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

作者：Fan Nai Jun; Gao Chun Fang^*; Wang Chang Song; Lv Jing Jing; Zhao Guang; Sheng Xin Hua; Wang Xiu Li; Li Dong Hui; Liu Qing Yin; Yin Jian

来源：Canadian Journal of Gastroenterology, 2012, 26(1): 41-47.

• Biomarker
• Colorectal cancer
• Gelsolin
• Proteomic

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.

• 出版日期2012-1