title: Characterization of the inflammatory response during Ehrlich ascitic tumor development.
abstract: BACKGROUND
  Ehrlich tumor is a mammary adenocarcinoma with aggressive behavior. Inoculated in mice peritoneal cavity, the Ehrlich tumor grows in ascitic form (EAT). Since inflammation modulates tumor progression we further investigated the inflammatory response during EAT growth.
  
  
  METHODS
  Balb/C mice were intraperitoneal inoculated with 5×10(5) Ehrlich cells and after every 2days, blood samples were collected for hemoglobin, hematocrit, platelets and leukocytes counts. The ascitic fluid was collected for protein concentration and cell count. Phenotype analysis of the peritoneal cells was made by FACS, prostaglandin E2 (PGE2) and cytokines by ELISA, nitric oxide (NO) by nitrate conversion protocol, and cyclooxygenase-1 (COX1), COX2 and inducible nitric oxide synthase (iNOS) by immunoblotting.
  
  
  RESULTS
  Following EAT inoculation into the peritoneal cavity there was a rapid increase in ascitis volume and protein concentration. The cell number in ascitis remained stable until day 8 (lag phase) followed by a sharp increase. As tumor progressed, blood leukocytes increased and erythrocyte decreased. Phenotypic analysis showed that during the lag phase the percentage of F4/80(+) cells remained similar to control levels and around 7% of this population was also positive for the GR1 marker. These double-positive cells (probably inflammatory monocytes) markedly increased at day 6. The percentage of F4/80-GR1(+)cells (probably neutrophils) was low and did not significantly vary during tumor progression. CD4(+) and CD8(+) cells were not detected in the time points analyzed. iNOS and COX1 expression increased after day 2 reaching peak levels on day 10. COX2 enzyme expression did not change significantly over time. Sustained increase in PGE2 and NO levels was observed. IL-10 and MCP-1 peaked at day 14 and IL-1β increased progressively till day 10. IFN-γ levels were low till day 10, increasing progressively after that.
  
  
  CONCLUSIONS
  These data extended the characterization of the inflammatory response during Ehrlich ascitis tumor growth, further validating it as a useful model for antitumor drugs screening.
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Ciências Biomédicas, Laboratório de Farmacologia da Dor e da Inflamação, Brazil. Electronic address: patricia.dias@icb.ufrj.br.
authors.forename: Patrícia Dias
authors.initials: PD
authors.lastname: Fernandes
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Ciências Biomédicas, Laboratório de Farmacologia da Dor e da Inflamação, Brazil.
authors.forename: Fabiana S
authors.initials: FS
authors.lastname: Guerra
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Ciências Biomédicas, Laboratório de Farmacologia da Dor e da Inflamação, Brazil.
authors.forename: Natália M
authors.initials: NM
authors.lastname: Sales
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Ciências Biomédicas, Laboratório de Farmacologia da Dor e da Inflamação, Brazil.
authors.forename: Thais B
authors.initials: TB
authors.lastname: Sardella
authors.affiliation: Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Imunologia, Universidade de São Paulo, Brazil.
authors.forename: Sonia
authors.initials: S
authors.lastname: Jancar
authors.affiliation: Universidade Federal do Rio de Janeiro, Instituto de Ciências Biomédicas, Laboratório Compartilhado, Brazil.
authors.forename: Josiane S
authors.initials: JS
authors.lastname: Neves
mesh_terms: D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000097:blood / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D007249:Inflammation / Q000097:blood / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C
keywords: Cyclooxygenase; Inducible nitric oxide sythase; Nitric oxide; Prostaglandin E2