualization of DSB repair kinetics, while comet assay and colony formation assays after DNA damage quantify DNA repair capacity. Cell cycle analysis via flow cytometry reveals checkpoint defects. These polyclonal knockout cells are particularly valuable for high-throughput screens assessing genotoxic agent efficacy. For additional technical details, please contact Ascent Research.
