Splice Variants of mRNA of Cytochrome P450 Genes: Analysis by the Nanopore Sequencing Method in Human Liver Tissue and HepG2 Cell Line

The analysis of cytochrome P450 transcripts was carried out by the nanopore sequencing in liver tissue samples of three donors and HepG2 line cells. It was demonstrated that direct mRNA sequencing with a MinION nanopore sequencer (Oxford Nanopore Technologies) makes it possible to obtain quantitative profiles for transcripts (and their splice variants) of cytochrome P450 superfamily genes encoding isoforms involved in metabolism of the majority (~80%) of drugs. The splice variant profiles substantially differ for donors. The cytochrome P450 gene expression at the transcript level is significantly weaker in cells of the HepG2 line compared with that in the normal liver tissue. This limits the capability of the direct mRNA nanopore sequencing for studying alternative splicing of cytochrome P450 transcripts in HepG2 cells. Both quantitative and qualitative profiles of the cytochrome P450 gene expression at the transcript level notably differ in human liver tissue and HepG2 cells.