Circulating Long Non-Coding RNAs Act as Biomarkers for Predicting 131I Uptake and Mortality in Papillary Thyroid Cancer Patients with Lung Metastases.

PURPOSE The aims of the current study were to explore plasma lncRNAs as a novel biomarker panel for the diagnosis of non-131I-avid lung metastases of PTC and to investigate the plasma lncRNA expression levels associated with survival in PTC patients with lung metastases. METHODS The expression of lncRNAs was examined using an lncRNA microarray chip. The lncRNAs with the most significant difference in expression between PTC patients with non-131I-avid lung metastases and PTC patients with 131I-avid lung metastases were verified by quantitative reverse-transcription polymerase chain reaction. The Kaplan-Meier method was used to determine whether the plasma lncRNA levels might be indicative of patient prognosis. RESULTS Compared with 131I-avid lung metastases, we discovered that two lncRNAs (ENST00000462717 andENST00000415582) were upregulated and two (TCONS_00024700 and NR_028494) were downregulated in the non-131I-avid lung metastases of PTC. Receiver operating characteristic curve (ROC) analyses indicated that the use of these four lncRNAs had high diagnostic sensitivity and specificity for predicting non-131I-avid lung metastases of PTC. The merged areas under the curve for ENST00000462717, ENST00000415582, TCONS_00024700,and NR_028494 in the training and validation sets were 0.890, 0.936, 0.975, and 0.918, respectively. Low (ENST00000462717 and ENST00000415582) and high plasma lncRNA levels(TCONS_00024700and NR_028494) were also found to be associated with better prognosis of PTC patients with lung metastases(P<0.001). CONCLUSIONS ENST00000462717, ENST00000415582, TCONS_00024700, and NR_028494 may be used as novel and minimally invasive markers for the diagnosis and prognostic assessment of non-131I-avid lung metastases from PTC.