Project 466714

Breast cancer has a very high survival rate when the disease is detected in an early stage. However only about 64% of all cases are found this early. An improved method of screening is needed in order to improve the overall survival rate of this deadly disease. Current measures used are mammograms, which are low dose x-rays of the breast. In addition to being very painful, these exams miss 1 in 5 cases of breast cancer, providing a false negative, leading to the progression of the disease in these individuals, and eventual later detection in later stages. We believe the answer is to develop a series of biomarkers that can be screened for in a patients blood sample and can accurately predict the presence of breast cancer. We have shown that microRNA (miRNA), specifically miR-526b and miR-655 promote more aggressive tumor behavior, as a consequence of their post-transcriptional regulation. The premature version of these miRNA, the pri-miRNA, are detectable in the blood and the expression can accurately distinguish the tumor stages, from patient blood samples. Cells that overexpress these miRNA release a varied abundance of proteins and factors into their surrounding microenvironment that promotes tumor growth and metastasis. We believe that by studying the effect these miRNAs have on the microenvironment, we will find potential biomarkers amongst the secretory proteins. Through the use of bioinformatics, cell-line functional assays and human tissue/plasma screening we can identify these important secretory proteins, validate the miRNA regulation, investigate the secretory proteins role in promoting growth and metastasis, and finally answer our question; can they predict the presence of breast cancer?