Fig. 1

CircNHSL1 is up-regulated in gastric cancer tissues and correlated with the progression and poor prognosis. a CircRNA microarray between 3 gastric cancer tissues without metastasis and 2 gastric cancer tissues with metastasis. b Schematic illustration of the formation of circNHSL1 via the circularization of exons in NHSL1 gene. Sanger sequencing conformed the head-to-tail splicing of circNHSL1. c Relative expression of circNHSL1 in cell lines by qRT-PCR. d and e The gel electrophoresis validated the existence of circNHSL1. Divergent primers amplified circNHSL1 in cDNA but not gDNA. GAPDH was used as a linear control. f Relative expression of circNHSL1 and NHSL1 mRNA in both MKN-28 and SGC-7901 cells was detected by qRT-PCR in the presence or absence of RNase R. g circNHSL1 was mainly located in the cytoplasm by nuclear-cytoplasmic fractionation assay. h Relative circNHSL1 expression in 93 paired fresh frozen normal gastric tissues and gastric cancer tissues. i The level of circNHSL1 was significantly higher in gastric cancer tissues with M1 stage than with M0 stage (p < 0.01). j Kaplan-Meier survival analysis (log-rank test) showed that gastric cancer patients with high circNHSL1 expression have a lower OS and DFS than these with low circNHSL1 expression (p < 0.01). All data are presented as the mean ± SEM. *p < 0.05, **p < 0.01