Expression of microRNAs in patients with pancreatic cancer and its prognostic significance.

OBJECTIVES: Investigation of expression profile of well-established microRNAs in pancreatic adenocarcinoma, and its correlation with clinicopathological factors.

METHODS: Eighty-eight samples of ductal pancreatic adenocarcinoma and 98 control samples were analyzed by real-time polymerase chain reaction for miR-21, miR-31, miR-122, miR-145, miR-146a, miR-155, miR-210, and miR-222 expressions. The results were normalized and then statistically analyzed using nonparametric statistical tests.

RESULTS: According to our results, miR-21, miR-155, miR-210, miR-221, and miR-222, were overexpressed in diseased tissues than in the control samples, whereas miR-31, miR-122, miR-145, and miR-146a were underexpressed. Additionally, the expressions of miR-21 and miR-155 were associated with tumor stage and poor prognosis.

CONCLUSIONS: The tumorigenic role of miR-21 and miR-155 was confirmed, whereas down-regulation of miR-31, miR-145, and miR-146a, in dispute with current literature, renders necessary the revision of use of microRNAs as biological markers.