Expression and prognosis role of indoleamine 2,3-dioxygenase in hepatocellular carcinoma.
OBJECTIVE
Immunoregulatory enzyme indoleamine 2,3-dioxygenase (IDO) plays an important role in immune tolerance. In some malignancies, the evidences were given to show that overexpression of IDO was related to poor prognosis of cancer patients.


METHODS
In this study, we investigated IDO expression in hepatocellular carcinoma (HCC) cell lines and 138 primary HCC clinical surgical specimens, and correlation of IDO expression with clinical outcomes and prognosis of HCC patients.


RESULTS
Reverse transcription-PCR analysis showed that in vitro IDO expression in HCC cell lines and non-cancerous liver cell line were dependent on IFN-gamma. Immunohistochemical detection revealed that IDO was overexpressed in 49 of 138 (35.5%) tumor resection samples, whereas 89 of 138 (64.5%) cases showed weak immunostaining. IDO overexpression was significantly correlated with high metastasis rates (P = 0.049). Kaplan-Meier survival curves showed that overexpression of IDO resulted in significantly poor prognosis (P = 0.017, log-rank test). Multivariate Cox's analysis showed that IDO expression was an independent prognostic factor for overall survival of HCC patients (P = 0.010).


CONCLUSIONS
Our data indicated that IDO may be a novel favorable prognostic indicator and candidate adjuvant therapeutic target for HCC.
Pan
Ke
K
State Key Laboratory of Oncology in Southern China and Department of Experimental Research, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, Yuexiu District, 510060, Guangzhou, Guangdong, People's Republic of China.
Wang
Hui
H
Chen
Min-shan
MS
Zhang
Hua-kun
HK
Weng
De-sheng
DS
Zhou
Jun
J
Huang
Wei
W
Li
Jian-jun
JJ
Song
Hai-feng
HF
Xia
Jian-chuan
JC
D014408:Biomarkers, Tumor / Q000235:genetics; D006528:Carcinoma, Hepatocellular / Q000201:enzymology / Q000235:genetics* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D045744:Cell Line, Tumor; D017931:DNA Primers; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000235:genetics*; D008113:Liver Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012334:RNA, Neoplasm / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016019:Survival Analysis; D016896:Treatment Outcome
D014408:Biomarkers, Tumor; D017931:DNA Primers; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D012334:RNA, Neoplasm