MicroRNA hsa-miR-370-3p suppresses the expression and induction of CYP2D6 by facilitating mRNA degradation

Abstract

Cytochrome P450 2D6 (CYP2D6) participates in the metabolism of approximately 20–25% of prescribed drugs. Genetic polymorphisms influence the expression and/or activity of CYP2D6, and inter-individual differences in drug activation and elimination caused by CYP2D6 genetic variants were reported. However, little is known about the potential modulation of CYP2D6 expression by microRNAs (miRNAs). In the current study, by using in silico prediction of the stabilities of miRNA/mRNA complexes, we screened 38 miRNA candidates that may interact with the transcript of CYP2D6. An inverse correlation between the expression of miRNA hsa-miR-370-3p and the expression of CYP2D6 was observed in human liver tissue samples. Electrophoretic mobility shift assays confirmed that hsa-miR-370-3p was able to directly bind to its cognate target within the coding region of the CYP2D6 transcript. The transfection of hsa-miR-370-3p mimics into the HepG2CYP2D6 cell line, a genetically modified cell line that overexpresses exogenous CYP2D6, was able to suppress the expression of CYP2D6 significantly at both mRNA and protein levels. The transfection of hsa-miR-370-3p mimics was also able to inhibit endogenous mRNA expression and/or protein production of CYP2D6 in HepaRG cells. Furthermore, in HepaRG, HepG2, and Huh7 cells, dexamethasone-induced expression of CYP2D6 was inhibited by hsa-miR-370-3p mimics. To investigate whether the miRNA mediated suppression is caused by inhibiting protein translation or promoting mRNA degradation, an actinomycin D assay was used to measure the stability of CYP2D6 transcripts. The results indicated that hsa-miR-370-3p mimics facilitated significantly the degradation of CYP2D6 mRNA. In addition, proteomics analyses of proteins isolated from the miRNA/mRNA/protein complex suggested that a group of multifunctional proteins facilitated the interaction between hsa-miR-370-3p and CYP2D6, thereby promoting mRNA degradation.

A functional SNP in the 3′‐UTR of TAP2 gene interacts with microRNA hsa‐miR‐1270 to suppress the gene expression

“…Due to large interindividual variability in the expression of both TAP2 and miR‐1270, and the small human samples available for use in this study, the correlation between the expression of the T allele at TAP2 (rs241456) and miR‐1270 is not strong, but does indicate a trend of negativity. It is a common phenomenon that the correlations between miRNAs and their cognate mRNAs in human samples are possibly confounded due to the complexity of gene regulation and the diversity of genetic and environmental background among human populations(Yu et al, ; Jin et al, ; Chen et al, ; Wang et al, ; Zeng et al, ).…”

“…Our previous studies demonstrated that miRNAs can modulate the expression of genes encoding drug metabolizing enzymes and transporters (Yu et al, ; Jin et al, ; Chen et al, ; Wang et al, ; Zeng et al, ). In this study, we hypothesized that a SNP in the 3′‐UTR of TAP2 interferes with miRNA binding, thus inhibiting the expression of the gene.…”

Multiple microRNAs function as self-protective modules in acetaminophen-induced hepatotoxicity in humans

“…Recent studies have shown that miRNAs influence the expression of drug metabolizing enzymes (DMEs) (Jin et al 2016; Mohri et al 2010; Tsuchiya et al 2006; Wang et al 2017; Yu et al 2010, 2015a, b, c; Zeng et al 2017), which may thereby influence drug efficacy and safety (Koturbash et al 2015). miRNAs have been linked to liver injury and represent candidate biomarkers of liver injury because they are sufficiently stable in a wide range of biofluids, including serum (Baraniskin et al 2012; Chen et al 2008).…”

Determinants of Cytochrome P450 2D6 mRNA Levels in Healthy Human Liver Tissue

“…Limitations of this study include (i) the lack of correction for multiple comparisons in the exploratory steps (for heuristic purposes to examine the potential predictors of CYP2D6 mRNA levels, before stepwise regression analysis), (ii) a relatively small sample size, and (iii) the focus on transcriptional regulators of CYP2D6 in investigating the determinants of CYP2D6 mRNA levels. Factors involved in post transcriptional regulation of CYP2D6 were not examined in this study, although microRNA hsa‐miR‐370‐3p was recently shown to bind to a coding region of CYP2D6 transcript and regulate CYP2D6 expression in liver cells . Due to the small sample size, the contribution of CYP2D6 SNPs of low allele frequency (accounting for ~ 70% of CYP2D6 SNPs identified in this study) to variable CYP2D6 mRNA levels was not examined in our liver tissue cohort.…”