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. 1996 Dec;70(12):8571–8583. doi: 10.1128/jvi.70.12.8571-8583.1996

The HNF1/HNF4-dependent We2 element of woodchuck hepatitis virus controls viral replication and can activate the N-myc2 promoter.

G Fourel 1, F Ringeisen 1, M Flajolet 1, F Tronche 1, M Pontoglio 1, P Tiollais 1, M A Buendia 1
PMCID: PMC190950  PMID: 8970982

Abstract

Transcriptional activation of myc family proto-oncogenes through the insertion of viral sequences is the predominant mechanism by which woodchuck hepatitis virus (WHV) induces liver tumors in chronically infected animals. The main target is N-myc2, a functional retroposon of the N-myc gene, but c-myc and N-myc are also marginally involved. Here we identify a major, liver-specific regulatory element in the WHV genome (We2) which efficiently activates the N-myc2 promoter in cultured hepatoma cells. In the context of the episomal viral genome, We2 governs the production of pregenomic RNA and thus plays a central role in the control of viral replication. We2 activity is primarily controlled by the liver-enriched HNF1 and HNF4 transcription factors, although NF1 and Oct proteins were also shown to bind in a central region. The expression of HNF1 and HNF4 appears to be maintained in woodchuck tumors. Thus, We2 is a prime candidate for controlling myc gene cis activation during WHV-induced hepatocarcinogenesis.

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Selected References

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