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Upregulation of plasma C9 protein in gastric cancer patients
Author(s) -
Chong PohKuan,
Lee Huiyin,
Loh Marie Chiew Shia,
Choong LeeYee,
Lin Qingsong,
So Jimmy Bok Yan,
Lim Khong Hee,
Soo Ross Andrew,
Yong Wei Peng,
Chan Siew Pang,
Smoot Duane T.,
Ashktorab Hassan,
Yeoh Khay Guan,
Lim Yoon Pin
Publication year - 2010
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.201000127
Subject(s) - downregulation and upregulation , cancer , blood proteins , medicine , cancer research , oncology , chemistry , biochemistry , gene
Abstract Gastric cancer is one of the leading causes of cancer‐related deaths worldwide. Current biomarkers used in the clinic do not have sufficient sensitivity for gastric cancer detection. To discover new and better biomarkers, protein profiling on plasma samples from 25 normal, 15 early‐stage and 21 late‐stage cancer was performed using an iTRAQ‐LC‐MS/MS approach. The level of C9 protein was found to be significantly higher in gastric cancer compared with normal subjects. Immunoblotting data revealed a congruent trend with iTRAQ results. The discriminatory power of C9 between normal and cancer states was not due to inter‐patient variations and was independent from gastritis and Helicobacter pylori status of the patients. C9 overexpression could also be detected in a panel of gastric cancer cell lines and their conditioned media compared with normal cells, implying that higher C9 levels in plasma of cancer patients could be attributed to the presence of gastric tumor. A subsequent blind test study on a total of 119 plasma samples showed that the sensitivity of C9 could be as high as 90% at a specificity of 74%. Hence, C9 is a potentially useful biomarker for gastric cancer detection.