Abstract
BACKGROUND/AIM: Several epigenetic alterations are involved in the development of breast cancer. The long noncoding RNA HOTAIR and related RNAs play a role in initiation of breast cancer and are promising targets for diagnostic biomarker and therapeutic studies. In this study, we aimed to investigate HMGA2 associated ceRNA HOTAIR pathway in breast cancer patients. MATERIALS AND METHODS: Forty breast cancer patients and ten healthy controls were included in this study, and then patients were divided into clinicopathologic groups. After total cell-free RNA isolation, expression levels of target RNAs were analysed by Real-Time PCR. The amount of gene expression was determined according to delta-delta Ct method and change in the expression was determined using the 2(-ΔΔCt) method. RESULTS: HOTAIR expression was significantly higher in the study group (especially in the ER negative group) than in the control group (p value = 0.006). When patients with relapse were compared with those without relapse, HMGA2 expression was significantly higher (p value = 0.048). There was a significant increase in miR-20a-5p expression (p value = 0.002) in the premenopausal group compared to the postmenopausal group, while there was a significant decrease in HMGA2 expression (p value = 0.002). A positive correlation between patient age and HMGA2 and a negative correlation between patient age and miR-20a-5p were found (respectively p value: 0.037 and p value: 0.006). Also, we found a negative correlation between HMGA2 and miR-20a-5p (p value: 0.027, correlation coefficient: -0.350). CONCLUSION: To our knowledge, this study is the first to examine the association of the HMGA2 associated HOTAIR axis with breast cancer in cell-free RNA from peripheral blood of patients. Our findings emphasize the potential of the HMGA2 associated HOTAIR axis as a prognostic biomarker and therapeutic target, especially in ER negative, postmenopausal onset, and relapsed breast cancer.