The clinical significance of circulating DSCAM-AS1 in patients with ER-positive breast cancer and construction of its competitive endogenous RNA network.

Long Non-Coding RNAs (lncRNAs), with diagnostic and therapeutic applications in malignancies, are newly described tumour-related molecules. Here, we reported the importance of circulating DSCAM-AS1 as the biomarker to detect Estrogen Receptor (ER)-positive breast cancer (BC) cases. Moreover, the expression of a BC-associated lncRNAs, namely DSCAM-AS1, was measured in tumoural and Paired Adjacent Non-Tumoral (PANT) tissue, as well as plasma, using Real-Time Polymerase Chain Reaction (RT-PCR). Besides, the correlations between gene expression and the clinicopathological features were analyzed. The diagnostic power of circulating DSCAM-AS1 in BC was estimated using the Area Under the Curve (AUC) value. Furthermore, we studied the DSCAM-AS1 associated with the network of competitive endogenous RNA (ceRNA) in BC using the literature review and in silico analysis. We found a significant increase in the expression levels of lncRNA in the tumour (P < 0.001) and in plasma (P < 0.001) of ER-positive BC patients. The sensitivity and specificity of DSCAM-AS1 in plasma for detection of BC from healthy controls were 100 and 97%, respectively (AUC = 0.98, P < 0.001). Accordingly, we suggest an elevated level of circulating DSCAM-AS1 as a candidate biomarker of ER-positive BC patients. Moreover, perturbation of DSCAM-AS1, as a ceRNA, acts in the tumor progression and drug resistance by affecting different cell signaling.