Discovery and verification of gelsolin as a potential biomarker of colorectal adenocarcinoma in the Chinese population: Examining differential protein expression using an iTRAQ labelling-based proteomics approach.

Abstract

OBJECTIVE:

To identify and validate potential biomarkers of colorectal adenocarcinoma using a proteomic approach.

METHODS:

Multidimensional liquid chromatography⁄mass spectrometry was used to analyze biological samples labelled with isobaric mass tags for relative and absolute quantitation to identify differentially expressed proteins in human colorectal adenocarcinoma and paired normal mucosa for the discovery of cancerous biomarkers. Cancerous and noncancerous samples were compared using online and offline separation. Protein identification was performed using mass spectrometry. The downregulation of gelsolin protein in colorectal adenocarcinoma samples was confirmed by Western blot analysis and validated using immunohistochemistry.

RESULTS:

A total of 802 nonredundant proteins were identified in colorectal adenocarcinoma samples, 82 of which fell outside the expression range of 0.8 to 1.2, and were considered to be potential cancer-specific proteins. Immunohistochemistry revealed a complete absence of gelsolin expression in 86.89% of samples and a reduction of expression in 13.11% of samples, yielding a sensitivity of 86.89% and a specificity of 100% for distinguishing colorectal adenocarcinoma from normal tissue.

CONCLUSIONS:

These findings suggest that decreased expression of gelsolin is a potential biomarker of colorectal adenocarcinoma.

• Authors: Nai-Jun Fan, Chun-Fang Gao, Chang-Song Wang, Jing-Jing Lv, Guang Zhao, Xin-Hua Sheng, Xiu-Li Wang, Dong-Hui Li, Qing-Yin Liu, Jian Yin
• Journal: Canadian journal of gastroenterology = Journal canadien de gastroenterologie (Can J Gastroenterol) Vol. 26 Issue 1 Pg. 41-7 (Jan 2012) ISSN: 0835-7900 [Print] Canada
• PMID: 22288069 (Publication Type: Journal Article, Validation Study)

Chemical References

• Biomarkers, Tumor
• Gelsolin
• Indicators and Reagents

Topics

• Adenocarcinoma (genetics, metabolism, pathology)
• Aged
• Asian People (genetics)
• Biomarkers, Tumor (biosynthesis)
• Blotting, Western
• China
• Chromatography, Liquid (methods)
• Colonic Neoplasms (genetics, metabolism, pathology)
• Colorectal Neoplasms (genetics, metabolism, pathology)
• Down-Regulation (physiology)
• Female
• Gelsolin (biosynthesis)
• Gene Expression Profiling
• Gene Expression Regulation, Neoplastic
• Humans
• Immunohistochemistry
• Indicators and Reagents
• Male
• Middle Aged
• Proteomics (methods)
• Rectal Neoplasms (genetics, metabolism, pathology)
• Tandem Mass Spectrometry (methods)