Conditionally immortalized intestinal epithelial cells. A new model for studying intestinal epithelial cell turnover

Gene expression profiles of ABC transporters and cytochrome P450 3A in Caco-2 and human colorectal cancer cell lines

PURPOSE

The mRNA levels of MDR1 (P-glycoprotein), multidrug resistance-associated proteins (MRP1, MRP2), cytochrome P450 3A (CYP3A) and villin in human colorectal cell lines (HCT-15, LoVo DLD-1, HCT-116 and SW620) were quantitatively compared with those in Caco-2 cells.

METHODS

The mRNA levels were determined by real time quantitative polymerase chain reaction and expressed as the relative concen trations of MDR1 mRNA to glyceraldehyde-3-phosphate dehydro genase (GAPDH) mRNA. RESULTSl MDR1 mRNA was expressed in HCT-15 LoVo and DLD-1 cells at similar or lower level to Caco-2. The expression of MRP mRNA in the cell lines tested was comparable with Caco-2. MRP. mRNA was detected only in HCT-116 and SW620 at significantly lower level than Caco-2. CYP3A mRNA was detected in HCT-15 LoVo, DLD-1 and SW620 at similar level to Caco-2.

CONCLUSIONS

HCT-15 LoVo and DLD-1 cells express proteins important for regulating the intestinal absorption of drugs, i.e., MDR1 MRP1 and CYP3A, whereas HCT-116 and SW620 cells were not acceptable for evaluation of absorption properties of drug candidates

Real-time quantitative polymerase chain reaction for MDR1, MRP1, MRP2, and CYP3A-mRNA levels in Caco-2 cell lines, human duodenal enterocytes, normal colorectal tissues, and colorectal adenocarcinomas

The expression levels of mRNAs for MDR1 (P-glycoprotein), multidrug resistance-associated proteins (MRP1, MRP2), and cytochrome P450 3A (CYP3A) in Caco-2 cells were quantitatively compared with those in human duodenal enterocytes, normal colorectal tissues, and colorectal adenocarcinomas. Caco-2 cells (passages 36-88) were kindly supplied by several laboratories in Japan. Human duodenal enterocytes were obtained from five healthy male volunteers. Normal colorectal tissues and colorectal adenocarcinomas were simultaneously obtained from seven patients with primary colorectal adenocarcinoma. MDR1, MRP1, MRP2, and CYP3A mRNA levels were determined by real-time quantitative polymerase chain reactions (PCR). Relative concentrations of mRNAs for target proteins (MDR1, MRP1, MRP2, and CYP3A) and glyceraldehyde-3-phosphate dehydrogenase in Caco-2 cells were 1.00 +/- 0.15, 1.02 +/- 0.06, 0.94 +/- 0.10, and 0.68 +/-0.60, respectively, and those in human enterocytes were about 12-, 3-, 7-, and 8000-fold higher than in the Caco-2 cells, respectively. In contrast, MDR1, MRP1, and CYP3A mRNA levels in Caco-2 cells were comparable to those in normal colorectal tissue and colorectal adenocarcinoma.

Molecular and pharmacokinetic properties of 222 commercially available oral drugs in humans

This study was performed to determine the exclusion criteria that differentiate poorly absorbed drugs from good drug candidates, and to accelerate drug development by exclusion of unnecessary assessment. The molecular and pharmacokinetic properties of 222 commercially available oral drugs were tabulated and their correlations were analyzed. The exclusion criteria obtained were 1) a molecular weight of more than 500, and 2) a ClogP value of more than 5. Exceptions to molecular weight criteria were compounds with a sugar moiety, high atomic weight, and large cyclic structure. It was also suggested that being a substrate for MDRI (P-glycoprotein) does not always result in poor bioavailability, and that drug development by chemical modification of a seed or lead compound with quantitative structure activity relationship analysis can result in lower bioavailability, higher bound fraction and lower urinary excretion, which would hamper later development processes and might result in considerable drug-drug interaction. The criteria should be adjusted according to the pharmacological profiles of the agents in question and depending on the estimated profit, but ignoring these criteria may result in a significant waste of time and money during drug development.