Newsday - June 19, 1991
Laurie Garrett - Staff Correspondent

The researcher spoke to thousands of scientists at the Seventh International Conference on AIDS, at a session devoted to understanding the link between cancer and the human immunodeficiency virus, which causes AIDS. Gallo's laboratory at the National Cancer Institute in Bethesda, Md., has been studying Kaposi's sarcoma, a malignant skin cancer found in about 20 percent of gay men with AIDS, and has shown that when cells of the immune system are infected with HIV they release a chemical that promotes the growth of Kaposi's sarcoma cells in test tubes.

Gallo said the chemical - called oncostatin - activates cancerous growth and causes Kaposi's Sarcoma tumors to swell and secrete fluids. That swelling, he said, can be blocked in the test tube and in mice by a drug called SPPG. The drug, whose chemical structure is unknown, is manufactured by Daiichi Pharmaceuticals of Japan. Daiichi, Gallo said, has reluctantly provided samples of SPPG for research purposes, and only six weeks ago signed a joint research agreement with the National Cancer Institute. Daiichi's reluctance is at least partly related to problems in manufacturing pure SPPG on a large scale, Gallo said.

"If we get too aggressive with Daiichi the whole deal will backfire on us," Gallo said at a news conference.

If test-tube studies of SPPG continued to look promising, Gallo said, clinical trials might begin soon.

Gallo also predicted gene therapy could hold promise for acquired immune deficiency syndrome, saying his laboratory has found a way to cancel out the effect of the virus' most dangerous gene, called tat.

Another viral gene product called tar interacts normally with tat. In test tubes, Gallo's laboratory has made gene product called super-tar and inserted it into cells. The result is a tar overload that shuts off tat, thereby eliminating the virus' ability to infect cells or reproduce. If such a super-tar were to be useful, it would involve gene therapy, "in which you could take cells from HIV-infected individuals, from their bone marrow, make the genetic insertion [of the super-tar] into the cells," and then put the altered cells back into the patient.

"Is it fantasy? No, it works in the laboratory. Theoretically, it could lead to a cure," Gallo said, although he admitted that at this point all clinical aspects of super-tar are purely speculative.

Gallo praised the work of Hans Feichtinger of the University of Innsbruck in Austria, who has found B-cell lymphomas in monkeys infected with the simian form of HIV. Feichtinger said that 40 percent of his monkeys have such tumors a year after simian HIV infection, and all the tumor cells are infected with the another virus - Epstein-Barr. He believes SIV and HIV make people and monkeys susceptible to the Epstein-Barr virus, which then causes the cancers.

But Dr. Lawrence Kaplan of the University of California in San Francisco did detailed analysis of lymphoma cells from 29 California AIDS patients and found only seven were infected with Epstein-Barr.

"As we prolong the survival of people with HIV disease we are going to face new problems," Dr. Ian Weller of London Hospital said. Such cancers are only the beginning, "and we'll inevitably see an increased incidence of these problems in the future that we can't now anticipate."
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