Down-regulation of long non-coding RNA GAS5 is associated with the prognosis of hepatocellular carcinoma.

INTRODUCTION Long non-coding RNAs (lncRNAs) have been investigated as a new class of regulators of cellular processes, such as cell growth, apoptosis, and carcinogenesis. lncRNA GAS5 has recently been identified to be involved in tumorigenesis of several cancers such as breast cancer, lung cancer and renal cancer. However, the regulation of GAS5 in hepatocellular carcinoma (HCC) has not yet been reported before. METHODS Expression of GAS5 in tumor and their normal matched tissues was determined by quantitative real-time PCR in n = 71 HCC patients, and its association with overall survival of patients was analyzed by statistical analysis. RESULTS The expression level of GAS5 was reduced in HCC in comparison to normal matched tissues (P < 0.05). It is also proved that GAS5 expression was to be associated with HCC tumor size, lymphnode metastasis and clinical stage (P < 0.05). In addition, the Kaplan-Meier survival curves revealed that low GAS5 expression was associated with poor prognosis in HCC patients. GAS5 expression was an independent prognostic marker of overall HCC patient survival in a multivariate analysis. CONCLUSIONS The study proved for the first time that GAS5 down regulated in a majority of HCC patients. Our results indicated that GAS5 expression was an independent prognostic factor for patients with liver cancer, which might be a potential valuable biomarker for HCC.