title: Effect of hypoxic stress on migration and characteristics of monocytes in uveal melanoma.
abstract: OBJECTIVE
  Among the characteristics of uveal melanoma that are associated with a poor prognosis are a large tumor size and the presence of increased numbers of lymphocytes and macrophages. In rapidly growing tumors, reduction in oxygen tension may occur with increased distance from blood vessels, which we hypothesize may lead to an inflammatory microenvironment, further stimulating tumor growth.
  
  
  OBJECTIVE
  To analyze whether hypoxia induces uveal melanoma cells to express proinflammatory cytokines and whether tumor supernatant (TSN) affects monocyte migration and differentiation.
  
  
  METHODS
  The expression of proinflammatory genes in freshly cultured uveal melanoma samples was studied in an in vitro 24-hour hypoxic culture system using quantitative polymerase chain reaction. In addition, cell lines cultured under normoxic and hypoxic conditions were used. The effect of TSN on monocyte chemotaxis was tested using a transwell migration system and by analyzing monocyte differentiation. The levels of the cytokines CCL2, IL6, and PGE2 in TSN were determined by enzyme-linked immunosorbent assay.
  
  
  METHODS
  Five cell lines (OCM8, 92.1, Mel270,Mel290 and OMM2.5) and 11 primary short-term cultures.
  
  
  RESULTS
  Exposure of freshly cultured uveal melanoma cells to hypoxia led to an increased expression of the proinflammatory cytokines PLGF (OMIM 601121), TGFβ (OMIM 190180), END1 (OMIM +131240), and ICAM1 (OMIM 147840) and a lower expression of AIMP1 (OMIM 603605) (EMAP2), CCL2 (MCP-1) (OMIM +158105), and IL1b (OMIM *147720). The TSN from cultured melanoma cell lines induced chemotaxis of monocytes, but this was independent of the normoxic or hypoxic state. The TSN of 1 cell line and 2 primary uveal melanoma cultures inhibited the dendritic cell maturation and did not induce M2 macrophage polarization in vitro.
  
  
  CONCLUSIONS
  Our results indicate that under hypoxic conditions, immune response genes are differentially expressed in cultured primary uveal melanoma cells. The TSN from uveal melanoma cell lines is capable of affecting the chemotactic response and maturation of monocytes in vitro, but this is irrespective of hypoxia.
authors.forename: Inge H G
authors.initials: IH
authors.lastname: Bronkhorst
authors.forename: Tina M L
authors.initials: TM
authors.lastname: Jehs
authors.forename: Eveline M
authors.initials: EM
authors.lastname: Dijkgraaf
authors.forename: Gregorius P M
authors.initials: GP
authors.lastname: Luyten
authors.forename: Pieter A
authors.initials: PA
authors.lastname: van der Velden
authors.forename: Sjoerd H
authors.initials: SH
authors.lastname: van der Burg
authors.forename: Martine J
authors.initials: MJ
authors.lastname: Jager
mesh_terms: D002465:Cell Movement; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics*; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D000860:Hypoxia / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008545:Melanoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D009000:Monocytes / Q000378:metabolism / Q000473:pathology*; D018384:Oxidative Stress / Q000235:genetics*; D016133:Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D014604:Uveal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000098943:Uveal Melanoma
chemical_list: D016207:Cytokines; D004273:DNA, Neoplasm