Quantitative assessment of human serum transferrin receptor in breast cancer patients pre- and post-chemotherapy using peptide immunoaffinity enrichment coupled with targeted proteomics

Clin Chim Acta. 2015 Aug 25;448:118-23. doi: 10.1016/j.cca.2015.05.022. Epub 2015 Jun 18.


Background: sTfR, a soluble form of transferrin receptor in serum, has been suggested as an indicator of bone marrow failure in breast cancer patients receiving chemotherapy. However, intensive chemotherapy could also cause a reduction of sTfR to a level below the LOQ of most assays.

Methods: An advanced liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based targeted proteomics assay coupled with peptide immunoaffinity enrichment (SISCAPA) was developed and validated for monitoring sTfR.

Results: Tryptic peptide 681VEYHFLSPYVSPK693 was selected as a surrogate analyte for quantification. High-abundant proteins were first removed from serum, followed by SISCAPA that was effective in surrogate peptide enrichment and sensitivity enhancement. The resulting LOQ can achieve 100ng/ml (~10-fold increase). Then, sTfR levels in breast cancer patients pre- and post-chemotherapy, and healthy volunteers were accurately quantified as 1.77±0.53μg/ml, 0.98±0.26μg/ml and 1.66±0.50μg/ml, respectively, using a standard addition method. While there was no evidence for a difference between patients and healthy volunteers, differential levels of sTfR pre- and post-chemotherapy were obtained. Comparison between SISCAPA-targeted proteomics and ELISA indicated that the former approach provided a lower value of sTfR.

Conclusions: SISCAPA-targeted proteomics may allow the quantification of low-abundant proteins in a more accurate manner.

Keywords: Breast cancer; Chemotherapy; Liquid chromatography-tandem mass spectrometry; SISCAPA; Serum transferrin receptor; Targeted proteomics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
  • Breast Neoplasms / blood*
  • Breast Neoplasms / drug therapy*
  • Chromatography, Liquid
  • Female
  • Humans
  • Middle Aged
  • Peptides / blood
  • Peptides / immunology*
  • Proteomics*
  • Receptors, Transferrin / blood*
  • Receptors, Transferrin / immunology*
  • Tandem Mass Spectrometry


  • Peptides
  • Receptors, Transferrin