circPTPRA suppresses the invasive phenotype in NSCLC cell lines.
(a) Quantification of circPTPRA and PTPRA transcript levels in circPTPRA-KD H23 cells and circPTPRA-KD H1755 cells assessed by qPCR. *p < .05, **p < .01 vs. Blank [unpaired Student's t-test]. (b) Quantification of circPTPRA and PTPRA transcript levels in circPTPRA-OE H522 cells and circPTPRA-OE H1755 cells assessed by qPCR. *p < .05, **p < .01 vs. Blank [unpaired Student's t-test]. (c) circPTPRA-KD H23 cells and circPTPRA-KD H1755 cells exhibited attenuated migration compared to cells transfected with a scrambled shRNA control in a scratch assay. *p < .05, **p < .01 vs. shCtrl [unpaired Student's t-test]. (d) circPTPRA-OE H522 cells and circPTPRA-OE H1755 cells exhibited enhanced migration compared to cells transfected with an empty plasmid control in a scratch assay. *p < .05, **p < .01 vs. p-Ctrl [unpaired Student's t-test]. (e) circPTPRA-KD H23 cells and circPTPRA-KD H1755 cells exhibited attenuated invasion compared to cells transfected with a scrambled shRNA control in a Transwell assay; scale bar = 100 μm. *p < .05, **p < .01 vs. shCtrl [unpaired Student's t-test]. (f) circPTPRA-OE H522 cells and circPTPRA-OE H1755 cells exhibited attenuated invasion compared to cells transfected with an empty plasmid control in a Transwell assay; scale bar = 100 μm. *p < .05, **p < .01 vs. p-Ctrl [unpaired Student's t-test]. (g and h) In vivo xenografts into nude BALB/c mice generated by tail vein injection of stably-transfected H23 cells were sacrificed 6 weeks later to assess lung lesions (n = 9 mice per group). Injection of (g) circPTPRA-KD H23 cells or scrambled shRNA control H23 cells or (h) circPTPRA-OE H23 cells or empty plasmid control H23 cells. *p < .05, **p < .01 vs. shCtrl or p-Ctrl [unpaired Student's t-test]. Left panels: Typical lung images with metastatic lesions; Middle panels: H&E lung tissue sections of metastatic lesions (100× magnification; scale bar = 100 μm); Right panel: Quantification of metastatic lesions.
All in vitro experiments: n = 3 biological replicates × 3 technical replicates. Data presented as means with error bars representing standard errors of the mean (SEMs). Abbreviations: circPTPRA-KD = NSCLC cells with shRNA-mediated circPTPRA knockdown, circPTPRA-OE = NSCLC cells with circPTPRA overexpression plasmid, H&E = hematoxylin and eosin, qPCR = quantitative real-time PCR.