Long Non-Coding RNAs - Current Methods of Detection and Clinical Applications

Long non-coding RNAs (lncRNA) are more than 200-nucleotide-long RNA molecules that affect multiple physiologic phenomena and have important regulatory functions in cells. Their levels are often altered in various malignancies, thus they represent a potential biomarker for the diagnostics, prognosis or recurrence of cancer. Their importance has recently led to an enormous increase in a number of publications on the subject. The most frequently studied lncRNAs are HOTAIR, MALAT1 and PCA3.

Numerous methods are currently being developed for the analysis or detection of lncRNA. They are mostly based on optical methods used for the detection of messenger RNAs, including polymerase chain reaction with reverse transcription, fluorescence in situ hybridisation or next-generation sequencing, but caution must be taken due to their structural differences. Here, we describe not only standard but also novel techniques for lncRNA detection, including chemiluminescent and electrochemical techniques.

Despite the great progress and plethora of papers on this topic, there is only one single approved lncRNA-based diagnostic test, a PCA3 test for the diagnosis of prostate cancer from the patients urine. All other tests are only in their research phase and need to be validated. Nevertheless, lncRNA diagnostics offer enormous potential and thus it is highly probable that other diagnostic tests on different lncRNA types will soon appear.