Three pancreatic cancer-associated antigens were characterized by use of monoclonal antibodies in immunobinding studies with various cellular and soluble target antigens, in immunoprecipitation, and ...in immunoperoxidase staining. C54-0 represents a tumor-associated Mr 122,000 antigen, which appears to be widely distributed on various epithelial tumors and to a lower extent on normal tissue. C1-N3 antigen exhibited a more restricted distribution, reacting with pancreatic and various gastrointestinal tract tumors as well as with chronically inflamed pancreatic tissue. The most specific antigen expression was observed for C1-P83 antigen, found on all exocrine tumors of the pancreas, but not on normal or chronically inflamed pancreatic tissue.
Thirty human renal cell carcinomas, subpassaged into NMRI-nu/nu mice, were analyzed during long term serial transplantation (range, 10-50 passages) with regard to their histological differentiation, ...mitotic activity, and DNA content. A quantitative methodology was applied to determine the mitotic rate. The DNA content was measured by flow cytometry. Only five tumors (four primaries and one metastasis) changed their mitotic rate significantly (P less than 0.01). In each case this change was paralleled by a simultaneous alteration of the DNA content. Histological pattern and nuclear grade remained stable in all but one tumor where the change in histological pattern occurred simultaneously with changes in DNA index and mitotic rate. These results indicate that the majority of renal cell carcinomas remain stable during long term serial transplantation, at least with regard to the parameters examined. This is a basic prerequisite for making the grafting of renal cell carcinomas into nude mice a reliable in vivo model for drug sensitivity testing. However, since a few of the transplanted tumors showed instability, continuous monitoring of phenotypic and genotypic tumor features is necessary during long term xenotransplantation.
