Non-coding RNAs: More Questions than Answers

The sequencing of the human genome marked not the end of the genomics field, but rather its beginning. After more than a decade since the first human genome was sequenced, annotated and published, researchers still have a long journey ahead to understand the meaning of all the information encoded in human’s DNA. This is mainly because there are other layers of information beyond the genome, for example, the epigenome and the transcriptome. Genomics and genetics mainly study the differences between genomes and gene expression changes. Transcriptomics studies the whole set of transcripts produced by a specific cell type at any given time. Finally, the epigenome is able to control the expression of different genes by various mechanisms. Importantly, there is a strong dynamic between the “static” genome, represented by the DNA molecule, the transcriptome, representing the transcripts that are expressed, and the epigenome, regulating all the information transacted between the genome and the transcriptome. Recently, new classes of transcripts with no protein-coding capacity non-coding RNAs (ncRNAs) have been described as part of the human transcriptome. The question that researchers are facing now is if the majority of these transcripts are functional. In this article, we provide some proofs that the majority, if not all, have a function in human cells and will have a big impact for cancer research.