Analysis of the prognostic role of regulatory T-lymphocyte-associated marker expression in resectable NSCLC.

10643 Background: Regulatory T-lymphocytes (Tregs) play a critical role in immune tolerance to tumor cells. Several molecules, including CD4, CD25, CD127, CTLA-4, IL-10 and TGFβ1 have been reported markers of Tregs. Another highly specific marker for Tregs is FoxP3, a transcription factor which appears to be a master control gene for their development and function. The aim of this study was to determine the expression of Treg-associated markers by RT-PCR and to correlate them with clinicopathological and prognostic variables in NSCLC. Methods: RNA was obtained from frozen lung specimens (tumor and normal lung) from resectable NSCLC patients (n = 135). RT-PCR was performed to analyze the expression of: CD4, CTLA-4, FoxP3, IL10, CD25, CD127 and TGFβ1. Relative expression was normalized by an endogenous gene (GUS) using the Pfaffl formulae. Statistical analyses were considered significant at p < 0.05. Results: Compared to normal lung tissue, tumor samples had significantly higher expression of CD25 (x2.1) an...