Relative mRNA expression of KP enzymes in HFA and AA versus glioma using qRT-PCR and analysis of the KYNA/KYN ratio and KYNA, PIC, QUIN, KYN and TRP concentrations in the cell culture supernatants of glioma, HFA and AA cells.

<p>(<b>A</b>) The dot plots indicate the relative mRNA expression normalised to HPRT mRNA expression; All cell cultures were untreated (C) and treated with IFN-γ (IFN) for 24 hours; Graphs indicate Log10 of the quantified values. No statistical significance was observed for 3-HAAO expression; QPRT expression in unstimulated glioma (n = 10) compared to unstimulated HFA cells (^µp = 0.0024); QPRT expression in stimulated glioma cells (n = 7) compared to stimulated HFA cells (^αp = 0.0015). ACMSD expression in stimulated glioma cells (n = 5) compared to unstimulated (^αp<0.05); ACMSD expression in unstimulated glioma cells (n = 9) compared to unstimulated HFA cells (^βp = 0.0029); ACMSD expression in unstimulated glioma cells compared to unstimulated AA (^µp<0.05). (<b>B</b>) Glioma cell cultures for the KYNA/KYN ratio and KYNA concentrations were untreated (n = 7) and treated with IFN-γ (n = 6) for 48 hours and untreated (n = 6) and treated with IFN-γ for 72 hours (n = 6); HFA cell cultures for the analysis of the KYNA/KYN ratio and KYNA concentrations were untreated (n = 8) and treated with IFN-γ (n = 8) for 48 hours and untreated (n = 5) and treated with IFN-γ for 72 hours (n = 5); All AA cell cultures were untreated (n = 3) and treated with IFN-γ (n = 3) for 48 hours; Bar graphs for the KYNA/KYN ratio and KYNA concentrations indicate Log10 of the quantified values; The KYNA/KYN ratio in glioma, HFA and AA cell cultures after 48 and 72 hours of IFN-γ stimulation compared to untreated cultures (^αβγµπp<0.001); KYNA concentrations in HFA cell cultures when treated with IFN-γ for 48 hours compared to when untreated after 48 hours (^αp<0.05); Glioma cell cultures for the analysis of QUIN and PIC concentrations were untreated (n = 7) and treated with IFN-γ (n = 6) for 48 hours and untreated (n = 5) and treated with IFN-γ for 72 hours (n = 5); HFA cell cultures for the analysis of QUIN and PIC concentrations were untreated (n = 10) and treated with IFN-γ (n = 9) for 48 hours and untreated (n = 5) and treated with IFN-γ for 72 hours (n = 5); No statistical significance was observed for QUIN and PIC; Glioma cell cultures for the analysis of KYN and TRP concentrations were untreated (n = 7) and treated with IFN-γ (n = 6) for 48 hours and untreated (n = 6) and treated with IFN-γ for 72 hours (n = 5); HFA cell cultures for the analysis of KYN and TRP concentrations were untreated (n = 9) and treated with IFN-γ (n = 9) for 48 hours and untreated (n = 5) and treated with IFN-γ for 72 hours (n = 5); KYN production in glioma cell cultures after 48 and 72 hours of IFN-γ stimulation compared to untreated cultures after 48 and 72 hours (^γβp<0.01); KYN production in HFA cell cultures after 48 hours of IFN-γ stimulation compared to untreated cultures after 48 hours (^αp<0.05); KYN production in AA after 48 hours of IFN-γ stimulation compared to the untreated cultures (^πp<0.05); TRP catabolism in AA cell culture supernatant after 48 hours of IFN-γ stimulation compared to untreated cultures after 48 hours (^πp<0.05); TRP catabolism in glioma cell culture supernatant after 48 and 72 hours of IFN-γ stimulation compared to untreated cultures after 48 hours (^γβp<0.05). No other statistical significance was observed.