Cancerous cells express proteins that are foreign to the host's body and which should therefore be recognized by the immune system and attacked, thus destroying the tumor. Oftentimes this system fails: the cancerous cell escape immune attack. Understanding how tumor cells are able to avoid detection is important to developing new anti-cancer treatments.
Richard Flavell and colleagues at Yale University have discovered that the cytokine molecule TGF-beta is key to suppressing the immune response to tumors, thus allowing cancers to thrive. Blocking the effects of TGF-beta could form the basis of a new therapy for cancer (Nature Medicine Vol. 7, No. 10, 01 Oct 2001).
Using transgenic mice engineered so that the T lymphocyte cells of their immune systems were insensitive to TGF-beta, the researchers found that these mice did not develop tumors when injected with cancerous cells, unlike normal mice which went on to develop tumors and die.
The authors conclude that if human T cells could also be made insensitive to the signaling effects of TGF-beta, then these findings "can be readily adapted to clinical situations to improve existent T-cell-mediated antitumor interventions."
Dr. Richard A. Flavell
Section of Immunobiology
Yale University School of Medicine and Howard Hughes Medical Institute
New Haven, CT
Tel: +1 203 737 2216
Fax: +1 203 737 2958
(C) Nature Medicine press release.
Message posted by: Trevor M. D'Souza