UCLA Scientists Identify Endocan as New Target for Glioblastoma Treatment

Glioblastoma kills quickly. The average person diagnosed with this aggressive brain tumor has between twelve and fifteen months to live. Only one in twenty survives five years. These numbers have barely budged in decades, which is why a discovery by UCLA researchers published this week in Nature Communications carries weight that extends beyond the laboratory.

The team, led by Dr. Harley Kornblum at the David Geffen School of Medicine, identified a protein called endocan as a critical player in how glioblastoma tumors survive and resist treatment. Endocan is produced by the endothelial cells that line blood vessels running through the tumor. What the researchers found is that endocan doesn't simply feed the tumor—it actively communicates with cancer cells in a way that makes them resistant to radiation, one of the standard weapons against glioblastoma.

The mechanism works like this: endocan binds to a receptor called PDGFRA on the surface of glioblastoma cells. This interaction triggers pathways that promote tumor growth and, critically, activate the tumor's defenses against radiation therapy. Tumors with high levels of endocan proved significantly more resistant to radiation in the lab. The discovery emerged from work using patient-derived tumor cells, genetically engineered mice, and computational databases the team had developed in earlier studies to map which molecules are active in tumor blood vessels.

What makes this finding actionable is that the researchers didn't just identify the problem—they tested a solution. Using a drug called ponatinib, which blocks the endocan-PDGFRA interaction, they found that survival extended in preclinical models and that tumors became more responsive to radiation. The implication is straightforward: if you can interrupt this conversation between the tumor's blood vessels and the cancer cells themselves, you might be able to make existing treatments work better.

There's another dimension to this work that speaks to why glioblastoma is so difficult to treat. Surgery can remove much of the tumor's core, but the infiltrative edge—the aggressive fingers of cancer that extend into surrounding brain tissue—often remains. Kornblum's team discovered that endocan plays a role in defining these edge regions, essentially helping the tumor organize itself in a way that makes it harder to eradicate completely. This edge is where recurrence typically begins.

The research also connects endocan's activity to a protein called cMyc, which is implicated in many cancers but has proven nearly impossible to target directly. By disrupting the endocan-PDGFRA axis, the researchers suggest it may be possible to indirectly interfere with cMyc's role in driving glioblastoma growth—a potential workaround to a problem that has long frustrated oncologists.

Kornblum emphasizes that the key insight is understanding how tumors exploit their relationship with blood vessel cells. "By targeting the crosstalk between glioblastoma and vascular endothelial cells, we can develop treatments that prevent the tumor from adapting and surviving," he said. The next phase of work will focus on validating these findings in actual human tumors, particularly in those infiltrative edge regions where the disease so often returns. The team also plans to test whether endocan inhibition can genuinely improve radiation responses in more complex settings.

For patients facing a glioblastoma diagnosis, this research represents the kind of incremental but genuine progress that matters. It's not a cure. It's not even a treatment yet. But it's a mechanism—a specific, targetable vulnerability in how these tumors survive. In a disease where the median survival has remained stubbornly short for years, understanding why tumors resist our best weapons and finding ways to disarm that resistance is the work that moves the needle.