hsa_circ_0013958: a circular RNA and potential novel biomarker for lung adenocarcinoma.

Circular RNAs (circ RNAs) are associated with cancer progression and metastasis, although little is known about their role in lung adenocarcinoma ( LAC). In the present study, microarrays were first used to screen for tumour-specific circ RNA candidates in LAC tissue. Thirty-nine circ RNAs were found to be up-regulated and 20 were down-regulated (fold change > 2.0). Among them, hsa_circ_0013958 was further confirmed to be up-regulated in all of the LAC tissues, cells and plasma. In addition, hsa_circ_0013958 levels were associated with TNM stage ( P = 0.009) and lymphatic metastasis ( P = 0.006). The area under the receiver operating characteristic curve was 0.815 (95% confidence interval = 0.727-0.903; P < 0.001). In addition, to further illustrate the bioactivities of hsa_circ_0013958 in LAC, si RNA-mediated inhibition of hsa_circ_0013958 was performed in vitro. The results showed that hsa_circ_0013958 promoted cell proliferation and invasion and inhibited cell apoptosis in LAC. Moreover, hsa_circ_0013958 was identified as a sponge of miR-134, and thus it up-regulated oncogenic cyclin D1, which plays a pivotal role in the development of non-small cell lung cancer. In conclusion, our results suggested that hsa_circ_0013958 could be used as a potential non-invasive biomarker for the early detection and screening of LAC. [ABSTRACT FROM AUTHOR]