Introduction: Long non-coding RNAs (lncRNAs) regulate and influence cancer cell development and tumor formation. However, the role for lncRNAs in gastric cancer has not been fully established. In this study, DGCR9 , a lncRNA, was significantly upregulated in gastric cancer cell lines.
Methods: The expression levels of DGCR9  in each patient between formalin-fixed, paraffin-embedded (FFPE) gastric cancer tissues and adjacent noncancer tissues (NAT) (n=102) were measured by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The effect of DGCR9  on cellular proliferation, migration, and glucose uptake was investigated in vitro, respectively.
Results: DGCR9  was shown to have increased expression in gastric cancer tissues and in gastric cancer cell lines. Further, DGCR9  was found to be associated with clinicopathological characteristics of patients with gastric cancer. In particular, DGCR9  was positively associated with lymph node invasion and tumor-node-metastasis (TNM) stage in gastric cancer patients. By in vitro functional analysis, knockdown of DGCR9  in gastric cancer cells suppressed cellular proliferation, migration, and glucose uptake. In contrast, overexpression of DGCR9  increased each of these cancer cell characteristics. 
Conclusions: DGCR9  was upregulated in gastric cancer tissues and was shown to accelerate cellular proliferation, migration, and glucose metabolism, all of which would promote the formation and development of gastric cancer.
Keywords: long noncoding RNA, DGCR9, gastric cancer, proliferation, migration, glucose metabolism