The effect of phorbol esters on tumor cell sensitivity to macrophage-mediated cytostasis |
| |
Authors: | L M Nycum M Fishman |
| |
Affiliation: | Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee 38101. |
| |
Abstract: | Macrophage-mediated cytostasis was measured in a mouse syngeneic system where EL4 thymoma cells were found to be inhibited by C57B1/6 mouse macrophages. When tumor cells were pretreated with TPA, they became resistant to macrophage-mediated stasis. Nonelutriated as well as elutriated cells enriched in G1/early S and late S were sensitive to macrophage-mediated stasis. However, when elutriated cells were treated with TPA, cells enriched in G1/early S were rendered resistant to the cytostatic activity of macrophages whereas cells enriched in late S were not. The TPA effect on tumor cell susceptibility to stasis was found to be reversible and a nontumor-promoting phorbol ester, alpha-PDD, was ineffective. |
| |
Keywords: | |
|
|