Oregon State University researchers have engineered a novel treatment approach for glioblastoma that dramatically improved survival rates in mice, offering a potential breakthrough for one of the deadliest cancers.
The experimental therapy increased median survival time by 50% in mice with the disease, according to findings published in the Journal of Controlled Release. The work centers on solving two fundamental obstacles that have stymied glioblastoma treatment for decades: penetrating the blood-brain barrier and targeting tumor cells while sparing healthy tissue.
Glioblastoma kills with ferocity. Fewer than 30% of patients survive two years after diagnosis, and over 95% die within five years. The cancer strikes roughly 3.19 people per 100,000 Americans annually, with median age at diagnosis around 64.
How the Sugar Coating Works
The research team, led by Oleh Taratula, Olena Taratula and Yoon Tae Goo at the OSU College of Pharmacy, developed lipid nanoparticles wrapped in a sugar coating designed to infiltrate the brain and accumulate inside tumors.
The sugar used was mannose, structurally similar to glucose. The blood-brain barrier normally relies on a protein transporter called GLUT1 to shuttle glucose into the central nervous system. The researchers discovered that GLUT1 also recognizes mannose, allowing the sugar-coated particles to hijack this existing transport pathway.
"Blood contains relatively high concentrations of glucose, and that's what the nanoparticles are competing against for GLUT1's attention," Oleh Taratula explained. "For the nanoparticles to get it, they need a densely coated sugar surface, and that's our central innovation. By chemically connecting mannose to cholesterol, a major structural component of the nanoparticles, we improved surface coverage sixfold."
The nanoparticles carried messenger RNA instructing cells to produce PTEN, a protein that suppresses tumor growth. Glioblastoma cells frequently lack or have inactive PTEN, allowing the cancer to proliferate unchecked.
A positively charged cholesterol derivative protected the mRNA from degradation during transit, keeping the genetic material intact inside the particles until delivery.
Glioblastoma tumors express GLUT1 at three times the level of normal brain tissue, causing the sugar-coated particles to preferentially accumulate in cancer cells rather than healthy ones. Restoring PTEN expression in tumor cells reinstated growth control mechanisms.
"Across repeated dosing, tumor shrinkage occurred without any measurable organ toxicity," Olena Taratula said.
The study was supported by the National Cancer Institute, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and the National Research Foundation of Korea. Additional researchers from the College of Pharmacy contributed to the work.
Author Jessica Williams: "This is the kind of targeted molecular engineering that makes you believe glioblastoma researchers might finally have a real shot at this disease."
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