Abstract
The expression of c-myc protein was studied in primary cultures of rat hepatocytes and rat liver-derived epithelial cell lines. The levels of the protein were determined by flow cytometry using a monoclonal antibody to the c-myc protein. Freshly isolated hepatocytes from normal adult male Fischer F344 rats had low but detectable levels of the protein which were similar in the different ploidies. Higher levels were detected in immortalised but untransformed rat liver cell lines, and increased expression was observed during passage through the cell cycle. Following in vitro transformation of one of the immortalised epithelial cell lines by ras genes, similar levels of c-myc expression to those present in the untransformed cells was maintained. Transformation by activated aflatoxin B1 (AFB1) resulted in lower levels of expression. The cell cycle related level of expression was also seen in the transformed cells. Similar results to those observed in the in vitro ras transfected liver-derived cell lines were obtained from in vivo AFB1-induced rat hepatoma cell lines. These results demonstrate that continuously dividing rat liver-derived cell lines have higher levels of expression of c-myc protein than non-dividing, freshly isolated hepatocytes, and that there is no further elevation in the levels observed when these cell lines are transformed. In some cases decreased levels can result from malignant transformation.
Full text
PDF


Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Berry M. N., Friend D. S. High-yield preparation of isolated rat liver parenchymal cells: a biochemical and fine structural study. J Cell Biol. 1969 Dec;43(3):506–520. doi: 10.1083/jcb.43.3.506. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cote G. J., Lastra B. A., Cook J. R., Huang D. P., Chiu J. F. Oncogene expression in rat hepatomas and during hepatocarcinogenesis. Cancer Lett. 1985 Mar;26(2):121–127. doi: 10.1016/0304-3835(85)90017-5. [DOI] [PubMed] [Google Scholar]
- Evan G. I., Hancock D. C. Studies on the interaction of the human c-myc protein with cell nuclei: p62c-myc as a member of a discrete subset of nuclear proteins. Cell. 1985 Nov;43(1):253–261. doi: 10.1016/0092-8674(85)90030-3. [DOI] [PubMed] [Google Scholar]
- Evan G. I., Lewis G. K., Ramsay G., Bishop J. M. Isolation of monoclonal antibodies specific for human c-myc proto-oncogene product. Mol Cell Biol. 1985 Dec;5(12):3610–3616. doi: 10.1128/mcb.5.12.3610-3616.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kruijer W., Skelly H., Botteri F., van der Putten H., Barber J. R., Verma I. M., Leffert H. L. Proto-oncogene expression in regenerating liver is simulated in cultures of primary adult rat hepatocytes. J Biol Chem. 1986 Jun 15;261(17):7929–7933. [PubMed] [Google Scholar]
- Makino R., Hayashi K., Sugimura T. C-myc transcript is induced in rat liver at a very early stage of regeneration or by cycloheximide treatment. Nature. 1984 Aug 23;310(5979):697–698. doi: 10.1038/310697a0. [DOI] [PubMed] [Google Scholar]
- Manson M. M., Legg R. F., Watson J. V., Green J. A., Neal G. E. An examination of the relative resistances to aflatoxin B1 and susceptibilities to gamma-glutamyl p-phenylene diamine mustard of gamma-glutamyl transferase negative and positive cell lines. Carcinogenesis. 1981;2(7):661–670. doi: 10.1093/carcin/2.7.661. [DOI] [PubMed] [Google Scholar]
- Morris H. P., Slaughter L. J. Historical development of transplantable hepatomas. Adv Exp Med Biol. 1977 May 22;92:1–19. doi: 10.1007/978-1-4615-8852-8_1. [DOI] [PubMed] [Google Scholar]
- Rabbitts P. H., Watson J. V., Lamond A., Forster A., Stinson M. A., Evan G., Fischer W., Atherton E., Sheppard R., Rabbitts T. H. Metabolism of c-myc gene products: c-myc mRNA and protein expression in the cell cycle. EMBO J. 1985 Aug;4(8):2009–2015. doi: 10.1002/j.1460-2075.1985.tb03885.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sinha S., Hockin L. J., Neal G. E. A system for transformation of rat liver cells in vitro by acute treatment with aflatoxin. Br J Cancer. 1987 Jun;55(6):595–598. doi: 10.1038/bjc.1987.121. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sinha S., Hockin L. J., Neal G. E. Transformation of a rat liver cell line: neoplastic phenotype and regulation of gamma glutamyl transpeptidase in tumour tissue. Cancer Lett. 1987 May;35(2):215–224. doi: 10.1016/0304-3835(87)90047-4. [DOI] [PubMed] [Google Scholar]
- Sinha S., Marshall C. J., Neal G. E. gamma-Glutamyltranspeptidase and the ras-induced transformation of a rat liver cell line. Cancer Res. 1986 Mar;46(3):1440–1445. [PubMed] [Google Scholar]
- Smith P. J., Nakeff A., Watson J. V. Flow-cytometric detection of changes in the fluorescence emission spectrum of a vital DNA-specific dye in human tumour cells. Exp Cell Res. 1985 Jul;159(1):37–46. doi: 10.1016/s0014-4827(85)80035-5. [DOI] [PubMed] [Google Scholar]
- Studzinski G. P., Brelvi Z. S., Feldman S. C., Watt R. A. Participation of c-myc protein in DNA synthesis of human cells. Science. 1986 Oct 24;234(4775):467–470. doi: 10.1126/science.3532322. [DOI] [PubMed] [Google Scholar]
- Thompson N. L., Mead J. E., Braun L., Goyette M., Shank P. R., Fausto N. Sequential protooncogene expression during rat liver regeneration. Cancer Res. 1986 Jun;46(6):3111–3117. [PubMed] [Google Scholar]
- Watson J. V. Flow cytometry in biomedical science. Nature. 1987 Feb 19;325(6106):741–742. doi: 10.1038/325741a0. [DOI] [PubMed] [Google Scholar]
- Watson J. V., Sikora K., Evan G. I. A simultaneous flow cytometric assay for c-myc oncoprotein and DNA in nuclei from paraffin embedded material. J Immunol Methods. 1985 Oct 24;83(1):179–192. doi: 10.1016/0022-1759(85)90071-7. [DOI] [PubMed] [Google Scholar]
