title: Cancer testis antigen SPAG9 is a promising marker for the diagnosis and treatment of lung cancer.
abstract: Cancer testis antigen sperm-associated antigen 9 (SPAG9) is highly expressed in many types of cancers. In the present study, to obtain a better understanding of the relevance of SPAG9 in cancer diagnosis and treatment, the expression of SPAG9 mRNA and protein in lung cancer specimens was evaluated by RT-PCR, western blotting and immunohistochemistry. ELISA was used to quantify the SPAG9 autoantibody in the peripheral blood of lung cancer patients. The results showed that the expression of SPAG9 mRNA and protein in the lung cancer tissues was significantly higher than that in the adjacent non-cancerous tissues (P<0.01). The level of the SPAG9 autoantibody in the serum of lung cancer patients was significantly higher than the level in the healthy controls (P<0.001), and the level of the SPAG9 autoantibody in the serum of untreated patients was significantly higher than that in treated patients (P=0.002). SPAG9 IgG antibody levels were significantly lower in treated adenocarcinoma and small cell lung cancer patients than these levels in the untreated patients (P=0.006, P=0.026, respectively), while no statistical difference was found between treated and untreated squamous cell carcinoma patients. Our results suggest that the SPAG9 antibody in serum is a promising marker for the diagnosis of lung cancer, and the level of the humoral immune response to this antigen appears to be related to the type of lung cancer.
authors.affiliation: Department of Immunology, Basic Medical College of Central South University, Changsha, Hunan 410078, P.R. China.
authors.forename: Biqiong
authors.initials: B
authors.lastname: Ren
authors.affiliation: Department of Immunology, Basic Medical College of Central South University, Changsha, Hunan 410078, P.R. China.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Wei
authors.affiliation: Laboratory of The Second People's Hospital of Hunan Province, Changsha, Hunan 410007, P.R. China.
authors.forename: Guoying
authors.initials: G
authors.lastname: Zou
authors.affiliation: Laboratory of The Second People's Hospital of Hunan Province, Changsha, Hunan 410007, P.R. China.
authors.forename: Junyu
authors.initials: J
authors.lastname: He
authors.affiliation: Laboratory of The Second People's Hospital of Hunan Province, Changsha, Hunan 410007, P.R. China.
authors.forename: Guofeng
authors.initials: G
authors.lastname: Xu
authors.affiliation: Laboratory of The Second People's Hospital of Hunan Province, Changsha, Hunan 410007, P.R. China.
authors.forename: Fei
authors.initials: F
authors.lastname: Xu
authors.affiliation: Department of Laboratory of Hunan University of Chinese Medicine, Changsha, Hunan 410007, P.R. China.
authors.forename: Yiran
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Laboratory of The Second People's Hospital of Hunan Province, Changsha, Hunan 410007, P.R. China.
authors.forename: Haowen
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Laboratory of The Second People's Hospital of Hunan Province, Changsha, Hunan 410007, P.R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Immunology, Basic Medical College of Central South University, Changsha, Hunan 410078, P.R. China.
authors.forename: Guoan
authors.initials: G
authors.lastname: Ma
authors.affiliation: Department of Immunology, Basic Medical College of Central South University, Changsha, Hunan 410078, P.R. China.
authors.forename: Ping
authors.initials: P
authors.lastname: Yu
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000378:metabolism* / Q000401:mortality; D016022:Case-Control Studies; D005260:Female; D015870:Gene Expression; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008168:Lung / Q000378:metabolism / Q000473:pathology; D008175:Lung Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000401:mortality; D008297:Male; D008875:Middle Aged
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D001323:Autoantibodies; D014408:Biomarkers, Tumor; D007074:Immunoglobulin G; C111047:SPAG9 protein, human