title: The influence of different microenvironments on melanoma invasiveness and microcirculation patterns: an animal experiment study in the mouse model.
abstract: OBJECTIVE
  To investigate the influence of different microenvironments on tumor microcirculation patterns and invasiveness capability.
  
  
  METHODS
  Melanoma B16 cells were injected into the abdominal cavity and skeletal muscle of C57 mice synchronously. CK-18 expression in melanoma was assessed to distinguish the malignant phenotype of tumors in the abdominal cavity from that in the skeletal muscle. HIF-1alpha, MMP-2 and MMP-9 expression and mRNA levels of MMP-2 and MMP-9 was detected to compare the mRNA levels of MMP-2 and MMP-9 from the two microenvironments. Cells positive for each immunohistochemical stain and the vessels representative of each type of microcirculation pattern were counted in two microenvironments.
  
  
  RESULTS
  CK-18 and HIF-1alpha expression of melanoma were significantly higher in the skeletal muscle than in the abdominal cavity (P<0.05). Compared with the abdominal cavity, melanoma cells in the skeletal muscle overexpressed MMP-2 and MMP-9 (P<0.05). Real time-PCR results also showed that MMP-2 and MMP-9 mRNA levels of melanoma were higher in the skeletal muscle than in the abdominal cavity (P<0.05). VM channels and endothelium-dependent vessels were the major microcirculation pattern in the skeletal muscle and in the abdominal cavity, respectively.
  
  
  CONCLUSIONS
  Different microenvironments affect invasiveness and blood supply patterns of melanoma.
authors.affiliation: Department of Pathology, Tianjin Cancer Hospital and Institute, Tianjin Medical University, Tianjin 300060, People's Republic of China.
authors.forename: Baocun
authors.initials: B
authors.lastname: Sun
authors.forename: Shiwu
authors.initials: S
authors.lastname: Zhang
authors.forename: Danfang
authors.initials: D
authors.lastname: Zhang
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Gu
authors.forename: Wenchao
authors.initials: W
authors.lastname: Zhang
authors.forename: Xiulan
authors.initials: X
authors.lastname: Zhao
mesh_terms: D034841:Abdominal Cavity; D000818:Animals; D004730:Endothelium, Vascular; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D053538:Keratin-18 / Q000378:metabolism; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008546:Melanoma, Experimental / Q000098:blood supply* / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008833:Microcirculation; D018482:Muscle, Skeletal; D009361:Neoplasm Invasiveness; D009368:Neoplasm Transplantation; D009389:Neovascularization, Pathologic
chemical_list: C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D053538:Keratin-18; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9