06 Aug 2013, BioSpectrum Bureau , BioSpectrum
Singapore: Scientists at the School of Medicine and Public Health at University of Wisconsin, US, have discovered a type of cell divison in human beings that was previously seen only in slime molds. The scientists stumbled upon the findings while they were trying to find a way to attack certain types of cancers that had too much DNA or extra sets of chromosomes. The scientists made the first observations of cytofission in humans, a type of cell division that occurs at a time other than normal division.
The research, which was supported by the National Institutes of Health, UW Carbone Cancer Center, American Cancer Society, the Mary Kay Foundation, and Effcansah.com, was published online in the Proceedings of National Academy of Sciences in July.
To start testing, they took a culture of cells and prevented the final stage of cell division, creating cells that were tetraploid, having four sets of chromosomes instead of two sets. Then during mitosis, the two sets of components are separated to opposite ends of the cell. Lastly, the original cell is cut into two daughter cells. To make cells that mimic cancer with twice as many chromosomes, Dr Mark Burkard, member of the UW Carbone Cancer Center and assistant professor of hematology-oncology in the Department of Medicine, University of Wisconsin, and his team blocked the cell from dividing into two, but the results weren't as straight forward as they anticipated.
Dr Burkard said that, "We couldn't figure it out because we found most of the cells were normal after that process. There were a few tetraploid cells so we eventually got to start our original research, but we couldn't understand why most of them seemingly hadn't undergone the process of becoming tetraploid. We started looking into it, and this whole publication came out of that."
The splitting occurred, unpredictably, during a delayed growth phase rather than at the end of mitosis. Dr Burkard, after observing the novel cellular splitting in late fall, already has a bead on a chemical that can block the division of tetra and polyploid cells, effectively blocking the growth of cancer-like cells with too much DNA. He and his lab are now exploring exactly how the chemical does so
"If you think of something as simple and old-fashioned as aspirin which was discovered in the 19th century, how it works wasn't discovered until 1971," said Dr Burkard. "We want to find out more quickly. Fortunately, we have tools that weren't available in 1971. That's what we're really focused on doing right now because we think that might impact patients in the near term."