Análise imunoistoquímica das subpopulações M1 e M2 de macrófagos associados a tumores (MATs) em carcinomas de células escamosas de língua

Abstract

Oral squamous cell carcinoma (OSCC) is more than 90% of malignant tumors of the oral mucosa, with infiltrative feature, aggressive clinical course and poor prognosis. A factor that can interfere in the OSCC prediction consists of the components of the tumor microenvironment. Tumor associated macrophages (TAMs) represent a portion of this cell population and are divided according to their state of polarization: M1 subtype that exerts anti-tumor properties and the M2 subtype that has anti-inflammatory activity. The list of TAMs with OSCC in young patients still unknown. The present study analyzed, through immunohistochemistry, the presence of subpopulations M1 and M2 of TAMs in a number of cases of squamous cell carcinoma of tongue (SCCT). Histological sections obtained from 44 cases of SCCT divided into two groups (11 cases of young patients ≤ 45, and 33 cases of elderly patients ≥ 60 years) were evaluated, thus being certain histopathological grades of malignancy. The material was subjected to double staining technique for the anti-CD68 monoclonal antibody, anti-CD163 and anti-HLA-DR, obtaining the distinction between TAMs M1 (CD68 / HLA-DR) and M2 (CD68 / CD163). Cases of SCCT analyzed in this study, compared to age 11 (25.0%) patients were young while 33 (75.0%) were elderly. For histopathological grading of malignancy proposed by WHO, the assessment of TAMs M1 showed medians of 12.3 in well-differentiated tumors; 5.8 in the moderately differentiated tumors and 5.8 in poorly differentiated lesions. For TAMs M2, lesions classified as well differentiated revealed a median of 10.7; moderately differentiated lesions exhibited a median of 2.7 and poorly differentiated tumors showed a median of 6.85. Regarding the histological grade of malignancy proposed by Bryne, the evaluation of TAMs M1 showed medians of 11.3 in tumors classified as low-grade and 5.55 in the highly malignant tumors. For TAMs M2, low-grade malignant lesions revealed a median of 8.7 and high-grade lesions exhibited a median of 4.00. This study suggests that the tumor microenvironment has a direct participation in the progression of the disease.