title: Proof of prometastatic niche induction by hepatic stellate cells.
abstract: BACKGROUND
  An interaction between tumor cells and the microenvironment, as well as the development of angiogenesis, are required to form liver metastases (LMs).
  
  
  METHODS
  Immunofluorescence detection of α-smooth muscle actin, desmin, Ki67, laminin, and CD31 was used to analyze the kinetics of tumor angiogenesis determinants, especially the contribution of hepatic stellate cells (HSCs) to angiogenesis in hepatic metastasis produced by intrasplenically injected LS174 colorectal cancer cells. Immunostaining was performed at various times (days 9, 14, 28, and 39).
  
  
  RESULTS
  At the earliest stage, micrometastases consisted of proliferating cancer cells, a well-organized network of activated HSCs and laminin deposits. No vascular network was observed. As the LMs grew in size, an organized vascular network appeared; the laminin network colocalized with CD31 immunostaining. At the later stages, all the immunostained markers became peripheral as a central necrosis developed. Purified activated HSCs isolated from transgenic mice livers developing hepatocellular carcinoma secreted laminin and showed enhanced human umbilical vein EC network formation in a Matrigel assay. In a coinjection LM experiment, activated HSCs enhanced the metastatic process. Moreover, colorectal LMs from six patients were analyzed, and a pattern of marker distribution similar to the coinjection experiment was found in human LMs.
  
  
  CONCLUSIONS
  For the first time, our results show that HSCs play a crucial role in organizing and accelerating the progression of metastasis in modulating the prometastatic niche, interacting with colorectal cancer cell recruitment, and the organization of angiogenesis during colorectal LM development. Therefore, HSCs may be an early therapeutic target in colorectal cancer therapies.
authors.affiliation: Univ Paris Diderot, Sorbonne Paris Cité, INSERM U965, Angiogenèse et recherche translationnelle, Hôpital Lariboisière, Paris, France; Univ Paris Diderot, Sorbonne Paris Cité, AP-HP, Hôpital Lariboisière, Chirurgie Digestive, Paris, France.
authors.forename: Clarisse
authors.initials: C
authors.lastname: Eveno
authors.affiliation: Univ Paris Diderot, Sorbonne Paris Cité, INSERM U965, Angiogenèse et recherche translationnelle, Hôpital Lariboisière, Paris, France.
authors.forename: Patricia
authors.initials: P
authors.lastname: Hainaud
authors.affiliation: Univ Paris Diderot, Sorbonne Paris Cité, INSERM U965, Angiogenèse et recherche translationnelle, Hôpital Lariboisière, Paris, France.
authors.forename: Aurore
authors.initials: A
authors.lastname: Rampanou
authors.affiliation: Univ Paris Diderot, Sorbonne Paris Cité, INSERM U965, Angiogenèse et recherche translationnelle, Hôpital Lariboisière, Paris, France; Univ Paris Diderot, Sorbonne Paris Cité, AP-HP, Hôpital Lariboisière, Physiologie Clinique Explorations Fonctionnelles, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Bonnin
authors.affiliation: Univ Paris Diderot, Sorbonne Paris Cité, INSERM U965, Angiogenèse et recherche translationnelle, Hôpital Lariboisière, Paris, France.
authors.forename: Sana
authors.initials: S
authors.lastname: Bakhouche
authors.affiliation: Univ Paris Diderot, Sorbonne Paris Cité, INSERM U965, Angiogenèse et recherche translationnelle, Hôpital Lariboisière, Paris, France.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Dupuy
authors.affiliation: Univ Paris Diderot, Sorbonne Paris Cité, INSERM U965, Angiogenèse et recherche translationnelle, Hôpital Lariboisière, Paris, France.
authors.forename: Jean-Olivier
authors.initials: JO
authors.lastname: Contreres
authors.affiliation: Univ Paris Diderot, Sorbonne Paris Cité, INSERM U965, Angiogenèse et recherche translationnelle, Hôpital Lariboisière, Paris, France; Univ Paris Diderot, Sorbonne Paris Cité, AP-HP, Hôpital Lariboisière, Chirurgie Digestive, Paris, France. Electronic address: marc.pocard@inserm.fr.
authors.forename: Marc
authors.initials: M
authors.lastname: Pocard
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism*; D002277:Carcinoma / Q000473:pathology; D006528:Carcinoma, Hepatocellular / Q000503:physiopathology; D015179:Colorectal Neoplasms / Q000473:pathology; D003893:Desmin / Q000378:metabolism; D042783:Endothelial Cells / Q000502:physiology; D005260:Female; D055166:Hepatic Stellate Cells / Q000502:physiology*; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D007797:Laminin / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000378:metabolism / Q000556:secondary*; D008810:Mice, Inbred C57BL; D016513:Mice, SCID; D009362:Neoplasm Metastasis; D009389:Neovascularization, Pathologic / Q000378:metabolism*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism
chemical_list: D000199:Actins; D015415:Biomarkers; D003893:Desmin; D019394:Ki-67 Antigen; D007797:Laminin; D019408:Platelet Endothelial Cell Adhesion Molecule-1; C544013:alpha-smooth muscle actin, mouse
keywords: Activated hepatic stellate cells; Angiogenesis; Colorectal liver metastases; Metastatic niche; Microenvironment