Plasma Membrane Proteomics of Human Breast Cancer Cell Lines Identifies Potential Targets for Breast Cancer Diagnosis and Treatment

Abstract

The use of broad spectrum chemotherapeutic agents to treat breast cancer results in substantial and debilitating side effects, necessitating the development of targeted therapies to limit tumor proliferation and prevent metastasis. In recent years, the list of approved targeted therapies has expanded, and it includes both monoclonal antibodies and small molecule inhibitors that interfere with key proteins involved in the uncontrolled growth and migration of cancer cells. The targeting of plasma membrane proteins has been most successful to date, and this is reflected in the large representation of these proteins as targets of newer therapies. In view of these facts, experiments were designed to investigate the plasma membrane proteome of a variety of human breast cancer cell lines representing hormone-responsive, ErbB2 over-expressing and triple negative cell types, as well as a benign control. Plasma membranes were isolated by using an aqueous two-phase system, and the resulting proteins were subjected to mass spectrometry analysis. Overall, each of the cell lines expressed some unique proteins, and a number of proteins were expressed in multiple cell lines, but in patterns that did not always follow traditional clinical definitions of breast cancer type. From our data, it can be deduced that most cancer cells possess multiple strategies to promote uncontrolled growth, reflected in aberrant expression of tyrosine kinases, cellular adhesion molecules, and structural proteins. Our data set provides a very rich and complex picture of plasma membrane proteins present on breast cancer cells, and the sorting and categorizing of this data provides interesting insights into the biology, classification, and potential treatment of this prevalent and debilitating disease.

Pan-Trk Immunohistochemistry Is an Efficient and Reliable Screen for the Detection of NTRK Fusions

“…TPM3 and TPM4 both encode tropomyosins that form part of the cytoskeleton in non-muscle cells and were shown to localize to the cell membrane in breast cancer. 10 The protein encoded by TRAF2 localizes to the cellular membrane as did pan-Trk IHC in the melanoma with the TRAF2-NTRK2 fusion. 11 Half of the present cases with ETV6 - NTRK3 fusions had nuclear staining.…”

Identification of the cis‑molecular neighbours of the immune checkpoint protein�B7‑H4 in the breast cancer cell‑line SK‑BR‑3 by proteomic proximity labelling

“…These may often dominate low-abundance cell surface proteins that are more difficult to extract and characterise, which are the focus of the present study. Thus far, few proteomic analyses of SK-BR-3 cells have been reported comparing proteins to a normal human mammary epithelial cell line (25), both of which used 2D-DIGE, which is inefficient at resolving membrane proteins. Thus, a more comprehensive list of the more abundant proteins was also presented in the present study.…”

ALCAM is a Novel Cytoplasmic Membrane Protein in TNF-α Stimulated Invasive Cholangiocarcinoma Cells

“…Determination of cytoplasmic membrane proteome may be a promising step towards the development of reliable diagnosis, prognosis, and drug design. Cytoplasmic membrane proteomics of several cancers have been identified (Kischel et al, 2008;Liu et al, 2010;Ziegler et al, 2014), but not in CCA. In this study, 7 novel cytoplasmic membrane proteins in TNF-α inducible CCA cell line were detected by nanoLC/MS/MS.…”