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Int J Clin Exp Pathol 2013;6(12):2835-2845

Original Article
Cancer testis antigen OY-TES-1 expression and serum immunogenicity in colorectal
cancer: its relationship to clinicopathological parameters

Bin Luo, Xiang Yun, Rong Fan, Yong-Da Lin, Shu-Jia He, Qing-Mei Zhang, Fa-Rong Mo, Fang Chen, Shao-Wen Xiao, Xiao-Xun Xie

Department of Histology & Embryology, School of Pre-clinical Medicine, Central Laboratory of Pre-clinical Medicine, Departments of Pediatrics,
Surgery, First Affiliated Hospital, Guangxi Medical University, Nanning 530021, Guangxi Zhuang Autonomous Region, China; Department of
Histology & Embryology, School of Pre-clinical Medicine, Guangxi Chinese Medicine University, Nanning 530001, Guangxi Zhuang Autonomous
Region, China. Equal contributors.

Received October 11, 2013; Accepted November 9, 2013; Epub November 15, 2013; Published December 1, 2013

Abstract: Cancer testis (CT) antigens are attractive targets for cancer immunotherapy because their expression is restricted in normal germ
line tissues but frequently detected in variety of tumors. OY-TES-1 is identified as a member of CT antigens. Current knowledge about OY-TES-
1 expression in colorectal cancer (CRC) is solely based on mRNA analysis. None of previous researches has studied OY-TES-1 at protein
level. In this study, OY-TES-1 polyclonal antibody was generated. The expression of OY-TES-1 mRNA and protein was detected by RT-PCR and
immunohistochemistry in 60 CRC and paired adjacent non-tumor tissues, 24 colorectal adenoma and 3 normal colon tissues, respectively.
Sera from 73 CRC patients were also tested for OY-TES-1 antibody by ELISA. Our results showed that the frequency of OY-TES-1 mRNA
expression was statistically higher in CRC (73.3%, 44/60) than that in adjacent non-tumor tissue (55.0%, 33/60) and colorectal adenoma
(45.8%, 11/24). For the first time, OY-TES-1 protein expression was found in (43.3%, 26/60) of CRC tissues, but absent in any of adjacent non-
tumor and colorectal adenoma tissues. No OY-TES-1 expression was found in normal colon by either RT-PCR or immunohistochemistry.
Furthermore, OY-TES-1 protein expression was correlated with tumor invasion stage (P=0.004) and histological grade (P=0.040). Anti-OY-TES-
1 antibody was detected in (9.6%, 7/73) of CRC patients’ sera but not in 76 healthy donors. This finding demonstrates that OY-TES-1 is
frequently expressed in CRC and is able to induce humoral immune response spontaneously in CRC patients, suggesting that it might be a
promising immunotherapy target for CRC. (IJCEP1310027).

Keywords: Cancer testis antigen, OY-TES-1, colorectal cancer

Address corresponding to: Dr. Xiao-Xun Xie, Department of Histology & Embryology, School of Pre-clinical Medicine, Guangxi Medical
University, 22 Shuangyong Road, Nanning 530021, Guangxi Zhuang Autonomous Region, China. Tel: 86-771-5358872; Fax: 86-771-5358872;
E-mail: xiaoxunxie@gmail.com; Dr. Shao-Wen Xiao, Department of Surgery, First Affiliated Hospital, Guangxi Medical University, 22 Shuangyong
Road, Nanning 530021, Zhuang Autonomous Region, China. Tel: 86-771-5356506; Fax: 86-771-5356506; E-mail: xsw57@yahoo.com