Molecular events associated with accelerated proliferative response in rat livers when partial hepatectomy is preceded by a sham operation.
BACKGROUND
When a sham operation is performed 6 h before partial hepatectomy (PH), the regenerative response is accelerated suggesting that sham operation itself contributes to cellular events leading to proliferation.


METHODS
In order to examine the mechanisms implicated in this acceleration, we compared the activation of several factors associated with the progression through the cell cycle at various times after PH and after PH preceded by sham operation (S6 h + PH). The effect of a single sham (S) and two combined sham operations (S6 h + S) was also examined. Nonoperated rats were used as controls (C).


RESULTS
The early factors NF-kappaB and Stat3 were activated after S6 h + PH and S6 h + S. C-jun expression was increased 0.5 h and 2 h after PH and 6 h after sham. There was no further increase in S6 h + PH and S6 h + S. In contrast, c-myc expression returned to baseline levels after S6 h and a new increase was observed 2 h after S6 h + PH but not after S6 h + S. P53 mRNA was significantly expressed 6 h after S6 h + PH, but at a level similar than that observed 6 and 12 h after PH alone. An earlier increase in c-Ha-ras mRNA and cyclin E protein was found in S6 h + PH, in comparison with PH alone.


CONCLUSIONS
The first divergent response between the two combined models involved c-myc expression. However, major differences related to the accelerated liver regenerative response observed after S6 h + PH were found at late time points associating an earlier expression of c-Ha-ras and nuclear cyclin E.
Laurent
S
S
Department of Gastroenterology, Université Catholique de Louvain, 1200 Brussels, Belgium.
Stärkel
P
P
Leclercq
I A
IA
Lambotte
L
L
Maiter
D
D
Horsmans
Y
Y
D000818:Animals; D049109:Cell Proliferation; D019927:Cyclin E / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D006498:Hepatectomy / Q000379:methods*; D008099:Liver / Q000473:pathology / Q000601:surgery*; D008110:Liver Extracts / Q000032:analysis; D008297:Male; D016328:NF-kappa B / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D012313:RNA / Q000302:isolation & purification; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D050796:STAT3 Transcription Factor; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D018631:ras Proteins / Q000378:metabolism
D019927:Cyclin E; D004268:DNA-Binding Proteins; D008110:Liver Extracts; C116115:MYCBP protein, human; D016328:NF-kappa B; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D050796:STAT3 Transcription Factor; C494088:Stat3 protein, rat; D015534:Trans-Activators; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D012313:RNA; D018631:ras Proteins