[OT] Designer T Cells Fight Prostate Cancer

[Guest guest]

Designer T Cells Fight Prostate Cancer

Experimental Treatment Uses Gene Therapy to Modify Immune System Cells

By Charlene Laino

WebMD Health News

Reviewed by Louise Chang, MD

April 20, 2009 (Denver) -- Using gene therapy, researchers have re-educated

patients' own immune systems to attack prostate tumors in the body.

In the first two patients treated, the experimental treatment reduced PSA levels

by 50% to 75%.

PSA levels are a measure of a protein called prostate-specific antigen produced

by cells in the prostate. High PSA levels can signal cancer; a reduction in PSA

of 50% or more after treatment is a sign that the patient is responding to the

treatment.

Both patients had advanced (metastatic) prostate cancer that had spread to other

parts of the body. The findings were reported at the annual meeting of the

American Association for Cancer Research.

How Designer T Cells Work

In the treatment, gene therapy is used to modify immune-system cells called T

cells in such a way as to attack the cancer, says Junghans, MD,

associate professor of surgery and medicine at Boston University.

Normally, prostate cancer cells fly under the radar of the immune system,

evading the body's surveillance mechanisms. The designer T cells target and

attach to a specific protein that is present on many tumor cells.

" We fool the T cells " into thinking the cancer is a foreign invader that needs

to be attacked and annihilated, he says. " T cells are the perfect killing

machine. "

As an extra boost, patients are also given chemotherapy.

To date, neither patient has developed any significant side effects.

Early Results 'Encouraging'

With higher doses of the designer T cells -- which the researchers plan to test

soon -- Junghans says he hopes to be able to cure men with metastatic prostate

cancer.

" I expect this, or some version of this, to become standard treatment within

five years, " he says.

Louis Weiner, MD, director of Lombardi Comprehensive Cancer Center in

Washington, D.C, says the approach marries two concepts that have been around

for about 20 years.

" What [the researchers] have done is to really combine two critical elements " --

redirecting the T cells to attack a cancer and creating more space for them

using chemotherapy, he tells WebMD.

While much more study is needed, " the early results are encouraging, " Weiner

says.

http://www.webmd.com/prostate-cancer/news/20090420/designer-t-cells-fight-prosta\

te-cancer?ecd=wnl_day_042109 & print=true

----------

----------

No virus found in this outgoing message.

Checked by AVG - www.avg.com

Version: 8.0.238 / Virus Database: 270.12.1/2071 - Release Date: 04/21/09

08:30:00