THE STIDIES OF TUMOR MAKERS AND THE DISTRIBUTION OF CARBOHYDRATE ANTIGENS IN THE PANCREATIC CARCINOMA TISSUES

Abstract

Paraffin embedded 64 pancreatic tissues including 26 cases of resectable pancreatic carcinomas, 12 cases of probe biopsy, 9 cases of operated chronic pancreatitis, and 17 cases of biopsied normal pancreas were examined by indirect immunoperoxidase staining. ABO and Lewis blood type were determined by hemagglutination test, and ABO blood type in saliva was done by hemagglutination inhibition assay. Monoclonal antibodies recognizing Le^a, sialylated Le^a, Le^x, and sialylated Le^x were produced by the immunizations of mice with colon cancer line, mixture of colon cancer lines, HL60, and the extract of stomach cancer tissue, respectively.
In non-cancerous tissue of chronic pancreatitis and normal pancreatic tissues, small pancreatic ducts adjacent to acini were stained by anti-A, B, and H antibodies, and its staining patterns were compatible to individual blood type. Staining of pancreatic ducts with anti-Le^a and antisialylated Le^a antibodies was observed in 92.3% of tested samples. Lewis blood type of negatively stained individuals was Lewis (a-b-). Le^x was observed in only 15.4% of cases, but sialylated Le^x was not seen at all in non-cancerous tissues.
On the contrary, in 38 cancerous tissues, the deletion of ABH blood type antigen was seen in 21 to 38 (55.8%) cases, and incompatible blood type antigen was not detected. Furthermore, the positively of tumor-associated antigens was as follows: 33 cases (86.8%) in sialylated Le^a, 6 cases (15.8%) in Le^x and 28 cases (73.7%) in sialylated Le^x.
From these studies, the following conclusions were obtained:
1) In non-cancerous pancreatic ducts, blood type compatible carbohydrate antigen is synthesized.
2) In pancreatic cancers, blood type carbohydrates are synthesized incompletely, followed by the deletion of the antigens.
3) This deletion of blood type carbohydrates in pancreatic tissues is significantly observed in nonsecretor cases.
4) In pancreatic tissues, sialylated Le^a is tumor-associated antigen. However, sialylated Le^x is tumor-specific antigen and could be must useful tumor marker.