Cellular distribution of a colonic adenoma-associated antigen as defined by monoclonal antibody Adnab-9.
Adenomatous colonic polyps constitute a precursor for colorectal cancer. Antibodies to these precancerous lesions might identify specific early tumor antigens. Adnab-9 is a murine monoclonal antibody raised against membranes of colonic adenomas. Adnab-9 binding in colonic washings (effluent) correlates with the presence of colorectal cancer. Immunohistochemical staining with Adnab-9 shows cytoplasmic reactivity in scattered cells in 4 of 31 adenomatous tissue sections, 0 of 14 sections of colorectal cancer cells, and 1 of 8 normal-appearing colonic mucosa specimens examined. Adnab-9 recognized a dominant M(r) 87,000 protein species in tissue extracts in the membrane-bound fraction of effluent by Western blotting. Adnab-9 binding by enzyme-linked immunosorbent assay in adenomatous extracts is higher than cancer or normal tissue, is membrane-bound, and is absent from established colorectal cancer cell lines. This distribution and nature of immunostaining suggest that Adnab-9 recognizes a determinant associated with the membrane component of a subpopulation of adenoma cells which may have a role in early colorectal neoplasia.
Tobi
M
M
Dept. of Medicine, Veterans Affairs Medical Center, Allen Park, Michigan.
Maliakkal
B J
BJ
Alousi
M A
MA
Voruganti
V
V
Shafiuddin
M
M
Yang
S
S
Gesell
M S
MS
An
T
T
Hatfield
J S
JS
Fligiel
S
S
D000236:Adenoma / Q000276:immunology*; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis; D015153:Blotting, Western; D003106:Colon / Q000276:immunology; D003110:Colonic Neoplasms / Q000276:immunology*; D015179:Colorectal Neoplasms / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007413:Intestinal Mucosa / Q000276:immunology; D014407:Tumor Cells, Cultured / Q000276:immunology
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; C030139:colon-specific antigen