Drugs used to restrict a specific fatty acid in the brains of rats with glioblastoma-like tumors dramatically shrank tumors and reduced new blood vessel growth, prolonging survival, according to the cover story of the August Journal of Cerebral Blood Flow & Metabolism.
Malignant gliomas are ultra-aggressive tumors that occur in the central nervous system, and are resistant to advanced therapies such as chemotherapy and radiation; they account for almost half of the 350,000 brain tumors now diagnosed in the United States.
"These rat model tumors were developed from human glioblastoma tumor cells and closely mimic human tumors in growth patterns and response to therapy," said lead researcher David Harder, professor in cardiovascular research. "The concept of targeting blood vessels that feed tumors as an approach to limit tumor growth is not a novel idea. However, blocking the specific fatty acid described in this study is novel, and holds great promise for use in humans."
Harder said he believed further studies could demonstrate that such drugs work in humans, and that higher concentrations or longer-term infusions could prove even more effective than this study's results. "If survival time could be extended, with a combination of surgical therapy and infusion with similar drugs, this could be a significant treatment option," he said.
Even cancer cells need oxygen to grow, and blocking the formation of specific fatty acids decreases blood vessel growth and oxygen supply to tumors. In the current study, Dr. Harder and colleagues infused drugs directly into the tumors over an extended period of time, using miniature osmotic pumps and a very small hole in the skull of the rats.
Relative to the control group, tumor size in the drug-infused rats was reduced by an average of 50 to 70 percent; survival time increased by five to seven days, the same as three to four months in human terms.
"These pumps have been used in humans for other diseases and can be designed for delivery of these drugs as well," said Harder. "We believe they can be used to deliver drugs to block angiogenesis in complex human tumors such as glioblastomas."
The research was conducted at the Medical College of Wisconsin in Milwaukee.