Abstract: | Metastatic variant sublines of the murine RAW117-P large cell lymphoma have been sequentially selected in vivo for enhanced liver (RAW117-H10) or lung (RAW117-L17) colonization. Such cell sublines were tested for their survival and growth in vitro in medium conditioned by soluble factors released from mouse kidney, brain, liver, or lung tissues. Liver-colonizing H10 and L17 sublines were growth-stimulated by target liver tissue-derived factors at concentrations that inhibited the growth of the parental cells. Lung-colonizing L17 as well as liver-colonizing H10 cells were stimulated by lung tissue factors at concentrations that growth-inhibited the parental cells. In contrast, there was no significant growth stimulation by factors from kidney or brain tissues. In general, the metastatic patterns of RAW117 cells correlated with their abilities to be stimulated by medium from target organ tissues, but other factors, such as organ-specific adhesion mechanisms 10-12], must also be involved in the specificity of blood-borne metastatic organ colonization. |