Expression analysis of autophagy-related long non-coding RNAs in Iranian patients with breast cancer

Autophagy has an established role in the development and progression of breast cancer. Recent studies have shown functional links between long non-coding RNAs (lncRNAs) and autophagy process. LINC01963, AL132989.1, RAB11B-AS1, PLBD1-AS1, AL139158.2, LOC105376805 (BX284668.5) and HERPUD2-AS1 (AC018647.2) are among autophagy related lncRNAs. In the current study, we compared expression of these seven lncRNAs between breast cancer samples and their paired non-cancerous tissues. RAB11B-AS1, HERPUD2-AS1 and PLBD1-AS1 were up-regulated in tumor samples compared with non-tumoral samples (Expression ratios (95% CI) = 2.56 (1.22-5.36), 2.13 (1.02-4.43) and 21.3 (10.36-43.89), respectively). ROC curve analysis indicated that PLBD1-AS1, RAB11B-AS1 and HERPUD2-AS1 had AUC values of 0.78, 0.61 and 0.6 for separation of breast cancer tissues from controls. Expression level of AL132989.1 in tumor tissues was associated with tubule formation (P value=0.02) in a way that tumor tissues with tubular formation score 1 had lower expression of AL132989.1. There was also a significant difference between expression levels of AL139158.2.1 among tumor tissues with different clinical stages (P value=0.02). Tumor tissues with higher clinical stages showed decreased expression of AL139158.2.1. In addition, there was also a significant difference between expression level of HERPUD2-AS1 in tumor tissues with different histological tumor grade and tubule formation (P value=0.03 and 0.003, respectively). Tumor tissues with higher histological tumor grade and higher tubule formation score showed higher expression of HERPUD2-AS1. Taken together, this study provides evidence for contribution of a number of recently identified autophagy-related lncRNAs in the pathogenesis of breast cancer.