Fig. 8

Therapeutic effects of lentivirus-mediated circ-hnRNPU over-expression in vivo. a, Representative images (left panels), in vivo growth curve (upper middle panel), weight at the end points (upper right panel), and immunohistochemical staining of Ki-67 and CD31 (lower right panels, arrowheads) of xenograft tumors formed by subcutaneous injection of MKN-45 cells into dorsal flanks of nude mice (n = 5 for each group) that received intravenous administration of lentiviral empty vector (LV-mock) or circ-hnRNPU (LV-circ-hnRNPU) as indicated. Scale bar: 100 μm. b, Representative images (left panel), quantification of lung metastatic colonization (middle panel), and Kaplan–Meier curves (right panel) of nude mice treated with tail vein injection of MKN-45 cells and LV-mock or circ-hnRNPU (LV-circ-hnRNPU) as indicated. Scale bar: 100 μm. c, Real-time qRT-PCR (normalized to β-actin) assay indicating the levels of NONO, c-Myc, and target genes in normal gastric mucosa (n = 40) and gastric cancer tissues (n = 81). d, Kaplan–Meier curves showing the overall survival of gastric cancer cases derived from KM Plotter database (http://kmplot.com/analysis) with low or high expression of NONO (cutoff value = 10.31), c-Myc (cutoff value = 10.63), GALNT2 (cutoff value = 8.36), GALNT6 (cutoff value = 9.14), MGAT1 (cutoff value = 9.13), or hnRNPU (cutoff value = 5.21). e, The mechanisms underlying tumor suppressive roles of circ-hnRNPU: as a circRNA derived from hnRNPU, circ-hnRNPU directly interacts with NONO to induce its cytoplasmic retention, which restrains nuclear NONO-facilitated c-Myc transactivation or cytoplasmic NONO-enhanced mRNA stability of glycosyltransferases and hnRNPU, resulting in repression of glycosylation and cancer progression. Analysis of variance or Student’s t test compared the difference in a and b. Mann–Whitney U test compared the difference in c. Log-rank test for survival comparison in b and d. *P < 0.05, **P < 0.01. Data are shown as mean ± s.e.m. (error bars) in a-c