Skip to content
My WebMD Sign In, Sign Up
Font Size

Designer T Cells Fight Prostate Cancer

Experimental Treatment Uses Gene Therapy to Modify Immune System Cells
By
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 Richard 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. 

Today on WebMD

Prostate Cancer Overview
SLIDESHOW
what is your cancer risk
HEALTH CHECK
 
woman speaking with doctor
VIDEO
Prostate Nerve Transplant
VIDEO
 
cancer fighting foods
SLIDESHOW
15 Cancer Symptoms Men Ignore
FEATURE
 
Prostate Enlarged
VIDEO
Picture Of The Prostate
ANATOMY
 
Prostate Cancer Quiz
QUIZ
screening tests for men
SLIDESHOW
 
Prostate Cancer Symptoms
VIDEO
Vitamin D
SLIDESHOW