MicroRNA-22 expression in hepatocellular carcinoma and its correlation with ezrin protein

Objective: Expression of microRNA-22 (miR-22) and ezrin protein (a membrane-cytoskeleton linking protein) in hepatocellular carcinoma (HCC) was investigated. Methods: Specimens of HCC and paracancerous tissue (control; approximate to 5cm away from tumour tissue) were collected from 192 patients. miR-22 expression was detected by real-time polymerase chain reaction; ezrin protein expression in tumour tissue was assessed immunohistochemically. Associations between miR-22 expression and clinicopathological features of HCC and ezrin expression were analysed. Results: miR-22 expression was lower in HCC tissue than in paracancerous tissue samples (median relative expression 0.676 versus 1.000 for control tissue). Expression of miR-22 was significantly associated with histological differentiation (relative expression 0.431 for lower grades of differentiation versus 0.918 for higher grades), and was associated with lymphatic metastasis (relative expression 0.518 if metastasis was present, 0.919 if absent). Survival time was shorter in patients with low miR-22 expression than in those with high expression (31.0 +/- 2.6 versus 52.2 +/- 5.1 months). There was a significant negative correlation between the expression of miR-22 and that of ezrin. Conclusions: miR-22 is downregulated in HCC and its expression is associated with the differentiation, metastasis and prognosis of the carcinoma. Ezrin is a potential regulatory protein of miR-22.