title: Up-regulation of TIMP-1 by genipin inhibits MMP-2 activities and suppresses the metastatic potential of human hepatocellular carcinoma.
abstract: OBJECTIVE
  Hepatocellular carcinoma is one of the most malignant human cancers with high metastatic potential. The aim of this study is to investigate the anti-metastatic effect of genipin and its underlying mechanism.
  
  
  METHODS
  The anti-metastatic potential of genipin was evaluated by both cell and animal model. Wound healing and invasion chamber assays were introduced to examine the anti-migration and anti-invasion action of genipin in human hepatocellular carcinoma cell HepG2 and MHCC97L; orthotopical implantation model was used for in vivo evaluation. Gelatin Zymography, Immunoblotting, quantitative real-time polymerase chain reaction and ELISA assays were used to study the mechanisms underlying genipin's anti-metastatic effect.
  
  
  RESULTS
  Genipin suppresses the motility and invasiveness of HepG2 and MHCC97L at non-toxic doses, which may be correlated to the inhibition of genipin on MMP-2 activities in the cells. No significant reduced expression of MMP-2 was observed either at mRNA or at protein level. Furthermore, genipin could specifically up-regulate the expression of TIMP-1, the endogenous inhibitor of MMP-2 activities. Silencing of TIMP-1 by RNA interference abolishes genipin's anti-metastaic effect. Activation of p38 MAPK signaling was observed in genipin-treated cells, which is responsible for the TIMP-1 overexpression and MMP-2 inhibition. Presence of SB202190, the p38 MAPK inhibitor, attenuates the anti-metastatic potential of genipin in hepatocellular carcinoma. Orthotopical implantation model showed that genipin could suppress the intrahepatic metastatic as well as tumor expansion in liver without exhibiting potent toxicity.
  
  
  CONCLUSIONS
  Our findings demonstrated the potential of genipin in suppressing hepatocellular carcinoma metastasis, and p38/TIMP-1/MMP-2 pathway may be involved as the key mechanism of its anti-metastasis effect.
authors.affiliation: School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, People's Republic of China.
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.forename: Meifen
authors.initials: M
authors.lastname: Zhu
authors.forename: Sai-Wah
authors.initials: SW
authors.lastname: Tsao
authors.forename: Kwan
authors.initials: K
authors.lastname: Man
authors.forename: Zhangjin
authors.initials: Z
authors.lastname: Zhang
authors.forename: Yibin
authors.initials: Y
authors.lastname: Feng
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000556:secondary; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D002756:Cholagogues and Choleretics / Q000494:pharmacology* / Q000627:therapeutic use; D015536:Down-Regulation; D020868:Gene Silencing; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D039823:Iridoids / Q000494:pharmacology* / Q000627:therapeutic use; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D016609:Neoplasms, Second Primary / Q000517:prevention & control*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000819:agonists / Q000235:genetics*; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D002756:Cholagogues and Choleretics; D007093:Imidazoles; D039823:Iridoids; D047428:Protein Kinase Inhibitors; D011725:Pyridines; D034741:RNA, Small Interfering; C560822:TIMP1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; C007834:genipin; D048051:p38 Mitogen-Activated Protein Kinases; D020778:Matrix Metalloproteinase 2; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole