Expression of long noncoding RNAs in breast cancer in relation to reproductive factors and tumor characteristics.

Long noncoding RNAs (lncRNA) regulate expressions of several cancer-related genes and pathways. Expression profiling of lncRNAs would pave the way for identification of dysregulated pathways in cancer. We assessed expression of FAS-anti sense 1 (FAS-AS1), Taurine Upregulated 1 (TUG1), OPA-interacting protein 5-AS1 (OIP5 -AS1), nuclear-enriched abundant transcript 1 (NEAT1), and highly upregulated in liver cancer (HULC) in breast tumor tissues and adjacent noncancerous tissues (ANCTs). TUG1 was downregulated in tumoral tissues. We found associations between TUG1 expression and mitotic rate, NEAT1 expression and breast feeding duration as well as FAS-AS1 and OPI5 expressions and menarche age. A combination of transcript levels of all genes had 88.5% sensitivity and 42.3% specificity in breast cancer diagnosis. The current study provides evidence for the contribution of lncRNAs in breast cancer in relation to reproductive factors and tumor characteristics.