Amazing stuff! This could be a major milestone!
"... A new study ... reveals just that: an alternate, previously unknown, route for DNA to travel between cells. Scientists ... found that in some cases when chromosomes failed to divide equally, DNA fragments remained behind in tiny sacs called micronuclei, which float in the cell's cytoplasm rather than the nucleus. Using fluorescently tagged ... cell lines, the researchers observed these micronuclei migrating from one cell to another carrying their DNA passengers with them, which was a surprising discovery. ...
“This has been well-established in organisms such as bacteria through a process called horizontal gene transfer, where bacteria share DNA with neighboring bacteria, allowing them to acquire a new function, such as resistance to antibiotics,” ... “But we were not aware of this type of transfer before in human cells.” ...
in cases of genomic instability, donor cells transferred micronuclei to recipient cells through bridge-like structures called nanotubes. The transfer occurred across multiple human cell types, including retinal pigment epithelial cells, kidney cells, and cancer cells. ...
To test whether this new DNA that came from another cell had a functional impact on the new cell, the scientists engineered donor cells with resistance to a specific antibiotic. After combining donor and recipient cells in culture and inducing chromosome damage, they found that recipient cells acquired the same antibiotic resistance – direct evidence that mammalian cells can trade genetic material through simple cell-to-cell contact. ..."
"In a recent Cell paper ... show that genomic instability drives human cells to transfer fragmented chromosomes to neighbors via tunneling nanotubes (TNTs), with heritable functional consequences, raising fundamental questions about intercellular communication, genome surveillance, and cancer evolution."
From the highlights and abstract:
"Highlights
• Genomic instability generates micronuclei and chromosome fragments in the cytoplasm
• Direct cell-cell contact triggers intercellular transfer of genomic DNA
• Transferred DNA fragments are functional and maintained within recipient cell genomes
• Intercellular DNA transfer can confer heritable phenotypic changes
Summary
The mammalian genome is safeguarded within the confines of the interphase nucleus. However, genomic instability can trigger the mislocalization of nuclear DNA to the cytoplasm within micronuclei or as fragmented chromosomes.
Beyond activating cell-autonomous signaling programs, whether such cytoplasmic DNA can elicit non-cell-autonomous consequences to nearby cells remains unclear. Here, we show that cytoplasmic DNAs undergo intercellular transfer through contact-dependent, cytoskeleton-based nanotube structures connecting adjacent human cells.
Diverse sources of genomic instability—including exposure to mitotic spindle poisons, ionizing radiation, and Cas9-induced chromosome breakage—promote nanotube-mediated DNA transfer in both cancerous and non-cancerous cells. Transferred DNA fragments are stably inherited as functional extrachromosomal genetic elements in the recipient host genome, thereby conferring heritable phenotypic traits to the recipient cell.
Our findings uncover a horizontal gene transfer-like mechanism through which direct cell-cell contact can propagate genomic instability and reshape mammalian genomes."
Broken chromosomes don’t stay home: Tunneling nanotubes carry damaged DNA between human cells (no public access)
Human cells can exchange genomic DNA that alters cell behavior (original news release) "Children’s Research Institute scientists discover that DNA transferred between cells can be inherited, remain biologically active"
Graphical abstract
Figure 1 Intercellular DNA transfer via nanotube-like connections in human cells
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