title: Production of cachexia mediators by Walker 256 cells from ascitic tumors.
abstract: In neoplasic cachexia, chemical mediators seem to act as initiators or perpetuators of this process. Walker 256 cells, whose metabolic properties have so far been little studied with respect to cancer cachexia, are used as a model for the study of this syndrome. The main objective of this research was to pinpoint the substances secreted by these cells that may contribute to the progression of the cachectic state. Since inflammatory mediators seem to be involved in the manifestation of this syndrome, the in vitro production of nitric oxide (NO), cytokines (tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6)), and prostaglandin E2 (PGE2) was evaluated in Walker 256 cells isolated from ascitic tumors. After 4 or 5 h, a significant increase in NO production was observed (2.55 +/- 1.56 and 4.05 +/- 1.99 nmol NO per 10(7) cells, respectively). When isolated from a 6-day-old tumor, a significantly lower production of IL-6 and higher production of TNF-alpha than in cells from a 4-day-old tumor were observed, indicating a relationship between the production of cytokines and the time of tumor development after implantation. Considerable production of PGE(2) by Walker 256 cells isolated from the 6-day-old tumor was also observed. Polyamines were also determined in Walker 256 cells. Levels of putrescine, spermidine, and spermine did not show significant differences in tumors developed during 4 or 6 days. Direct evidence of the release of proinflammatory cytokines and PGE2 by Walker 256 cells suggests that these mediators can drive the cachectic syndrome in the host, the effect being dependent on tumor development time.
authors.affiliation: Department of Biochemistry, UFPR-Federal University of Paraná, Curitiba, CEP, PR, Brazil.
authors.forename: Rosilene
authors.initials: R
authors.lastname: Rebeca
authors.forename: Lívia
authors.initials: L
authors.lastname: Bracht
authors.forename: Guilhermina Rodrigues
authors.initials: GR
authors.lastname: Noleto
authors.forename: Glaucia Regina
authors.initials: GR
authors.lastname: Martinez
authors.forename: Silvia Maria Suter Correia
authors.initials: SM
authors.lastname: Cadena
authors.forename: Eva Gunilla Skare
authors.initials: EG
authors.lastname: Carnieri
authors.forename: Maria Eliane Merlin
authors.initials: ME
authors.lastname: Rocha
authors.forename: Maria Benigna Martinelli
authors.initials: MB
authors.lastname: de Oliveira
mesh_terms: D000818:Animals; D001119:Arginase / Q000378:metabolism; D001202:Ascitic Fluid / Q000473:pathology*; D015317:Biogenic Polyamines / Q000378:metabolism; D002100:Cachexia / Q000209:etiology / Q000378:metabolism*; D002279:Carcinoma 256, Walker / Q000150:complications* / Q000473:pathology; D045744:Cell Line, Tumor; D015232:Dinoprostone / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014508:Urea / Q000378:metabolism
chemical_list: D015317:Biogenic Polyamines; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D014508:Urea; D001119:Arginase; D015232:Dinoprostone