The APOBEC3A Knockout AGS Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population disrupting the APOBEC3A gene in the AGS human gastric adenocarcinoma cell line. This loss-of-function model enables study of APOBEC3A??s contributions to innate antiviral defense and tumor mutagenesis in the absence of endogenous enzymatic activity. The polyclonal format preserves population heterogeneity and is suitable for pathway analysis, drug response profiling, and functional genomics applications.
The AGS host cell line originates from a gastric adenocarcinoma, retaining wild-type p53 and serving as a standard model for gastric cancer research, including H. pylori infection studies, epithelial barrier function, and tumorigenesis. These adherent epithelial cells express gastric mucosal markers, providing a physiologically relevant context for analyzing cancer-associated mutagenesis and innate immune pathways. The intact p53 status preserves DNA damage checkpoints, facilitating direct assessment of APOBEC3A-induced genomic alterations.
APOBEC3A is a cytidine deaminase that catalyzes C-to-T mutations on single-stranded DNA, driving kataegis and cancer genome evolution. Its expression is induced by interferons (IFN-??, IFN-??, IFN-??) via IFNAR-JAK1-TYK2 signaling, leading to STAT1 phosphorylation and synergistic activation with IRF1. APOBEC3A accesses ssDNA substrates by interacting with the RPA complex and PCNA at replication forks. The resulting uracil lesions activate ATR-ATRIP, promoting Chk1-mediated signaling and ??H2AX foci formation, with prolonged damage triggering p53-dependent apoptosis. Crosstalk with NF-??B and other ISGs integrates APOBEC3A into antiviral and stress networks.
In the AGS gastric cancer model, APOBEC3A knockout removes a primary endogenous mutational source, enabling clean assessment of APOBEC signature contributions. Interferon treatment or APOBEC3A overexpression in parental cells induces ??H2AX foci and apoptosis, effects absent in the knockout. This system is ideal for studying H. pylori-driven NF-??B and STAT1/IRF1-mediated APOBEC3A upregulation, and for dissecting APOBEC3A??s role in kataegis, replication stress, and drug resistance mutations during therapeutic challenge.
Researchers can use this knockout model for whole-exome sequencing to define APOBEC-associated mutation signatures, and ??H2AX immunofluorescence to quantify DNA damage. Co-immunoprecipitation with RPA and PCNA, and deamination assays verify interaction and enzymatic loss. Drug sensitivity panels with Annexin V flow cytometry reveal APOBEC3A-dependent chemoresistance and apoptosis. Migration and invasion assays assess metastatic behavior. This polyclonal population is a versatile tool for studying APOBEC3A in innate immunity, viral restriction, and cancer genome instability. For details, contact Ascent Research.
