This new approach to inhibiting blood vessel growth, or angiogenesis, delivers "intraceptors" that sequester VEGF, a "linchpin" protein needed to make blood vessels, says Dr. Balamurali K. Ambati, corneal specialist at the Medical College of Georgia and corresponding author on the study.
In a test tube as well as animal models for corneal injury and the deadly skin cancer, melanoma, MCG researchers have reduced destructive blood vessel proliferation by up to two-thirds. Findings are published in the May issue of Investigative Ophthalmology & Visual Science. "We have a promising new preclinical approach to treat conditions that involve blood vessel formation," says Dr. Ambati. These include corneal injury, the blinding wet form of macular degeneration, diabetic retinopathy and tumors, which need blood and oxygen to survive. Other angiogenesis inhibitors in use or under study target VEGF (vascular endothelial growth factor) after it has moved outside the cell, says Dr. Ambati, reducing new blood vessel growth by 30 percent to 50 percent.
"In theory, our approach works several steps ahead of where existing angiogenesis inhibitors work," he says. "The idea is that, hopefully, this would give you a therapeutic advantage by stopping VEGF where it's produced. Scientists have found that several types of cells, including blood vessel cells and cancer cells, can make their own VEGF and receptor. If you have a junkie shooting up and making his own drug, you need to get inside him to break that cycle; getting his dealer is not enough. We have focused our research on attacking VEGF within cells. We want to break that autocrine loop," he says of the cell's ability to supply itself with VEGF and a receptor.