Down-regulation of a panel of immune-related lncRNAs in breast cancer.

Breast cancer is a common neoplasm among women. This type of cancer is among malignancies in which role of long non-coding RNAs (lncRNAs) has been extensively explored. Some recently recognized lncRNAs have been less investigated in this neoplastic condition. LncRNAs that regulate tumor immunity are among those contributing in the pathogenesis of cancer. In the present expression assay, we compared expressions of nine immune-related lncRNAs namely lnc-MICAL3-2 (AC016027.1), lnc-DDX31 (AL445645.1), LINC01063, LINC02381, ENST0000615051 (AC083809.1), AC009237.14 (lnc-TRIM43B-1), ENST0000603791, LINC1234 and AC008760.1 between breast cancer samples and their paired non-cancerous samples. Expression levels of lnc-MICAL3-2, lnc-DDX31, LINC01063, LINC02381, ENST0000615051 and lnc-TRIM43B-1 were significantly decreased in breast cancer samples compared with paired control tissues (Posterior mean difference= -2.774, -2.012, -2.012, -2.015, -0.884 and -2.872; P values= 0.019, 0.0001, 0.0001, 0.0001, 0.032 and 0.0001, respectively). Expression levels of these lncRNAs have been associated with a number of clinical characteristics of breast cancer patients. Lnc-TRIM43B-1 had the highest performance in distinguishing between tumoral and non-tumoral tissues (AUC=0.82, Sensitivity=76%, Specificity=73.24%). As these lncRNAs could differentiate tumor samples from control samples, they might be regarded as putative tissue markers for breast cancer.