CCAT2 is a lung adenocarcinoma-specific long non-coding RNA and promotes invasion of non-small cell lung cancer

The prognosis of non-small cell lung cancer (NSCLC) is still poor, and it is necessary to identify effectively diagnostic and prognostic biomarkers for NSCLC. Recent evidence demonstrates that long non-coding RNA (lncRNA) is actively transcribed from human genome. Some lncRNAs show a time- or tissue-specific expression manner and play important roles in diverse biological processes. Additionally, various cancer-associated lncRNAs have been identified, such as metastasis-associated lung adenocarcinoma transcript 1 for lung cancer. Here, we characterized the expression profile of a novel lncRNA, colon cancer-associated transcript 2 (CCAT2), in lung cancer and found that CCAT2 was significantly over-expressed in NSCLC tissues compared with paired adjacent normal tissues, with an average up-regulation fold of 7.5. Intriguingly, over-expression of CCAT2 was significantly associated with lung adenocarcinoma (p = 0.033) but not squamous cell cancer. Silencing CCAT2 by siRNA led to inhibition of proliferation and invasion in NSCLC cell lines in vitro. Additionally, CCAT2 combined with CEA could predict lymph node metastasis. Our findings indicate that CCAT2 is a lung adenocarcinoma-specific lncRNA and promotes invasion of NSCLC and highlight its potential as a biomarker for lymph node metastasis.