The association between CD4+ CD25+ regulatory T cells and non-small cell lung carcinoma

Abstract

Lung cancer is the second most common malignancy in the USA, and it is the leading cause of cancer-related deaths among men and women. Regulatory T cells (Tregs) in peripheral blood play crucial roles in suppressing antitumor immune responses in cancer patients. A defect in the immune response may contribute to tumor growth. This study was conducted to test the hypothesis that regulatory T cell lymphocytes might contribute to immune dysfunction in non-small cell lung carcinoma (NSCLC) patients, with a specific aim of determining its role in the development and progression of NSCLC. CD4+ CD25+ Treg cell enumeration by flow cytometry was performed for 30 NSCLC patients both preoperatively and postoperatively, together with 20 controls. Higher percentages of CD4+ CD25+ Treg cells were found in NSCLC patients both pre- (11.24 ± 5.34) and postoperatively (8.75 ± 4.66) in comparison to the control group (2.16 ± 0.97); this difference was statistically significant (p < 0.001). From this study we concluded that the CD4+ CD25+ Treg population increased significantly and correlated with clinical staging in NSCLC patients: healthy donor < stage I < stage II < stage III whether preoperatively (r = 0.5, p = 0.005) or postoperatively (r = 0.4, p = 0.008). Treg cells decreased significantly after surgical removal of the tumors, from 11.24 ± 5.34 to 8.75 ± 4.66; the difference was statistically significant (p < 0.001). From this study we concluded that CD4+ CD25+ Treg lymphocytes increased in NSCLC patients; their percentage correlates with tumor staging, and it decreases following surgical removal of the tumor. Thus, manipulation of these regulatory T cells could lead to new strategies for the treatment of cancer.