The ABCB1 Knockout 786-O Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population derived from the human 786-O renal cell carcinoma line, targeting the ABCB1 gene encoding P-glycoprotein (P-gp). This heterogeneous pool of cells, each carrying distinct gene disruptions, provides a loss-of-function model for studying multidrug resistance without the limitations of clonal selection. The polyclonal format enables robust representation of cellular responses, making it ideal for screening applications and mechanistic studies in cancer biology.
The 786-O cell line originates from a primary clear cell renal adenocarcinoma and is characterized by a frameshift mutation in the VHL tumor suppressor gene (codon 104), resulting in constitutive stabilization of hypoxia-inducible factors (HIFs) and aberrant activation of hypoxia signaling pathways. These adherent epithelial cells are a standard model for VHL-mutant clear cell carcinoma, extensively employed to study hypoxia-driven angiogenesis, tumor metabolism, and drug sensitivity. The VHL-deficient background provides a relevant context for investigating the intersection of oxygen-sensing pathways and chemoresistance.
ABCB1 encodes P-glycoprotein, an ATP-dependent efflux pump of the ABC transporter family that actively exports diverse hydrophobic substrates, including chemotherapeutic agents such as doxorubicin, paclitaxel, and vinblastine. This transporter reduces intracellular drug accumulation and is a primary mediator of multidrug resistance. Expression of ABCB1 is transcriptionally regulated by nuclear receptors NR1I2 (PXR) and NR1I3 (CAR), and is further modulated by stress-responsive factors HIF1A, NF-??B, and p53. At the plasma membrane, P-gp interacts with scaffold proteins caveolin-1, ezrin, NHERF1, and PDZK1, linking it to the actin cytoskeleton. Its activity can be inhibited by competitive antagonists, making it a critical node in pharmacokinetics and drug resistance.
In 786-O cells, where VHL mutation leads to HIF stabilization and potential upregulation of ABCB1, this knockout model provides a valuable platform for dissecting hypoxia?Cchemoresistance crosstalk. Disruption of the ABCB1 gene eliminates P-gp-mediated drug efflux, allowing researchers to directly assess substrate specificity, transporter kinetics, and the efficacy of novel inhibitors in a clear cell renal carcinoma background. This system is particularly relevant for investigating how hypoxia-driven signaling influences multidrug resistance, a critical issue in renal cancer therapy.
This knockout product is suited for a spectrum of applications, including multidrug resistance mechanism studies, P-gp substrate and inhibitor screening, drug bioavailability assays, and pharmacokinetic modeling. Compatible downstream assays encompass western blotting and RT-qPCR for expression profiling, Rhodamine 123 efflux and intracellular drug accumulation experiments to quantify transport activity, MTT cytotoxicity tests to evaluate chemosensitivity, and flow cytometry for surface P-gp detection. Transport inhibition studies and CRISPR validation via Sanger sequencing or T7E1 assay further support robust characterization. For additional information or technical support, please contact Ascent Research.
