To investigate the effects of circCSPP1 mediated autophagy on the proliferation and metastasis ability of gastric cancer cells.

The human gastric cancer cells NCI-N87 were divided into Vector group (transfected with Vector), circCSPP1 group (transfected with circCSPP1) and inhibitor group (transfected with circCSPP1 and incubated with 10 μmol·L^-1 chloroquine). The MKN-45 cells were divided into sh-NC group (transfected with circCSPP1 shRNA-NC), sh-circCSPP1 group (transfected with circCSPP1 shRNA) and agonist group (transfected with circCSPP1 shRNA + 1 μmol·L^-1 sirolimus). Flow cytometry was used to detect cell apoptosis. Transwell was used to detect cell migration and invasion. Western blot were used to detect the expression levels of microtubule associated protein light chain 3-Ⅱ (LC3-Ⅱ) and p62 protein.

In NCI-N87 cells: the apoptosis rates of Vector, circCSPP1 and inhibitor groups were (7.95±0.66)%, (3.93±0.62)% and (7.37±0.85)%; the number of cell migrations were 122.50±12.25, 169.40±16.09 and 109.00±8.22; the number of cell invasions were 73.38±12.33, 117.30±12.78 and 55.25±8.73; the relative expression levels of LC3-Ⅱ protein were 0.40±0.06, 1.13±0.11 and 0.44±0.08; the relative expression levels of p62 protein were 1.62±0.15, 0.21±0.08 and 1.43±0.16. The differences of above indexes were statistically significant between the circCSPP1 group and the inhibitor and Vector groups (all P<0.05). In MKN-45 cells: the cell apoptosis rates of sh-NC, sh-circCSPP1 and agonist groups were (6.81±0.68)%, (12.02±0.78)% and (5.76±1.21)%; the number of cell migrations were 191.60±21.43, 87.50±10.76 and 155.60±10.36; the number of cell invasions were 150.00±11.55, 61.63±11.39 and 154.50±17.99; the relative expression levels of LC3-Ⅱ protein were 1.08±0.05, 0.13±0.03 and 1.18±0.06; the relative expression levels of p62 protein were 0.15±0.03, 1.29±0.08 and 0.19±0.04. Compared with the sh-circCSPP1 group, the differences of above indicators in the agonist and sh-NC groups were statistically significant (all P<0.05).

circCSPP1 can improve the proliferation and metastasis ability of gastric cancer cells by inducing autophagy.