CCAT1: a pivotal oncogenic long non-coding RNA in human cancers

Long non-coding RNAs (lncRNAs) compose a group of non-protein-coding RNAs - more than 200 nucleotides in length. Recent studies have shown that lncRNAs play important roles in different cellular processes, including proliferation, differentiation, migration and invasion. Deregulation of lncRNAs has been widely reported in human tumours, in which they are able to function as either oncogenes (on the one hand) or tumour suppressor genes (on the other). Deregulation of CCAT1 (colon cancer-associated transcript-1), an oncogenic lncRNA, has been documented in different types of malignancy, such as gastric cancer, colorectal cancer and hepatocellular carcinoma. In this regard, enforced expression of CCAT1 exerts potent tumorigenic effects by promoting cell proliferation, invasion and migration. Recent evidence has also shown that CCAT1 may serve as a prognostic cancer biomarker. In this review, we provide an overview of current evidence relating to the role and biological function of CCAT1 in tumour development.

Long non-coding RNA CASC11 interacts with hnRNP-K and activates the WNT/β-catenin pathway to promote growth and metastasis in colorectal cancer

The abnormal expression of many long non-coding RNAs (lncRNAs) has been reported in the progression of various tumors, and these lncRNAs can be useful as diagnostic indicators and anti-tumor targets. Therefore, it is important to identify lncRNAs that can be used for the clinical prevention and treatment of colorectal cancer (CRC). Here, we report that cancer susceptibility candidate 11 (CASC11) was upregulated in CRC tissues; increased CASC11 expression in CRC was associated with tumor size, serosal invasion, lymph metastasis, and the tumor-node-metastasis (TNM) stage. Functional experiments showed that CASC11 can promote CRC cell proliferation and metastasis in vitro and in vivo. Furthermore, CASC11 can target heterogeneous ribonucleoprotein K (hnRNP-K) to activate WNT/β-catenin signaling in CRC cells. In addition, we found that c-Myc directly bound to the promoter regions of CASC11 and increased promoter histone acetylation to enhance CASC11 expression. Together, our findings indicate that the novel lncRNA CASC11 may serve as a candidate diagnostic biomarker and a promising therapeutic target for CRC.