IBD susceptibility loci associated with interacting IBD susceptibility candidate genes in the protein-protein network analysis comprising HEK293 cells.

IBD susceptibility loci associated with interacting IBD susceptibility candidate genes in the protein-protein network analysis comprising HEK293 cells.</p

Protein-protein network analysis; STRING database.

<p>Interactions between candidate IBD susceptibility genes and genes identified as correlated with meTIMP, 6-TGN and/or the meTIMP/6-TGN concentration ratio (marked with an orange star).</p

Scatterplots of genes selected for a proven or potential relationship to thiopurines (RT qPCR data).

<p>Scatterplots illustrating the co-variation between the relative gene expression levels of the genes with the most significant correlation coefficients with the concentration of A) 6-TGN, B) meTIMP or C) the meTIMP/6-TGN concentration ratio.</p

Gene expression in HepG2 cells not transfected to express XO after combined treatment with 6MP+AP.

<p>Genes differently expressed when comparing incubation with 6MP (6 μM) +AP (100 μM) with 6MP alone (6 μM) in HepG2 cells not transfected to express XO. Cells were incubated with drugs for 73 h before isolation of RNA and analysis. Values are presented as mean of three experiments ± SD. Differences were compared with the two-sided t-test and <i>P</i>-values were corrected for multiple testing. 6MP 6-mercaptopurine, AP allopurinol, XO xanthine oxidase, RQ relative gene expression, A; <i>P</i> = 0.06, B; <i>P</i> = 0.05, C; <i>P</i> = 0.05, D; <i>P</i> = 0.05, <i>* P <</i> 0.05, <i>** P <</i> 0.01.</p

IBD susceptibility loci associated with interacting IBD susceptibility candidate genes in the protein-protein network analysis comprising HepG2 cells.

<p>IBD susceptibility loci associated with interacting IBD susceptibility candidate genes in the protein-protein network analysis comprising HepG2 cells.</p

Concentration of thiopurine metabolites in (A) HepG2 cells not transfected to express XO and in (B) HepG2 cells transfected to express XO.

<p>Concentration of thiopurine metabolites in HepG2 cells incubated with 6MP (6 μM) or the combination 6MP (6 μM) + AP (100 μM) for 73 h. Metabolites were measured by HPLC. Values are mean ± SD of three experiments. No differences in absolute metabolite concentrations were observed between the two conditions when compared with the two-sided t-test and <i>P</i>-values were corrected for multiple testing. 6MP 6-mercaptopurine, AP allopurinol, 6TGN thioguanine nucleotides, meTIN methylated thioinosine nucleotides, TIMP thioinosine monophosphate, 6TX thioxanthine, 6TXMP thioxanthosine monophosphate.</p

Relative gene expression levels (RT qPCR data) of purine/thiopurine related genes <i>vs.</i> metabolite profiles.^a

a<p>Reverse transcription qPCR data, in the expanded patient cohort (n = 54), of genes showing significant results either in a Spearman rank order correlation analysis or in a Mann-Whitney U-test. Significant group differences are indicated in bold. Abbreviations: R20; meTIMP/6-TGN concentration ratio >20, Median; median metabolizer, R4; meTIMP/6-TGN concentration ratio ≤5.7.</p

A multiple linear regression model for the meTIMP/6-TGN concentration ratio.^a

a<p>The regression model is based on the expanded patient cohort (n = 54), using the natural logarithm of the meTIMP/6-TGN concentration ratio as dependent variable and the gene expression levels (dC_T values) of <i>CD1D</i>, <i>PLCB2</i>, <i>NT5E</i>, <i>TPMT</i>, <i>TUSC2</i>, and glucocorticosteroid therapy as independent variables. A higher dC_T value is associated with a lower gene expression level. <i>R²</i> = 0.46, <i>P</i> = 3×10⁻⁵.</p

Scatterplots of genes identified by means of microarray screening (RT qPCR data).

<p>Scatterplots illustrating the co-variation between the relative gene expression levels of the genes with the most significant correlation coefficients with the concentration of A) 6-TGN, B) meTIMP or C) the meTIMP/6-TGN concentration ratio.</p

Gene expression in HEK293 cells after combined treatment with 6MP+AP.

<p>Genes differently expressed when comparing incubation with 6MP (3 μM) +AP (100 μM) with 6MP alone (3 μM) in HEK293 cells. Cells were incubated with drugs for 73 h before isolation of RNA and analysis. Values are presented as mean of three experiments ± SD. Differences were compared with the two-sided t-test and <i>P</i>-values were corrected for multiple testing. 6MP 6-mercaptopurine, AP allopurinol, RQ relative gene expression, A; <i>P</i> = 0.05, <i>* P <</i> 0.05, <i>** P <</i> 0.01.</p