Zeitschrift für klinische und zelluläre Immunologie
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Abstrakt

Indoleamine 2,3-Dioxygenase as A Prognostic Factor in Patients with Non-Small Cell Lung Cancer

Takeshi Hanagiri, Misako Fukumoto, Yukiko Koyanagi, Yukari Furutani and Fumihiro Tanaka

Background: Indoleamine 2,3-dioxygenase (IDO) is an immunomodulatory enzyme produced by tumor cells and some alternatively activated macrophages and other immunoregulatory cells. The purpose of the present study was to evaluate the prognostic value of the relative expression of the forkhead/winged helix transcription factor 3 (Foxp3) and IDO in non-small cell lung cancer (NSCLC) tissues.
Methods: The NSCLC tissues from 141 patients who underwent complete surgical resection were collected at the time of surgery. The relative expression levels of Foxp3 and IDO in the tissues were determined by quantitative RT–PCR.
Results: The histological types of cancer seen in these patients included 105 adenocarcinomas, 24 squamous cell carcinomas and 12 other types of carcinoma. The average expression levels of Foxp3 and IDO relative to that of ß-actin in the NSCLC tissue were 0.052 ± 0.147% and 0.088 ± 0.157%, respectively. The relative expression of Foxp3 tended to increase with the relative expression of IDO (R=0.451, P=0.001). The five-year survival rates of the patients according to the relative expression of Foxp3 were 78.3% and 71.9% in the lower and higher groups, respectively. According to the relative expression of IDO, the five-year survival rate was 83.2% in the lower expression group, and 67.9% in the higher expression group. There was a significant difference between the lower and higher IDO expression groups (p=0.0389).
Conclusions: The expression of IDO tended to have a positive correlation with the expression of Foxp3. The higher expression of IDO was therefore a significantly unfavorable prognostic factor in patients with NSCLC.