We selected a human cell line (Caco-2, C2BBE1 clone) expressing the efflux transporters P-gp, BCRP, and MRP2, and have knocked down the expression of one transporter at a time. Knockdown cell lines can be evaluated in different ways. For example, as a standalone model the P-gp knockdown is a cleaner BCRP assay system. When used in combination with control cells, it can identify P-gp substrates. Our knockdown was achieved using short hairpin RNA (shRNA) in a lentiviral vector, an approach that is capable of producing stable phenotypes.
Our cell lines for evaluation of hepatic and renal uptake transporters were created by stable transfection of transporter genes into HEK293 cells. For initial set-up, stable transfections are more laborious and challening than transient transfections, but they result in permanent insertion into the genome. This allows us to fully characterize the phenotypes of our cells.
All Absorption Systems cell lines have been extensively characterized and validated:
Molecular Biology for Phenotypic Expression
• Quantitative PCR for mRNA expression
• Western blot for protein expression
• Immunofluorescence for protein localization
Assay Window and Phenotype Stability
• Growth rate
• Passage number
• Days in culture
• Assay window
Appropriate and Robust Functional Expression
• Uptake and/or bidirectional transport
• Polarization and barrier properties (cell lines in bidirectional transport format)
Our CellPort Analytics™ database captures up to ten years of data for our cell lines. This tool helps us ensure our cell lines are behaving optimally, according to stringent criteria we’ve established based on extensive knowledge and experience.
Transporter Reference Guide Ebook
Waiving Clinical Studies
Recommended ResourcesEx Vivo Evaluation of Regional Differences in the Expression and Function of Active Drug Transporters and Metabolic Enzymes in Rat and Human Intestine
Functional assessment of multiple P-glycoprotein (P-gp) probe substrates: influence of cell line and modulator concentration on P-gp activity
CellPort Transporters Services Portfolio