title: Serological identification of TROP2 by recombinant cDNA expression cloning using sera of patients with esophageal squamous cell carcinoma.
abstract: We applied serological analysis of recombinant cDNA expression libraries (SEREX) to cases of esophageal squamous cell carcinoma (SCC) to identify tumor antigens. One of the clones identified was TROP2, which is known as calcium signal transducer. To evaluate the clinical significance of serum anti-TROP2 antibodies (s-TROP2-Abs) in patients with esophageal SCC, the presence of s-TROP2-Abs was analyzed by Western blotting using bacterially expressed TROP2 protein. We found that 23 of 75 (31%) patients were positive for s-TROP2-Abs. Positivity in terms of s-TROP2-Abs showed a significant association with tumor size but not with other clinicopathological features. The protein expression levels of TROP2 were much higher in esophageal SCC cell lines as compared to those in normal esophageal mucosa and its immortalized cells although the mRNA expression levels were not necessarily elevated in malignant cell lines and tissues. Immunohistochemical studies showed that the expression of TROP2 protein in esophageal SCC specimens was noticeably higher than that found in mild hyperplasia of esophageal mucosae. Thus, s-TROP2-Abs seemed useful in the diagnosis of SCC and may be a candidate for serum tumor markers.
authors.affiliation: Department of Academic Surgery, Chiba University, Graduate School of Medicine, Chiba, Japan.
authors.forename: Kazue
authors.initials: K
authors.lastname: Nakashima
authors.forename: Hideaki
authors.initials: H
authors.lastname: Shimada
authors.forename: Takenori
authors.initials: T
authors.lastname: Ochiai
authors.forename: Mari
authors.initials: M
authors.lastname: Kuboshima
authors.forename: Namiko
authors.initials: N
authors.lastname: Kuroiwa
authors.forename: Shinichi
authors.initials: S
authors.lastname: Okazumi
authors.forename: Hisahiro
authors.initials: H
authors.lastname: Matsubara
authors.forename: Fumio
authors.initials: F
authors.lastname: Nomura
authors.forename: Masaki
authors.initials: M
authors.lastname: Takiguchi
authors.forename: Takaki
authors.initials: T
authors.lastname: Hiwasa
mesh_terms: D000368:Aged; D000951:Antigens, Neoplasm / Q000032:analysis* / Q000276:immunology; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000276:immunology; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000737:chemistry* / Q000175:diagnosis*; D015815:Cell Adhesion Molecules / Q000032:analysis* / Q000276:immunology; D045744:Cell Line, Tumor; D003001:Cloning, Molecular / Q000379:methods; D018076:DNA, Complementary / Q000032:analysis; D004273:DNA, Neoplasm / Q000032:analysis; D000071858:Epithelial Cell Adhesion Molecule; D004938:Esophageal Neoplasms / Q000737:chemistry* / Q000175:diagnosis*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins / Q000032:analysis
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D015815:Cell Adhesion Molecules; D018076:DNA, Complementary; D004273:DNA, Neoplasm; D000071858:Epithelial Cell Adhesion Molecule; D011994:Recombinant Proteins