Researchers disable cancer's growth control centers in childhood tumors

Cancer cells have a hidden weakness: they build liquid droplets inside their nuclei that act like power hubs, gathering the molecules needed to fuel unchecked growth. Now researchers have figured out how to dismantle them.

The discovery centers on translocation renal cell carcinoma (tRCC), a rare kidney cancer that strikes children and young adults. It's aggressive, treatment options are sparse, and survival rates have barely budged in years. But a team at Washington University School of Medicine found something striking: the cancer's fuel source isn't hidden in the DNA itself—it's in how cancer cells weaponize RNA, the molecule that normally just carries genetic instructions.

Here's what's happening inside these cancer cells. Fusion proteins created by the cancer recruit RNA to build what researchers call "condensates"—liquid-like droplets that form inside the cell nucleus. Think of them as microscopic meeting rooms where cancer-promoting genes get switched on. An RNA-binding protein called PSPC1 reinforces these droplets, making them even more effective at driving tumor growth. Without these hubs, the cancer loses its ability to expand.

Dissolving the problem

The researchers used precision tools like CRISPR gene editing and advanced sequencing to map exactly how these droplets form and function. Then came the intervention: they engineered a nanobody—a tiny protein fragment—that latches onto the cancer's fusion proteins like a key fitting into a lock. When triggered by a chemical signal, the nanobody activates a dissolver protein that literally melts the droplets apart.

In lab cultures and mouse models, this approach stopped tumor growth entirely. No tumor expansion. No activation of cancer-driving genes. The hubs simply fell apart.

"This is exciting because tRCC has very few effective treatment options today," said Yubin Zhou, MD, PhD, one of the lead researchers. "Targeting condensate formation gives us a brand-new angle to attack the cancer, one that traditional drugs have not addressed. It opens the door to therapies that are much more precise and potentially less toxic."

What makes this work even more significant: many other pediatric cancers are driven by similar fusion proteins. Leukemias, sarcomas, and other childhood malignancies all rely on comparable mechanisms. The researchers believe a tool that dissolves these condensates could work across multiple cancer types—a generalized strategy for cutting off growth at its source.

This isn't a cure yet. The work is still in early stages, moving from mouse models toward potential human trials. But it represents a fundamental shift in how researchers think about attacking childhood cancer. Instead of trying to poison the cancer cell directly, they're targeting the architecture that makes the cancer work in the first place. Just as cutting the power to a building shuts down everything inside it, dismantling cancer's droplet hubs eliminates its ability to function.

The research was published in Nature Communications in January 2025.