Oncogene alterations in in vitro transformed rat tracheal epithelial cells.
10 derivations of rat tracheal epithelial (RTE) cells, including normal cells, normal primary cultures, 7 tumorigenic cell lines and 1 nontumorigenic cell line transformed in vitro by treatment with 7,12-dimethylbenz[a]anthracene (DMBA), benzo[a]pyrene (BP) and/or 12-O-tetradecanoylphorbol-13-acetate (TPA) were examined for oncogene alterations. No abnormalities of Ha-ras or Ki-ras were seen that were suggestive of amplification, rearrangement or the presence of RFLPs. Analysis of specific-point mutations in Ha-ras using Pst I digestion (codon 12, GGA to GCA) or Ha-ras and Ki-ras using Xba I (codon 61, CAA to CTA) were negative. In one cell line derived by DMBA treatment, changes in the c-myc restriction digest pattern were seen after incubation with Bam HI and Hind III. Northern analysis revealed consistent differences between normal and transformed cells when probed with Ha-ras; c-myc expression was of low intensity, and the expression of Ki-ras could not be detected. Transfection of RTE cell DNAs into NIH/3T3 cells did not result in the appearance of morphologic transformants. The studies suggest that Ha-ras or Ki-ras codon 61 A to T transversions (CAA to CTA) are not associated with the immortal/tumorigenic phenotype in RTE cells transformed by DMBA or TPA, and are in contrast to results reported in some other biological systems.
Mass
M J
MJ
Carcinogenesis and Metabolism Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711.
Schorschinsky
N S
NS
Lasley
J A
JA
Beeman
D K
DK
Austin
S J
SJ
D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D015152:Blotting, Northern; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D004247:DNA / Q000187:drug effects / Q000235:genetics*; D004848:Epithelium; D005784:Gene Amplification; D015321:Gene Rearrangement; D011905:Genes, ras / Q000235:genetics*; D008297:Male; D009693:Nucleic Acid Hybridization; D015689:Oncogene Protein p21(ras) / Q000235:genetics; D009857:Oncogenes / Q000187:drug effects / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016271:Proto-Oncogene Proteins c-myc; D012313:RNA / Q000187:drug effects / Q000235:genetics; D051381:Rats; D013755:Tetradecanoylphorbol Acetate; D014132:Trachea / Q000166:cytology; D014162:Transfection
D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D015127:9,10-Dimethyl-1,2-benzanthracene; D012313:RNA; D004247:DNA; D015689:Oncogene Protein p21(ras); D013755:Tetradecanoylphorbol Acetate