HOUSTON A targeted delivery combination selectively crosses the tight barrier that protects the brain from the bloodstream to home in on and bind to brain tumors, a research team led by scientists from The University of Texas MD Anderson Cancer Center reported in the January issue of the Journal of Clinical Investigation.
In experiments with mice, the researchers demonstrated that the targeted particles guide payloads to image tumors, treat tumors, or can potentially do both to monitor treatment as it occurs. Their findings open a new research avenue for detecting and treating brain tumors in human patients.
"We've identified an iron-mimic peptide that can hitch a ride on a protein complex that transports iron across the blood-brain barrier," said co-senior author Wadih Arap, M.D., Ph.D., professor in the David H. Koch Center at MD Anderson. "Employing the iron transport system selectively opens the blood-brain barrier for tumor imaging and treatment while keeping it otherwise intact to play its protective role."
The barrier thwarts drug delivery because its tight layering of blood vessel cells and certain types of brain cells forms a nearly impenetrable wall against most blood-borne compounds, which can harm the brain. The iron-transporting transferrin protein and receptor complex is a potential path to treatment, the authors noted, because its receptor gene is the most overexpressed in human glioblastomas.
Glioblastomas are the most common form of primary brain tumor among adults and are one of the most lethal cancers -- patients have a median survival rate of one year. They resist radiation and chemotherapy and often invade areas of the brain where full surgical removal is impossible.
Peptide + viral particle = targeting
Arap and Renata Pasqualini, Ph.D., professor in the Koch Center and co-senior author on the paper, developed the screening, targeting and delivery processes used in the p
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University of Texas M. D. Anderson Cancer Center