Nicotinamide N-Methyltransferase Expression in Cervical Adenocarcinoma and Its Clinical Significance

Introduction: Nicotinamide N-methyltransferase (NNMT) is a metabolic enzyme increasingly implicated in tumor progression and resistance to treatment. It is overexpressed in human cancers including glioblastoma, gastric, pancreatic, lung and colorectal cancers. The role of NNMT in cervical adenocarcinoma has not been studied thus far. We aimed to evaluate expression of NNMT in cervical adenocarcinoma and investigate its prognostic significance. Methods: NNMT expression was assayed in 18 cases of cervical adenocarcinoma and 19 cases of benign cervical tissue. NNMT immunoreactivity was scored by multiplying staining intensity with percentage of immunoreactive cells. Results: The expression of NNMT was significantly higher in cervical adenocarcinoma than in benign tissue (p = 0.024). NNMT expression was significantly higher in patients with locally advanced than early cervical cancer (p = 0.031). NNMT expression was higher in patients with tumor size greater than 4 cm and in those with poorly differentiated tumors compared to patients with tumors of 4 cm or less and well-moderate differentiation, respectively (p = 0.044, p = 0.014). Conclusion: Although on a preliminary level, this is the first study to detect an overexpression of NNMT in cervical adenocarcinoma and an increased expression associated with advanced stage, increased tumor size and poor differentiation. NNMT has been shown to carry prognostic and therapeutic importance in a variety of cancers, and it can be a potential treatment target in cervical adenocarcinomas.