NEW CELL-LINES OF GASTRIC AND PANCREATIC-CANCER - DISTINCT MORPHOLOGY, GROWTH-CHARACTERISTICS, EXPRESSION OF EPITHELIAL AND IMMUNOREGULATORY ANTIGENS

Two new cell lines from stomach cancers and one from a pancreatic carc inoma are presented. MZ-GC-1 was established from a hepatic metastasis of a well differentiated gastric adenocarcinoma. MZ-GC-2 was derived from ascites induced by a poorly differentiated gastric adenocarcinoma . MZ-PC-1 originated from the pleural effusion of a moderately well di fferentiated pancreatic ductal adenocarcinoma. MZ-GC-1 cells were adhe rent and partially polarized, connected tightly via desmosomes. In con trast MZ-GC-2 cells consisted of slightly adherent or floating subpopu lations and displayed no desmosomes. MZ-PC-1 cells were adherent and s howed polarized growth, connected by apical junctional complexes. Cell doubling times were 7 days for MZ-GC-1 and 45 h for MZ-GC-2 and MZ-PC -1 cells. MZ-GC-2 and MZ-PC-1 gave rise to nude mouse tumours, resembl ing the original lesions. Chromosome analysis of the cell lines reveal ed a high range of numerical abnormalities. Each cell line had cytoker atin patterns fitting well to typical in vivo patterns. Furthermore th e cell lines expressed a panel of antigens typical for gastrointestina l epithelia. Unique for MZ-PC-1 were high amounts of secreted Ca19-9. gamma-Interferon enhanced HLA-class I antigens up to twofold and induc ed ICAM-1 expression on each cell line. HLA-class II antigens were dif ferentially enhanced by gamma-interferon. Due to their distinct charac teristics the three tumour cell lines may be useful models in the inve stigation of the cell biology and immunogenicity of gastrointestinal t umours.