Blockage of HGF/c-Met system by gene therapy (adenovirus-mediated NK4 gene) suppresses hepatocellular carcinoma in mice.
OBJECTIVE
Hepatocyte growth factor promotes cancer development through cell motility-promoting and angiogenic effects. NK4, a fragment of hepatocyte growth factor, acts as its receptor antagonist. We assessed effects of NK4 gene therapy against human hepatocellular carcinoma cells (HUH7) transplanted into mice.


METHODS
NK4 gene transduction was mediated by adenovirus (AdCMV.NK4). LacZ expression adenovirus (AdCMV.LacZ) was used as a control. NK4 effects on HUH7 cells first were studied in vitro. Subcutaneous HUH7 tumors established in athymic nude mice were injected with AdCMV.NK4 (n=6) or AdCMV.Lacz (n=6). Finally, after HUH7 cells were injected into the portal vein in mice with severe combined immunodeficiency to establish hepatic tumors, mice systemically were injected with AdCMV.NK4 (n=6) or AdCMV.LacZ (n=6).


RESULTS
NK4 inhibited hepatocyte growth factor-induced phosphorylation of c-Met in HUH7 cells. Invasion and migration of HUH7 cells were inhibited by NK4 transfection, which also suppressed growth of transplanted subcutaneous and liver tumors (p<0.001, p<0.01 respectively), and improved mouse survival (p<0.05). Angiogenesis assessed by small vessel density was significantly decreased in the NK4-treated group.


CONCLUSIONS
NK4 inhibited tumor cell motility and angiogenesis, greatly suppressing growth of HUH7 tumors transplanted into mouse liver. NK4 gene therapy thus showed apparent promise for treatment of hepatocellular carcinoma.
Son
Gakuhei
G
First Department of Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan.
Hirano
Tadamichi
T
Seki
Ekihiro
E
Iimuro
Yuji
Y
Nukiwa
Toshihiro
T
Matsumoto
Kunio
K
Nakamura
Toshikazu
T
Fujimoto
Jiro
J
D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D045744:Cell Line, Tumor / Q000502:physiology; D002465:Cell Movement; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D017228:Hepatocyte Growth Factor / Q000037:antagonists & inhibitors / Q000235:genetics*; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000235:genetics*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D023421:Models, Animal; D009374:Neoplasms, Experimental; D009389:Neovascularization, Pathologic / Q000517:prevention & control*
C066855:HGF protein, human; D017228:Hepatocyte Growth Factor