CABYR Is a Novel Cancer-Testis Antigen in Lung Cancer

• Published in: Clinical cancer research Vol. 13; no. 4; pp. 1288 - 1297
• Main Authors: Luo, Chonglin, Xiao, Xueyuan, Liu, Danhui, Chen, Shaosong, Li, Mingying, Xu, Anjian, Liu, Jifu, Gao, Shugeng, Wu, Shanshan, He, Dacheng
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 15-02-2007
• Subjects: Antibodies, Neoplasm - blood; Antibodies, Neoplasm - immunology; Antibody Specificity; Antigens, Neoplasm - biosynthesis; Antigens, Neoplasm - blood; Antigens, Neoplasm - genetics; Antigens, Neoplasm - immunology; Antineoplastic agents; Biological and medical sciences; CABYR; Calcium-Binding Proteins - biosynthesis; Calcium-Binding Proteins - blood; Calcium-Binding Proteins - genetics; Calcium-Binding Proteins - immunology; cancer-testis antigen; Cell Line, Tumor; HeLa Cells; Humans; Immunohistochemistry; immunotherapy; K562 Cells; lung cancer; Lung Neoplasms - blood; Lung Neoplasms - genetics; Lung Neoplasms - immunology; Male; Medical sciences; Pharmacology. Drug treatments; Phosphoproteins - biosynthesis; Phosphoproteins - blood; Phosphoproteins - genetics; Phosphoproteins - immunology; Pneumology; Protein Isoforms; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; Testis - immunology; Tumors of the respiratory system and mediastinum; Lung disease; Cancer testis antigen; Tumor associated antigen; Respiratory disease; Lung cancer; Bronchus disease; Malignant tumor; Bronchopulmonary
• ISSN: 1078-0432; 1557-3265
• DOI: 10.1158/1078-0432.CCR-06-1742

Purpose: Cancer-testis (CT) antigens are often expressed in a proportion of tumors of various types. Their restricted normal tissue
expression and immunogenicity make them potential targets for immunotherapy. CABYR is a calcium-binding tyrosine phosphorylation–regulated
fibrous sheath protein initially reported to be testis specific and subsequently shown to be present in brain tumors. This
study was to determine whether CABYR is a novel CT antigen in lung cancer.
Experimental Design: mRNA expression of CABYR-a/b (combination of CABYR-a and CABYR-b) and CABYR-c was examined in 36 lung cancer specimens, 14
cancer cell lines, and 1 normal cell line by conventional and real-time reverse transcription-PCR. Protein expression of CABYR
was analyzed in 50 lung cancer tissues by immunohistochemistry. Antibodies specific to CABYR were analyzed in sera from 174
lung cancer patients and 60 healthy donors by ELISA and Western blot.
Results: mRNA expression of CABYR-a/b and CABYR-c was observed, respectively, in 13 and 15 of 36 lung cancer tissues as well as in
3 and 5 of 14 cancer cell lines, whereas neither of them was observed in adjacent noncancerous tissues or the normal cell
line. Protein expression of CABYR-a/b and CABYR-c was observed, respectively, in 20 and 19 of 50 lung cancer tissues. IgG
antibodies specific to CABYR-a/b and CABYR-c were detected, respectively, in 11% and 9% of sera from lung cancer patients
but not from the 60 healthy donors.
Conclusion: CABYR is a novel CT antigen in lung cancer and may be a promising target for immunotherapy for lung cancer patients.