Different deficiencies in the prevention of tumorigenic-low-metastatic murine K-1735b melanoma cells from producing metastases.

To produce metastasis, malignant tumor cells must be able to complete a sequence of many steps that depend not only on tumor cell properties but also on ability of the tumor cells to interact effectively with host homeostatic mechanisms to avoid destruction. Therefore, it should be possible to isolate clonal populations non- or low metastatic. In a study of K-1735 clones introduced into normal syngeneic hosts, the reasons for the lack of or low ability of metastasis production did indeed differ among different clones. Some clones were identified that were low metastatic in syngeneic C3H/HeN mice because of antigenic characteristics. Others failed to give rise to metastases because they could not survive and grow once arrested in the lung parenchyma. These data suggested that the success of future studies dealing with genetic analysis of the metastatic phenotype could depend on the use of appropriate tumor cell populations.