Long non-coding RNAs: novel prognostic biomarkers for liver metastases in patients with early stage colorectal cancer

// Hui Kong 1 , Ying Wu 1 , Mengou Zhu 2 , Changwen Zhai 3 , Jing Qian 1 , Xue Gao 4 , Shuyang Wang 1 , Yingyong Hou 3 , Shaohua Lu 3, * , Hongguang Zhu 1, 4, * 1 Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, China 2 Harvard College, Harvard University, Cambridge, MA, USA 3 Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai, China 4 Division of Surgical Pathology, Huashan Hospital, Fudan University, Shanghai, China * These authors have contributed equally to this work Correspondence to: Hongguang Zhu, email: hongguang_702@163.com Keywords: prognostic biomarker, long non-coding RNA, early stage colorectal cancer, liver metastasis, quantitative RT-PCR Received: December 06, 2015 Accepted: June 12, 2016 Published: July 06, 2016 ABSTRACT Liver metastasis is the primary cause of death for colorectal cancer (CRC) patients. To investigate the prognostic value of long non-coding RNAs (lncRNAs) on colorectal liver metastases, quantitative reverse-transcriptase PCR (quantitative RT-PCR) was performed on 15 lncRNAs in 51 stage IV CRC with liver metastases and 57 stage I/II CRC specimens. The expression levels of four lncRNAs (GAS5, H19, MEG3 and Yiya) were significantly different between liver metastases and primary tumors of stage IV CRC patients. Furthermore, the high expression levels of GAS5 and Yiya were significantly associated with future occurrence of liver metastases in early stage CRC patients. Kaplan-Meier analysis showed that the high expression levels of GAS5 or Yiya were correlated with poor prognosis of early stage CRC patients (p = 0.0206 and 0.0005 for GAS5 and Yiya, respectively). Yiya expression was proved to be an independent prognostic indicator of colorectal liver metastases in a multivariate analysis (relative risk = 10.7; p < 0.0001). Our study revealed that GAS5 and Yiya were promising prognostic biomarkers of liver metastases for early stage CRC patients.