Detection of cytochrome P450 and other drug-metabolizing enzyme mRNAS in peripheral blood mononuclear cells using DNA arrays

The purpose of this study was to determine whether the expression of cytoch rome P450 (CYP) enzyme mRNAs, other drug-metabolizing enzyme mRNAs, and tra nsporter mRNAs can be detected using DNA arrays. Total RNA was isolated fro m peripheral blood mononuclear cells of 10 multiple sclerosis patients and 10 age- and sex-matched controls. The mRNA was reverse transcribed to radio labeled cDNA, and the resultant cDNA was used to probe a DNA array containi ng several thousand known human genes. The signals corresponding to several CYPs, drug-metabolizing, and transporter mRNAs was substantially above bac kground. The results demonstrate that the DNA array technique has the sensi tivity and the selectivity for applications in the pharmaceutical sciences. The mean values for mRNAs of specific CYPs and drug-metabolizing enzymes i n peripheral blood cells were compared with reported values for liver. The capabilities of DNA arrays may prove useful for characterizing CYP expressi on in a variety of clinical samples.