Cancer cell vesicles carry genome-wide DNA and mitochondria

Cancer cell vesicles can be left behind as a tumour cell moves across a surface. Rather than simply retracting its trailing edge, the cell sometimes releases a large membrane-bound structure containing DNA, mitochondria and other intracellular components.

A study published in Nature Cell Biology on October 28, 2026, describes a previously unrecognized population of these structures. The researchers call them motile vesicles, or MoVes.

Their most striking feature is not just what they contain. It is how they form: a living cancer cell can shed these structures while actively migrating, without undergoing cell death or disintegration.

What a moving cancer cell leaves behind

Cell migration involves a coordinated sequence of changes in shape and attachment. The leading edge extends forward, establishes new contacts with the surrounding surface, and pulls the cell body along. Meanwhile, the rear of the cell retracts.

During that final step, the researchers observed thin membrane extensions stretching behind migrating cancer cells. Large vesicular structures formed at the tips of these extensions before eventually detaching.

The released structures measured approximately 2–5 micrometres across, making them considerably larger than many conventional extracellular vesicles, which are typically measured in nanometres.

Electron microscopy revealed an unexpectedly rich internal architecture. MoVes contained mitochondria, lysosomes, elements of the endoplasmic reticulum and components of the Golgi apparatus.

In other words, migrating cells were leaving behind membrane-enclosed packages containing substantial portions of their own molecular machinery.

The phenomenon was initially characterized in human and mouse breast cancer cell lines. The researchers also examined several other cancer cell types, including colorectal cancer, cervical cancer, uveal melanoma and sarcoma cell lines.

MoVes were observed across the cancer cell lines examined, although their abundance varied considerably.

They were rare in most non-transformed cells studied. But an important experiment showed that their production was not necessarily exclusive to malignant cells.

When the researchers induced epithelial-to-mesenchymal transition in non-tumour epithelial cells, MoVes production increased.

This transition, commonly abbreviated EMT, involves changes in cell adhesion, shape and motility. It allows epithelial cells to acquire characteristics associated with a more migratory state and is frequently implicated in cancer invasion.

The experiment linked MoVes formation to a specific mode of cell movement rather than malignancy alone.

A vesicle population that carries the tumour cell's genomic signature

Perhaps the most unexpected finding concerned the genetic material inside MoVes.

The team isolated vesicles released by 4T1 mouse breast cancer cells and performed whole-genome sequencing on the recovered DNA.

The sequence data covered the parental cells' genome and reproduced their characteristic mutational landscape.

Among the shared variants were mutations affecting Trp53, Brca2, Kit and Pik3cg. The researchers independently confirmed selected mutations using additional molecular techniques.

This provides evidence that actively migrating tumour cells can release extracellular structures carrying genomic information that reflects the mutational profile of the cells from which they originated.

There is an important distinction, however, between recovering genome-wide sequences from a population of vesicles and demonstrating that every individual vesicle contains an intact copy of every chromosome.

The experiment established the former. It did not establish the latter.

Additional analyses indicated that some of the DNA associated with MoVes was protected from enzymes that degrade exposed extracellular DNA. This was consistent with a fraction of the genetic material being enclosed within the vesicle membrane.

The result may be relevant to liquid biopsy research, which seeks to identify tumour-derived molecules in biological fluids.

At present, though, the study does not demonstrate that MoVes can be reliably detected in patients' blood or used as a diagnostic biomarker.

The mitochondria were not merely cellular debris

MoVes also contained mitochondria, the organelles responsible for much of the cell's ATP production through oxidative phosphorylation.

Finding mitochondria in an extracellular structure does not necessarily mean they are functional. They could be damaged organelles being expelled from the cell.

To assess their condition, the researchers used a fluorescent dye that accumulates in mitochondria with an intact membrane potential.

MoVes-associated mitochondria retained this signal, suggesting that they remained functionally polarized.

The researchers then tested whether this mitochondrial cargo could influence another cell.

They used 4T1 breast cancer cells whose mitochondrial DNA content had been artificially depleted. These cells had impaired mitochondrial function and provided a model for testing metabolic effects.

The mitochondrial DNA depletion was partial, not complete.

When isolated MoVes were added to these recipient cells, microscopy showed uptake of vesicle-associated mitochondria.

The researchers also measured oxygen consumption and mitochondrial ATP-linked respiration.

Both increased after MoVes treatment compared with untreated recipient cells.

Similar metabolic improvements were observed with some other populations of large extracellular vesicles, indicating that this functional capacity is not necessarily unique to MoVes.

The findings support a role for extracellular vesicle-associated mitochondrial cargo in altering cellular energy metabolism.

They do not establish how frequently such metabolic transfer occurs inside a living tumour, or whether it provides a selective advantage to cancer cells in patients.

The metabolic experiments were conducted in cultured cells with experimentally impaired mitochondrial function, rather than in an intact tumour microenvironment.

Does this help cancer spread?

The link between MoVes formation and cell migration makes the discovery particularly relevant to cancer biology.

Cell motility is a central component of tumour invasion and metastasis. The vesicles also contain proteins associated with adhesion, migration and epithelial-to-mesenchymal transition.

These properties raise the possibility that MoVes participate in interactions between migrating tumour cells and their surroundings.

But the evidence does not yet establish that MoVes promote metastasis.

The study primarily characterized their formation, ultrastructure, molecular contents and selected functional effects.

In cell-culture experiments, newly released MoVes remained associated with the surface on which the parent cell had migrated. They were not observed freely floating away immediately after release.

This matters because the discovery should not be interpreted as evidence that these vesicles naturally circulate throughout the body carrying entire tumour genomes.

The researchers also conducted experiments involving administered vesicles in mice, but these did not demonstrate that naturally produced MoVes drive tumour dissemination or metastatic growth.

The broader significance lies in a different observation.

Cell migration is usually understood in terms of how cells change shape, generate force and move through tissues.

This study adds another consequence of that movement: a migrating cancer cell can release structures containing genomic material, organelles and proteins associated with its cellular state.

Some of that material can subsequently affect the metabolism of recipient cells under experimental conditions.

A cancer cell, then, may leave behind more than evidence of where it has travelled. Its trailing edge can deposit a molecular package carrying part of its genetic identity and functioning cellular machinery.