INVIVO SELECTION OF A HIGHLY METASTATIC CELL-LINE FROM A HUMAN PANCREATIC-CARCINOMA IN THE NUDE-MOUSE

A cell line with high metastatic capacity to the liver was established by sequential passages of a human pancreatic cancer cell line through the nude mouse liver. A subline, L3.5, established after five passage s of the fast-growing variant (FG) of the human pancreatic cancer COLO 357 through the nude mouse liver produced extensive hepatic metastase s in 100% of experimental animals when injected into the spleen. The i ncidence of pulmonary metastases decreased from 43% for FG to 9% for L 3.5. The L3.5 cell line showed aggressive growth with almost complete replacement of the hepatic parenchyma in one third of the mean time re quired for the development of macroscopic metastases of FG in the live r after splenic injections of tumor cells. This study indicates that t he nude mouse provides a good model for in vivo selection of metastati c cells from human pancreatic cancer. The L3.5 cell line will be valua ble in the study of human pancreatic cancer metastasis, particularly i n the area of survival and growth of metastatic cells in the microenvi ronment of the liver.