The Clinical Relevance of Long Non-Coding RNAs in Cancer

Abstract

Non-coding RNAs have long been associated with cancer development and progression, and since their earliest discovery, their clinical potential in identifying and characterizing the disease has been pursued. Long non-coding (lncRNAs), a diverse class of RNA transcripts >200 nucleotides in length with limited protein coding potential, has been only modestly studied relative to other categories of non-coding RNAs. However, recent data suggests they too may be important players in cancer. In this article, we consider the value of lncRNAs in the clinical setting, and in particular their potential roles as diagnostic and prognostic markers in cancer. Furthermore, we summarize the most significant studies linking lncRNA expression in human biological samples to cancer outcomes. The diagnostic sensitivity, specificity and validity of these non-coding RNA transcripts is compared in the various biological compartments in which they have been detected including tumor tissue, whole body fluids and exosomes.

Keywords: biomarker; cancer diagnosis; cancer prognosis; circulating lncRNAs; exosomes; sensitivity; specificity.

Figure 1

Mechanisms of action of long non-coding RNAs (lncRNAs) and implications for modulation of cancer phenotype. LncRNAs regulate gene expression by controlling chromatin condensation, promoting or inhibiting DNA transcription, influencing mRNA splicing, determining mRNA stability, and promoting or inhibiting mRNA translation into proteins. This leads to deregulated cell homeostasis, originating some of the aberrant phenotypes described as cancer hallmarks.