March 10, 2005

Breakthrough in cancer gene therapy endows immune cells with ability to
target metastatic prostate cancer without causing toxic immune
suppression.

In a major breakthrough in cancer gene therapy, a Northwestern
University researcher has endowed immune cells with the ability to
specifically target metastatic prostate cancer in mice without causing
the toxic immune suppression that has been associated with earlier forms
of cancer gene therapy.

Chung Lee, John T. Grayhack, M.D., Professor of Urology at Northwestern
University Feinberg School of Medicine, and his laboratory group
described the adoptive transfer gene therapy technique in the March
issue of Cancer Research.
Lee is also a researcher at The Robert H. Lurie Comprehensive Cancer
Center of Northwestern University. The researchers first rendered immune
cells known as CD8+ T cells insensitive to transforming growth factor
beta (TGF-beta), a powerful, naturally occurring substance in the body
that enables cancer cells to evade surveillance by the body's immune
system. The immunosuppressive effect of TGF-beta in cancer progression
is well established.

After inserting a mutated form of the TGF-beta receptor into CD8+ T
cells, Lee and associates transplanted the tumor-specific immune cells
into mice that had been given a particularly aggressive form of prostate
cancer, called TRAMP-C2.

TRAMP-C2 prostate cancer cells produce large amounts of TGF-beta, and
possess such potent immunosuppressive power that regular CD8+ T cells
are unable to infiltrate tumor tissues, Lee explained.
The mice received a single injection of tumor-reactive
TGF-beta-insensitive CD8+ T cells, tumor-specific TGF-beta-sensitive
CD8+ T cells or untreated CD8+ T cells at three (early cancer), seven or
21 days (advanced cancer) after they had been injected with the prostate
cancer cells.

Lee and co-researchers found that the tumor-reactive
TGF-beta-insensitive CD8+ T cells infiltrated prostate cancer tumors and
effectively destroyed the TRAMP-C2 cells.

knowledge is power - growing old is mandatory - growing wise is optional    
"Many more men die with prostate cancer than of it. Growing old is
invariably fatal. Prostate cancer is only sometimes so."
http://community.webtv.net/PALMER_ENT/doc