Relationship between the expressions of indoleamine 2, 3-dioxygenase in hepatocellular carcinoma and clinicopathological parameters

Objective: To explore the expressions of indoleamine 2, 3-dioxygenase (IDO) in hepatocellular carcinoma and analyze its relationship with clinicopathological parameters.

Methods: Quantitative real-time polymerase chain reaction (PCR), fluorogenic quantitative PCR, immunohistochemical and immunofluorescence were used to detect the expression of indoleamine 2, 3-dioxygenase in hepatocellular carcinoma.

Results: The IDO mRNA expression in cancerous tissues increased markedly than that in the corresponding non-cancerous tissues (2(-ΔΔCT) = 1.71, P = 0.001) . The immunohistochemical and immunofluorescence results showed that IDO protein was expressed in cytoplasm of hepatocellular carcinoma and tumor-surrounding tissues. But there was no expression in normal liver tissues from benign hepatic lesions and corresponding non-cancerous tissues. An over-expression of IDO protein was detected in 43 patients (48.3%) , a low expression in 25 (28.1%) and no expression in 21 (23.6%). Relationship between IDO expression and clinicopathological parameters: an over-expression of IDO in HCC was associated with recurrence, survival time, metastasis and TNM stage (P < 0.05), but not associated with patient's cirrhosis, AFP level, histological differentiation type, Barcelona clinic liver cancer stage, gender, age, HbsAg positivity, number of tumors and tumor size (P > 0.05).

Conclusions: An over-expression of IDO in HCC patients may affect patient prognosis.