Cells Build Tiny Chemical Factories; Cancer May Exploit Them

Cells build tiny chemical factories inside themselves, and cancer cells may be exploiting them. A team at MIT has found that kinases, a class of enzymes that regulate cell growth, form liquid-like droplets through a process called phase separation, as GEN News reported. Inside these droplets, kinase activity runs roughly 90,000 times faster than in the rest of the cell — a difference so extreme that kinases operating in less than 1 percent of a cell's volume account for more than 99 percent of its total kinase activity, according to research published in Cell Reports00537-1).

The findings, from the MIT lab of Lea and Case, suggest a new way to think about what goes wrong in cancer. When a kinase called FAK is overexpressed — a common pattern in tumors — it begins to form these droplets, also known as condensates. Once formed, the condensates concentrate FAK to levels roughly 2,350 times higher than in the surrounding cell fluid: 106 micromolar inside the dense phase, compared to 45 nanomolar outside it. The condensed kinase then phosphorylates itself at a rate that, per unit time, far outpaces what the same molecule does elsewhere in the cell.

"This is essentially a switch," one of the researchers told Phys.org. "The patterns of what is actually getting phosphorylated were very different inside of the droplet compared to what might be happening in a non-droplet context."

The implication, if it holds up: cancers may not just overproduce kinases — they reorganize them spatially, creating micro-environments where growth signals amplify beyond what normal cells can achieve. Phase separation is not unique to cancer; the MIT team estimates that about 45 percent of the 500 human kinases have the molecular features needed to form droplets. But in cancer, the mechanism appears to stay permanently switched on.

For drug developers, that distinction matters. Most kinase inhibitors today target the kinase's active site — the pocket where it grabs phosphate groups from ATP molecules to pass them along to target proteins. Condensate formation changes where that chemistry happens and how fast. A drug that blocks the kinase's canonical activity might not reach the same concentrated reaction inside the droplet. The implication, the researchers suggest, is that inhibitors were optimized in dilute conditions where droplets don't form — leaving open whether they fully suppress activity inside them.

This is not an abstract concern. Kinase inhibitors make up one of the largest drug classes in oncology. Pfizer, Novartis, and AstraZeneca each have portfolios worth billions built around kinases discovered and screened using traditional biochemistry — conditions that don't replicate the dense-phase environment inside a condensate. If the MIT findings hold, those screening conditions may have systematically missed kinases that function primarily inside droplets, or optimized inhibitors against the wrong version of the target. The same applies to any drug designed to hit a kinase that can exist in both dilute and condensed states, which the researchers estimate covers nearly half the kinome.

Biomolecular condensates — the broader term for these liquid droplets — have attracted serious drug-hunting money in recent years. Nereid Therapeutics, Dewpoint Therapeutics, and Faze Medicines have each raised venture funding specifically to target condensates in cancer, neurodegeneration, and cardiovascular disease. None have a condensate-targeting drug in late-stage trials yet, but the space has matured enough that pipeline watchers track them as a distinct category. The MIT finding adds a specific mechanism — kinase condensate amplification — that the field did not have a clear picture of before.

The therapeutic translation risk is real. Condensate biology is real biology, but rewiring it into a drug target is a different problem than identifying the mechanism. The MIT paper describes what happens in cells and what the concentration effects look like in vitro; it does not demonstrate that droplet disruption can be achieved selectively, or that doing so would suppress tumor growth without intolerable side effects. Normal cells also use phase separation for legitimate signaling — killing all condensates is not an option. Researchers not affiliated with the MIT team who work in the condensate field have noted in published reviews that achieving selective inhibition without disrupting the healthy condensates the body relies on is the central challenge for any drug development program in this space. The timeline from mechanism to IND is uncertain; five years would be fast for a straightforward targeted therapy, and this is not straightforward.

"Interfering with FAK ability to form droplets could offer a new strategy for cancer drug development," the researchers noted in Phys.org.

The finding also raises questions about whether the same spatial reorganization applies to other kinases beyond FAK. If dozens of kinases can form droplets, and if the resulting concentration effects amplify signaling in ways the classical view of kinase biology missed, cancer researchers may need to look at drug targets they already knew well — but in an entirely different structural context.

The work is at the Cell Reports stage: real biology, not yet demonstrated in a clinical trial. The condensate mechanism has been described in other protein systems, and the researchers argue the same logic applies to kinases. Whether the mechanism translates to human tumors, and whether droplet disruption can be achieved without wrecking the normal kinases the body also needs, are open questions. The pathway from enzyme compartment to therapeutic target is real but unproven.

What the paper offers is a structural explanation for something oncologists have observed without fully understanding: why some cancers are hypersensitive to kinase inhibitors even when the target protein appears normal in abundance. The answer may not be how much of the kinase is present, but where it is — and whether it has condensed.