Fig. 2
TDO2 modulated Trp/Kyn metabolism to regulate tumor progression. A 105 SMC-7721/HepG2 (VEC) and TDO2 overexpression SMC-7721/HepG2 (OE) cells were cultured in 2 ml culture medium on day 0. After 48 h of culture, the Kyn concentration in the supernatant was determined using Elisa analysis. B Immunohistochemical staining of Kyn in high stage (H-S) and low stage (L-S) tumor tissues from liver cancer patients. The scale bar is 100 μm. C Cell proliferation of SMC-7721/HepG2 treated with PBS or Kyn (10 µM). D The colony formation rates of SMC-7721/HepG2 treated with PBS or Kyn (10 µM). E The tumor volume of SMC-7721 pre-treated with PBS or Kyn (10 µM, 72 h). F The tumorigenic capability of SMC-7721 pre-treated with PBS or Kyn (10 µM, 72 h). *p < 0.05, **p < 0.01, n.s, no significant difference