Foxp3 expressed by tongue squamous cell carcinoma cells correlates with clinicopathologic features and overall survival in tongue squamous cell carcinoma patients.

The forkhead transcription factor, Foxp3, has been identified as a key player in CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) function and a definitive marker of Tregs. Recently, it was reported that Foxp3 could be expressed by tumor cells themselves. The present study was to investigate the expression of Foxp3 in tongue squamous cells carcinoma (TSCC) cells and its clinical significance. In this study, the expression of Foxp3 by TSCC cells was demonstrated in TSCC tissue samples and three TSCC cell lines using immunohistochemical staining, realtime-PCR and Western blotting, and its clinical significance were statistically analyzed. The immunohistochemical assay in TSCC paraffin-embedded samples showed positive staining in 48 of 81 (59.3%) cases. The expression was significantly associated with pathologic differentiation (P=0.040) and T stage (P=0.000), and furthermore, inversely associate with patient survival (P=0.021). Multivariate analysis (Cox regression) suggested that Foxp3 expression in TSCC cells was an independent prognostic indicator for TSCC (P=0.032).