CircRNA circ-PDCD11 is highly expressed in lung large-cell carcinoma and predicts poor survival

Circ-PDCD11 (hsa_circ_0019853, 461 bp) has been characterized as an oncogenic circRNA in breast cancer, while its function in other cancers is unclear. In this study, we explored the role of circ-PDCD11 in lung cancer.Plasma samples were obtained from patients with lung large-cell carcinoma (LLCC, n = 40), lung squamous cell carcinoma (LSCC, n = 40), lung adenocarcinoma (LA, n = 40) and small-cell lung cancer (SCLC, n = 40) as well as healthy controls (Control, n = 40). Paired tumor and nontumor tissue samples were obtained from all patients. Expression of circ-PDCD11 in these samples was determined by RT-qPCR. The role of plasma circ-PDCD11 in the diagnosis of LLCC was analyzed with ROC curve. A five-year follow-up was performed to analyze the role of plasma circ-PDCD11 in the prognosis of LLCC.Plasma circ-PDCD11 was specifically upregulated in LLCC but not in other lung cancer types, compared to the controls. Increased circ-PDCD11 expression in tumor tissues compared to nontumor tissues was only observed in LLCC patients but not in other lung cancer types. Increased plasma circ-PDCD11 levels effectively separated LLCC patients from patients with other types of cancers. High plasma circ-PDCD11 levels were closely correlated with poor survival of LLCC patients. Plasma circ-PDCD11 levels were closely correlated with tumor metastasis, but not tumor size of LLCC.CircRNA circ-PDCD11 is highly expressed specifically in LLCC and predicts poor survival.