Fig. 1.

The expression and characterization of circDOCK1 in OS cells and tissues. A circDOCK1 expression in OS tissues was measured by qRT–PCR. B The association of circDOCK1 expression with overall survival in 70 OS patients was evaluated by Kaplan–Meier analysis. C Relative serum circDOCK1 levels in OS patients and non-OS carriers (n = 70). D Diagnostic value of serum circDOCK1 by ROC curve. E CircDOCK1 expression in OS cells (normalized to hFOB 1.19 cells). F Sanger sequencing of circDOCK1, with the arrows indicating splice sites. G After treatment with RNase R, the abundance of circDOCK1 and linear DOCK1 in U2OS and MG63 cell lines was determined by qRT–PCR (normalized to Mock). H qRT-PCR products of linear and circular products amplified with convergent and divergent primers with and without RNase R treatment. I qRT–PCR analysis of circDOCK1 and DOCK1 expression in OS cells after actinomycin D treatment. J qRT–PCR analysis of isolated cytoplasmic and nuclear fractions. K FISH assays using circDOCK1 and negative control probes in the MG63 and U2OS cell lines (scale bar = 10 μm). The data are presented as the mean ± SD of three independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001, ns: nonsignificant