ABSTRACT
ObjectiveTo investigate whether neuronal intermediate filament protein(NF-66) could be used as a molecular marker for the determination of malignancy of insulinoma.MethodsThe expression of NF-66 protein was detected in insulinoma and pana - cancerous tissues and 3 insulinoma cell lines by immunohistochemistry staining. The relationship between the expression of NF-66 protein and the clinicopathological characteristics,survival was analyzed by univariate and multivariate statistical analysis.ResultsExpression of NF-66 was found in 102(77％ ) out of 132 insulinomas and none of 98 paired control (P =4.86 × 10-31 ).NF-66 was highly expressed in 3 insulinoma cell lines.The expression of NF-66 was found in 96 (81％) out of 118 benign tumors (P =0.003),while out of 14 malignant insulinomas,6(43％ ) were found to express NF-66 ( P =0.003 ).The expression of NF-66 was significantly associated with tumor size (3 cm as the cut-off point),distant metastasis (38％ vs 81％,P =0.013) and distant plus lymph node metastasis (46％ vs 81％,P =0.009),respectively.The expression of NF-66 was not correlated with age,gender,recurrence and overall survival.ConclusionsDown-regulation of NF-66 was significantly associated with tumor malignancy,suggesting that NF-66 could be a potentially novel molecular bionarker to distinguish malignancy from benign insulinoma.