Diminution of the development of experimental metastases produced by murine metastatic lines in essential fatty acid-deficient host mice

In a previous study we found that the capacity for spontaneous metastases o f tumors developed after subcutaneous transplantation of RSV-transformed Ba lb/c 3T3 cells was reduced in essential fatty acids (EFA)deficient host ani mals, In the present study, we have extended our investigation by consideri ng the requirement of EFA for the formation of lung colonies obtained by i. v. injection of two metastatic murine cell lines of different origin: (1) T 3 cells, a highly metastatic cell line isolated from a fibrosarcoma, and (2 ) the F10 variant of B16 melanoma (B16-F10 cells), We found that EFA defici ency reduces the lung colonization of both T3 cells and B16-F10 cells witho ut affecting the retention of tumor cells in the lung, NK cells did not see m to be involved in the diminution of lung colonization in EFA-deficient an imals, Furthermore, by examining histologically the lung parenchyma at succ essive intervals after tumor cell injection, we found that, in comparison w ith control mice, EFA-deficient animals had fewer lung colonies and a preva lence of smaller microcolonies during the entire period of observation, Thi s led us to conclude that the diminution in development of tumor colonies i n the lungs of EFA-deficient host animals was related to a reduced growth r ate of tumor cells at this site, (C) Kluwer Academic Publishers.