Stroma derived COL6A3 is a potential prognosis marker of colorectal carcinoma revealed by quantitative proteomics

// Jie Qiao 1, 2, * , Cai-Yun Fang 3, * , Sun-Xia Chen 2 , Xiao-Qing Wang 2 , Shu-Jian Cui 4 , Xiao-Hui Liu 2 , Ying-Hua Jiang 2 , Jie Wang 2 , Yang Zhang 2 , Peng-Yuan Yang 1, 2, 3 , Feng Liu 1, 2 1 Department of Medical Systems Biology of School of Basic Medical Sciences, Shanghai, China 2 Institutes of Biomedical Sciences Fudan University, Shanghai, China 3 Department of Chemistry, Fudan University, Shanghai, China 4 College of Bioscience and Biotechnology, Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, Yangzhou University, Yangzhou, China * These authors have contributed equally to this work Correspondence to: Feng Liu, e-mail: liuf@fudan.edu.cn Peng-Yuan Yang, e-mail: pyyang@fudan.edu.cn Keywords: colorectal cancer, tumor microenvironment, fibroblast, proteomics, COL6A3 Received: February 10, 2015      Accepted: August 04, 2015      Published: August 18, 2015 ABSTRACT Colorectal cancer (CRC) represents the third most common cancer in males and second in females worldwide. Here, we performed a quantitative 8-plex iTRAQ proteomics analysis of the secreted proteins from five colonic fibroblast cultures and three colon cancer epithelial cell lines. We identified 1114 proteins at 0% FDR, including 587 potential secreted proteins. We further recognized 116 fibroblast-enriched proteins which were significantly associated with cell movement, angiogenesis, proliferation and wound healing, and 44 epithelial cell-enriched proteins. By interrogation of Oncomine database, we found that 20 and 8 fibroblast-enriched proteins were up- and downregulated in CRC, respectively. Western blots confirmed the fibroblast-specific secretion of filamin C, COL6A3, COL4A1 and spondin-2. Upregulated mRNA and stroma expression of COL6A3 in CRC, which were revealed by Oncomine analyses and tissue-microarray-immunohistochemistry, indicated poor prognosis. COL6A3 expression was significantly associated with Dukes stage, T stage, stage, recurrence and smoking status. Circulating plasma COL6A3 in CRC patients was upregulated significantly comparing with healthy peoples. Receiver operating characteristic curve analysis revealed that COL6A3 has better predictive performance for CRC with an area under the curve of 0.885 and the best sensitivity/specificity of 92.9%/81.3%. Thus we demonstrated that COL6A3 was a potential diagnosis and prognosis marker of CRC.