Table 2.
Tryptophan (TRP), kynurenine (KYN), 5-hydroxy-tryptophan (5-HTP), serotonin (5-HT) plasma levels and tumor tissue expression of enzymes involved in TRP metabolism.
| Plasma metabolite levels | |||||
|---|---|---|---|---|---|
| TRG 1–2 (n = 17) | TRG 3–5 (n = 28) | p-value | |||
| Median | Q1, Q3 | Median | Q1, Q3 | ||
| TRP μg/mL | 8.43 | 7.06, 10.71 | 10.24 | 8.37, 11.93 | <0.05 |
| KYN μg/mL | 0.31 | 0.24, 0.46 | 0.41 | 0.30, 0.53 | |
| 5HTP μg/mL | 0.06 | 0.05, 0.07 | 0.05 | 0.04, 0.06 | |
| 5HT μg/mL | 0.01 | 0.005,0.01 | 0.01 | 0.001, 0.02 | |
| Gene expression of involved enzymes | |||||
| TRG 1–2 (n = 25) | TRG 3–5 (n = 27) | p-value | |||
| Median | Q1, Q3 | Median | Q1, Q3 | ||
| IDO1 (RQ) | 66.87 | 23.08, 138.6 | 57.46 | 25.73, 98.07 | |
| TDO2 (RQ) | 67.21 | 40.12, 148.7 | 185.8 | 57.74, 250.0 | <0.05 |
| TPH1 (RQ) | 1.68 | 0.66, 6.44 | 2.97 | 0.82, 12.0 | |
RQ, relative quantitation.