OBJECTIVETo examine the expression of cytokine-induced apoptosis inhibitor1 (CIAPIN1) in gastric cancer and normal mucosa tissues, and to investigate its effects on migration and invasion of gastric cancer cells.

METHODSImmunohistochemistry was used to detect CIAPIN1 expression in 15 samples of normal gastric mucosa tissues, 148 samples of gastric cancer tissues (42 of non-metastasis gastric cancer tissues without other organs or lymph node metastasis, 106 of metastasis gastric cancer tissues with lymph node metastasis), and 37 samples of gastric cancer lymph node metastasis tissues. Association of CIAPIN1 expression with clinicopathological characteristics of gastric cancer was analyzed by Chi-square test. SGC-7901 cell lines of high CIAPIN1 expression and low CIAPIN1 expression were established. Transwell assay was applied to detect the invasion and migration of CIAPIN1-regulated gastric cancer cells.

RESULTSPositive rate of CIAPIN1 expression in gastric cancer tissues was lower than that in normal gastric mucosa tissues (41.2% vs. 86.7%, P=0.0008), and in metastasis gastric cancer tissues was also lower than that in non-metastasis gastric cancer tissues (34.9% vs. 71.4%, P=0.0000). Furthermore, the positive rate of CIAPIN1 expression was closely related to the TNM staging of gastric cancer (TNM stage I(, II( and III( were 55.0%, 53.5% and 24.4%, respectively, P=0.0037). But there was no significant difference of positive expressive rate between metastatic gastric cancer tissues and metastatic lymph node tissues(34.9% vs. 21.6%, P=0.3700). Transwell assay showed that up-regulated CIAPIN1 expression would significantly reduce, while down-regulated CIAPIN1 expression would significantly promote the invasion and migration of SGC-7901 cells (all P<0.05).

CONCLUSIONPositive rate of CIAPIN1 expression is low in gastric cancer tissues and shows inhibition of invasion and migration of gastric cancer cells.