Published online Dec 27, 2020. doi: 10.4254/wjh.v12.i12.1198
Peer-review started: June 15, 2020
First decision: July 30, 2020
Revised: August 26, 2020
Accepted: October 28, 2020
Article in press: October 28, 2020
Published online: December 27, 2020
Processing time: 185 Days and 15.9 Hours
Liver reduction is the main curative treatment for primary liver cancer, but its use remains limited as liver regeneration requires a minimum of 30% functional parenchyma.
To study the dynamics of the liver regeneration process and consequent behavior of cell cycle regulators in rats after extended hepatectomy (90%) and postoperative glucose infusions.
Post-hepatectomy liver failure was triggered in 84 Wistar rats by reducing their liver mass by 90%. The animals received a post-operative glucose infusion and were randomly assigned to two groups: One to investigate the survival rate and the other for biochemical analyses. Animals that underwent laparotomy or 70% hepatectomy were used as controls. Blood and liver samples were collected on postoperative days 1 to 7. Liver morphology, function, and regeneration were studied with histology, immunohistochemistry, and western blotting.
Postoperative mortality after major resection reached 20% and 55% in the first 24 h and 48 h, respectively, with an overall total of 70% 7 d after surgery. No apparent signs of apoptotic cell death were detected in the extended hepatectomy rat livers, but hepatocytes displaying a clear cytoplasm and an accumulation of hyaline material testified to changes affecting their functional activities. Liver regeneration started properly, as early events initiating cell proliferation occurred within the first 3 h, and the G1 to S transition was detected in less than 12 h. However, a rise in p27 (Kip1) followed by p21 (Waf1/Cip1) cell cycle inhibitor levels led to a delayed S phase progression and mitosis. Overall, liver regeneration in rats with a 90% hepatectomy was delayed by 24 h and associated with a delayed onset and lower peak magnitude of hepatocellular deoxyribonucleic acid synthesis.
This work highlights the critical importance of the cyclin/cyclin-dependent kinase inhibitors of the Cip/Kip family in regulating the liver regeneration timeline following extended hepatectomy.
Core Tip: There is a current pandemic of obesity and diabetes and the chronic liver damages they cause, and the outcomes of patients undergoing liver mass reduction for malignant diseases are poor. To design efficient strategies that limit the risk of post-hepatectomy liver failure, we used a rat model to clarify the causes of death after enlarged liver resection. Compared with standard 2/3 hepatectomy, enlarged resection resulted in a loss of hepatocyte functional activities and impaired regenerative capacities, which were associated with an overexpression of p21 and p27 inhibitors. The use of extracorporeal support device with p21 and p27 should be considered for the management of severe liver failure following extended hepatectomy.