ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Tuesday, April 2, 1996 TAG: 9604020085
SECTION: NATIONAL/INTERNATIONAL PAGE: A1 EDITION: METRO
DATELINE: WASHINGTON A VACCINE FROM GENETICALLY ENGINEERED CELLS ERADICATES
SOURCE: ASSOCIATED PRESS
note: above
Fakhrai is the lead author of a study that will be published today in the Proceedings of the National Academy of Sciences.
Cancers of the brain, breast, lung, colon and prostate all secrete a substance called transforming growth factor-beta, or TGF-B, which suppresses the immune system and protects the cancer, Fakhrai said.
``TFG-beta cloaks the cancer cells so they are not recognized by the immune system,'' Fakhrai said.
To alert the immune system to the presence of cancer, the UCLA researchers developed a way to prevent tumor cells from making TGF-B.
Using rats with brain cancer, the scientists removed cancer cells and purified the tumor DNA. They used this DNA to make a protein that blocks the genetic process that leads to secretion of TGF-B.
``We actually created molecules that attach to precursors of TGF-B and instructed them genetically to stop working,'' Fakhrai said.
The new molecules were used to inoculate a group of rats with cancer. Another group of rats with cancer received only placebo shots.
Among the rats receiving the anti-TGF-B vaccinations, 100 percent survived for the 12 weeks of the experiment and the cancers were destroyed by the animals' immune system cells. The control rats, which received only the placebo, all died swiftly.
Fakhrai said the technique has been approved for human experimentation by a committee at the National Institutes of Health and is awaiting action by the Food and Drug Administration. Once approved, Fakhrai said UCLA researchers plan to offer the experimental therapy to patients with glioblastoma, an invariably fatal brain cancer.
``We hope to be using this vaccine technology in humans by this summer,'' said Dr. Keith Black, a UCLA neurosurgeon and a co-author of the study.
Carol Kruse, a cancer researcher at the University of Colorado Health Center, said the UCLA cancer vaccine was ``impressive'' and may offer real hope for a cancer that now is always lethal.
``This may prolong the lives of patients with brain cancer,'' she said. ``It may not be a cure, but it could be a significant step forward for these patients.''
Fakhrai said the anti-TGF-B protein worked like a true vaccine in the laboratory rats. After the first experiment, he said the vaccinated rats were injected with 100,000 brain cancer cells, about 20 times the dose that routinely kills laboratory rats. The inoculated rats were not affected, he said.
``All the rats survived with no evidence of further cancer,'' he said. ``It seems that once the animals' immunity is boosted, they hold onto that benefit and remain immune to the cancer.''
First human trials of the cancer vaccine will be in brain cancer patients with a very poor prognosis. If the vaccine works, said Fakhrai, then it may be tried later for other types of cancer that also secrete TGF-B.
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