Cholesterol makes cells’ nuclei squishy, helping melanoma spread

Melanoma is one of the most dangerous common skin cancers. It starts in melanocytes, the skin cells that make melanin, the pigment that gives skin its colour.

Cancer doesn’t appear overnight. A normal cell becomes cancerous in steps, as its DNA and its gene-control systems pick up changes over time. These changes push the cell to do three things: divide too much, avoid being destroyed by the immune system, and spread into other parts of the body. This spread is called metastasis, and it is what makes many cancers deadly.

Researchers want to know which changes matter most because those changes can become targets for treatment.

Becoming squishy

A recent study led by scientists at the U.S. National Institutes of Health reported an unexpected driver of cancer spread: cholesterol in the membrane around the cell nucleus. The nucleus is the cell’s control room, where most of the DNA is stored. It’s wrapped in a thin nuclear envelope, like a flexible shell.

The team found this pattern in melanoma and also in breast and prostate cancers. When cholesterol levels in the nuclear envelope were high, the nucleus became easier to deform. In other words, it became more squishy. This is important because cancer cells often have to squeeze through tight gaps between other cells to spread. A squishier nucleus makes that squeezing easier, so the cancer can invade new tissues more successfully.

High cholesterol did something else, too: it made the nuclear envelope more fragile. Fragile envelopes were more likely to tear in small, local spots. When a tear happens, the DNA inside can be exposed to forces that damage it. Damaged DNA can lead to new mutations, and some of those new mutations can make the cancer even more aggressive.

When the researchers lowered cholesterol levels in cancer cells, the cells became less invasive and less aggressive.

These findings also help explain an earlier observation: people with melanoma who were taking statins — drugs that lower cholesterol in the blood — seemed to show slower progression, on average, than people who were not.

Too much LBR

A big question arose: how did the cancer cells raise cholesterol in the nuclear envelope?

The study pointed to a protein called the lamin B receptor (LBR). Think of LBR as a tool with two parts sitting in the inner nuclear membrane. One part helps attach DNA (packed with proteins) to the inner surface of the nucleus. The other part helps the cell make cholesterol.

In many melanoma samples, the researchers found that cells produced too much LBR. When LBR levels were high, the cellular cholesterol levels rose as well, and the nucleus became both more deformable and more fragile. When the team reduced the LBR levels, the nuclear envelope became tougher and less easily deformed.

Curiously, if the researchers used a version of LBR that couldn’t do its cholesterol-making job, then boosting the LBR didn’t produce the same fragile, squishy nucleus. This suggested the cholesterol-making function was central to the effect.

The team also tested what happened when they removed cholesterol directly from cell membranes: the nuclear membranes became much less fragile than in untreated cells. This fit the idea that cholesterol was changing the physical properties of the nuclear envelope.

A treatment target

The researchers then asked a bigger question: could this process start early in cancer development? If high LBR and high cholesterol appear early, then repeated small tears in the nuclear envelope could increase DNA damage over time. More DNA damage could then raise the chances of new mutations, leading to the cancer becoming more malignant.

The team engineered melanoma cells in two versions: one set with normal LBR levels and the other where LBR had been silenced (i.e. which lacked LBR). They injected these cells into mice. Tumours from the control cells showed more ruptured nuclear envelopes than tumours made from LBR-silenced cells. This supported the idea that LBR could help melanoma invade and spread in a living organism.

Finally, the researchers checked patient data in the real world. In one large melanoma dataset, called TCGA-SKCM, patients whose tumours showed higher LBR expression early tended to have worse outcomes. Put together, the evidence suggested that LBR could be a useful therapeutic target for slowing cancer metastasis.

“The finding that LBR-mediated cholesterol production causes nuclear envelope fragility is intriguing in the context of cancer, as high cholesterol has been associated with tumour development and immune cell invasion in melanoma,” the researchers wrote in their paper. “Furthermore, epidemiological studies have shown that long-term statin use to decrease serum cholesterol is associated with decreased cancer progression and severity in many cancer subtypes, including melanoma.”

“Increased cholesterol synthesis driven by upregulated LBR could serve as a metabolic enhancer,” the authors continued, “increasing tumor cells’ ability to proliferate and cope with nutrient-deprived conditions. Together, our findings suggest that LBR could be a prognostic indicator in early melanoma disease progression, and could serve as a drug target to prevent metastatic dissemination of melanoma, thereby improving prognosis for patient survival.”

Curiosity-driven

Scientists first discovered LBR’s cholesterol-related role more than 25 years ago in research that had nothing to do with cancer. In the 1970s and 1980s, researchers studying fungi identified genes involved in making sterols — which are cholesterol-like molecules in fungi.  In the 1990s, when scientists compared DNA sequences, they noticed that a human gene, LBR, resembled a  sterol-making gene in fungi.

That raised a curious question: could the human gene replace the broken fungal gene? It could. That experiment was early evidence that LBR is an enzyme that processes sterol.

Years later, that basic biology link helped researchers connect LBR to nuclear cholesterol and the spread of cancer. It’s a clean example of how “why does this work this way?” research can eventually matter to medicine, even when no one can predict the connection in advance.

D.P. Kasbekar is a retired scientist.

Published – March 18, 2026 07:15 am IST