A role for the fyn oncogene in metastasis of methylcholanthrene-induced fibrosarcoma A cells.

Expression of various oncogenes (ras, myc, erbB2, src, fyn, yes and sis) in a high-metastatic clone (MH-02) derived from a murine methylcholanthrene-induced fibrosarcoma A (Meth A) was compared with those of its parent clone (ML-01) by Northern blot analysis. Two oncogenes, fyn, belonging to the tyrosine-kinase family, and sis, belonging to the cellular-growth-factor family, were found to have higher signals (3.6-fold and 1.8-fold respectively) in MH-02 than in ML-01 cells. To explore the possibility that higher expression of these oncogenes is involved in enhanced metastasis of the MH-02 clone, ML-01 was transfected by a fyn vector and the metastatic potential of the transfectant was examined. Mice administered fyn-transfected ML-01 cells had significantly increased metastatic nodules in the lung, as compared with those whose ML-01 cells were transfected with control vector without the fyn gene. The result indicates that the fyn gene is one of the factors governing the metastatic potential of Meth A cells.