The ABCC3 Knouckout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population generated from the HT29 human colorectal adenocarcinoma cell line, designed to disrupt the ABCC3 gene. This pool of knockout cells lacks functional multidrug resistance-associated protein 3 (MRP3) and provides a heterogeneous, non-clonal model for studying transporter biology.
The host cell line, HT29, is a well-established human colorectal adenocarcinoma model that retains wild-type p53 and microsatellite stability. HT29 cells can differentiate into enterocyte-like cells under appropriate conditions, making them valuable for investigations of intestinal epithelial transport, drug absorption, and colorectal cancer biology.
ABCC3 encodes MRP3, an ATP-binding cassette transporter that mediates the ATP-dependent efflux of organic anion conjugates, including glucuronide and glutathione conjugates, bile acids, and certain anticancer drugs. Its expression is transcriptionally activated by the stress-responsive factor NRF2, as well as by nuclear receptors such as the constitutive androstane receptor (CAR), pregnane X receptor (PXR), and farnesoid X receptor (FXR). Functionally, MRP3 operates in concert with phase II conjugation enzymes like UDP-glucuronosyltransferases (UGTs) and glutathione S-transferases (GSTs), and with other ABC transporters (e.g., ABCC1, ABCC2) to eliminate xenobiotics and endogenous metabolites. Disruption of ABCC3 leads to increased intracellular accumulation of drug conjugates and bile acids, potentially enhancing chemosensitivity and altering detoxification dynamics.
In the HT29 colorectal cancer background, ABCC3 knockout disrupts a key mechanism of chemoresistance and detoxification. The polyclonal nature of this model avoids single-cell clonal artifacts and better represents tumor heterogeneity, while the intact p53 pathway allows examination of the interplay between transporter-mediated drug efflux and DNA damage-induced apoptosis. The ability of HT29 cells to undergo enterocytic differentiation further enables studies of vectorial bile acid and drug conjugate transport across intestinal epithelium, making this system particularly relevant for colorectal cancer research where ABCC3 upregulation correlates with poor therapeutic outcomes.
Typical applications include quantitative drug accumulation assays using fluorescent substrates (e.g., calcein-AM), intracellular drug retention measurements, and cell viability profiling following exposure to chemotherapeutics such as cisplatin or irinotecan. Bile acid transport can be monitored with fluorescent bile acid derivatives, facilitating analysis of enterohepatic circulation. Transcriptomic approaches (RNA-seq) reveal how loss of ABCC3 rewires NRF2-dependent detoxification networks. This model supports drug resistance studies, pharmacokinetic evaluation of MRP3 substrates, and screening of transporter modulators. For further details and availability, please contact Ascent Research.
