Cancer researchers at the Lankenau Institute for Medical Research (LIMR), part of Main Line Health, have developed a novel treatment that inhibits the growth of malignant tumors and activates an immune response to those tumors.
LIMR Professor Susan Gilmour, PhD, and her colleagues have been studying polyamines, small molecules that are greatly increased in tumors compared to normal tissues. The researchers set out to discover the effects of blocking polyamine activity in malignant tumors. With their collaborator, Dr. Otto Phanstiel, PhD, of the University of Central Florida, they developed a combination treatment consisting of two therapeutic agents: one that limits polyamine biosynthesis in cells and another that blocks the uptake of polyamines into tumor cells.
“We found that our polyamine blockade therapy [PBT] provided a dual attack on tumors by starving them of polyamine growth factors and by activating an immune attack on those tumors,” said Eric Alexander, PhD, research assistant professor in Dr. Gilmour’s laboratory, and the lead author of the study. “Our data showed that the combination treatment was significantly more effective at battling tumors than either treatment alone.”
Tumors of mice treated with PBT showed reductions in myeloid cells that suppress immune attack on tumor cells and significant increases in tumor-specific cytotoxic T cells. The study highlighted the important role that polyamines play in modulating the immune response in tumors and how this novel therapy can boost the natural immune response to combat tumor growth.
“PBT offers an exciting potential as an adjunct cancer treatment both with conventional chemotherapy and in stimulating anti-tumor immune responses with the newer tumor immunotherapies,” said Dr. Gilmour. “We look forward to continuing our studies and helping to advance this novel polyamine targeted therapy into the clinic.”
Their manuscript “A novel polyamine blockade therapy activates an anti-tumor immune response” was published in a recent edition of the biomedical journal Oncotarget. Other researchers involved in the study included Allyson Minton and Molly Peters, also of LIMR. Their research was funded by the National Cancer Institute, the U.S. Department of Defense, and the John B. Deaver Foundation.