An update on long intergenic noncoding RNA p21: a regulatory molecule with various significant functions in cancer

Long intergenic noncoding RNA p21 was mapped on the human chromosome 6p21.2. Accordingly, it was firstly described by promoting the p53-dependent apoptosis in the mouse. Also, it is a new lncRNA playing some vital roles in the cell cycle, apoptosis, cell proliferation, tumorigenesis, invasion, metastasis, and angiogenesis. In this regard, it was shown that,lincRNA-p21regulates these biological processes involved in carcinogenesis through various signaling pathways including Notch signaling, JAK2/STAT3, and AKT/mTOR pathways. Another mechanism by thatlincRNA-p21can affect these processes is a cross-talk with different miRNAs. In vitro and in vivo studies revealed dysregulation oflincRNA-p21in various human cancers. In addition, emerging evidence demonstrated that,lincRNA-p21can be considered as a potential prognostic and therapeutic biomarker in cancers. Also,lincRNA-p21enhances the response to radiotherapy for colorectal cancer. However, the molecular mechanisms oflincRNA-p21in carcinogenesis have not been fully elucidated so far. So, this review summarizes the function oflincRNA-p21,as a tumor suppressor factor in different biological processes implicated in cancers.