Immunohistochemical Expression of Adult Stem Markers in Salivary Mucoepidermoid Carcinoma with Relevance to Molecular Profiling: Any Prognostic Implications and Oncogenic Mechanisms Eked?

Background/objective: Salivary Mucoepidermoid Carcinoma (MEC) is a heterogeneous malignancy, whose molecular characteristics extend beyond CRTC1/3:MAML2 fusion. This study describes the immunohistochemical expression of CD133, CD44, OCT4, and Mammalian ENA (MENA) in Salivary MEC and their potential relevance to molecular profiling. Methods: This study tested forty cases of MAML2-rearranged MEC using Immunohistochemistry (IHC) for the expression of CD133, CD44, OCT4, and MENA. Specific antibodies for each marker were utilized (CD133, CD44, OCT4, and MENA). The POU5F1 FISH probe from Empire Genomics (USA) was also employed to detect any alteration corresponding to OCT4. The selection of these adult stem markers as targets in our study is based on their established associations with cancer stem cells and the possible roles in tumorigenesis, metastasis, and treatment resistance in some carcinomas and adenocarcinomas. Results: The investigation demonstrated a negative expression pattern for CD133, CD44, and OCT4 immunostains in all cases, questioning the involvement in the pathogenesis of salivary MEC. In contrast, MENA showed a diffuse positive expression in all cases. Furthermore, the POU5F1 FISH probe revealed no alterations in the forty samples analyzed. Conclusion: These findings suggested the noninvolvement of cancer stem cells in the pathogenesis of salivary MEC. The overexpression of MENA suggests its co-expression that may extend beyond stemness or pluripotency. [ABSTRACT FROM AUTHOR]