DERIVATION OF DUCT-LIKE CELL-LINES FROM A TRANSPLANTABLE ACINAR CELL-CARCINOMA OF THE RAT PANCREAS

Two cell lines were derived from a transplantable acinar cell carcinom a that had been established from a primary carcinoma of the pancreas i n an azaserine-treated Lewis rat. The cultured tumor cells initially p roduced amylase, but production of exocrine enzymes ceased after 1-2 w eeks in culture. The cultured cells were tumorigenic in Lewis rats, an d one line produced solid tumors composed of ductlike structures surro unded by dense fibrous tissue. The second cell line produced partially solid and partially cystic tumors with a mixed phenotype of squamous, mucinous, and glandular areas when it grew in vivo following regrafti ng. Both cell lines lost structural and immunohistochemical acinar cel l markers while acquiring duct cell markers during culture and regraft ing. These studies provide strong support for the hypothesis that duct like carcinomas can arise from neoplastic pancreatic acinar cells in r ats.