CircRPPH1 promotes cell proliferation, migration and invasion of non-small cell lung cancer via the PI3K/AKT and JAK2/STAT3 signalling axes.

Non-small cell lung cancer (NSCLC) has markedly increased morbidity and mortality rates worldwide. Circular RNAs were shown to regulate NSCLC progression. But the underlying pathways of the circRPPH1-mediated regulation of NSCLC still need further exploration. We evaluated circRPPH1 levels in NSCLC tissues and cell lines via qRT-PCR. Moreover, using ectopic plasmid incorporation and siRNA assays, we analysed the circRPPH1-mediated regulation of cell proliferation (CP), cell migration (CM) and cell invasion (CI) in NSCLC cell lines (H1975 and A549 cells), using CCK-8, colony forming, scratch wound and transwell assays, respectively. CircRPPH1 levels were remarkably high in the NSCLC tissues and cell lines. The transfection experiments showed that circRPPH1 overexpression was able to promote CP, CM and CI of NSCLC cells, while CP, CM and CI were significantly restrained by the knockdown of circRPPH1. We also displayed that circRPPH1 knockdown suppressed the cell progression via inactivating the PI3K/AKT and JAK2/STAT3 signalling axes. Subsequently, in vivo experiment in nude mice was demonstrated that the inhibition of circRPPH1 could reduce the tumour growth of NSCLC. circRPPH1 may accelerate the growth and metastasis of NSCLC, in culture conditions and in animal models, by stimulating the PI3K/AKT and JAK2/STAT3 signalling axes, thus promoting the development of NSCLC.