Implications of Long Noncoding RNAs in Cancer Epigenetics

Epigenetic regulation of gene expression and genome function is essential to establish and maintain diverse cellular functions during mammalian development—alteration of which leads to cancer. Coordinated by chromatin and DNA modifier proteins and noncoding RNAs, epigenetic mechanisms impact chromatin structure and control the accessibility of genes and genomic elements and thereby influence their targeting by protein machinery. Epigenetic processes are extensively reprogrammed in cancer cells resulting in altered histone modifications, DNA methylation, and expression of long noncoding RNAs (lncRNAs), disrupting normal patterns of gene expression. These findings bring a new perspective to our understanding on the underlying causes of cancers in that epigenomic abnormalities are equally important as the genetic alterations. Accumulating evidence suggests that lncRNA-mediated processes that control locus and cell-type specific gene expression to significantly impact cellular transformation. Here, we discuss the molecular characteristics of lncRNAs, and review the recent advances in how lncRNA-mediated processes that are linked to cancer epigenetics.