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Changes in Cellular Ploidy and Autophagic Responsiveness During Rat Liver Carcinogenesis

Department of Tissue Culture, Institute for Cancer Research, The Norwegian Radium Hospital, Montebello, 0310 Oslo 3, Norway

Per E. Schwarze

Department of Tissue Culture, Institute for Cancer Research, The Norwegian Radium Hospital, Montebello, 0310 Oslo 3, Norway

Gunnar Saeter

Department of Tissue Culture, Institute for Cancer Research, The Norwegian Radium Hospital, Montebello, 0310 Oslo 3, Norway

Liver carcinogenesis was initiated in young rats by diethylnitrosamine/partial hepatectomy and promoted by dietary 2-acetylaminofluorene (for 4 weeks). Eight weeks after initiation, hepatocytes were isolated by means of collagenase perfusion and analyzed by means of flow cytometry. Whereas cells and cell nuclei from normal or hepatectomized livers were predominantly tetraploid, most of the hepatocytes/nuclei from carcinogen-treated rats were diploid. Neoplastic liver nodules and hepatocellular carcinomas also contained almost exclusively diploid nuclei, suggesting that diploidization may be an essential feature of liver carcinogenesis. Two-parametric analysis (simultaneous flow cytometric determination of DNA and protein content within the same cell) revealed that the diploid cells were only half as big as the tetraploid cells. They could therefore be separated from the latter by centrifugal elutriation. Normal, isolated hepatocytes responded to amino acid deprivation by increasing their rates of autophagic sequestration (measured with electroinjected (¹⁴C)sucrose as a probe) and endogenous protein degradation, the resulting protein loss eventually leading to cell death. Hepatocytes from carcinogen-treated rats were much less responsive to amino acid deprivation, preserved their protein better, and survived for longer periods of time in culture than did normal cells. The reduced autophagic responsiveness may conceivably give carcinogen-altered cells a survival advantage even in vivo, that could contribute to their outgrowth during carcinogenesis.

• 1. Farber E (1984). Cellular biochemistry of the stepwise development of cancer with chemicals: G.H.A. Clowes memorial lecture. Cancer Res. 44: 5463–5474.[Abstract/Free Full Text]
• 2. Gordon PB, Tolleshaug H, and Seglen PO (1985). Use of digitonin extraction to distinguish between autophagic-lysosomal sequestration and mitochondrial uptake of (14C)sucrose in hepatocytes. Biochem. J. 232: 773–780.[Web of Science][Medline] [Order article via Infotrieve]
• 3. Hanigan HM, Hunt JM, Campbell HA, and Pitot HC (1984). Growth of carcinogen-altered rat hepatocytes in the liver of syngeneic recipients without the use of genotoxic agents. Proc. Am. Assoc. Cancer Res. 25: 147.
• 4. Murphree AL and Benedict WF (1984). Retinoblastoma: Clues to human oncogenesis. Science 223: 1028–1033.[Abstract/Free Full Text]
• 5. Neal GE and Butler WH (1978). A comparison of the changes induced in rat liver by feeding low levels of aflatoxin B1 or an azo dye. Br. J. Cancer 37: 55–60.[Web of Science][Medline] [Order article via Infotrieve]
• 6. Rutenburg AM, Kim H, Fischbein JW, Hanker JS, Wasserkrug HL, and Seligman AM (1969). Histochemical and ultrastructural demonstration of -glutamyltranspeptidase activity. J. Histochem. Cytochem. 17: 517–526.[Abstract]
• 7. Rønning ØW, Lindmo T, Pettersen EO, and Seglen PO (1981). The role of protein accumulation in the cell cycle control of human NHIK 3025 cells. J. Cell. Physiol. 109: 411–418.[CrossRef][Web of Science][Medline] [Order article via Infotrieve]
• 8. Ronning ØW, Pettersen EO, and Seglen PO (1979). Protein synthesis and protein degradation through the cell cycle of human NHIK 3025 cells in vitro. Exp. Cell Res. 123: 63–72.[CrossRef]
• 9. Scherer E (1984). Neoplastic progression in experimental hepatocarcinogenesis. Biochim. Biophys. Acta 738: 219–236.[Medline] [Order article via Infotrieve]
• 10. Schulte-Hermann R (1985). Tumor promotion in the liver. Arch. Toxicol. 57: 147–158.[CrossRef][Web of Science][Medline] [Order article via Infotrieve]
• 11. Schwarze PE, Pettersen EO, and Seglen PO (1986). Characterization of hepatocytes from carcinogen-treated rats by two-parametric flow cytometry. Carcinogenesis 7: 171–173.[Abstract/Free Full Text]
• 12. Schwarze PE, Pettersen EO, Shoaib MC, and Seglen PO (1984). Emergence of a population of small, diploid hepatocytes during hepatocarcinogenesis. Carcinogenesis 5: 1267–1275.[Abstract/Free Full Text]
• 13. Schwarze PE, Pettersen EO, Tolleshaug H, and Seglen PO (1986). Isolation of carcinogen-induced, diploid hepatocytes by centrifugal elutriation. Cancer Res. (in press).
• 14. Schwarze PE and Seglen PO (1980). Protein metabolism and survival of rat hepatocytes in early culture. Exp. Cell Res. 130: 185–190.[CrossRef][Web of Science][Medline] [Order article via Infotrieve]
• 15. Schwarze PE and Seglen PO (1985). Reduced autophagic activity, improved protein balance and enhanced in vitro survival of hepatocytes isolated from carcinogen-treated rats. Exp. Cell Res. 157: 15–28.[CrossRef][Web of Science][Medline] [Order article via Infotrieve]
• 16. Schwarze PE, Tolleshaug H, and Seglen PO (1985). Uptake and degradation of asialo-orosomucoid in hepatocytes from carcinogen-treated rats. Carcinogenesis 6: 777–782.[Abstract/Free Full Text]
• 17. Seglen PO (1976). Preparation of isolated rat liver cells. Methods Cell Biol. 13: 29–83.[Medline] [Order article via Infotrieve]
• 18. Seglen PO and Gordon PB (1982). 3-Methyladenine: Specific inhibitor of autophagic/lysosomal protein degradation in isolated rat hepatocytes. Proc. Natl. Acad. Sci. (USA) 79: 1889–1892.[Abstract/Free Full Text]
• 19. Seglen PO and Gordon PB (1984). Amino acid control of autophagic sequestration and protein degradation in isolated rat hepatocytes. J. Cell Biol. 99: 435–444.[Abstract/Free Full Text]
• 20. Seglen PO, Grinde B, and Solheim AE (1979). Inhibition of the lysosomal pathway of protein degradation in isolated rat hepatocytes by ammonia, methylamine, chloroquine and leupeptin. Eur. J. Biochem. 95: 215–225.[Web of Science][Medline] [Order article via Infotrieve]
• 21. Simard A, Cousineau G, and Daoust R (1968). Variations in cell cycle during azo dye hepatocarcinogenesis. J. Natl. Cancer Inst. 41: 1257–1263.[Web of Science][Medline] [Order article via Infotrieve]
• 22. Stanbridge EJ, Der CJ, Doersen C-J, Nishimi RY, Peehl DM, Weissman BE, and Wilkinson JE (1982). Human cell hybrids: Analysis of transformation and tumorigenicity. Science 215: 252–259.[Abstract/Free Full Text]
• 23. Styles J, Elliott BM, Lefevre PA, Robinson M, Pritchard N, Hart D, and Ashby J (1985). Irreversible depression in the ratio of tetraploid: diploid liver nuclei in rats treated with 3'-methyl-4-dimethylaminoazobenzene (3'M). Carcinogenesis 6: 21–28.[Abstract/Free Full Text]
• 24. Yunis JJ (1983). The chromosomal basis of human neoplasia. Science 221: 227–236.[Abstract/Free Full Text]

Toxicologic Pathology, Vol. 14, No. 3, 342-348 (1986)
DOI: 10.1177/019262338601400309


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This Article Abstract Free Full Text (Free PDF) Free Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Seglen, P. O. Articles by Saeter, G. Search for Related Content PubMed PubMed Citation Articles by Seglen, P. O. Articles by Saeter, G. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB 2-ACETYLAMINOFLUORENE N-NITROSODIETHYLAMINE Social Bookmarking                         What's this?