title: Reversible transformation by v-sis: a model cell line for analysis of transformation by antisense methods.
abstract: Cellular homologs of v-sis are implicated in numerous human tumor types (Eva et al., 1982; Betsholtz et al., 1984; Johnson et al., 1985; Bronzert et al., 1987; Igarashi et al., 1987; Nister et al., 1988a,b; Versnel et al., 1988; Matsui et al., 1989), but whether tumor growth is maintained by sis expression alone or requires additional changes is unknown. To distinguish these possibilities, we studied reversible transformation of NIH-3T3 cells bearing an inducible v-sis construction. Cells subcultured from 10 of 18 tumors, all less than 0.1 gram and less than or equal to 21 days in age, reverted to a normal phenotype by four criteria, but again exhibited transformation upon induction. Thus, activation of the v-sis autocrine loop alone is sufficient for initiation of tumors. Cells from the remaining and larger, 0.5 +/- 0.7 gram, tumors did not revert by any criteria. This suggests that subsequent tumor growth is maintained by acquisition of irreversible change(s) that occurs at high frequency in vivo.
authors.affiliation: Department of Pathology, University of California, San Diego, La Jolla 92093.
authors.forename: P M
authors.initials: PM
authors.lastname: Carpenter
authors.forename: M
authors.initials: M
authors.lastname: Mercola
authors.forename: D
authors.initials: D
authors.lastname: Mercola
mesh_terms: D016475:3T3 Cells; D000085:Acetates / Q000494:pharmacology*; D019342:Acetic Acid; D000818:Animals; D016375:Antisense Elements (Genetics); D015152:Blotting, Northern; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D006801:Humans; D007700:Kinetics; D051379:Mice; D020575:Oncogene Proteins v-sis; D009857:Oncogenes; D010641:Phenotype; D015183:Restriction Mapping; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics*; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D000085:Acetates; D016375:Antisense Elements (Genetics); D020575:Oncogene Proteins v-sis; D015682:Retroviridae Proteins, Oncogenic; D019342:Acetic Acid