Discovery of Tamoxifen and N-Desmethyl Tamoxifen Protein Targets in MCF-7 Cells Using Large-Scale Protein Folding and Stability Measurements

ABSTRACT: The proteins in an MCF-7 cell line were probed for tamoxifen (TAM) and n-desmethyl tamoxifen (NDT) induced stability changes using the Stability of Proteins from Rates of Oxidation (SPROX) technique in combination with two different quantitative proteomics strategies. Together the SILAC- and iTRAQ-SPROX experiments described here enabled over 1000 proteins to be assayed for TAM- and NDT- induced protein stability changes, and a total of 163 and 200 protein hits were identified in the TAM and NDT studies, respectively. A subset of high confidence hits were assessed for experimental links to the ER using a STRING analysis. TAM was shown to induce stabilization of Y-box binding protein 1 (YBX1), a protein recently shown to bind the estrogen receptor. TAM was shown to directly interact with purified recombinant YBX1 with Pulse Proteolysis (PP). These results support YBX1 as a direct protein target of TAM. Proteins with altered expression levels with TAM and NDT treatment were identified with SILAC quantitation. In total, 799 and 671 proteins were probed for TAM- and NDT- induced expression changes, respectively, and 49 and 30 proteins had altered expression. This work also involved the use of a novel data analysis strategy to identify protein targets of ligands using the SPROX technique.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Permanent Cell Line Cell, Cell Culture

DISEASE(S): Breast Cancer

SUBMITTER: Ryenne Ogburn  

LAB HEAD: Michael C. Fitzgerald

PROVIDER: PXD006732 | Pride | 2019-11-08

REPOSITORIES: Pride