Document Detail


Changes in cellular ploidy and autophagic responsiveness during rat liver carcinogenesis.
MedLine Citation:
PMID:  3787117     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
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.
Authors:
P O Seglen; P E Schwarze; G Saeter
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Toxicologic pathology     Volume:  14     ISSN:  0192-6233     ISO Abbreviation:  Toxicol Pathol     Publication Date:  1986  
Date Detail:
Created Date:  1987-01-21     Completed Date:  1987-01-21     Revised Date:  2009-07-01    
Medline Journal Info:
Nlm Unique ID:  7905907     Medline TA:  Toxicol Pathol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  342-8     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
2-Acetylaminofluorene
Animals
Autophagy*
Diethylnitrosamine
Liver Neoplasms, Experimental / chemically induced,  genetics*,  physiopathology
Male
Phagocytosis*
Ploidies*
Proteins / metabolism
Rats
Rats, Inbred Strains
Chemical
Reg. No./Substance:
0/Proteins; 53-96-3/2-Acetylaminofluorene; 55-18-5/Diethylnitrosamine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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