Expression patterns of LNCRNA-GAS5 and its target APOBEC3c gene through miR-103 in breast cancer patients

Recently, correlation between lncRNA-GAS5 and miR-103 was studied. In addition, we predicted interaction between miR-103 and APOBEC3C, computationally. On the basis of these results, the first time we planned to evaluate the possible involvement of GAS5 in breast carcinogenesis and to reveal any correlation between GAS5 and APOBEC3C, miR-103 molecules. APOBEC enzymes are important players in immunity and may contribute to carcinogenesis. APOBEC3C belong to cytidine deaminases that able to mutate DNA and RNA by converting cytidine to uridine. Lately, more attention have been focused on non-coding RNAs, which was shown to regulate many key biological processes. Mounting evidence indicated that the aberrant expression of some lncRNAs include; LncRNA-GAS5 and miRNA 103, might play an important functional role in cancer biology. In this study, 40 paired tumor and normal samples that were grouped according to the types of breast cancer and clinical characteristics of patients, were observed with gene expression analysis and APOBEC3C gene sequencing. Expression level of APOBEC3C and lncRNA-GAS5 were significantly down-regulated. However, miRNA expression level significantly up-regulated. The expression of GAS5 was positively correlated with the expression of APOBEC3C and negatively correlated with the expression of miR-103. As a result of APOBEC3C gene screening no mutation was observed. In conclusion, we observed reduced expression levels of APOBEC3C and LncRNA-GAS5, and increased expression level of miRNA 103 in breast cancer patients. In order to understand the relationship between the breast tumors and biomarkers; further analysis is warranted.