Neoplastic transformation of mouse C3H 10T1/2 and Syrian hamster embryo cells by heavy ions

C3H 10T1/2 mouse-embryo fibroblasts were used for transformation
experiments to study the effectiveness of various heavy ions with
energies up to 20 MeV/u and LET values from 170 to 16.000 keV/μm.
The transformation frequency per unit absorbed dose decreased with
increasing ionization density; at the highest values of LET we
found a decrease even of the transformation efficiency per unit
fluence. Uranium ions at energies of 5, 9, and 16.3 MeV/u did not
induced any transformation. In additional studies piimary Syrian
hamster embryo cells (SHE) were exposed to heavy ions in order to
characterize cytological and molecular changes which may be
correlated with neoplastic transformation. Growth behaviour,
chromosomal status, tumorigenicity in nude mice, and expression of
oncogenes of transformed cell lines were examined.