[Human esophageal carcinoma antigens screened by serologic analysis of recombinant cDNA expression libraries (SEREX)].
OBJECTIVE
In malignant transformation, mutant gene products and dysregulated proteins can become tumor antigens and activate immunoreactions. Therefore, auto-antibodies exist in sera of cancer patients. Serologic analysis of recombinant cDNA expression libraries (SEREX) using autologous and allogenic patient sera provides a powerful approach to identify tumor antigens. This study was to identify esophageal cancer antigens with SEREX for serologic diagnosis, gene therapy, and immune therapy.


METHODS
Expression library of cDNA from esophageal squamous cell carcinoma was constructed. SEREX screened out 21 positive clones from the 1.6x10(6) clones in the established library. The 21 positive clones were subcloned to monoclonality and submitted to in vivo excision of pBluescript phagemids. The nucleotide sequences of cDNA inserts were analyzed with DNASIS and BLAST software on EMBL and GenBank. According to the bioinformatics analyses, serologic immunoreactions of 4 colons in 10 samples of esophageal cancer serum and 10 samples of normal control serum were further detected by SADA.


RESULTS
Of the 21 positive clones, 4 had no homology to any known genes, 17 were known fragments which were defined as antigens of esophageal cancer for the first time. The serologic immunoreaction rates of 4 selected antigens, including Ribosomal protein S4, and so on, were 40%, 60%, 70%, and 30%, respectively, in cancer sera, and 0%, 10%, 20%, and 20%, respectively, in normal sera.


CONCLUSIONS
Antigens, such as Ribosomal protein S4, are frequently involved in serologic immunoreactions of esophageal cancer. The 21 antigens identified by the present study can be used as potential targets for gene therapy and serologic biomarkers of esophageal cancer.
Yu
Long
L
Department of Cellular and Molecular Biology, Cancer Institute, Chinese Academy of Medical Sciences, Beijing, 100021, P. R. China.
Hu
Hai
H
Ran
Yu-Liang
YL
Peng
Liang-Ping
LP
Li
Jiang-Wei
JW
Yang
Zhi-Hua
ZH
D000912:Antibodies, Neoplasm / Q000097:blood; D000951:Antigens, Neoplasm / Q000097:blood* / Q000235:genetics; D001323:Autoantibodies / Q000097:blood; D002294:Carcinoma, Squamous Cell / Q000097:blood / Q000235:genetics / Q000276:immunology*; D018076:DNA, Complementary / Q000235:genetics; D004938:Esophageal Neoplasms / Q000097:blood / Q000235:genetics / Q000276:immunology*; D015723:Gene Library; D006801:Humans; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics; D012269:Ribosomal Proteins / Q000097:blood* / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid
D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D001323:Autoantibodies; D018076:DNA, Complementary; D012333:RNA, Messenger; D012269:Ribosomal Proteins; C031798:ribosomal protein S4