14 October 2015

Protein modifications in human breast cancer

We have discovered biomarkers that make it possible to distinguish breast cancer cells from non-cancerous cells, based on identifying chemical modifications of histones, the molecules about which DNA strands are wound to keep them in the cell nucleus. The method uses a high-field magnet to spread out the signals from different parts of the histone, to locate the site(s) of chemical modifications.

What did scientists discover?

We have resolved and identified dozens of proteoforms of small, DNA-binding proteins — the "histones" found in the cell nucleus — from both cancerous and non-cancerous cells. We identify one variant that is present only in non-cancerous cells, whose absence might serve as a future biomarker that indicates the presence of breast cancer. Additional insight is provided from increased binding of phosphorus to these proteins during cell division ("mitosis"), which might also serve as future biomarkers for proliferation of cancerous cells during breast cancer invasion.

Why is this important?

Breast cancer was the second leading cause of cancer related mortality for females in 2014. We find that certain proteins are potential indicators for detecting the presence of cancer and determining the type of cancer.

Who did the research?

Y. Chen1, M. E. Hoover2, X. Dang3, A. A. Shomo3, X. Guan1, A. G. Marshall1,3, M. A. Freitas2*, and N. L. Young1*

1NHMFL, Tallahassee; 2The Ohio State University College of Medicine; 3Chemistry & Biochemistry, FSU

Why did they need the MagLab?


This research was conducted in the 14.5T Ion Cyclotron Resonance Magnet at the MagLab's ICR Facility.

The protein constructed from a single gene may exhibit sequence variants and chemical modifications (see Figure). The only way to distinguish and identify the resulting “proteoforms” is by top-down mass spectrometry, that is, the ability to isolate every single proteoform of the protein. The mass spectrum that contains resonances from every one of the proteoforms contained in the sample is so large and complex that it demands the highest possible mass resolution, which is provided by the MagLab’s high-field Fourier transform ion cyclotron resonance mass spectrometers.

Details for scientists


This research was funded by the following grants: G.S. Boebinger (NSF DMR-1157490), A. G. Marshall (NSF CHE-1019193), M. A. Freitas (NIH CA107106)

For more information, contact Alan Marshall.


  • Research Area: Biochemistry
  • Research Initiatives: Life
  • Facility / Program: ICR
  • Year: 2015
Last modified on 16 October 2015