Elucidating the immunohistochemistry of Nanog: A transcription marker in the oral squamous cell carcinoma with emphasis on its origin as embryonic stem cell

BACKGROUND: Nanog is a key transcription factor regulating pluripotency in mammalian early embryos and pluripotent stem cells. Nanog plays a central role in pluripotency and forms autoregulatory loops to maintain ESC (embryonic stem cell) identity. Oral squamous cell carcinoma (OSCC) is an extensively studied malignancy that occurs due to accumulated genetic and epigenetic changes. Hence, the current study was done to evaluate role of Nanog in OSCC. OBJECTIVE: The present study was done to evaluate Nanog role in OSCC. MATERIALS AND METHODS: Thirty normal subjects and 30 patients of oral squamous cell carcinoma (OSCC) were included in study. The cases were staged clinically based on tumour node metastasis (TNM) staging and graded histopathologically using modified Broder's grading system. Thirty tissue sections of OSCC were subjected to immunohistochemistry (IHC) with Nanog antibody. Random fields were chosen and 300 cells were counted in five areas and mean percentage of immunopositive cells were calculated. The results were analysed using ANOVA test. RESULTS: The results demonstrated a statistically significant difference between normal subjects and in patients with OSCC with respect to mean of IHC score (P = 0.0001*). High mean values for Nanog in tissue with OSCC in both histopathological (P = 0.0001*) and clinical grading (P = 0.0276*) with statistically significant result were observed. CONCLUSION: The increased expression of Nanog in patients with OSCC was statistically significant, suggesting its role as diagnostic biomarker. Statistically significant result with respect to clinical staging and histopathological grading of Nanog expression in patients with OSCC suggests its role as prognostic biomarker also.