The CBR3 Knockout NCI-H1299 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the NCI-H1299 human non-small cell lung carcinoma line. The CBR3 gene, encoding NADPH-dependent carbonyl reductase 3, has been disrupted to create a loss-of-function model. The polyclonal format avoids clonal selection bias and is suitable for robust functional studies. The cells are validated for CBR3 disruption at genomic and transcript levels.
The NCI-H1299 host cell line was established from a lymph node metastasis of a non-small cell lung carcinoma. It is an epithelial, adherent cell line that harbors a homozygous deletion of TP53, resulting in p53 protein deficiency. This genetic background is extensively used in oncology research to investigate drug resistance, DNA damage response, and redox regulation, particularly in lung adenocarcinoma models.
CBR3 catalyzes NADPH-dependent reduction of carbonyl-containing compounds, including anthracyclines like doxorubicin. Its expression is regulated by the NRF2/KEAP1 pathway; under oxidative stress, NRF2 dissociates from KEAP1, translocates to the nucleus, and binds antioxidant response elements (ARE) to promote CBR3 transcription. The enzyme converts doxorubicin to doxorubicinol, a cardiotoxic metabolite, and reduces prostaglandin E2 to prostaglandin F2alpha. NADPH serves as a required cofactor for its catalytic activity.
Combined with the p53-null background, CBR3 knockout in NCI-H1299 cells disrupts the NRF2/KEAP1/ARE-mediated detoxification pathway, creating a valuable model to study anthracycline resistance. This system helps elucidate how loss of carbonyl reductase activity influences drug sensitivity, cardiotoxicity risk, and oxidative stress response. It is especially useful for probing the interplay between p53 status and NRF2-driven redox adaptation in lung cancer.
Research applications include quantifying doxorubicinol via LC-MS to monitor CBR3 enzymatic activity, MTT cell viability assays to assess doxorubicin sensitivity, and measuring reactive oxygen species (ROS) to evaluate oxidative stress. The polyclonal knockout cells can be used in high-throughput screening for carbonyl reductase inhibitors and in biochemical assays for prostaglandin conversion. Validation is carried out by RT-qPCR for CBR3 mRNA and Western blot for protein expression. For additional technical information, please contact Ascent Research.
