Monday, March 10, 2008

Cellular Rewind <<


Cells on the verge of division (mitotic exit) were once thought to have a pre-destined fate. Cell division was known to be irreversible. However, researchers from the Oklahoma Medical Research Foundation have successfully achieved the impossible, by pushing a cell at mitotic exit back into M phase using chemical agents. Their paper ‘The reversibility of mitotic exit in vertebrate cells’ (Nature, 2006), details this amazing accomplishment.

The mitotic exit stage of cell development is controlled by the breakdown of a type of cyclin, (cyclin B) and also by Cdk1 (cyclin-dependant-kinase 1) inhibitors. By removing both of these factors after the cell had undergone mitotic exit, complete mitosis was reversed, and the cell reverted back to M phase. They observed a re-condensation of chromatids, re-breaking of the nuclear envelope, healing of the cleavage furrow and reformation of microtubules into the mitotic spindle. In most cells, the metaphase plate also reformed, a characteristic feature of a cell in M phase.

This incredible discovery has many future applications, in both research techniques (such as the culture of cells) and in medicine, particularly in anti-cancer drugs. It holds great potential for certain types of cancers where cell division continues uncontrollably, by halting division while still maintaining the integrity of the surrounding cells. This technique would also be able to inhibit the divison of certain groups of cells, which may not be cancerous but which have acquired an unwanted genetic variation.

Still interested?
Check out these links:
http://www.nature.com/nature/journal/v440/n7086/full/nature04652.html

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