Two New C3H Mouse Ascites Tumor Cell Lines Capable of Proliferation in vivo and in Suspension Culture: Morphological, Karyological, Kinetic, and Immunological Properties

The establishment of mouse tumor cell lines capable of proliferating in vivo and in suspension culture was undertaken. The MM-46 tumor line, initiated from primary mammary carcinoma arising in a C3H/He mouse, was maintained for over 100 generations in the peritoneal cavities of syngenic mice. At the 50th generation of the tumor suspension, cultures were initiated. The established cell lines, designated TMT-1 and TMT-2, were characterized in vitro and in vivo. The morphological finding indicated that TMT-1 and TMT-2 cells from mice closely resembled the MM-46 tumor cells. The oncogenic potential of the cultured cells was comparable to that of the original ascites tumor. The population doubling time of TMT-1 and TMT-2 cell lines was about 12 hr in mice, whereas the population doubling time of both cell lines lengthened to 20 hr in suspension culture. The increase of doubling time in culture was due to the prolongation of the G1, period. The cell lines, TMT-1 and TMT-2, whether from culture or mice, possessed colony forming ability in soft agar medium. The colony forming ability of the cells decreased gradually through in vivo passages but it recovered upon recultivation of the cells from mouse to culture. Chromosome analysis and cytotoxicity test by anti-MM antiserum indicated that TMT-1 and TMT-2 cell lines closely resembled and had been derived from MM-46 tumor line. Therefore, it is possible to assay cell survival in vitro after in vivo experiments on these cells.