Long non-coding RNAs (lncRNAs), a newly discovered class of ncRNA molecules, have been widely accepted as crucial regulators of various diseases including cancer. Increasing numbers of studies have demonstrated that lncRNAs are involved in diverse physiological and pathophysiological processes, such as cell cycle progression, chromatin remodeling, gene transcription, and posttranscriptional processing. Aberrant expression of lncRNAs frequently occurs in gastrointestinal cancer and plays emerging roles in cancer metastasis. In this review, the authors focus on and outline the regulatory functions of recently identified metastasis-associated lncRNAs, and evaluate the potential roles of lncRNAs as novel diagnostic biomarkers and therapeutic targets in gastrointestinal cancer.
Regulating function of HOTAIR in gastrointestinal cancer
In nucleus, HOTAIR recruits PRC2 complex and represses pri-miR-34a transcription epigenetically. By inducing histone H3K27 methylation in WIF-1’s promoter region, HOTAIR decreases WIF-1 expression. In cytoplasm, HOTAIR serves as “sponges” for miR-331-3p and miR-152, leading to the increase of target genes HER2 and HLA-G. PRC2: Polycomb repressive complex2.