Identification of CCDC62-2 as a novel cancer/testis antigen and its immunogenicity.
Cancer/testis (CT) antigens are expressed in normal germ line tissues and various cancers. They are considered promising target molecules for immunotherapy for patients with various cancers. To identify CT antigens, we performed serological identification of antigens by recombinant expression cloning. The humoral immune response of cancer patients against a newly defined antigen was analyzed. A testicular cDNA library was immunoscreened with serum obtained from a gastric adenocarcinoma patient whose primary cancer had regressed once and most liver metastases had disappeared transiently. We isolated 55 positive cDNA clones comprising 23 different genes. They included 4 genes with testis-specific expression profiles in the Unigene database, including coiled-coil domain containing 62 (CCDC62). RT-PCR analysis showed that the expression of 2 splice variants of CCDC62 was restricted to the testis in normal adult tissues. In malignant tissues, CCDC62 variant 2 (CCDC62-2) was aberrantly expressed in a variety of cancers, including stomach cancer. A serological survey of 191 cancer patients with a range of different cancers by ELISA revealed antibodies to CCDC62-2 in 13 patients, including stomach cancer. None of the 41 healthy donor serum samples were reactive in the same test. The serum reaction against CCDC62-2 was confirmed by western blot. CCDC62-2 is a CT antigen that is immunogenic in cancer patients.
Domae
Shohei
S
Department of Immunology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, 2-5-1 Shikata-cho, Okayama, Japan.
Nakamura
Yoichi
Y
Nakamura
Yurika
Y
Uenaka
Akiko
A
Wada
Hisashi
H
Nakata
Masao
M
Oka
Mikio
M
Kishimoto
Koji
K
Tsukamoto
Goichi
G
Yoshihama
Yasuto
Y
Matsuoka
Junji
J
Gochi
Akira
A
Kohno
Shigeru
S
Saika
Takashi
T
Sasaki
Akira
A
Nakayama
Eiichi
E
Ono
Toshiro
T
D000230:Adenocarcinoma / Q000276:immunology*; D000368:Aged; D000951:Antigens, Neoplasm / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D001483:Base Sequence; D015153:Blotting, Western; D017931:DNA Primers; D018076:DNA, Complementary; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000276:immunology*; D013737:Testis / Q000276:immunology*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*
D000951:Antigens, Neoplasm; C531357:CCDC62 protein, human; D017931:DNA Primers; D018076:DNA, Complementary; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014157:Transcription Factors