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Lack of C/EBP? gene expression results in increased DNA synthesis and an increased frequency of immortalization of freshly isolated mice hepatocytes

Authors :
Gretchen J. Darlington
Milton J. Finegold
Nai-dy Wang
Dongcheul Kang
Humberto E. Soriano
M J Hicks
W Harrison
Source :
Hepatology. 27:392-401
Publication Year :
1998
Publisher :
Ovid Technologies (Wolters Kluwer Health), 1998.

Abstract

The CCAAT/enhancer binding protein alpha (C/EBP alpha) binds to specific promoter sequences and directs transcription of many genes expressed in the liver. Overexpression of C/EBP alpha in established cell lines inhibits cell proliferation. Primary hepatocytes from newborn C/EBP alpha(-/-) mice and normal littermates were used to determine whether the absence of C/EBP alpha increased proliferation and/or transformation of these cells in vitro. DNA synthesis, as measured by bromodeoxyuridine (BrdU) incorporation 24 hours postharvest, was fourfold higher in cells from C/EBP alpha(-/-) pups. Established cell lines were derived from 7 of 8 hepatocyte cultures initiated from null mutants, 4 of 23 cultures from heterozygotes, and 0 of 12 cultures from wild-type animals. C/EBP alpha(-/-) cultures had epithelial morphology, showed bile canaliculi, and expressed albumin messenger RNA (mRNA). When cultured on Matrigel, which promotes differentiation, cell lines derived from C/EBP alpha(-/-) mice formed cords and increased albumin mRNA expression by 1.7- to 3.8-fold. C/EBP alpha(-/-) cell lines exhibited rapid growth and rapid accumulation of chromosomal abnormalities, and were capable of forming nodules when inoculated into the abdominal subcutaneous tissue of nude mice. Our data show that C/EBP alpha is an important regulator of hepatocyte proliferation and participates in the maintenance of the nontransformed hepatic phenotype in vitro.

Details

ISSN :
15273350 and 02709139
Volume :
27
Database :
OpenAIRE
Journal :
Hepatology
Accession number :
edsair.doi...........06b24091176c340b8c6f00fc05a79358
Full Text :
https://doi.org/10.1002/hep.510270212