The role of OCT4 and CD44 in lower lip carcinogenesis.

Purpose: Carcinogenesis is characterized by the transformation of normal cells into malignant cells. Concerning the lower lip, exposure to UV radiation is the main etiological factor associated with the development of epidermoid carcinomas and actinic cheilitis. According to the hierarchical model theory, cancer development is driven by populations of cancer stem cells. In this context, this study aimed to compare the expression of octamer-binding transcription factor 4 (OCT4) and CD44 in 40 lower lip epidermoid carcinoma (LLEC) and 40 actinic cheilitis (AC) cases.

Methods: OCT4 and CD44 expressions were assessed semi-quantitatively according to the percentage of positive epithelial cells (PP) and intensity of expression (IE), resulting in a total immunolabeling score (PIT).

Results: No statistically significant differences were detected between OCT4 and CD44 immunoexpression and clinicopathological parameters, except for lymph node metastasis, in which a decrease in CD44 expression in the core tumor of cases with lymph node metastasis was observed. Furthermore, decreased CD44 expression was observed in LLEC cases when compared to AC cases.

Conclusions: The findings reported herein suggest a higher participation of CD44 in early carcinogenesis stages. In addition, the imbalance between OCT4 and CD44 immunoexpressions suggests the presence of different neoplastic cell subpopulations.