Low expression of lncRNA NBAT-1 promotes gastric cancer development and is associated with poor prognosis.

Purpose: This study aimed to investigate the regulatory effect of long non-coding RNA (lncRNA) NBAT-1 (neuroblastoma associated transcript 1) on the development and prognosis of gastric cancer (GC), and its underlying mechanism.

Methods: NBAT-1 expression in GC tissues, paracancerous tissues and normal gastric tissues was detected by quantitative real-time polymerase chain reaction (qRT-PCR). We also detected NBAT-1 expression in GC cell lines. Correlation between NBAT-1 expression and TNM stage was analyzed. Overexpression plasmid of NBAT-1 was transfected into SGC-7901 and MGC-823 cells, followed by detection of proliferation and cell cycle by CCK-8 (cell counting kit-8) assay and flow cytometry. NBAT-1 localization in GC cells was accessed by chromatin fractionation. Finally, PTEN expression in GC cells overexpressing NBAT-1 was determined by Western blot analysis.

Results: NBAT-1 and PTEN were lowly expressed in GC tissues compared with paracancerous tissues and normal gastric tissues. GC patients with stage Ⅲ-Ⅳ presented lower expression of NBAT-1 than those with stage Ⅰ-Ⅱ. Besides, lower expression of NBAT-1 was found in GC patients with N2-N3 compared with those with N0-N1. NBAT-1 expression was not correlated with TNM stage and distant metastasis in GC patients. Upregulation of NBAT-1 in GC cells inhibited proliferation and arrested cell cycle. Chromatin fractionation results indicated that NBAT-1 was mainly localized in the cytoplasm of SGC-7901 and MGC-823 cells. NBAT-1 overexpression remarkably upregulated PTEN expression in GC cells.

Conclusions: Low expression of NBAT-1 promotes GC development by downregulating PTEN expression.