Transformation by viral and cellular oncogenes of a mouse BALB/3T3 cell mutant resistant to transformation by chemical carcinogens.
The mouse cell line MO-5 is resistant to transformation by various chemical carcinogens and also by UV irradiation (C. Yasutake, Y. Kuratomi, M. Ono, S. Masumi, and M. Kuwano, Cancer Res. 47:4894-4899, 1987). Northern (RNA) blot analysis showed active expression of ras and myc genes in MO-5 and BALB/3T3 cells. The effect of transfection of various oncogenes on transformation was compared in MO-5 cells and parental BALB/3T3 cells. Activated c-H-ras, c-N-ras, and v-mos gene induced transformation foci of MO-5 and BALB/3T3. Introduction of the polyomavirus middle T-antigen (mTag) or the Rous sarcoma virus-related oncogene v-src, however, efficiently transformed BALB/3T3 but not MO-5 cells. Expression and phosphorylation of mTag and the associated c-src proteins were observed in mTag-transfected clones of MO-5 as in BALB/3T3 and phosphorylation of the src protein was observed in v-src-transfected BALB/3T3 and MO-5 clones. Hybrids between mTag- or v-src-induced transformants of BALB/3T3 and untransformed MO-5 maintained the transformation phenotype, suggesting that no dominant suppressor of transformation exists in MO-5. A hybrid clone between BALB/3T3 and MO-5 induced efficient transformation foci after transfection with the mTag gene, suggesting that the deficient transformation phenotype of MO-5 was recessive. Instead, some other alteration of MO-5, plausibly membrane function, might lead to abortive transformation by chemical carcinogens and also by mTag and the v-src gene product.
Ono
M
M
Department of Biochemistry, Oita Medical School, Japan.
Yakushinji
M
M
Segawa
K
K
Kuwano
M
M
D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics; D002273:Carcinogens / Q000494:pharmacology; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D002472:Cell Transformation, Viral; D005786:Gene Expression Regulation; D005799:Genes, Dominant; D011905:Genes, ras; D006601:Hexoses / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009857:Oncogenes; D011505:Protein-Tyrosine Kinases / Q000235:genetics; D014162:Transfection; D014466:Ultraviolet Rays
D000952:Antigens, Polyomavirus Transforming; D002273:Carcinogens; D006601:Hexoses; D011505:Protein-Tyrosine Kinases