Human P-Glycoprotein / MDR1 Drug Interaction Assay Kit & Screening Services
| Product Family | Product Number | Product Description | Technical Manual |
| Human P-Glycoprotein / MDR1 | HPGP-48 | Human P-Glycoprotein / MDR1 Drug Interaction Assay in 2x 48-well format | Technical Manual |
The materials provided in the assay kit for MDR1 / Human P-Glycoprotein Drug Interaction are formatted to allow for two independent 48-well assay setups. Each aliquot of HCT-Pgp Cells is provided as a single-use assay reagent and provides sufficient volume to dispense 48 assay wells of HCT-Pgp cells into one 96-well plate. If desired, the two aliquots of HCT-Pgp cells may be thawed, combined to generate a single cell suspension, and then dispensed into all wells of an assay plate.
The kit contains two aliquots of HCT-Pgp cells and two black, sterile, collagen-coated 96-well assay plates. In addition to HCT-Pgp cells and assay plates, this kit includes Cell Recovery Medium (CRM-p) used to perform a rapid thaw of the -80°C HCT-Pgp cells, Compound Screening Medium supplemented with daunorubicin (CSM+DR) used to prepare drug treatment media, Wash Buffer, two aliquots of Lysis Reagent, and the potent reference inhibitor Tariquidar.
HCT-Pgp cells are a proprietary cell line derived from human colorectal adenocarcinoma cells that have been extensively selected for high-level expression of native P-glycoprotein. The primary application of this MDR1 drug interaction assay kit is to rapidly assess drug candidates as either inhibitors, substrates, or non-substrates of P-glycoprotein. This is accomplished by co-treating the cells with varying concentrations of the test drug and a fixed concentration of daunorubicin, a well-characterized fluorescent substrate for P-glycoprotein mediated transport.
For more information, view the Technical Manual.
What is MDR1?
Human P-glycoprotein (P-gp) is also known as MDR1 or ABCB1, the human multidrug resistance protein 1. It is a 170kDa transmembrane glycoprotein that functions as an ATP-dependent efflux transporter present in the human body’s epithelial tissues.
P-gp is comprised of twelve membrane-spanning domains and two cytosolic nucleotide-binding domains. The transmembrane domains comprise several substrate binding pockets capable of interacting with a broad range of both endogenous and foreign small molecule chemotypes. Xenobiotic substrates of P-gp range from pollutants, such as those encountered through unintended exposure to industrial and agricultural chemicals, to small molecule drugs that are intentionally administered for therapeutic benefit.
P-gp is highly expressed in gastrointestinal epithelium, liver, pancreatic and kidney cells, and capillary endothelial cells that establish the blood-brain barrier. Multidrug resistance research has found MDR1 expressed at high levels on the lines of transformed and tumor cells. In combination with the activities of Cytochrome P450 oxidases, the robust efflux activity of P-gp plays a critical role in limiting the absorption and systemic physiological distribution of xenobiotics and facilitating their ultimate elimination from the body. The MDR1 transporter role is important for drug-drug interaction (DDI) and drug safety assessments.
Drug Safety Assessment
Determining if a drug candidate has incidental activity as either a substrate or an inhibitor of the P-gp transporter is a vital component of the drug safety assessment process. A drug that is a P-gp substrate or an inhibitor can profoundly alter the rate of absorption, distribution, metabolic conversion, and eventual excretion (ADME) of co-administered drugs, thereby significantly shifting their respective therapeutic efficacies and toxicologic profiles. Assessing a drug’s potency as an interactor with P-gp, and thus its potential liability for inducing downstream drug-drug interactions, is mandated by the FDA.
The MDR1 multidrug resistance transporter impacts public health and is associated with nosocomial infections and developments with antibiotics and mortality. MDR1 is also often cited as a transporter for drug-drug interaction in product labels and particularly in the use of digoxin. The EMA and FDA recommend at minimum in vitro MDR1 tests for interaction.
MDR1 / Human P-Glycoprotein Drug Interaction Assay Data
The effect of drug treatments on the intracellular accumulation of daunorubicin in HCT-Pgp cells. Increasing concentrations of drugs that are substrates for P-gp compete with daunorubicin for transporter occupancy, resulting in corresponding increases in intracellular accumulation of the fluorescent probe. HCT-Pgp cells provide low-nanomolar sensitivities to drugs that are inhibitors of P-gp. The reference inhibitor Tariquidar is provided with this assay kit.