Comparative study on Lewis lung tumor lines with 'low' and 'high' metastatic capacity. I. Growth rate, morphology and resistance to host defence.

A highly metastatic variant (LLT-HH) of liver metastasizing Lewis lung tumor (LLT) has been selected. Comparative studies were made on proliferation rate, morphological characteristics and host cell interaction of these two lines. Increased metastasis formation seemed to result from the selection of cells with increased resistance to nonspecific host effector cells.