Search

Breast cancer is the second most common type of cancer among women with an expected ∼192,000 newly diagnosed cases in the United States this year alone. Early detection methods are becoming increasingly important for guiding treatment options and decisions. Currently, standard molecular diagnostic tests of breast cancer characterize patient cases by estrogen receptor (ER), progesterone receptor (PR) and Her2neu status. The recently discovered biomolecule, microRNA (miRNA), is being assessed as a novel diagnostic tool; however, since miRNA is a regulatory molecule it is likely that expression is cell-type and location specific, thus studies that don't specifically study malignant and normal cells may mask miRNA patterns within tissue. The goal of our study was to evaluate miRNA expression within sub-regions of formalin-fixed paraffin-embedded breast cancer tissue. Utilizing a combination of laser-based and manual microdissection techniques, we evaluated the expression of several breast cancer associated miRNA via TaqMan chemistry. We dissected selected areas of tumor and normal cells, as well as a grid-like pattern over entire tissue sections to separately evaluate each histopathological region. The data suggest there is heterogeneity of miRNA expression within the tumor and the surrounding normal tissue. In order study this phenomenon in more detail, we are now adapting a new two-dimensional amplification (2D-PCR) device to measure miRNA levels across tissue specimens with fine resolution. This approach to examining miRNA profiles in tissue sections may lead to novel findings with diagnostic or prognostic implications for breast cancer patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2999.