Expression of proto-oncogenes and cytoskeletal actin gene in foreign body-induced murine sarcomas.

To investigate possible differences in the process of tumorigenesis induced by genotoxic and non-genotoxic agents, the expression of several oncogenes and cytoskeletal actin gene was examined in murine sarcomas induced by foreign body (plastics) and 3-methylcholanthrene treatments. RNAs isolated from the resultant tumors were analyzed by dot blot and Northern blot hybridization with various oncogene probes. Levels of expression of c-myc, c-Ha-ras, c-Ki-ras, c-N-ras c-raf, c-src and cytoskeletal actin were similar and in distinguishable in both sarcoma groups. c-yes, c-erbB and c-sis transcripts were not detected in either. The single difference found was concerned with high levels of c-fos expression in fibrous capsules formed around the foreign body plastic material. Thus the pattern of expression of the above cellular genes was not specific and could not be used to distinguish sarcomas induced by non-genotoxic treatments from those caused by genotoxic exposure.