Pancreatic Cancer and MicroRNAs

MicroRNAs (miRNAs) are recently discovered non-coding small RNAs that play a role as regulators of genetic expressions in eukaryotic cells. It comprises about 20 nucleotides, which contains seed sequence to bind 3'-untranslated lesion of specific target mRNA. It regulates self-renewal, proliferation and differentiation via post-transcriptional gene slicing in normal situation. Aberrant expressions of miRNAs are observed in many cancers as well. miRNAs in cancer cells have been investigated extensively to have a role in tumorigenesis, invasion, metastasis and chemoresistance. In cancer cells, miRNAs act both as tumor suppressors or oncogenes by doing down-regulation of oncogenes or up-regulation of tumor suppressors, respectively. This suggests miRNAs can be potential therapeutic and diagnostic targets in cancers. Pancreatic cancer is one of the most lethal tumors. In spite of many efforts, overall 5-year survival rate of pancreatic cancer is still very low (<5%). Recently, several miRNAs as an oncomir (acting like oncogenes or tumor suppressor genes) are discovered in pancreatic cancer. Here, the role of miRNAs in pancreatic cancer will be discussed and its possibility of diagnostic/therapeutic target will be also mentioned.