Researchers have discovered that the remnants left behind after cells divide contain RNA, which, when taken up by other cells, can spread the cancer's genetic blueprint. This discovery opens the door to exploiting this mechanism to treat cancer. During the final stages of cell division, or mitosis, a short-lived intercellular "bridge" called the midbody connects the two daughter cells, recruiting and positioning the machinery that ultimately separates them.
Initially, the researchers thought that the remaining midbodies - midbody residues - that were left after the cells were separated would be degraded immediately. However, recent research has found that midbody remnants are released and may promote the proliferation of tumor cells and stem cells. A new study led by researchers at the University of Wisconsin-Madison examined the content, organization and behavior of midbodies to better understand their role in the body.
"People think of the midbody as the place where cells die or are recycled after dividing," said Ahna Skop, the study's corresponding author. "But one person's trash is another person's treasure." The midbody is a small packet of information that cells use to communicate. "
They found that midbody RNA produces proteins involved in guiding cells' purposes, including their ability to differentiate (pluripotency) and form cancerous tumors (tumorigenesis). This finding suggests that mesosomes are vectors for cancer to spread in the body.
Ahna Skop, the corresponding author of the study, said: "A cell divides into three things: two cells and a midbody remnant, a new signaling organelle. What surprised us was that the midbody was full of genetic information - RNA, which has nothing to do with cell division at all, but probably plays a role in cell communication."
Many midbody remnants are taken up by one of the daughter cells where they play an important role in the separation process, but if they escape, they are taken up by another cell and mistakenly start using the midbody RNA as if it were its own blueprint.
"The remnants of the mesobody are very small," Schop said. "It's only a micron in size, which is one millionth of a meter. But it's like a small lunar lander. It has everything it needs to maintain information about the workings of dividing cells. It can drift away from the site of mitosis, enter your bloodstream, and land on another cell far away."
Previous research has shown that in normally dividing cells, stem cells, and cancer cells, cancer cells are more likely to accumulate midbodies, which is associated with increased cell proliferation and tumor growth behavior.
The researchers also discovered a gene called Arc, which is key in loading RNA into midbody and midbody residues. Arc is also linked to molecular processes in the brain related to learning and memory.
"The loss of Arc results in the absence of RNA in the midbody and prevents the RNA message from reaching the recipient cell," Scope said. "We believe that this memory gene is important for all cells to transmit RNA messages."
Further research could harness the power of midbody RNA to deliver drugs directly to cancer cells or prevent them from dividing. "We believe our findings represent a huge target for cancer detection and treatment," Schop said.
The research was published in the journal Developmental Cell.