Long Noncoding RNA N-BLR Upregulates the Migration and Invasion of Gastric Adenocarcinoma.

Background/Aims: Gastric cancer is one of the most common malignant tumors worldwide with poor prognosis due to a lack of effective treatment modalities. Recent research showed that a long noncoding RNA named N-BLR modulates the epithelial-to-mesenchymal transition (EMT) process in colorectal cancer. However, the biological role of N-BLR in gastric cancer still remains to be explored. The aim of this study was to investigate the possibility of N-BLR as an EMT modulator in gastric cancer. Methods: The expression of N-BLR was measured by quantitative polymerase chain reaction in fresh gastric cancer tissue, paired adjacent normal tissues and cell lines. Fresh gastric tissues, paired samples obtained by surgery and clinical data were collected prospectively. Knockdown of N-BLR was induced by small interfering RNA (siRNAs). Cell number and viability were assessed after treatment with siRNAs. The ability of N-BLR to promote metastasis was measured using migration and invasion assays. Additionally, an inverse correlation between N-BLR and miR-200c was measured by TaqMan microRNA assays. Western blotting was performed to detect EMT and apoptosis markers upon knockdown of N-BLR. Results: N-BLR expression was significantly elevated in gastric cancer cell lines and tissues compared to that in a normal gastric cell line and adjacent normal tissues (p<0.01). Two different siRNAs significantly reduced cell proliferation of gastric cancer cells compared to the siCT. siRNAs for N-BLR significantly suppressed migration and invasion in AGS and MKN28 cells. N-BLR expression was inversely correlated with miR-200c, which is known to regulate EMT. Conclusions: In this study, we confirmed N-BLR as a regulator of the EMT process in gastric cancer.