Researchers at Jefferson Medical College have used DNA therapy and the host immune system to stave off the development of cancer in mice. Pharmacologist Eric Wickstrom, Ph.D., and research associate Janet B. Smith, Ph. D, have used a treatment called antisense therapy to prevent the development of Burkitt's lymphoma in laboratory mice, showing that this protection is aided by the mouse's own immunity.
One of the limitations of effectively treating Burkitt's lymphoma with chemotherapy is that the drugs eventually wear off, says Dr. Wickstrom, professor of microbiology and immunology and a member of Jefferson's Kimmel Cancer Center and the Cardeza Foundation for Hematological Research. The cancer cells often develop resistance to chemotherapy and the cancer returns.
In the study, normal mice were injected with Burkitt's lymphoma mouse tumor cells. The mice were given complementary DNA therapy for seven consecutive days. The scientists found that not only did the antisense treatment delay the onset of tumor development, it also decreased the size and mass of any resulting tumors. In one mode of treatment, tumors were totally blocked from forming.
The scientists think that this strategy--using antisense therapy while at the same time revving the immune system--may also work in human patients who have relapsed after chemotherapy effectively halted their disease. In addition to Burkitt's lymphoma, such a therapy might be applied against many types of lymphoma, leukemia, multiple myeloma, breast cancer, ovarian cancer, lung cancer and colon cancer.
The next step, Dr. Wickstrom says, is to test the therapy in humans. "My clinical colleagues here at Jefferson would like to test this therapy in a small group of patients. We've asked the National Cancer Institute for assistance with that trial."
Their results appear in the August issue of the Journal of the National Cancer Institute.