Noncoding RNA in Cholangiocarcinoma.

Cholangiocarcinomas (CCAs) are tumors with a dismal prognosis. Early diagnosis is a key challenge because of the lack of specific symptoms, and the curability rate is low due to the difficulty in achieving a radical resection and the intrinsic chemoresistance of CCA cells. Noncoding RNAs (ncRNAs) are transcripts that are not translated into proteins but exert their functional role by regulating the transcription and translation of other genes. The discovery of the first ncRNA dates back to 1993 when the microRNA (miRNA) lin-4 was discovered in Caenorhabditis elegans . Only 10 years later, miRNAs were shown to play an oncogenic role in cancer cells and within 20 years miRNA therapeutics were tested in humans. Here, the authors review the latest evidence for a role for ncRNAs in CCA and discuss the promise and challenges associated with the introduction of ncRNAs into clinical practice.