Quantitative Profiling of Post-translational Modifications by Immunoaffinity Enrichment and LC-MS/MS in Cancer Serum without Immunodepletion

Mol Cell Proteomics. 2016 Feb;15(2):692-702. doi: 10.1074/mcp.O115.052266. Epub 2015 Dec 3.


A robust method was developed and optimized for enrichment and quantitative analysis of posttranslational modifications (PTMs) in serum/plasma samples by combining immunoaffinity purification and LC-MS/MS without depletion of abundant proteins. The method was used to survey serum samples of patients with acute myeloid leukemia (AML), breast cancer (BC), and nonsmall cell lung cancer (NSCLC). Peptides were identified from serum samples containing phosphorylation, acetylation, lysine methylation, and arginine methylation. Of the PTMs identified, lysine acetylation (AcK) and arginine mono-methylation (Rme) were more prevalent than other PTMs. Label-free quantitative analysis of AcK and Rme peptides was performed for sera from AML, BC, and NSCLC patients. Several AcK and Rme sites showed distinct abundance distribution patterns across the three cancer types. The identification and quantification of posttranslationally modified peptides in serum samples reported here can be used for patient profiling and biomarker discovery research.

MeSH terms

  • Acetylation
  • Breast Neoplasms / blood
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / pathology
  • Carcinoma, Non-Small-Cell Lung / blood
  • Carcinoma, Non-Small-Cell Lung / genetics*
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Cell Line, Tumor
  • Chromatography, Liquid
  • Female
  • Humans
  • Leukemia, Myeloid, Acute / blood
  • Leukemia, Myeloid, Acute / genetics*
  • Leukemia, Myeloid, Acute / pathology
  • Methylation
  • Neoplasm Proteins / biosynthesis*
  • Neoplasm Proteins / blood
  • Protein Processing, Post-Translational / genetics
  • Proteomics / methods
  • Tandem Mass Spectrometry


  • Neoplasm Proteins