Biological characterization of three new spontaneous mouse lymphomas and comparison with the leukemia P388

Three spontaneous lymphomas of 23- to 24-month-old (AB/Jena X DBA/2 Jena)F1 females were serially transplanted into syngeneic hosts. They were histologically classified as malignant lymphoblastic lymphomas (ABDt2 and ABDt5) and as a malignant lymphoma of histiocytic type (ABDt6). All lymphomas disseminated into the liver, spleen, and pancreas, whereas ABDt2 and ABDt5 additionally infiltrated the bone marrow and leptomeninx. None of the tumors showed a leukemic growth form, but extreme granulocytosis was observed in leukemia P388-bearing mice. Since the lymphomas ABDt2 and ABDt5 expressed T-cell differentiation antigens Ly-1, Ly-2, and Ly-3, they are thought to be of T-cell origin. On the contrary to the lymphocytes of parental mouse strain ABDt2 and ABDt5 cells reacted with anti H-2.23 allosera. All tumors have been found to be sensitive to at least 5/7 clinically used anticancer drugs. But only ABDt2- and P388-bearing mice survived longer than 60 days after treatment with the potent anticancer drug 1,4-benzoquinone-guanylhydrazone-thiosemicarbazone (ambazone). Successful chemotherapy of both tumors was accompanied with resistance of the hosts against the second transplant of the same tumor. Summarizing the characteristics of the newly established transplantation tumors it is concluded that they can be recommended as screening models in the search for new antineoplastic agents.