MYC helps cancer cells survive the very treatments designed to kill them
For decades, the protein MYC has been understood as a molecular accelerant — a force that drives cancer cells to grow and multiply beyond all restraint. Researchers at Oregon Health & Science University have now uncovered a second, more insidious role: when chemotherapy and radiation inflict their intended damage on tumor DNA, MYC rushes to the wound and orchestrates the repairs, allowing cancer cells to survive treatments designed to destroy them. This discovery reframes a long-standing clinical mystery — why some tumors seem to endure whatever medicine throws at them — and opens a narrow but promising door toward therapies that might finally strip cancer of this hidden resilience.
- MYC, already one of the most dangerous proteins in cancer biology, has been caught performing a second job: acting as a repair crew that patches the DNA damage chemotherapy and radiation are meant to make lethal.
- The stakes are sharpest in pancreatic cancer, where MYC runs at full throttle and patient outcomes are among the worst — tumors with high MYC activity show measurably greater DNA repair capacity and shorter survival.
- This hidden repair function explains a cruel paradox: the more aggressively a tumor is treated, the more MYC may be activated to undo that damage, effectively turning the therapy into a pressure that strengthens the cancer's defenses.
- MYC has long been dismissed as 'undruggable,' but its newly identified repair role may be structurally distinct enough to target — offering scientists a specific vulnerability to exploit without disabling MYC's essential functions in healthy cells.
- Researchers at OHSU are already pursuing drugs that could block MYC's repair function selectively, a strategy that could make existing chemotherapy and radiation dramatically more effective for millions of patients with MYC-driven cancers.
Cancer cells are remarkably skilled at surviving the treatments designed to kill them, and researchers at Oregon Health & Science University have now identified a key reason why. A protein called MYC — long known as a master switch that accelerates tumor growth — turns out to play a second, unexpected role: when DNA is broken by chemotherapy or radiation, a modified form of MYC travels directly to the damage site and recruits the cellular machinery needed to repair it.
Published in Genes & Development, the finding reframes decades of understanding about MYC. Scientists knew it drove growth and metabolism inside the cell nucleus, but no one had seen it moonlighting as a DNA repair coordinator. First author Gabriel Cohn explained that in aggressive cancers like pancreatic cancer, where MYC operates at high intensity, tumor cells face constant DNA damage — from their own frantic division, from poor blood supply, and from treatment itself. Yet they survive. MYC, the research suggests, is why. Cells with an active, modified form of the protein repaired DNA more efficiently and endured stress that would have killed other cells. In patient-derived pancreatic cancer data, tumors with high MYC activity showed greater repair capacity and worse outcomes.
The clinical implication is stark. Chemotherapy and radiation work by overwhelming cancer cells with DNA damage. If a tumor is exceptionally good at repairing that damage — because MYC is orchestrating the fix — the treatment loses its edge. Senior author Rosalie Sears framed it plainly: patients with MYC-driven cancers may be caught in a cruel arithmetic where the very drugs meant to save them are being quietly neutralized.
Yet the discovery also opens a new angle of attack. MYC has historically been considered 'undruggable' — its structure resists conventional drug binding, and blocking it entirely risks harming healthy cells. But its DNA repair function may be more vulnerable to precise interference. If drugs can be designed to disable that specific role without touching MYC's normal activity, cancer cells could be made far more susceptible to existing treatments. Sears and her OHSU colleagues are already working toward that possibility — a targeted strategy that, if successful, could reshape outcomes for the millions of patients whose tumors depend on MYC to survive.
Cancer cells are remarkably good at surviving the very treatments designed to kill them. Researchers at Oregon Health & Science University have now identified a crucial reason why: a protein called MYC, already infamous for fueling tumor growth, also acts as a cellular repair crew, fixing the DNA damage that chemotherapy and radiation inflict.
The discovery, published in Genes & Development, reframes how scientists understand MYC's role in cancer. For decades, researchers knew that MYC worked inside the cell nucleus like a master switch, flipping genes on to accelerate growth and metabolism. But the new work reveals something unexpected. When DNA breaks—whether from the stress of rapid cell division or from cancer-killing drugs—a modified version of MYC travels directly to the damage site and recruits repair machinery to fix it. This is not MYC's traditional job. This is MYC doing something it was never supposed to do, and doing it with lethal efficiency.
Gabriel Cohn, the study's first author, explained the stakes plainly: in aggressive cancers like pancreatic cancer, where MYC runs at high throttle, tumor cells experience constant DNA damage from their own frantic growth, from poor blood supply, and from chemotherapy. Yet they survive. The research suggests MYC is the reason. By actively promoting DNA repair, the protein allows cancer cells to endure conditions that should kill them. The team tested this directly. Cells with an active, modified form of MYC repaired DNA more efficiently and survived stress that would have destroyed other cells. The effect was most pronounced in pancreatic cancer, one of the deadliest malignancies. When researchers examined patient-derived pancreatic cancer cells and tumor data, they found that tumors with high MYC activity showed increased DNA repair capacity and were associated with worse outcomes for patients.
This finding illuminates a long-standing clinical puzzle: why do some tumors resist chemotherapy and radiation? The standard logic of these treatments is straightforward—overwhelm cancer cells with so much DNA damage that they cannot survive. But if a tumor cell is exceptionally skilled at repairing that damage, it can weather the assault and keep growing. MYC appears to be the skill that makes this possible.
Senior author Rosalie Sears, who leads the research, framed the problem this way: cancer therapies depend on overwhelming tumor cells with DNA damage. If a cancer cell is very good at fixing that damage, it survives treatment and continues to grow. The implication is stark. Many patients with MYC-driven cancers face a cruel arithmetic: the treatments meant to save them may be less effective because MYC is helping their tumors repair the damage those treatments cause.
What makes this discovery potentially transformative is that it offers a new angle of attack. MYC has long been considered "undruggable"—its structure does not lend itself to drug binding, and blocking it entirely risks harming healthy cells that depend on normal MYC function. But this newly identified role in DNA repair might be more vulnerable to interference. If scientists can develop drugs that block MYC's repair function specifically, without shutting down everything MYC does in normal cells, they might make cancer cells more susceptible to existing treatments. Sears and her colleagues at OHSU are already pursuing this possibility. The challenge is real and the stakes are high. MYC ranks among the two most important cancer-driving genes in human biology. A drug that could selectively disable its repair function could reshape treatment for the millions of patients whose tumors depend on MYC to survive.
Citas Notables
MYC isn't just helping cancer cells grow—it's also helping them survive some of the very treatments designed to kill them— Rosalie Sears, senior author, OHSU
If we can interfere with MYC's role in DNA repair without shutting down everything MYC does in healthy cells, we may be able to make cancer cells more vulnerable to treatment— Rosalie Sears
La Conversación del Hearth Otra perspectiva de la historia
So MYC was already known to be a problem in cancer. What made this discovery feel new?
The novelty is in the mechanism. Everyone knew MYC turned genes on and made cancer cells grow faster. But this work shows MYC also physically travels to broken DNA and fixes it. That's a completely different job—not about controlling genes, but about hands-on repair work.
And this matters because chemotherapy works by breaking DNA?
Exactly. Chemotherapy's whole strategy is to damage DNA so badly that cancer cells die. But if MYC is repairing that damage, the cancer cells survive. The treatment fails.
Why is pancreatic cancer hit especially hard by this?
Pancreatic cancer cells already have MYC running at very high levels. So they're already stressed from their own rapid growth, from poor blood supply, from everything. Then you add chemotherapy. But MYC is there, fixing the damage, letting the cells endure what should kill them.
Is there a way to stop MYC from doing this repair work?
That's the question everyone is asking now. MYC has been impossible to drug because its structure doesn't work well with traditional drug molecules. But if you can target just the repair function, not the growth function, you might be able to make cancer cells vulnerable again.
What happens if you succeed?
You'd have a way to make existing chemotherapy work better. You're not inventing a new drug—you're making the old ones lethal again to cancer cells that have learned to survive them.
And if you fail?
Then MYC stays undruggable, and patients with MYC-driven cancers keep facing treatment resistance. The problem doesn't get solved.