Optimization and exploitation of the serological proteome analysis to identify autoantibodies as biomarkers of colorectal cancer
(2014)
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- Authors
- Supervisors
- Feron, Olivier
- Abstract
- In developed countries, colorectal cancer (CRC) is a leading cause of cancer. Because this disease develops slowly over years and often starts with the apparition of polyps that may evolve in a malignant tumor, this cancer is particularly suitable for screening. However, current techniques of detection lack specificity and sensitivity, or are invasive, reducing the compliance of the patients. Thus, there is a need to find new biomarkers to improve the detection of CRC at an early stage and to reduce its incidence. In this work, we focused on autoantibodies (aAb) produced by the immune system as potential CRC biomarkers since they combine several advantages including stability, specificity and early production in the course of the disease. Human tumor-associated antigens (TAA) of interest were identified by the serological proteome analysis (SERPA) approach, based on the combination of 2D-gel electrophoresis and after transfer onto membranes, immunoblotting with sera from tumor-bearing mice or cancer patients. In order to improve this technique, we introduced the ‘hypoxia’ parameter in this setting to mimic the tumor microenvironment and to increase the antigenic diversity of the tumor cell lysates. Also, to allow the formation of immune complexes in a non-denaturing manner, we developed and implemented a method that we named ‘SID-DIGE’ for Sequential Immunoaffinity Depletion – Differential In Gel Electrophoresis. This method consists in the depletion by affinity chromatography of tumor cell lysates using aAb from control and tumor-bearing mouse, and the comparison of differentially depleted lysates using 2D-DIGE. This strategy led to the identification of the phosphorylated form of eEF2 as the target of specific aAb that represent early biomarkers of colorectal tumors in mice and adenoma developing in a subset of patients. More generally, this study validated (i) the interest of hypoxic conditions to improve the identification of aAb as CRC biomarkers and (ii) the potential of the SID-DIGE protocol to identify new TAA not detectable using conventional SERPA.
- Affiliations
Citations
Grandjean, M. (2014). Optimization and exploitation of the serological proteome analysis to identify autoantibodies as biomarkers of colorectal cancer. https://hdl.handle.net/2078.5/28637