Nafiseh Ghanbari - Science Faculty, Science and Art University, Yazd, Iran
Sayyed Mohsen Miresmaili - Yazd Cardiovascular Research Center, Shahid Sadooghi University of Medical Sciences, Yazd, Iran.
Ali Dehghani Froozabadi - Yazd Cardiovascular Research Center, Shahid Sadooghi University of Medical Sciences, Yazd, Iran

Introduction: Oncological diseases such as breast cancer persist one of the most common causes of death. Genetics studies augmented cancer research significantly. Recent studies showed that in addition to genetic disorders, the development of cancer is triggered by epigenetic changes. Changes in DNA methylation and miRNA expression are critical factors, controlling oncogenesis and metastasis. DNA methylation is an important epigenetic modification that often leads to silencing on the gene transcription. As a rule, cancer cells are characterized by irregular DNA methylation patterns, appeared by global hypomethylation and gene-specific hypermethylation. Aim: To analyze expression of miR-373 in human breast cancer cells and to explore the effect of 5- azacitidine(5-aza), a demethylatiing agent on expression level of metastamicroRNA (miR-373) in MCF-7 cell line Methods: The study was performed on wild-type MCF-7 cell line. Cells were treated with 5-aza. Relative expression levels of miRNA-373 examined, using quantitative RT-PCR. The MTT assay was used to monitor cell viability. Results: We analyze the miR-373 expression in MCF-7. Changes of miRNA-373 was detected in cell lines. The significant up-regulation was found for miRNA-373 level. 5-aza treatment caused an increase of miRNA-373 level in MCF-7 cells. Pretreatment of MCF-7 cell line with 5-aza resulted in the increase of miRNA-373 expression. Conclusion: It was shown that use of 5-aza can up-regulated the expression of miRNA-373 in breast cancer cells. The Epidrugs such as 5-aza not only possess the demetylation effect, but also by changes in expression of miRNAs, involved in metastasis, cell proliferation, migration and metastasis