Abstract: Background and purpose: Gastric cancer is the second leading cause of cancer death. It is the most common gastrointestinal malignant tumor in East Asia, Eastern Europe and parts of Central and South America. This study aimed to explore the role of long-chain noncoding RNA (lncRNA) antidifferentiation noncoding RNA (ANCR) targeting miR-331 in regulating the proliferation and invasion of gastric cancer cells and its mechanism. Methods: Sixty cases of clinical gastric cancer samples and 20 cases of corresponding non-tumor tissue specimens were collected in Henan Cancer Hospital from January 1, 2016 to December 1, 2016. The expression levels of ANCR in gastric cancer tissues and different gastric cancer cell lines were detected by real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR). The relationship between the expression of ANCR and the clinicopathological features of gastric cancer patients was analyzed. The effect of ANCR on the proliferation of gastric cancer cells was detected by plate clone assay. Transwell assay was used to detect the effect of ANCR on the invasiveness of gastric cancer cells. Tumor formation assay in nude mouse models detected effect of ANCR on xenograft. The dual luciferase reporter assay detected the interaction between ANCR and miR-331. Results: The expression of ANCR in gastric cancer tissues was significantly higher than that in normal tissues (4.18±0.28 vs 1.45±0.15, t=12.36, P=0.045). Compared with other gastric cancer cell lines, the expression levels of ANCR in BGC-823 and MGC-803 cells were significantly higher (9.12±0.52, t=14.51, P=0.019). Inhibiting the expression of ANCR attenuated the proliferation (98.8±10.4) and invasive ability (175.9±5.7) of the gastric cancer cells. The ability of gastric cancer cells to form xenograft in nude mice was inhibited by suppressing the expression of ANCR (223.4±13.4 vs 115.6±10.7, t=13.28, P=0.014). Dual luciferase assay results confirmed that ANCR could directly regulate the expression of miR-331 and its fluorescence activity. Conclusion: ANCR can regulate the expression of miR-331 and affect the proliferation and invasion of
gastric cancer cells.

Key words: Antidifferentiation noncoding RNA, miR-331, Gastric cancer, Proliferation, Invasion