The ABCB1 Knockout 769-P Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human renal cell carcinoma line 769-P. In this product, the ABCB1 gene has been disrupted using CRISPR/Cas9 technology, generating a heterogeneous pool of cells with loss-of-function alleles at the target locus. This polyclonal format provides a versatile model for studying the functional consequences of ABCB1 ablation without the limitations of single-cell clonal selection, allowing robust assessment of gene function in a population context.
The 769-P cell line originates from a primary clear cell renal adenocarcinoma and has been extensively employed as a model of renal cell carcinoma. As an adherent epithelial cancer cell line, it retains key features of kidney tumor biology, including characteristic signaling and drug response profiles. Its use as a host for this knockout model enables targeted investigation of resistance mechanisms directly within a cancerous renal epithelial background, which is highly relevant to clinical drug resistance in renal malignancies.
ABCB1 encodes P-glycoprotein, a membrane-resident ATP-binding cassette transporter that actively expels a broad spectrum of structurally diverse compounds, including chemotherapeutic agents, from the cell interior. Transcription of ABCB1 is regulated by nuclear receptors such as PXR (NR1I2) and CAR (NR1I3), as well as stress-responsive factors including NF-??B, NRF2, and HIF1A, integrating signals from xenobiotic exposure, oxidative stress, and hypoxia. Functional activity of P-glycoprotein is modulated by direct interactions with pharmacological inhibitors like verapamil and cyclosporine A, as well as with membrane lipids and caveolin-1. Through its efflux activity, ABCB1 reduces intracellular drug bioavailability, directly impacting the efficacy of substrate drugs in cancer cells and contributing to the multidrug resistance phenotype.
In the context of 769-P renal cell carcinoma cells, ABCB1-mediated drug efflux is a major contributor to chemoresistance. By disrupting this gene, the knockout polyclonal population loses its ability to effectively export P-glycoprotein substrates, rendering the cells sensitized to a range of anticancer agents. This model thus provides a critical tool for disentangling the contribution of active efflux to drug sensitivity and for evaluating strategies to overcome multidrug resistance in kidney cancer, where ABCB1 expression often correlates with poor therapeutic outcomes.
Researchers can employ this knockout model to investigate ABCB1-dependent drug resistance pathways, screen for novel MDR1 reversal agents, and conduct functional transport assays. Typical experiments include quantifying ABCB1 expression by western blotting or RT-qPCR, confirming loss of P-glycoprotein by flow cytometry, and measuring intracellular accumulation of fluorescent substrates such as Rhodamine 123 or Calcein-AM. Cytotoxicity profiling with chemotherapeutics using MTT or ATP-based viability readouts, as well as apoptosis detection assays, further delineate the impact of transporter loss on drug sensitivity. For further details or to obtain this product, please contact Ascent Research.
