The Roles and Diagnostic Potential of Long Non-Coding RNAs in Some Cancers: A Review

Since their discovery, non-coding RNAs have been known as key regulators of gene expression. Gaining a better understanding about their biogenesis and function may provide valuable knowledge about the heterogeneity of malignancies and contribute to identification of diagnostic, prognostic and therapeutic targets. Long non-coding RNAs (lncRNAs) are a group of RNAs composed of >200 nucleotides that play important regulatory roles in gene transcription, splicing and epigenetics as well as in biological processes involved in cell cycle, development and pluripotency. Generally, the expression levels of lncRNAs are lower than protein-coding genes, but they exhibit more tissue-specific expression patterns. Recent studies have suggested involvement of cancer-specific lncRNAs including HOTAIR, ANRIL, FENDRR, GAS5 and H19 in tumorigenesis, tumor cell proliferation, invasion, migration, apoptosis and angiogenesis. Expression of lncRNAs is tissue-specific and may vary depending on the stage of tumor progression. In this review, we summarize current knowledge on the roles of lncRNAs in some cancers and their potential as diagnostic and prognostic targets.