Identifying microRNA patterns that may predict early onset breast cancer in Lebanese women.

Abstract

Background: Breast cancer is the most common cancer in females around the world. In Lebanon it accounts for over one third of all female cancer diagnoses. Lebanese patients get aggressive breast cancer, at a younger age and 10 years earlier than women in the West. It is therefore important to understand the pecularities of breast cancer in our population in order to determine novel methods of screening that allows the detection of this early onset breast cancer. There is increasing evidence that miRNA dysegulation plays an important role in tumorigenesis, cancer progression and metastasis. microRNA have been emerging also as potential biomarkers that correlate with disease onset and progression.Aims: The aim of this study is to identify a specific miRNA signature in Lebanese women with early onset breast cancer in order to develop a biomarker for the disease.Methods: The aims of this study were achieved by extracting miRNA from archived breast cancer tissue from patients at the AUBMC. Assessment of potential patterns of miRNA expression and dysregulation were accomplished through microarray analysis, whereas specific miRNA dysregulation were assessed using quantitative real-time PCR.Results: miRNA profiles analysis revealed specific patterns in patients depending on their menopausal state. Using quantitative real-time PCR, we have determined that miR-10b and miR-148b are significantly elevated in patients with early onset breast cancer, whereas miR-155 is a marker of postmenopausal breast cancer onset. We have also determined that miR-221 is significantly elevated with the overexpression of Her2-neu; while miR-21 expression correlated significantly with tumor stage.Conclusion: Our preliminary findings indicate that miRNA isolated from breast tumor tissue, may serve as potential markers for early onset breast cancer in Lebanese women. These findings will benefit from expanding the patient pool size, and moving to the analysis of miRNA in patient plasma.