A Comparative Study of HOTAIR Expression in Breast Cancer Patient Tissues and Cell Lines.

Objective: Recent data suggest that increased levels of the HOTAIR long non-coding RNA (IncRNA) are involved in the development of various types of malignancy, including breast cancer. The aim of present study was to investigate HOTAIR IncRNA expression profile in breast cancer (BC) patients and cell lines. Materials and Methods: In this experimental study, expression level of HOTAIR IncRNA was evaluated in BC and normal tissues of 15 patients as well as MDA-MB-231, MCF-7 and MCF-10A cell lines, using quantitative reverse-transcription polymerase chain reaction (qRT-PCR). HOTAIR IncRNA expression levels were estimated using 2(-Delta Delta Ct) method. Further, receiver operating characteristic (ROC) curve analysis was done to evaluate the selected IncRNA diagnostic potential. The Cox's proportional hazards regression model was performed to evaluate the predictive value of this IncRNA level in BC patients. Results: The results of present study demonstrated no significant difference in the expression of HOTAIR IncRNA in MCF7 and MDA-MB-231 cancer cell lines compared to MCF-10A as normal cell line (P>0.05). However, we observed a significantly increase in the expression of HOTAIR in BC patients compared to normal tissues (P<0.001). Significant associations were found between gene expression and tumour size and margin. We found 91.1% sensitivity and 95.7% specificity of circulating HOTAIR with an area under the ROC curve of 0.969. The Kaplan-Meier analysis indicated significant correlation between HOTAIR expression and overall survival. Conclusion: This study demonstrated that expression of HOTAIR is increased in BC and might be associated with its progression. According to these findings, HOTAIR expression could be proposed as biomarkers for BC early diagnosis and prognosis.