Until now biologists have thought that human cells can only replicate using a type of cell division called cytokinesis, where a somatic (body) cell splits into two new daughter cells after doubling the quantity of DNA that it contains via a process called mitosis. Dr. Mark Burkard from the University of Wisconsin Carbone Cancer Centre however, has discovered that this is not in fact the only way!
The new type of cell division, called klerokinesis, appears to occur in somatic cells that already have more DNA in them than they should and results in the production of two daughter cells that actually have the correct number of chromosomes in them!
Although cells containing more DNA in them than they should may not sound like a big deal, it is and many cancers and diseases such as Down’s Syndrome are actually the result of this extra genetic material. For example, about 35% of all pancreatic cancer cells and 14% of breast cancer cells have three sets of chromosomes in them rather than two!
Dr. Burkard and his colleagues believe that klerokinesis may actually be one of the body’s emergency ‘back-up’ defences to eliminate cells with too much genetic material in them so that they don’t build up in the body. This hypothesis appears to be supported by the results of his research, which found that 90% of the cells that he had purposely tried to produce with three chromosomes instead of two in them (as part of his breast cancer research), divided early in the mitotic cell cycle after an unusually long rest period to produce ‘normal' cells!
Dr. Burkard and his colleagues are excited about discovering that abnormal cell division rarely has any long-term detrimental side-effects and believe that this research could have huge implications in our war against cancer. In fact Dr. Burkard has said that he would like be able to actually push 99% of cells towards klerokinesis by the end of his research as “if we could push the cell towards this new type of division, we might be able to keep cells normal and lower the incidence of cancer”.