Background: Sharing the role of immune suppression, interleukin-10 (IL-10), transforming growth factor beta (TGF-beta), and vascular endothelial growth factor (VEGF) are critical genes in several aspects of tumorigenesis. To elucidate the role of these cytokines in esophageal squamous cell carcinoma (ESCC), their relative mRNA expression in tumoral tissue compared with corresponding tumor-free tissue was evaluated.
Methods: A total of 49 patients with histologically confirmed ESCC were included in the study prior to any therapeutic interventions. Quantitative analysis of the mRNA expression was performed by real-time reverse transcription-polymerase chain reaction and the clinicopathologic associations were assessed.
Results: The mRNA of IL-10, VEGF, and TGF-beta was frequently overexpressed in 53.2%, 44.9%, and 37.5% of ESCC patients, respectively. TGF-beta was significantly co-expressed with IL-10 and with VEGF. Although VEGF was not independently associated with increased tumor size (p = 0.065), concomitant overexpression of VEGF with TGF-beta was significantly correlated with increased size of the tumor (p < 0.05).
Conclusions: Overexpression of IL-10, TGF-beta, and VEGF plays an important role in ESCC and consequently leads to the frequent event of immune evasion in ESCC. TGF-beta is concomitantly overexpressed with IL-10 and with VEGF in ESCC. A stimulatory signal from TGF-beta to VEGF is necessary for VEGF to promote tumor progression.