Influence of drugs and nutrients on transporter gene expression levels in Caco-2 and LS180 intestinal epithelial cell lines.

PURPOSE

The aim of this study was to investigate the influences of various drugs and nutrients on the expression levels of intestinal drug transporters PEPT1, MDR1, MRP2 and MRP3, and drug-metabolizing enzyme CYP3A4.

METHODS

Quantitative reverse transcriptase polymerase chain reaction was used to quantitate transporter and CYP3A4 mRNAs. Western blotting was used to determine protein levels of P-gp. Transport studies of P-gp were performed using cultured Caco-2 cell monolayers.

RESULTS

The expression of MDR1 mRNA was increased by all-trans retinoic acid and in glucose-depleted medium, whereas little change of MRP2 and MRP3 mRNA was observed in Caco-2 cells. Substrates and inducers of P-gp or CYP3A4 tended to produce parallel changes in the expression of MDR1 and CYP3A4 mRNA in LS180 cells, whereas in Caco-2 cells no such coordinate response was observed, possibly due to the absence of the expression of steroid xenobiotic receptor (SXR) in this cell line.

CONCLUSION

Several drugs and nutrients were found to affect transporter gene expression level in two human intestinal epithelial cell lines. Since SXR is involved in some expression-regulatory processes, and Caco-2 cells lack SXR, LS180 cells as well as Caco-2 cells should be used for the study of the regulation of intestinal transporters.