Long Noncoding RNA ROR Regulates Proliferation, Invasion, and Stemness of Gastric Cancer Stem Cell.

Gastric cancer remains an incurable malignance and the second leading cause of cancer death globally. Recent progress in gastric cancer research has demonstrated the crucial roles of cancer stem cells (CSCs) in the development, metastasis, and drug resistance of this disease. Various studies have highlighted the role of long noncoding RNAs (lncRNAs) in the pathogenesis of gastric cancer. In this study, through fluorescence-activated cell sorting, we isolated gastric CSCs (GCSCs) from MKN-45 cells and demonstrated for the first time that lncRNA ROR was highly expressed in CD133 GCSCs. Overexpression of lncRNA ROR significantly increased, but knockdown of lncRNA ROR inhibited the proliferation and invasion of GCSCs. Most importantly, lncRNA ROR led to upregulation of several key stemness transcriptional factors, such as OCT4, SOX2, and NANOG, as well as CD133 GCSC. Our data demonstrated that lncRNA ROR was associated with core stemness transcriptional factors and the pluripotent state of GCSCs. These results further improved our understanding of the functional cross talking network during development of GCSCs and may provide novel target for the diagnostics and therapeutics of gastric cancer.