[Expression and clinical significance of long non-coding RNA CCAT1 in gastric cancer]

Objective: To investigate the expression and clinical significance of long non-coding RNA colon cancer associated transcript-1 (CCAT1) in gastric cancer (GC), and to further explore the effect of CCAT1 on cell proliferation of GC. Methods: The mRNA expressions of CCAT1 in GC tissues and matched adjacent normal tissues from 62 patients who received resection for gastric carcinoma between January 2013 and May 2015 in Nanjing Medical University Affiliated Wuxi Second Hospital and expressions in GC cell lines were assessed by quantitative real-time PCR (qRT-PCR). The clinical significance of CCAT1 expression was then analyzed. The expressions of CCAT1 in MGC-803 and SGC-7901 cells were inhibited by small interfering RNA (siRNA) transfection. The effect of CCAT1 on cell proliferation was studied by cell counting kit (CCK)-8 assay. Results: The expressions of CCAT1 mRNA in GC tissues were significantly higher than in the normal tissues (3.39±2.37 vs 1.28±0.74, P<0.05). Compared with immortalized human gastric epithelial cell line (GES-1), the expressions of CCAT1 mRNA were significantly higher in GC cell lines MGC-803 and SGC-7901 (3.07±0.69, 2.23±0.32 vs 1.01±0.12, both P<0.05). Besides, the expression of CCAT1 varied significantly among patients with different TNM stage, depth of invasion, and lymph node metastasis (χ(2) =5.199, 5.395, 9.239, all P<0.05). The results of CCK-8 assay showed that down-regulation of CCAT1 in MGC-803 and SGC-7901 cells significantly inhibited the cell proliferation (both P<0.05). Conclusions: CCAT1 is up-regulated in GC and may be significantly correlated with the progression of GC. Decreased expression of CCAT1 can suppress the proliferation of GC cells. CCAT1 might be used as a novel target for GC early diagnosis and treatment.