MicroRNAs in pancreatic ductal adenocarcinoma: new diagnostic and therapeutic clues.

MicroRNAs (miRNAs) are small non-coding RNAs 19-24 nucleotides in length that regulate gene expression of target genes by translational repression. They regulate crucial processes such as development, proliferation, apoptosis, stress response and differentiation. Recent reports support a role for miRNAs in the initiation and progression of human malignancies; in particular, aberrant expression of miRNAs can contribute to carcinogenesis by promoting the expression of proto-oncogenes or by inhibiting the expression of tumor suppressor genes. Large high-throughput studies in patients revealed that miRNA profiling allows classifying tumors with high accuracy and predicting their outcome. In this review, we summarize recent knowledge about miRNA expression in pancreatic ductal adenocarcinoma, their possible molecular implications, and finally, we discuss the possible repercussion of these findings in terms of diagnosis and treatment of this disease.