Just like humans, cells have memory too, according to research conducted by Harvard Medical School researchers who have effectively isolated genes that can erase a cell's memory when suppressed. This action makes the cell more susceptible to reprogramming and makes the process more efficient, allowing them to create stem cells with the potential to grow into any kind of cell type.
"We began this work because we wanted to know why a skin cell is a skin cell, and why does it not change its identity the next day, or the next month, or a year later?" said Konrad Hochedlinger, co-senior author of the study, in a press release.
Each cell in the human body possesses the same DNA blueprint, and the on and off switching of these genes during development is what determines the type of cell each will become in its adult life. Using this new information, manipulation of these genes will become easier and allow scientists to unlock dormant parts of an adult cell's genome and reprogram it into another cell type.
The researchers discovered that the chromatic regulator CAF-1 played a big part in retaining cellular memory and by inhibiting this factor, reprogramming, or erasing a cell's memory, becomes much easier.
"The CAF-1 complex ensures that during DNA replication and cell division, daughter cells keep their memory, which is encoded on the histones that the DNA is wrapped around," said Ulrich Elling, co-first author of the study. "When we block CAF-1, daughter cells fail to wrap their DNA the same way, lose this information and covert into blank sheets of paper. In this state, they respond more sensitively to signals from the outside, meaning we can manipulate them much more easily."
CAF-1 can effectively allow cell memory to be erased and rewritten, giving scientists the ability to alter the development of cells into different types.
"The cells forget who they are, making it easier to trick them into becoming another type of cell," said Sihem Cheloufi, second co-first author of the study.
The findings were published in the Dec. 9 issue of Nature.