Proteomic Profiling of Triple-negative Breast Carcinomas in Combination With a Three-tier Orthogonal Technology Approach Identifies Mage-A4 as Potential Therapeutic Target in Estrogen Receptor Negative Breast Cancer

Abstract

Breast cancer is a very heterogeneous disease, encompassing several intrinsic subtypes with various morphological and molecular features, natural history and response to therapy. Currently, molecular targeted therapies are available for estrogen receptor (ER) ؊ and human epidermal growth factor receptor 2 (Her2)-positive breast tumors. However, a significant proportion of primary breast cancers are negative for ER, progesterone receptor (PgR), and Her2, comprising the triple negative breast cancer (TNBC) group. Women with TNBC have a poor prognosis because of the aggressive nature of these tumors and current lack of suitable targeted therapies. As a consequence, the identification of novel relevant protein targets for this group of patients is of great importance. Using a systematic two dimensional (2D) gel-based proteomic profiling strategy, applied to the analysis of fresh TNBC tissue biopsies, in combination with a three-tier orthogonal technology (two dimensional PAGE/silver staining coupled with MS, two dimensional Western blotting, and immunohistochemistry) approach, we aimed to identify targetable protein markers that were present in a significant fraction of samples and that could define therapy-amenable sub-groups of TNBCs. We present here our results, including a large cumulative database of proteins based on the analysis of 78 TNBCs, and the identification and validation of one specific protein, Mage-A4, which was expressed in a significant fraction of TNBC and Her2-positive/ER negative lesions. The high level expression of Mage-A4 in the tumors studied allowed the detection of the protein in the tumor interstitial fluids as well as in sera. The existence of immunotherapeutics approaches specifically targeting this protein, or Mage-A protein family members, and the fact that we were able to detect its presence in serum suggest novel management options for TNBC and human epidermal growth factor receptor 2 positive/estrogen receptor negative patients bearing

Advancement of mass spectrometry-based proteomics technologies to explore triple negative breast cancer

“…Another label-based proteomics study reported that PTPN12, a tyrosine phosphatase, inhibited cellular transformation and metastasis of TNBC cells 104 . A systematic 2D gel-based proteomic study of TNBC tissue biopsies uncovered Mage-A4 105 , a family member of Mage-A, as a unique biomarker for TNBC and HER2 patients. Additionally, a label-free proteomic study identified Iroquois homeobox protein 1 (IRX1), which is involved in metanephric nephron development, as a potential plasma biomarker for TNBC 106 .…”

Trends of triple negative breast cancer research (2007–2015)

“…[2] Women with TNBC have a poor prognosis due to the aggressive nature and lack of suitable targeted therapies. [3] Presently, research progression for TNBC has not yet been studied. Thus, it is necessary to monitor the global TNBC research.…”

Comparative Profiling of Triple-Negative Breast Carcinomas Tissue Glycoproteome by Sequential Purification of Glycoproteins and Stable Isotope Labeling

“…In the past few years, several studies have discovered a few breast cancer associated tissue markers, such as estrogen and progesterone receptors, HER2/neu (erbB2), p53, Ki-67/MIB-1 and vascular endothelial growth factor (VEGF) [6,7]. In addition, Mage-A4 was identified as potential therapeutic target in TNBC [8].…”