A link has been found between a particular type of gastrointestinal cancer and T-cell functioning. The discovery, reported in the 22 June 2006 issue of Nature (Vol. 441, No.7096, pp. 1015-1019), may have implications for patient treatment and aid the development of new therapies.
Children with the syndrome familial juvenile polyposis (FJP) develop gastrointestinal polyps that can sometimes become cancerous. Around half of all patients carry an inherited mutation in one copy of the SMAD4 gene, and it's thought that cancer develops if the remaining copy becomes inactivated in the epithelial cells that line the gastrointestinal tract.
John Letterio and colleagues studied mice in which the Smad4 gene was deleted in specific cell types. When the gene was deleted in epithelial cells, mice did not develop cancer. But when the gene was deleted in T cells, which play a role in the immune system, mice developed epithelial cancers throughout the gastrointestinal tract.
Although the role of T cells in FJP has yet to be determined, the findings show that a genetic alteration in one cell type can induce cancer formation in a different tissue, increasing our understanding of the role of the microenvironment in tumour development.
John Letterio (Case Western Reserve University, Cleveland, OH, USA)
(C) Nature press release.
Message posted by: Trevor M. D'Souza