The ABCG2 Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal HT29 population harboring a disrupted ABCG2 (BCRP) gene, providing a loss-of-function model for studying the ATP-binding cassette efflux transporter. This heterogeneous pool of edited cells avoids single-cell clone selection and is ideal for applications not requiring isogenicity. The gene disruption abolishes ABCG2-mediated efflux, enabling direct investigation of drug transport, chemoresistance, and metabolite handling.
The parental HT29 cell line is a microsatellite-stable, adherent epithelial line derived from a colorectal adenocarcinoma of a 44-year-old female. HT29 cells carry a homozygous p53 (R273H) mutation and serve as a model of the intestinal epithelium, capable of enterocytic differentiation. This background is particularly relevant for studying intestinal drug absorption and the contribution of apical transporters to bioavailability.
ABCG2 is a plasma membrane homodimeric efflux pump for diverse substrates including chemotherapeutics (doxorubicin, mitoxantrone, topotecan), endogenous metabolites (heme, urate), and fluorescent dyes (Hoechst 33342, pheophorbide A). Its expression is transcriptionally regulated by HIF-1??, NRF2 (KEAP1?CNRF2?CARE), PXR, CAR, PPAR??, AhR, and the ??-catenin/TCF4 complex, integrating cellular stress and xenobiotic signals. ABCG2 directly interacts with inhibitors like Ko143 and fumitremorgin C and functionally cooperates with P-glycoprotein (ABCB1) and MRP1 (ABCC1) in multidrug resistance.
In HT29 cells, ABCG2 knockout abrogates drug and dye extrusion, increasing intracellular accumulation and sensitivity to mitoxantrone and doxorubicin. Loss of ABCG2 also eliminates the side population phenotype linked to cancer stem cells and may affect enterocytic differentiation. Thus, this polyclonal knockout model is valuable for exploring ABCG2??s role in intrinsic and acquired drug resistance in colorectal cancer, the interplay with p53, and the connection between efflux activity and stemness in intestinal epithelium.
This knockout model supports fluorescence-based efflux assays (Hoechst 33342, rhodamine 123, pheophorbide A), intracellular drug accumulation measurements, cell viability assays for chemosensitization, and side-population flow cytometry. Additional applications include urate transport assays, co-immunoprecipitation studies (e.g., with PTEN, EGFR), promoter luciferase reporter assays for ??-catenin/TCF4 or NRF2 regulation, and inhibitor potentiation experiments using Ko143. It serves as a versatile tool for drug resistance, transporter pharmacology, and cancer stem cell research. For further information, please contact Ascent Research.
