Migração de células T regulatórias em carcinoma de células escamosas de cavidade bucal e de lábio: fatores de prognóstico clínico e microscópico

Abstract

T Regulatory (Treg) cells represent a T CD4+ lymphocytes subpopulation that displays important roles in the regulation and suppression of immune responses. We investigated the expression of Treg cell markers CD4, CD25, CTLA-4 and FoxP3 by immunohistochemistry in samples of oral cavity squamous cell carcinoma (OCSCC) and lip squamous cell carcinoma (LSCC). The relationship of Treg markers with survival data was also evaluated. We observed a higher percentual of CD4 (P=0.019) and FoxP3 (P=0.040) positive cells in OCSCC samples when compared with LSCC. OCSCC showed lower percentual of CTLA-4+ cells than LSCC (P0.0001). Moreover, CD4/FoxP3, CD4/CD25 and CD4/CTLA-4 ratio was significantly greater in OCSCC, indicating higher numbers of Treg cell phenotype in OCSCC. A log-rank test showed that patients with high counts of CD4; CD4/FoxP3, CD4/CD25 and CD4/CTLA-4 showed a decrease of survival in relation to patients with low cell counts (P0.05). In line with this findings, samples with high numbers of CD4 (P=0.015) and FoxP3 (P=0.018) exhibited greater proliferative index. Our findings suggest an association of Treg cells phenotype with poor prognosis; this might result from suppression of anti-tumor immune responses by Treg cells in OSCC.