Establishment of new ascites hepatomas

The hepatomas of the Donryu rats induced by feeding 4.dimethyl. aminoazobenzene for more than 191 days were transplanted into the brain of newborn rats of the same strain and the formed tumors were transplanted into the peritoneal cavity of adult rat of the same strain for the purpose to obtain transplantable strain of ascites hepatoma. As the result 4 lines of transplantable ascites hepatomas have been establised. The cells of these 4 hepatomas resembled their original liver tumor cells, respectively, showing the similar morphologic appearance to their mother cell. They showed less differentiated or more malignant characteristics in those taken from the tumor at the more advanced stages of DAB feeding. The liver tissues from the rat fed on DAB for 191 days had no tumor inducing activity when they were inoculated into the brains of the newborn rats (C 74). The liver tumors of the rats fed for more than 236 days produced the tumors in brain, which was serially transplantable (C 82), and kept the original morphologic pattern through serial transplantation and even in those growing in ascites. The tumor cells of the C 82 line showed the least malignancy among the 4 lines of ascites hepatoma established. Those of the C 83 line, which originated from the rat fed on DAB for 264 days, demonstrated the type of well.differentiated liver cell carcinoma with the trabecular arrangement of the tumor cells, but in ascites form they grew more rapidly than those of C 82. Those having most malignant characteristics were the cells of C 84.A which were derived from the rat fed on DAB for 312 days, and they were of the type of undifferentiated liver cell carcinoma. The island forming capacity of the C 84·A cells was the weakest among those of the 4 lines. C 84·B cells were also those derived from the same rat as that from which C 84.A originated and also showed the type of poorly differentiated liver cell carcinoma, but less malignant than those of C 84.A.