Fig. 7.

circLMTK2 expression is upregulated in GC. (a) c-Myc mRNA levels were repressed by silencing circLMTK2 or miR-150-5p overexpression in GC cells. In contrast, c-Myc mRNA levels were enhanced by circLMTK2 overexpression in GC cells. The data are the means ± SEM of three experiments. *P < 0.05; **P < 0.01 (Student’s t-test) (b) c-Myc protein levels were repressed by silencing circLMTK2 or miR-150-5p overexpression in GC cells. In contrast, c-Myc protein levels were enhanced by circLMTK2 overexpression in GC cells. (c) Left: Diagram of putative miR-150-5p binding sites in the 3′-UTR of c-Myc. The mutant sequences c-Myc 3′-UTR sequences used in the luciferase reporter constructs are indicated in red. Right: Relative activities of luciferase reporters containing c-Myc 3′-UTR variants cotransfected with miR-150-5p or negative control mimics in HEK 293 T cells. ****P < 0.0001 (Student’s t-test). (d) Correlation between circLMTK2 and c-Myc levels in GC tissues. Pearson’s correlation coefficient values (r) and P values are as indicated. (e) Relative circLMTK2 mRNA levels in 120 matched human GC/normal tissues. The values are expressed as medians with interquartile ranges. (f) Kaplan-Meier analysis of the correlation between circLMTK2 expression and overall survival (OS) in 120 patients with GC. Log-rank tests were used to determine statistical significance. The patients were divided into two groups according to the median value of circLMTK2 expression