Analysis of microRNAs differential expression profile in breast cancer using microarrays

Abstract

Metastasis is a process responsible for the death of approximately 90% of cancer patients and involves multiple steps in which neoplasic cells invade the adjacent stroma in a path called epithelial mesenchymal transition (EMT). During this stage, neoplasic cells respond to adjacent stroma signals changing their own cellular characteristics (epithelium), reducing cellular adhesion and acquiring mesenchymal properties such as mobility. Finally, they enter in the lymphatic and blood vessels spreading to distant tissues where micro metastasis are created, and grow to originate new tumors.Recent studies suggest the existence of a miRNA network acting as regulators of the tumor metastasis event. The current project is within the range of functional genomics of cancer and refers to the study of the role of miRNAs in tumor metastasis in patients with breast cancer. We intend to use the microarray technology to investigate the expression of microRNAs and proteins potentially involved in the processes of invasion and metastasis in breast carcinomas. The central idea is to trace microRNAs differential expression signatures in tumors of patients with invasive metastatic breast carcinomas and in patients without metastatic carcinomas.Once microRNAs can act either as suppressors or promoters of metastasis accordingly to the RNAm targets and expression of key-role proteins, our hypothesis is based on the idea that some microRNAs have differential expression levels in breast tumors with metastatic potential. These microRNAs would be associated to the metastasis process. Once identified, they could be used as useful biomarkers to the identification of potentially metastatic tumors. The results will be useful for better understanding the genetic and molecular basis of the metastasis development in breast cancer, as well as the microRNAs role in this process.