Análise comparativa da imunoexpressão de OCT4 e CD44 em carcinoma epidermoide de lábio inferior e queilite actínica

Abstract

The carcinogenesis process is characterized by the transformation of a normal cell into a malignant cell, due to cumulative genetic alterations, influenced by the genetic predisposition of the patient, as well as by environmental factors. In the lower lip, exposure to UV radiation is the main etiological factor associated with the development of epidermoid carcinomas and actinic cheilitis. By the hierarchical model theory in carcinogenesis, the development, growth and metastasis of cancer are driven by a small population of tumor stem cells, with multipower ability and self-renewal. The aim of this study was to compare the expression of OCT4 and CD44 in 40 cases of lower lip epidermoid carcinoma (LLEC) and 40 cases of actinic cheilitis (AC), being analyzed the clinicopathological features and immunoexpression of these proteins. This markers can be used to provide information about diagnosis, progression and prognosis in these lesions. OCT4 and CD44 expression was assessed semiquantitatively by percentage of positive epithelial cells (PP) and intensity of expression (IE), resulting in total immunolabeling score (PIT) ranging from 0 to 7. OCT4 immunoexpression was shown to be both nuclear and cytoplasmic for most cases of AC and LLEC, while for CD44 it was membranous. No statistically significant differences were found between OCT4 and CD44 immunoexpression and clinicopathological parameters, except for lymph node metastasis in which there was a decrease in OCT4 expression in the core tumor of cases with lymph node metastasis. There was a negative and statistically significant correlation between the immunoexpression of these markers in the core tumor. Also, decreased CD44 expression was observed in LLEC cases when compared to AC cases. The results of this study suggest a higher participation of these proteins in early stages of carcinogenesis. In addition, the imbalance of OCT4 and CD44 immunoexpression in the tumor core suggests the presence of different subpopulations of neoplastic cells with distinct pluripotency phenotype, associated with different degrees of cell differentiation.