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Prostaglandin E 2 Content of Regressing and Progressing Moloney Sarcomas
Author(s) -
Wechsler Sally J.,
Eurell Thomas E.,
Russell Stephen W.
Publication year - 1986
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.40.2.159
Subject(s) - biology , prostaglandin e2 , in vitro , cancer research , prostaglandin e , macrophage , sarcoma , cell , prostaglandin , neoplasm , pathology , endocrinology , biochemistry , genetics , medicine
Regressing mouse Moloney sarcomas contain macrophages that are activated for tumor cell killing, while those found in progressively growing sarcomas either cannot kill or do so very poorly. Prostaglandin E 2 (PGE2) has been shown to down‐regulate macrophage activation in vitro. The study described here was designed, therefore, to ascertain and compare the concentrations of PGE 2 in regressing and progressing Moloney sarcomas. Tumors were harvested for extraction and analyzed using conditions that minimized artifactual increases in PGE 2 levels attributable to de novo synthesis. Concentrations of PGE 2 were higher in progressing, compared to regressing, Moloney sarcomas during the early stages of tumor development. At nearly all time points, however, whether the neoplasms were of regressing or progressing type, the estimated concentrations of PGE 2 in tumors exceeded the level that completely inhibits macrophage activation for tumor cell killing in vitro, that is, 10 −8 M. These data suggest either that PGE 2 is not responsible for down‐regulating activation in Moloney sarcomas or that, if PGE 2 is responsible for the negative regulation of activation in progressing Moloney sarcomas, there must be something in regressing sarcomas that prevents the hormone from having its inhibitory effect.