This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Torroella-Kouri, M. Articles by Lopez, D. M. Search for Related Content PubMed PubMed Citation Articles by Torroella-Kouri, M. Articles by Lopez, D. M.

Diminished Expression of Transcription Factors Nuclear Factor B and CCAAT/Enhancer Binding Protein Underlies a Novel Tumor Evasion Mechanism Affecting Macrophages of Mammary Tumor–Bearing Mice

¹ Department of Microbiology and Immunology, University of Miami School of Medicine and the Sylvester Comprehensive Cancer Center, Miami, Florida; ² Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York; and ³ Department of Biomedical Sciences, Florida Atlantic University, Boca Raton, Florida

Requests for reprints: Diana M. Lopez, University of Miami School of Medicine, P.O. Box 016960 (R-138), Miami, FL 33101. Phone: 305-243-6632; Fax: 305-243-4409; E-mail: dlopez{at}med.miami.edu.

Interactions between malignant tumors and the host immune system shape the course of cancer progression. The molecular basis of such interactions is the subject of immense interest. Proinflammatory cytokines produced by macrophages are critical mediators of immune responses that contribute to the control of the advancement of neoplasia. We have shown that the expressions of interleukin 12 (IL-12) and inducible nitric oxide synthase (iNOS) are decreased in macrophages from mammary tumor–bearing mice. In this study, we investigated the causes of IL-12 dysregulation and found deficient nuclear factor B (NFB) and CCAAT/enhancer binding protein (C/EBP) expression and function in tumor bearers' peritoneal macrophages. The constitutive expressions of NFB p50, c-rel, p65, and C/EBP and ß, as well as the lipopolysaccharide-induced nuclear translocation and DNA binding of NFB components and C/EBP and ß, are profoundly impaired in macrophages from mice bearing D1-DMBA-3 tumors. Because similar findings occur with the iNOS gene, it seems that it represents a novel mechanism by which tumor-derived factors interfere with the host immune defenses.

This article has been cited by other articles:

				A. Saccani, T. Schioppa, C. Porta, S. K. Biswas, M. Nebuloni, L. Vago, B. Bottazzi, M. P. Colombo, A. Mantovani, and A. Sica p50 Nuclear Factor-{kappa}B Overexpression in Tumor-Associated Macrophages Inhibits M1 Inflammatory Responses and Antitumor Resistance Cancer Res., December 1, 2006; 66(23): 11432 - 11440. [Abstract] [Full Text] [PDF]