Drugs used to inhibit a specific fatty acid in brains with glioblastoma-like tumours not only reduced new blood vessel growth and tumour size dramatically, but also prolonged survival, according to a study on mice by researchers at the Medical College of Wisconsin in Milwaukee.
"These rat model tumours were developed from human glioblastoma tumour cells and closely mimic human tumours in growth patterns and response to therapy," said lead researcher David Harder, Ph.D., Kohler Co. Professor in Cardiovascular Research.
"The concept of targeting blood vessels that feed tumours as an approach to limit tumour 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," he added.
Previous studies from the Harder lab have shown that specific fatty acids generated in the brain induce new blood vessel growth known as angiogenesis.
Harder and colleagues designed these studies on the premise that all cells, including cancer cells, require oxygen for growth and that blocking formation of specific fatty acids would decrease blood vessel growth and oxygen supply to tumours, retarding their growth.
In the new study, they compared three sets of rats with induced tumours, two groups using either one of two inhibitor drugs, 17-ODYA or miconazole, to block the fatty acid CYP epoxygenase and a control group, receiving a placebo.
Drugs were infused directly into the tumours over an extended period of time, using specially designed miniature osmotic pumps and a very small burr hole in the skull. The pumps, similar to those used in humans, were buried just beneath the skin through a tiny incision.
Researchers found that as compared to the control group, tumour size in the drug-infused groups was reduced by an average 50 to 70 percent, and survival time increased by five to seven days, equivalent to three to four months in terms of human survival.
"These pumps have been used in humans for other diseases and can be designed for delivery of these drugs as well. We believe they can be used to deliver drugs to block angiogenesis in complex human tumours such as glioblastomas," Harder said.
The study is published in the August 2008 Journal of Cerebral Blood Flow and Metabolism.