The APOBEC3A Knockout 143B Polyclonal Cells represent a CRISPR/Cas9-mediated gene-disrupted polyclonal population derived from the human osteosarcoma cell line 143B. This product provides a heterogeneous pool of cells harboring targeted disruptions in the APOBEC3A locus, enabling loss-of-function studies without clonal selection bias. The polyclonal format offers a representative knockout phenotype across a mixed background, suitable for applications requiring a broad cellular context. Use of the CRISPR/Cas9 system ensures efficient gene targeting, and the resulting population is validated for reduced or absent APOBEC3A expression, as confirmed by standard genomic and proteomic assays.
The host 143B cell line is a well-characterized human osteosarcoma model originally derived from a 13-year-old female patient. This adherent cell line is widely employed in bone cancer research, particularly for investigating tumorigenesis, metastasis, and the bone microenvironment. 143B cells exhibit a transformed phenotype, high metastatic potential, and responsiveness to innate immune stimuli, making them an ideal background for studying APOBEC3A-mediated processes. Their malignant properties, combined with the loss of APOBEC3A, create a powerful system for dissecting the intersection of cancer biology and innate immunity.
APOBEC3A is a cytidine deaminase that edits single-stranded DNA by deaminating cytosine to uracil, leading to C-to-T mutations. Its expression is strongly induced by type I interferons (IFN-??/??) and type II interferon (IFN-??) through the JAK-STAT pathway. Upstream, ligand binding to IFNAR1/IFNAR2 activates JAK1 and TYK2 kinases, which phosphorylate STAT1 and STAT2. These transcription factors form the ISGF3 complex with IRF9, directly promoting APOBEC3A transcription. Additionally, DNA damage signals via ATM and ATR can upregulate APOBEC3A. In its antiviral role, APOBEC3A hypermutates viral genomes such as HIV-1 and restricts retrotransposons. However, its off-target activity generates mutations in host genomic DNA, including in key cancer genes like TP53 and MYC. APOBEC3A interacts with single-stranded DNA substrates and cooperates with DNA repair factors such as uracil DNA glycosylase (UNG) and replication protein A (RPA), linking it to the DNA damage response.
In the context of osteosarcoma, APOBEC3A expression contributes to a distinct mutational signature frequently observed in human tumors. The 143B polyclonal knockout model allows researchers to isolate APOBEC3A-dependent mutagenesis from other mutation sources, providing a clean system for studying how this enzyme drives genomic instability in bone cancer. Furthermore, the loss of APOBEC3A in a metastatic cell line enables investigation of its roles in tumor progression, immune evasion, and response to DNA-damaging therapies. This model is particularly relevant for exploring the dual nature of APOBEC3A as both an antiviral defender and a source of oncogenic mutations.
This knockout cell pool is suited for a variety of advanced experimental applications. Researchers can perform HIV-1 restriction assays to quantify viral hypermutation, analyze global mutation signatures via RNA sequencing, or examine DNA damage responses using ??H2AX immunofluorescence. Additional assays include western blotting and RT-qPCR to confirm pathway activation, transwell migration assays to assess metastatic behavior, and cell viability studies following genotoxic stress. The integration of APOBEC3A loss with the 143B osteosarcoma background makes this product a versatile tool for cancer biology, immunology, and drug discovery. For further technical details and ordering information, please contact Ascent Research.
