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Updated: Mar 16, 2026

Methods to Study Epithelial Transport Protein Function and Expression in Native Intestine and Caco-2 Cells Grown in 3D
Published on: March 16, 2017
Caco-2 cells - expression, regulation and function of drug transporters compared with human jejunal tissue
S Brück1, J Strohmeier1, D Busch1
1Department of Clinical Pharmacology, Center of Drug Absorption and Transport, University Medicine, Greifswald, Germany.
Background:
Induction or inhibition of drug transporting proteins by concomitantly administered drugs can cause serious drug-drug interactions (DDIs). However, in vitro assays currently available are mostly for studying the inhibitory potential of drugs on intestinal transporter proteins, rather than induction. Therefore, this study investigated the suitability of the frequently used intestinal Caco-2 cell line to predict transporter-mediated DDIs as caused by induction via activation of nuclear receptors.
Methods:
TaqMan® low density arrays and LC-MS/MS based targeted proteomics were used to evaluate transporter expression in Caco-2 cells in comparison with jejunal tissue, in culture-time dependence studies and after incubation with different known inducers of drug metabolism and transport. Additionally, studies on ABCB1 function were performed using Transwell® assays with [3 H]-digoxin and [3 H]-talinolol as substrates after incubation with the prototypical inducers rifampicin, St John's wort, carbamazepine and efavirenz.
Results:
The gene and protein expression pattern of drug transporters in Caco-2 cells and jejunal tissue differed considerably. For some transporters culture-time dependent differences in mRNA expression and/or protein abundance could be determined. Finally, none of the studied prototypical inducers showed an effect either on mRNA expression and protein abundance or on the function of ABCB1.
Conclusion:
Differences in transporter expression in Caco-2 cells compared with jejunal tissue, as well as expression dependence on culture time must be considered in in vitro studies to avoid under- or overestimation of certain transporters. The Caco-2 cell model is not suitable for the evaluation of DDIs caused by transporter induction. Copyright © 2016 John Wiley & Sons, Ltd.
Insights
The Caco-2 cell line is not suitable for predicting drug-drug interactions caused by transporter induction. This study found significant differences in transporter expression compared to human jejunal tissue, rendering it unreliable for induction studies.
Area of Science:
- Pharmacology
- Drug Metabolism and Transport
Background:
- Drug-drug interactions (DDIs) can arise from altered drug transporter activity.
- Existing in vitro assays primarily assess transporter inhibition, not induction.
- Investigating induction potential is crucial for comprehensive DDI evaluation.
Purpose of the Study:
- To evaluate the Caco-2 cell line's suitability for predicting transporter-mediated DDIs caused by induction.
- To compare drug transporter expression in Caco-2 cells with human jejunal tissue.
- To assess the impact of culture time and known inducers on transporter expression and function.
Main Methods:
- Gene and protein expression analysis using TaqMan® low density arrays and LC-MS/MS.
- Functional assays of ABCB1 (P-glycoprotein) using radiolabeled substrates (digoxin, talinolol).
- Incubation with prototypical inducers: rifampicin, St John's wort, carbamazepine, and efavirenz.
Main Results:
- Significant differences observed in drug transporter expression between Caco-2 cells and jejunal tissue.
- Culture time influenced mRNA and protein levels of some transporters.
- Prototypical inducers did not alter ABCB1 mRNA, protein abundance, or function in Caco-2 cells.
Conclusions:
- Caco-2 cell transporter expression varies with culture time and differs from human jejunal tissue.
- These discrepancies necessitate careful consideration to avoid misinterpreting in vitro DDI data.
- The Caco-2 cell model is unsuitable for evaluating drug-drug interactions stemming from transporter induction.
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