A Vaccine For Brain Cancer?

          WASHINGTON--A vaccine from genetically engineered cells
          eradicates tumors in laboratory rats and may be ready for
          testing on a vicious kind of human brain cancer by this
          summer, researchers say.
          Habib Fakhrai, a University of California, Los Angeles,
          cancer scientist, said the vaccine has the effect of
          removing a biological disguise from cancer cells, thus
          turning them into targets that are tracked down and killed
          by the body's own immune system.
          Fakhrai is the lead author of a study that will be published
          Tuesday in 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," said Fakhrai.
          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 then 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," said
          Fakhrai.
          The new molecules were then 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 %
          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 now 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 Fakrai, then it may be tried later for other
          types of cancer that also secrete TGF-B.