Overexpression of AKR1B10 in nasopharyngeal carcinoma as a potential biomarker

BACKGROUND: Nasopharyngeal carcinoma (NPC) is one of the most common cancers in Southern China. Aldo-keto reductase 1B10 (AKR1B10) is upregulated in multiple tumors and plays an oncogenic role. OBJECTIVE: To examine the expression of AKR1B10 at mRNA and protein levels in nasopharyngeal tumors and correlate its expression with clinicopathological parameters. METHODS: A tissue microarray, paraffin blocks, and frozen surgical nasopharyngeal samples were procured. Western blot and immunohistochemistry were used to estimate AKR1B10 protein expression, and mRNA levels were detected by real time RT-PCR. RESULTS: We found that AKR1B10 expression was increased in malignant tissues compared to the normal tissues (p = 0.000). In NPC tissues, AKR1B10 expression appeared high specifically in squamous cell carcinoma, but low in basal cell carcinoma, adenoid cystic carcinoma, adenocarcinoma and undifferentiated carcinoma (p = 0.000). AKR1B10 expression also demonstrated correlation with tumor differentiation, with a high level in well and moderately differentiated but a low level in poorly differentiated carcinoma (p = 0.000). AKR1B10 was also upregulated in hyperplasia and benign tumors (p = 0.000), and demonstrated a specific nuclear distribution in these non-cancerous diseases. CONCLUSIONS: AKR1B10 is overexpressed in nasopharyngeal hyperplasia, benign tumors, and carcinomas, being a potential new biomarker.