Abstract

Introduction: MicroRNAs are made up of 18 to 25 nucleotides from the non-coding regions of the DNA. Recently, MicroRNAs have been discovered to play a significant role in numerous aspects of cell cycle and cell growth, such as controlling apoptosis, cell proliferation or even cell responses to injurious stimuli like hypoxia. In addition, in neoplasms whether benign or malignant, the expression of MiRNAs is greatly altered in which some are up-regulated and others are down-regulated. In any case, this leads to disturbances in the cell cycle and cell homeostasis. This paper is a retrospective study attempting to shed light on the most common MiRNAs which are significantly over or under expressed in breast cancer and their specific roles in the cancer pathway. Method: In this paper the EndNote program 10 was used to research PubMed published articles regarding MiRNAs in Breast Cancer. In the search box, the terms “MiRNAs” and “Breast cancer” were typed and publication years were specified to range from 2005 – 2010. Results: After searching with the above criteria, 260 records were found. The abstracts of these records were then studied thoroughly in order to come up with the most relevant data to the objective of this paper. Conclusion: Our review suggests that MiRNAs have a key role in the development and progression of breast cancer. However, more studies are required to delineate key MiRNAs whose expression are altered in the onset and progression of breast cancer. With carefully designed translational studies, MiRNAs can serve a novel role in the detection, diagnosis, prognosis, and possible treatment of breast cancer.