The CBR4 Knockout NCI-H1299 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population derived from the human NCI-H1299 lung adenocarcinoma cell line, with targeted disruption of the CBR4 gene. This loss-of-function model enables investigation of carbonyl reductase 4 function in non-small cell lung cancer (NSCLC) contexts. The polyclonal nature provides a diverse genetic background for robust population-level studies without selecting for single-cell clones.
NCI-H1299 is an epithelial cell line established from a lymph node metastasis of a lung adenocarcinoma. It harbors a homozygous deletion of TP53, making it p53-null, a characteristic that is common in metastatic NSCLC and linked to genomic instability and altered stress responses. Widely employed in NSCLC research, this line is particularly suited for studies on tumor progression, metastasis, and drug resistance.
CBR4 encodes a cytosolic NADPH-dependent carbonyl reductase that catalyzes the reduction of various endogenous and exogenous carbonyl compounds, including quinones, reactive aldehydes, and ketones. This enzyme plays a central role in xenobiotic metabolism, steroid hormone processing, and the oxidative stress response, regenerating NADP+ in the process. CBR4 expression is transcriptionally regulated by stress-responsive factors such as NRF2 and the aryl hydrocarbon receptor (AHR). In the NRF2 pathway, oxidative or electrophilic stress disrupts the KEAP1-NRF2 interaction, leading to NRF2 stabilization and nuclear translocation, where it induces a battery of cytoprotective genes including CBR4, NQO1, and glutathione S-transferases (GSTs). AHR similarly mediates xenobiotic-sensing responses. Downstream, CBR4 detoxifies reactive carbonyl species and quinones, thereby maintaining NADPH/NADP+ balance and protecting against lipid peroxidation and protein carbonylation. Through these interactions, CBR4 contributes to cellular defense against electrophilic stressors and chemotherapeutic agents.
In the NCI-H1299 background, CBR4 knockout disrupts this detoxification axis, leading to the accumulation of reactive carbonyl species and elevated intracellular oxidative stress. Loss of CBR4 impairs NADPH homeostasis and sensitizes cells to electrophilic stressors and chemotherapeutic agents, including cisplatin and doxorubicin, as predicted by its role in reducing drug-derived quinones and reactive intermediates. Combined with the p53-null status of NCI-H1299, this model allows dissection of CBR4-dependent redox adaptations that are independent of canonical p53-mediated stress responses, highlighting alternative resistance mechanisms in lung cancer.
This polyclonal knockout model supports a wide range of experimental designs. Researchers can perform carbonyl reductase activity assays, NADPH/NADP+ measurement, and ROS detection using DCFDA to quantify oxidative stress phenotypes. Cell viability and apoptosis assays (e.g., Annexin V staining) under oxidative insults or chemotherapy exposure assess drug sensitization. RT-qPCR and western blotting verify CBR4 disruption, while metabolomic profiling uncovers shifts in carbonyl species. Such studies are valuable for investigating carbonyl metabolism in lung cancer, redox biology, xenobiotic toxicity screening, and the development of combinatorial treatment strategies. For technical inquiries or ordering, please contact Ascent Research.
