Arefeh Tajik - M.Sc student university of Guilan
Soheila Talesh Sasani - Assistant Professor University of Guilan
Fereshteh Fakor - Associate Professor Guilan University of Medical Science

Background and Aim: Breast cancer has been known as a significant cause of cancer death among women in which various factors are involved, such as epigenetic factors. Long non-coding RNAs (lncRNAs) refer to a group of RNAs that are not involved in protein generation. This type of RNAs contribute to different regulatory processes, such as regulation of gene expression and may cause some disorders. HOTAIR ,as a lncRNA, plays an oncogenic role in several cancers, such as breast, gastric, colorectal, and cervical cancer. Recent studies showed that HOTAIR was highly expressed in breast cancer tissues and its level in primary tumors can be an risk factor for metastasis and survival. By recruiting PRC۲ to specific target genes which leads to H۳K۲۷ trimethylation and silencing of tumor suppressor genes, HOTAIR promotes breast cancer cell invasion. HOXD۱۰, encods a repressor protein that inhibits cell migration and invasion, is blocked via effect of HOTAIR lncRNA on the gene's promoter. According to findings, there is a notable relationship between alteration of HOTAIR expression and breast cancer progress in human, and this association is evaluated in this study.Methods: Tumoral and healthy breast tissues were obtained from breast cancer patients. Total RNA, including lncRNAs, was extracted by using TRIZOL reagent and followed by cDNA synthesis. Specific primers were designed via Oligo۷ for HOTAIR gene and GAPDH gene, as an internal control, and qRT-PCR carried out. Then obtained data were analyzed throughout SPSS software and Graph Pad Prism.Results: The qRT-PCR results showed high expression of HOTAIR gene is associated with breast cancer(p<۰.۰۵).Conclusion: HOTAIR is an important lncRNA playing fundamental roles in gene expresion changes. qRT-PCR results showed HOTAIR alteration in breast cancer patients, and it may be used as a biomarker in breast cancer prognosis. However, because our small sample size further research in greater population with different ethnicities are suggested.

HOTAIR gene, LncRNA, qRT-PCR, Breast cancer