Volume 3 Supplement 1

23rd Congress of the International Association for Breast Cancer Research

Open Access

Prevention of thymic atrophy in mammary tumor bearers by IFN-gamma

  • V Charyulu1,
  • B Adkins2,
  • D Lobo2 and
  • DM Lopez2
Breast Cancer Research20013(Suppl 1):A17

https://doi.org/10.1186/bcr341

Received: 10 May 2001

Published: 31 May 2001

Development of the in vivo transplantable D1-DMBA-3 mammary tumors results in an alteration of several cytokines in the host, and IFN-γ is one of the most severely downregulated. Notably, the thymuses of these mice display a profound atrophy that is associated with a severe depletion of CD4+8+ thymocytes. Investigations into the possible mechanisms that lead to this thymic atrophy revealed that the levels of proliferation assessed by in vivo labeling with 5' -bromo-2'-deoxyuridine (BrdU) were similar in control and tumor-bearing mice. However, our studies implicated a modest increase in apoptosis, coupled with an arrest at the triple negative stage of differentiation in the thymic hypocellularity in tumor bearers. We have transfected the DA-3 mammary tumor cell line, derived in vitro from the in vivo D1-DMBA tumors, with the IFN-γ gene and showed the production of high levels of IFN-γ protein by the transfected cells. Inoculation of hosts with IFN-γ transfected cells 4 days prior to challenge with the D1-DMBA-3 tumor resulted in a blockage of the thymus involution in these mice. In contrast, using in the same protocol untransfected DA-3 cells, the progressive atrophy observed in animals with D1-DMBA-3 tumors was observed. These results suggest that the lack of IFN-γ may be an important factor in the thymic atrophy that occurs during mammary tumorigenesis.

Authors’ Affiliations

(1)
Florida Atlantic University, Department of Health Sciences
(2)
Department of Microbiology and Immunology, University of Miami School of Medicine

Copyright

© BioMed Central Ltd 2001

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