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Updated: May 16, 2025
Systems Biology of Metabolic Regulation by Estrogen Receptor Signaling in Breast Cancer
Published on: March 17, 2016
Native top-down proteomics enables discovery in endocrine-resistant breast cancer
Fabio P Gomes1, Kenneth R Durbin2, Kevin Schauer3
1Virginia Commonwealth University, Richmond, VA, USA.
Abstract:
Oligomerization of proteoforms produces functional protein complexes. Characterization of these assemblies within cells is critical to understanding the molecular mechanisms involved in disease and to designing effective drugs. Here we present a native top-down proteomics (nTDP) strategy to identify protein assemblies (≤70 kDa) in breast cancer cells and in cells that overexpress epidermal growth factor receptor (EGFR), which serves as a resistance model of estrogen receptor-alpha (ER)-targeted therapies. This nTDP approach identified ~104 complexoforms from 17 protein complexes, which revealed several molecular features of the breast cancer proteome, including EGFR-induced dissociation of nuclear transport factor 2 (NUTF2) assemblies that modulate ER activity. We found that the K4 and K55 post-translational modification sites discovered with nTDP differentially impact the effects of NUTF2 on the inhibition of the ER signaling pathway. The characterization of endogenous proteoform-proteoform/ligand interactions revealed the molecular diversity of complexoforms and their role in breast cancer growth.
Insights
This study introduces a native top-down proteomics method to analyze protein complexes in breast cancer cells. The technique identified key interactions, including how epidermal growth factor receptor affects estrogen receptor signaling via nuclear transport factor 2.
Area of Science:
- Proteomics
- Molecular Biology
- Cancer Research
Background:
- Protein complex characterization is vital for understanding disease mechanisms and drug development.
- Epidermal growth factor receptor (EGFR) overexpression is a model for resistance to estrogen receptor-alpha (ER)-targeted therapies.
Purpose of the Study:
- To develop and apply a native top-down proteomics (nTDP) strategy for identifying protein assemblies in breast cancer cells.
- To investigate the role of EGFR in modulating ER activity through protein complex interactions.
Main Methods:
- Utilized native top-down proteomics (nTDP) to identify protein assemblies up to 70 kDa.
- Analyzed breast cancer cells and cells overexpressing EGFR.
Main Results:
- Identified approximately 104 complexoforms from 17 protein complexes.
- Revealed EGFR-induced dissociation of nuclear transport factor 2 (NUTF2) assemblies impacting ER activity.
- Discovered that specific post-translational modification sites on NUTF2 differentially affect ER signaling inhibition.
Conclusions:
- The nTDP strategy effectively characterizes endogenous proteoform-proteoform/ligand interactions.
- Protein complex diversity plays a significant role in breast cancer progression.
- Findings provide insights into molecular mechanisms of breast cancer and potential therapeutic targets.
