Upregulation of a novel lncRNA LINC01980 promotes tumor growth of esophageal squamous cell carcinoma

An increasing number of long noncoding RNAs (IncRNAs) have been discovered, and dysregulation of lncRNAs plays critical roles in tumorigenesis and tumor progression. In this study, we identified a novel lncRNA LINC01980, located in both the cytoplasm and nucleus, which was significantly upregulated in esophageal squamous cell carcinoma (ESCC) tissues through microarray profiling. Further analysis revealed that LINC01980 overexpression was positively correlated with deeper invasion of cancer, positive lymph node metastasis, and advanced TNM stage. Additionally, high LINC01980 expression in ESCC tissues was associated with poor prognosis. In vitro and in vivo experiments demonstrated that LINC01980 promoted ESCC growth. EdU incorporation assay implied that LINC01980 accelerated ESCC proliferation. Flow cytometry analysis showed that knockdown of LINC01980 induced cell cycle arrest and increased apoptosis. Microarray analysis indicated that LINC01980 upregulated the expression of growth arrest and DNA damage inducible 45 alpha (GADD45A). Further experiments demonstrated that GADD45A promoted ESCC cell growth, indicating that GADD45A may be a downstream target of LINC01980. In conclusion, this study identified LINC01980 as a novel potential oncogene in ESCC, which can be a promising biomarker for prognosis and therapeutic targeting in ESCC. (C) 2019 Published by Elsevier Inc.