Proteomic Analysis to Identify Novel Circulating Breast Cancer Markers
Abstract
Twenty serum samples from healthy women and breast cancer patients at different stages were fractionated using two separate antibody columns to remove highly abundant proteins. Samples were randomized prior to fractionation and mass spectrometry testing. Each fraction was digested with trypsin and subsequently analyzed by LC-MS. Peptides were targeted based on the disease to control peak intensity ratios measured in the averages of all mass spectra in each group and t-tests of the intensity of each individual peak. A series of preprocessing steps were employed to produce an expansive list of peptides for further investigation and sequencing. These steps included spectral alignment, baseline subtraction, normalization, identifying of local maxima, further identifying "large" maxima as peaks, and looking for signs of differential expression. The antibody columns removed 20 of the most abundant proteins in serum. Using LC-MS and bioinformatics analysis we found 12 differentially expressed peaks in the Cancer vs. Healthy groups. Efforts are ongoing to identify targeted peptide ion signals using tandem matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS/MS). Serum fractionation using specific antibody columns followed by LC-MS and bioinformatics analysis is a feasible approach to peptide profiling in health women and breast cancer patients.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2005
- Accession Number
- ADA449897
Entities
People
- Francisco J. Esteva
Organizations
- The University of Texas MD Anderson Cancer Center