Major but not minor hepatectomy accelerates engraftment of extrahepatic tumor cells.
BACKGROUND
The effect of hepatectomy and hepatic regeneration on intra- and extrahepatic tumor growth is still controversially discussed. Herein we studied the effect of minor (30%) or major (70%) hepatectomy on engraftment of extrahepatic tumor cells, and the role of tumor neovascularization and tumor cell migration.


METHODS
Green fluorescent protein (GFP)-transfected CT26.WT colorectal cancer cells were implanted in dorsal skinfold chambers of syngeneic BALB/c mice. Animals underwent 30% (30%Phx, n = 8) or 70% hepatectomy (70%Phx, n = 8). Sham-operated animals served as controls (n = 8). Angiogenesis and neovascularization as well as tumor cell migration, proliferation and growth were studied over 14 days using intravital fluorescence microscopy, histology and immunohistochemistry.


RESULTS
After both minor and major hepatectomy tumor proliferating cell nuclear antigen (PCNA) expression increased significantly (P < 0.05) when compared with nonhepatectomized controls. However, only major but not minor hepatectomy accelerated neovascularization (P < 0.05) and tumor cell migration (P < 0.05). This was associated with a significantly (P < 0.05) enhanced tumor growth after 70%Phx when compared with 30%Phx and controls. The rate of apoptotic cell death was not affected by major or minor hepatectomy.


CONCLUSIONS
Regeneration after major hepatectomy accelerates extrahepatic tumor cell engraftment, most probably by acceleration of neovascularization and induction of tumor cell migration.
Rupertus
Kathrin
K
Department of General, Visceral, Vascular and Pediatric Surgery, University of Saarland, 66421 Homburg/Saar, Germany.
Kollmar
Otto
O
Scheuer
Claudia
C
Junker
Bastian
B
Menger
Michael D
MD
Schilling
Martin K
MK
D000818:Animals; D045744:Cell Line, Tumor; D005260:Female; D049452:Green Fluorescent Proteins; D006498:Hepatectomy; D007150:Immunohistochemistry; D008115:Liver Regeneration / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D009362:Neoplasm Metastasis / Q000473:pathology*; D009374:Neoplasms, Experimental / Q000473:pathology*; D009389:Neovascularization, Pathologic; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism
D018809:Proliferating Cell Nuclear Antigen; D049452:Green Fluorescent Proteins