Suppression of natural tumor resistance by tumor promoters
- PMID: 7039836
Suppression of natural tumor resistance by tumor promoters
Abstract
The findings of the present and other studies (4,7) show that TPA and other tumor-promoting esters suppress various in vitro manifestations of natural cell-mediated tumor resistance: (a) prevention of enhancement of macrophage cytocidal activity; (b) suppression of cytocidal capacity by activated macrophages; and (c) suppression of cytolytic activity of NK cells. Moreover, they abrogate host tumor resistance in vivo. These suppressive effects of tumor promoters on natural antitumor effector systems may constitute a fundamental mechanism in carcinogenesis.