CircPTN promotes angiogenesis via the MiR-595/LYRM5 signaling pathway in non-small cell lung cancer

Background: Non-small cell lung carcinoma (NSCLC) is a highly malignant tumor with a poor prognosis worldwide. Some studies have demonstrated that circular pleiotrophin (circPTN) plays critical roles in tumorigenesis and tumor development. However, little is known about the role of circPTN in NSCLC. Methods: The circPTN expression in human NSCLC tissues was measured via quantitative real-time polymerase chain reaction (qRT-PCR). The function and potential mechanisms of circPTN in NSCLC angiogenesis were also investigated. We aimed to explore the function and potential mechanisms and clinical significance of circPTN in NSCLC. Results: We first found that circPTN was markedly upregulated in NSCLC tissues. A higher circPTN level was closely associated with angiogenesis and significantly shorter overall survival in patients with NSCLC. We then found that circPTN promoted angiogenesis in NSCLC. More importantly, we found that circPTN facilitated angiogenesis by regulating the expression of LYRM5 in NSCLC. Mechanistically, LYRM5 could be a direct target of microRNA-595 (miR-595). Additionally, we demonstrated that circPTN upregulated LYRM5 expression by sponging miR-595, which promoted NSCLC angiogenesis in NSCLC. Conclusions: We found that circPTN serves as a competing endogenous ribonucleic acid that promotes angiogenesis via the miR-595/LYRM5 signaling pathway in NSCLC. Targeting circPTN might be a promising new therapeutic strategy for NSCLC.