Hypoxia and lncRNAs in gastrointestinal cancers

Hypoxia is a hallmark of the tumor microenvironment, and hypoxia regions are frequently found in gastrointestinal cancers, which are associated with worse patients’ survival and therapy resistance. However, the potential mechanisms of hypoxic tumor microenvironment still need to be further elucidated, especially about the roles of long non-coding RNAs (lncRNAs) in hypoxic tumor regions. In recent years, a great mount of independent research showed that many lncRNAs were modulated by hypoxia, and these lncRNAs were named as “hypoxia-regulated lncRNAs”. In this review, the recent developments in the expression, regulation and functions of hypoxia-regulated lncRNAs in gastrointestinal cancers were summarized. In this review, we summarized and figured out recent studies concerning the expression and biological mechanisms of hypoxia-regulated lncRNAs in gastrointestinal cancers. The related studies were obtained through a systematic search of PubMed, Embase and Cochrane Library. Hypoxia-regulated lncRNAs have various roles in the regulation of metabolism, autophagy, invasion and metastasis in the hypoxic microenvironment. More importantly, hypoxic-regulated lncRNAs have a variety of potential mechanisms in gastrointestinal tumors, including epigenetic, lncRNA-miRNA interaction, lncRNA-protein interactions. Hypoxia-regulated lncRNAs will undoubtedly be developed as targets and promote the progress in ideal therapies for gastrointestinal cancer patients.