Changes in nucleolar transcriptional activity and nuclear DNA content during the first steps of rat hepatocarcinogenesis

Autor: J de Gerlache, Micheline Kirsch-Volders, Véronique Préat, Ph. Castelain, A. Deleener, H. Alexandre
Přispěvatelé: Cell Genetics, Vrije Universiteit Brussel
Rok vydání: 1987
Předmět:
Génétique du développement
Cancer Research
Silver
Transcription
Genetic
Normal diet
Nucleolus
Population
Liver Neoplasms -- chemically induced -- physiopathology -- ultrastructure
Biology
Precancerous Conditions -- physiopathology -- ultrastructure
RNA
Neoplasm -- biosynthesis
Silver stain
Liver Neoplasms
Experimental
Cell Nucleolus -- physiopathology -- ultrastructure
Nucleolus Organizer Region
medicine
Animals
Humans
Diethylnitrosamine
RNA
Neoplasm
Feulgen stain
education
Nucleolus Organizer Region -- physiopathology -- ultrastructure
Silver -- diagnostic use
education.field_of_study
Carbon Tetrachloride Poisoning
Liver Neoplasms
Experimental -- chemically induced -- physiopathology -- ultrastructure
Liver Neoplasms
Hepatobiliary disease
DNA
Neoplasm
General Medicine
2-Acetylaminofluorene
Molecular biology
Staining
Cell nucleus
medicine.anatomical_structure
DNA
Neoplasm -- metabolism
Precancerous Conditions
Cell Nucleolus
Zdroj: Carcinogenesis, 8 (2
ISSN: 1460-2180
0143-3334
DOI: 10.1093/carcin/8.2.195
Popis: Two complementary genetic parameters were followed in liver parenchymal cells during the first steps of rat hepatocarcinogenesis: the expression of nucleolar genes estimated from their silver stainability and the nuclear DNA content determined after Feulgen staining. Putative preneoplastic lesions as foci and nodules were induced by the triphasic 'Gerlans protocol'. Initiation with a single dose of diethylnitrosamine (DEN) was followed by a selection of initiated cells with 2-acetylaminofluorene (2-AAF) in combination with a single necrogenic dose of CCl4 as a proliferative stimulus. Finally after 1 week of normal diet, the animals were treated or not with phenobarbital (PB) for periods up to 2 months. Serial sections were analysed after silver staining (AgNO3), methyl-green--pyronin staining (Unna-Brachet) and Feulgen staining with densitometric and morphometric methods. Silver staining, which is known to stain an acidic protein associated with rRNA synthesis, increased gradually with the duration of the PB treatment. Morphometry revealed an increase in both nucleolar and nuclear volume; the fraction of nuclei with one nucleolus also increased. These results seem to point towards an increase of nucleolar activity in the early steps of PB promotion. Moreover, this shift cannot be ascribed to an increase of DNA content. Indeed, a parallel study on neighbouring sections stained with Feulgen revealed a shift towards a population of diploid nuclei, in contrast to normal liver cells, which are mostly tetraploid. The observed diploidisation may therefore provide a functional advantage for the expansion of putative preneoplastic cells.
info:eu-repo/semantics/published
Databáze: OpenAIRE
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