Correlation of miR-494 expression with tumor progression and patient survival in pancreatic cancer.

MicroRNA-494 (miR-494) expression is aberrant in various types of human cancer. However, the prognostic value of miR-494 in pancreatic cancer remains unclear. The level of miR-494 expression was determined in 99 pairs of primary pancreatic cancer and their corresponding, adjacent non-tumor tissues by using quantitative reverse transcriptase polymerase chain reaction. We also analyzed the associations between miR-494 expression and clinicopathological features. The survival correlations were analyzed by using the Kaplan-Meier method and Cox proportional hazards model. The level of miR-494 expression was significantly downregulated in pancreatic cancer tissues (mean relative expression level ± SD, 0.48 ± 0.11) as compared to matched adjacent normal tissues (1.80 ± 0.28, P < 0.05). We found significant correlations between the miR-494 expression levels and TNM stage (P = 0.009), lymphatic invasion (P = 0.036), vascular invasion (P = 0.011), distant metastasis (P = 0.007), and tumor grade (P = 0.031). Pancreatic cancer patients with a low miR-494 expression level had a shorter overall survival than those with a high miR-494 expression level (P < 0.05). Reduced miR-494 expression in pancreatic cancer tissues is correlated with tumor progression and might be an independent, poor prognostic factor for patients with pancreatic cancer.