The APEX1 Knockout HT29 Polyclonal Cells product provides a CRISPR/Cas9-edited polyclonal knockout cell population in which the APEX1 gene has been disrupted in the HT29 human colorectal adenocarcinoma cell line. This loss-of-function model is designed for investigators seeking to interrogate APEX1-dependent processes without the limitations of transient silencing methods. The polyclonal nature of the population reflects gene editing across a pool of cells, yielding a heterogeneous knockout pool suitable for robust functional studies.
HT29 cells are a widely studied human colorectal adenocarcinoma cell line with epithelial morphology, originally derived from a primary colon tumor. They serve as a model system for colorectal cancer biology, epithelial barrier function, and cellular differentiation. HT29 cells maintain characteristic features of intestinal epithelium, making them valuable for investigating oncogenic signaling, drug response, and the molecular underpinnings of colorectal cancer progression.
APEX1 encodes a multifunctional protein central to DNA base excision repair (BER) and redox regulation of transcription factors. Its endonuclease activity excises apurinic/apyrimidinic sites, while its redox function reduces oxidized cysteine residues in transcription factors NF-??B, AP-1, p53, HIF-1??, and Sp1, enhancing their DNA-binding. APEX1 is activated by oxidative stress (ROS), DNA damage, p53, and HIF-1??, and interacts with BER components XRCC1, PARP1, PCNA, DNA ligase III, and cofactors TRX, p300, PCAF. Downstream, it promotes NF-??B/AP-1 target genes, influencing cell cycle and apoptosis. The pathway includes ROS ?? APEX1 ?? TRX ?? NF-??B/AP-1 ?? antioxidant response elements.
In the colorectal cancer context, APEX1??s dual roles are particularly significant. Elevated APEX1 expression is associated with resistance to chemotherapeutics such as cisplatin and 5-fluorouracil, commonly used in colon cancer treatment. By utilizing this HT29-based knockout model, researchers can dissect APEX1 contributions to drug sensitivity, DNA repair capacity, and redox-driven survival signaling in an epithelial colorectal adenocarcinoma background. The model provides a relevant platform to study how loss of APEX1 impacts tumor cell behavior, including proliferation, apoptosis, and stress adaptation.
This polyclonal knockout population supports diverse applications. Users can validate APEX1 loss via western blotting, measure target gene expression by RT-qPCR (e.g., c-Myc, HIF-1??), and assess DNA repair with comet assays. NF-??B reporter assays and immunofluorescence probe APEX1??s regulatory roles, while colony formation and drug sensitivity tests (cisplatin, 5-FU) evaluate chemoresistance. For technical inquiries, please contact Ascent Research.
