title: MicroRNA-29b suppresses tumor angiogenesis, invasion, and metastasis by regulating matrix metalloproteinase 2 expression.
abstract: Hepatocellular carcinoma (HCC) is a highly vascularized tumor with frequent intrahepatic metastasis. Active angiogenesis and metastasis are responsible for rapid recurrence and poor survival of HCC. We previously found that microRNA-29b (miR-29b) down-regulation was significantly associated with poor recurrence-free survival of HCC patients. Therefore, the role of miR-29b in tumor angiogenesis, invasion, and metastasis was further investigated in this study using in vitro capillary tube formation and transwell assays, in vivo subcutaneous and orthotopic xenograft mouse models, and Matrigel plug assay, and human HCC samples. Both gain- and loss-of-function studies showed that miR-29b dramatically suppressed the ability of HCC cells to promote capillary tube formation of endothelial cells and to invade extracellular matrix gel in vitro. Using mouse models, we revealed that tumors derived from miR-29b-expressed HCC cells displayed significant reduction in microvessel density and in intrahepatic metastatic capacity compared with those from the control group. Subsequent investigations revealed that matrix metalloproteinase-2 (MMP-2) was a direct target of miR-29b. The blocking of MMP-2 by neutralizing antibody or RNA interference phenocopied the antiangiogenesis and antiinvasion effects of miR-29b, whereas introduction of MMP-2 antagonized the function of miR-29b. We further disclosed that miR-29b exerted its antiangiogenesis function, at least partly, by suppressing MMP-2 expression in tumor cells and, in turn, impairing vascular endothelial growth factor receptor 2-signaling in endothelial cells. Consistently, in human HCC tissues and mouse xenograft tumors miR-29b level was inversely correlated with MMP-2 expression, as well as tumor angiogenesis, venous invasion, and metastasis.
  
  
  CONCLUSIONS
  miR-29b deregulation contributes to angiogenesis, invasion, and metastasis of HCC. Restoration of miR-29b represents a promising new strategy in anti-HCC therapy.
authors.affiliation: Key Laboratory of Gene Engineering of Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Guangzhou, PR China.
authors.forename: Jian-Hong
authors.initials: JH
authors.lastname: Fang
authors.forename: Hui-Chao
authors.initials: HC
authors.lastname: Zhou
authors.forename: Chunxian
authors.initials: C
authors.lastname: Zeng
authors.forename: Jine
authors.initials: J
authors.lastname: Yang
authors.forename: Yinglin
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiuzhi
authors.initials: X
authors.lastname: Huang
authors.forename: Jing-Ping
authors.initials: JP
authors.lastname: Zhang
authors.forename: Xin-Yuan
authors.initials: XY
authors.lastname: Guan
authors.forename: Shi-Mei
authors.initials: SM
authors.lastname: Zhuang
mesh_terms: D000818:Animals; D002196:Capillaries / Q000502:physiology; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism / Q000556:secondary*; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D045325:HCT116 Cells; D057809:HEK293 Cells; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000473:pathology; D009368:Neoplasm Transplantation; D009389:Neovascularization, Pathologic / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D015398:Signal Transduction / Q000235:genetics; D014183:Transplantation, Heterologous
chemical_list: C532045:MIRN29a microRNA, human; D035683:MicroRNAs; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2