Expression analysis of CBR3-AS1 and androgen receptor genes in breast cancer

Long non-coding RNAs (lncRNAs) have been shown to participate in the pathogenesis of a variety of cancers including breast cancer. The lncRNA Carbonyl reductase 3-Antisense 1 (CBR3-AS1) has been implicated in some human malignancies in association with androgen receptor (AR). In the present study, we evaluated the expression of CBR3-AS1 and AR transcripts in 52 breast cancer tissues, their corresponding adjacent non-cancerous tissues (ANCTs) and two breast cancer cell lines (MDA-MB-231 and MCF-7). We extracted data of our previously published work regarding expression level of Zinc-finger enhancer binding protein (ZEB1) in the same cohort of patients. CBR3-AS1 was up-regulated in MDA-MB-231 compared with ANCTs. AR was significantly down-regulated in both breast cancer cell lines compared with ANCTs. AR expression was lower in tumoral tissues compared with ANCTs but it did not reach the level of significance. CBR3-AS1 expression has been shown to be significantly elevated in tumor tissues compared with ANCTs (fold change = 4.178, P = 0.021). No significant associations have been detected between the level of transcripts and patients' data except for an association between AR expression and cancer stage (P = 0.037). In luminal B subtype, AR transcript levels were more frequently down-regulated (P = 0.015). A significant correlation has been detected between the levels of CBR3-AS1 and AR transcripts in tumor tissues but not in ANCTs. No significant correlation has been detected between the levels of AR and ZEB1 transcripts in tumor tissues or in ANCTs. The observed significant up-regulation of CBR3-AS1 in breast cancer tissues and cell lines is in line with the suggested oncogenic role of this lncRNA in other cancers.