Fig. 1.

Expression of IDO1 and IDO2 in human primary tumors and tumor cell lines. a Micro-dissected human gastric-, colon-, and renal cell carcinomas were analyzed for IDO1 and IDO2 expression by RT-PCR. Water instead of cDNA was used as negative (NC), IFN-γ-treated DCs [5] as positive control (PC). PCR products (β-Actin: 407 bp, IDO1: 321 bp, IDO2: 371 bp) were separated on agarose gel. b Human pancreas- (Capan-1), colon- (HCT116), cervix- (Hela), hepatocellular- (HepG2), and renal carcinoma (RCC68) cell lines either treated with IFN-γ or untreated were analyzed as described earlier. c Hela cells were treated either with transfection reagent instead of siRNA (Mock), 100 nM control siRNA (CTR siRNA), or siRNA specific for IDO1 (IDO1 siRNA) and stimulated with IFN-γ. IDO1 and IDO2 transcription was detected as described earlier. d The relative expression level of IDO1 after siRNA treatment was analyzed in Hela cells by qRT-PCR. IDO1 expression levels of transfected cells were correlated with those of untransfected cells (mean value ± SD)