Blocking one protein stopped glioblastoma tumours from forming in lab models

Glioblastoma remains one of the most difficult cancers to treat, often returning within months even after surgery, radiation and chemotherapy. Researchers at the Ohio State University Comprehensive Cancer Center have identified a protein called SET as a possible weak point in the tumor’s defenses, reporting that blocking it stopped tumors from forming in preclinical models. The approach is not designed to replace existing treatment but to make standard chemotherapy and radiation work better against a cancer that has resisted major advances for decades.

The protein researchers targeted: SET

SET is one of several proteins that glioblastoma cells use to suppress an enzyme called PP2A, which normally acts as a brake on the signals that drive uncontrolled cell growth and help cancer cells repair damage after treatment. By interfering with SET, the Ohio State team was able to restore PP2A’s normal restraining activity inside tumor cells. In the preclinical models used for the study, that single change was enough to prevent tumors from forming in the first place, rather than only slowing tumors that had already taken hold.

Glioblastoma cells appear to rely on SET alongside two related proteins, ANP32A and CIP2A, to keep PP2A suppressed, according to coverage of the work by ScienceDaily. Having more than one protein capable of doing the same suppressive job is part of why the cancer has proven so hard to disable with a single treatment, since knocking out one suppressive pathway can leave the tumor able to fall back on another.

That redundancy is a recurring theme in cancer biology more broadly, where tumors often maintain several overlapping ways to disable the same protective mechanism. Identifying SET specifically gives researchers a defined molecular target to pursue with drug development, rather than treating PP2A suppression as a vague, unaddressable feature of the disease.

How glioblastoma resists standard treatment

Glioblastoma tumors are known for infiltrating healthy brain tissue in finger-like projections that make complete surgical removal essentially impossible, and for containing populations of highly adaptable cells that can survive radiation and chemotherapy that kills off the bulk of the tumor. PP2A’s normal job in a healthy cell is to help restrain the kind of runaway growth and damage-repair signaling that lets cancer cells persist through treatment. When glioblastoma cells suppress PP2A using SET and its related proteins, they effectively disable one of the body’s own internal checks on tumor growth.

PP2A belongs to a broader family of enzymes called phosphatases, which work opposite to the kinases that switch cell-growth signals on, effectively acting as an off switch for pathways that would otherwise keep dividing and repairing damaged cells indefinitely. Restoring that off switch inside a tumor, rather than trying to overwhelm the tumor with an external toxin, is part of what distinguishes this strategy from more conventional chemotherapy.

Making tumors more vulnerable to radiation

Beyond preventing tumor formation outright, the researchers found that targeting SET and its related proteins made cancer cells more vulnerable to radiation therapy. That finding points toward a combination strategy rather than a standalone cure: restoring PP2A activity would not need to kill tumor cells directly if it instead strips away the resistance that currently lets those cells survive radiation and chemotherapy doses that would otherwise be effective. Combination approaches of this kind are a common goal in cancer research generally, since they aim to extend the usefulness of treatments already approved for patient care rather than requiring an entirely new drug to clear the full regulatory process alone.

From lab models to a potential human treatment

The work so far has been conducted in preclinical models, the laboratory and animal systems researchers use to test a biological idea before it can be tried in people, and the Ohio State team has been clear that human testing will be needed to determine whether targeting SET is both safe and effective in patients. That step typically involves additional laboratory validation, then a phased sequence of clinical trials that first check for safety in small groups of patients before testing whether the treatment actually improves outcomes at a larger scale. SciTechDaily’s report on the findings notes that the appeal of the approach lies partly in the possibility of pairing it with therapies doctors already use, rather than waiting on a treatment built entirely from scratch.

Developing a drug that can safely and selectively block a protein like SET, without disrupting the same protein’s normal function elsewhere in the body, is itself a significant undertaking that can take years even after a promising laboratory target has been identified. Researchers pursuing this class of cancer therapy generally look first for existing compounds that already interact with the target before committing to designing an entirely new molecule.

Why a new angle on glioblastoma matters

Treatment options for glioblastoma have changed relatively little in the past two decades compared with progress made against many other cancers, which is part of why researchers are drawn to strategies that make existing chemotherapy and radiation more effective rather than searching solely for a replacement drug. Medical Xpress’s coverage of the Ohio State research frames the SET-PP2A pathway as one of several molecular weak points scientists are now probing across different cancer types, with glioblastoma serving as one of the hardest tests of whether the strategy can work in a tumor that has defeated so many earlier approaches.

Because glioblastoma is studied so intensively relative to its rarity, findings from this kind of research often carry implications beyond a single tumor type, informing how scientists think about treatment-resistant cancers more broadly. A strategy that succeeds against one of the hardest cancers to treat tends to draw closer attention from researchers working on other aggressive tumors that rely on similar resistance mechanisms.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

More from Morning Overview