Fumagillin treatment of hepatocellular carcinoma in rats: an in vivo study of antiangiogenesis.
OBJECTIVE
To investigate the effect and possible mechanisms of antiangiogenesis therapy for HCC in rats.


METHODS
Adult male LEW/SsN rats were divided into 3 groups, 25 animals each. Group A was the control group. Groups B and C were given diethylnitrosamine, 5 mg/kg/d. In addition, group C rats received an intraperitoneal injection of fumagillin, 30 mg/(kg x d). Five animals in each group were killed at 6th, 12th, 18th, 20th and 24th wk to evaluate the development of HCC and metastasis. Weight of the rats, liver tumors, and number of organs involved by HCC were measured at each stage. We compared methionine aminopeptidase-2 (MetAP-2) mRNA, Bcl-2 mRNA, telomerase mRNA, and telomerase activity at 24th wk in the liver tissue of group A rats and tumor tissue of HCC from group B and C rats.


RESULTS
No HCC developed in group A, but tumors were present in group B and C rats by the 18th wk. At wk 20 and 24, the median liver weight in group B was 0.64 g (range: 0.58-0.70 g) and 0.79 g (range: 0.70-0.90 g) (P = 0.04), and that in group C was 0.37 g (range: 0.35-0.42 g) and 0.39 g (range: 0.35-0.47 g) (P = 0.67). The liver weight in group C rats was significantly lower than that in group B rats (P = 0.009). At the same time, the median metastasis score (number of organ systems involved) was 3 (range2-3) in group B, and 1 (range 1-2) in group C, a significant difference between the groups (P = 0.007, 0.004). The levels of MetAP-2 mRNA were significantly higher in groups B and C than in group A (P = 0.025), and significantly higher in group C than in group B (P = 0.047). The level of Bcl-2 mRNA was significantly higher in group B than in group A (P = 0.024), but lower in group C than in group B, although not significantly (P = 0.072). Telomerase mRNA was significantly higher in group B than in group A (P = 0.025), but significantly lower in group C than in group B (P = 0.016). The same inter-group relationship was also true for telomerase activity (P = 0.025 and 0.046).


CONCLUSIONS
Fumagillin effectively inhibits both liver tumor growth and metastasis in rats in vivo. A possible mechanism is fumagillin-induced inhibition of MetAP-2, which plays an essential role in endothelial cell proliferation. Inhibition of MetAP-2 also results in inhibition of Bcl-2 and telomerase activity.
Sheen
I-Shyan
IS
Liver Research Unit, Chang Gung Memorial Hospital, Taipei, Taiwan, China.
Jeng
Kuo-Shyang
KS
Jeng
Wen-Juei
WJ
Jeng
Chi-Juei
CJ
Wang
Yi-Ching
YC
Gu
Shu-Ling
SL
Tseng
Shin-Yun
SY
Chu
Chien-Ming
CM
Lin
Chia-Hui
CH
Chang
Kuo-Ming
KM
D000626:Aminopeptidases / Q000235:genetics; D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000188:drug therapy* / Q000556:secondary; D003510:Cyclohexanes; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics; D008114:Liver Neoplasms, Experimental / Q000098:blood supply / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D008666:Metalloendopeptidases / Q000235:genetics; D009389:Neovascularization, Pathologic / Q000188:drug therapy*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011917:Rats, Inbred Lew; D012717:Sesquiterpenes; D013047:Specific Pathogen-Free Organisms; D019098:Telomerase / Q000235:genetics / Q000378:metabolism
D020533:Angiogenesis Inhibitors; D003510:Cyclohexanes; D005231:Fatty Acids, Unsaturated; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D012717:Sesquiterpenes; C026211:fumagillin; D005954:Glucosephosphate Dehydrogenase; D019098:Telomerase; D000626:Aminopeptidases; C106541:methionine aminopeptidase 2; D008666:Metalloendopeptidases