Protooncogene expression in normal and tumor-infiltrating phagocytes.
Expression of cellular protooncogene was investigated in freshly isolated human leukocytes and in tumor-associated macrophages isolated from murine fibrosarcomas. Normal leukocytes express high levels of c-fos and c-raf-1 transcripts. Expression of c-fos and c-raf-1 in leukocytes differ in many respects; in particular, agents that stimulate leukocyte functions augment c-fos expression but have no effects on c-raf-1 transcription. Tumor-associated macrophages constitutively express c-fos protooncogene at levels higher than peritoneal macrophages. Moreover, in contrast to what happens in peritoneal macrophages, tumor-associated macrophages do not respond to endotoxin with an increase in c-fos expression.
Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
B
B
Bottazzi
Z G
ZG
Chen
N
N
Polentarutti
F
F
Chiaffarino
A
A
Mantovani
F
F
Colotta
D000818:Animals; D005354:Fibrosarcoma / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D066298:In Vitro Techniques; D007962:Leukocytes / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D010586:Phagocytes / Q000378:metabolism*; D011519:Proto-Oncogenes