Detection of anti-CUEC-23 antibodies in serum of patients with esophageal squamous cell carcinoma: a possible new serum marker for esophageal cancer.
BACKGROUND
Serological identification of antigens by recombinant cDNA expression cloning (SEREX) is an established method for detecting new tumor-specific antigens. Antibodies to SEREX antigens may be useful for the detection of esophageal squamous cell carcinoma (SCC).


METHODS
A phage cDNA library of a human esophageal SCC cell line was screened using sera of patients with esophageal SCC. The presence and levels of serum antibodies to SEREX antigens were established by Western blotting and enzyme-linked immunosorbent assay (ELISA) using purified recombinant antigen proteins, respectively.


RESULTS
The newly identified esophageal SCC antigen is encoded by a novel gene located on chromosome 1, here designated CUEC-23. Serum CUEC-23-antibodies (s-CUEC-23-Abs) were detected in 14 of 54 patients with esophageal SCC (26%) by Western blot analysis. Esophageal SCCs were positive for s-CUEC-23-Abs together with CEA, SCC-Ag or CYFRA21-1 in 44, 41 and 52% of cases, respectively. There was no detectable association between the presence of s-CUEC-23-Abs and clinicopathological variables. ELISA showed that the levels of s-CUEC-23-Abs were significantly higher in patients with esophageal SCC than in healthy volunteers (17% in the former using the mean+3 SD of s-CUEC-23-Abs in healthy controls as the cutoff).


CONCLUSIONS
A new tumor antigen, CUEC-23, was identified by SEREX screening. s-CUEC-23-Abs might be a useful serum marker to detect esophageal SCC.
Shimada
Hideaki
H
Department of Gastroenterological Surgery, Chiba Cancer Center, 666-2 Nitona-cho, Chuou-ku, Chiba, 260-8717, Japan. hshimada@chiba-cc.jp
Kagaya
Akiko
A
Shiratori
Tooru
T
Nomura
Fumio
F
Takiguchi
Masaki
M
Matsubara
Hisahiro
H
Hiwasa
Takaki
T
D000368:Aged; D000912:Antibodies, Neoplasm / Q000032:analysis*; D000951:Antigens, Neoplasm / Q000097:blood; D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000097:blood*; D002294:Carcinoma, Squamous Cell / Q000276:immunology*; D004938:Esophageal Neoplasms / Q000276:immunology*; D005260:Female; D015723:Gene Library; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D015843:Serpins / Q000097:blood
D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D015843:Serpins; C051072:squamous cell carcinoma-related antigen