Viewpoint: Cells are a lot more plastic than we thought

Dr Richard Kia is a Clinical Training Fellow in the MRC Centre for Drug Safety Science

“Recent major discoveries in the field of developmental and stem cell biology continue to dismantle our long-held notion that mammalian cells, especially adult cells, do not convert into other cell types.

“Research led by the 2012 Nobel Laureate, Shinya Yamanaka, has shown that mature mammalian cells can be “reprogrammed” by genetic manipulation to a state similar to the stem cells found in embryos.

Tantalising potential

“These cells are able to divide indefinitely and are pluripotent – that is, they have the ability to differentiate into all types of somatic cells, such as liver cells or nerve cells. They therefore offer a tantalising potential to fulfil the escalating needs in cell replacement therapy for patients with organ failure, and may enable us to model in the laboratory the mechanism of how diseases occur and screen new drugs.

“Two articles published in the journal Nature by the same group of scientists however, offer even more compelling evidence that mammalian cells are able to switch their state.

”They reported that cellular reprogramming of mice cells into a pluripotent state can also occur by the introduction of strong external stimuli, such as a short exposure to a mildly acidic solution – without the need for expensive genetic modulators such as viral vectors and proprietary reprogramming reagents.

“They also showed that the generated cells are similar to embryonic stem cells with a pluripotent potential. More intriguingly, they could also be manipulated using different culture conditions to produce cells with an even broader level of potency which have the ability to contribute towards the development of placental tissues, unlike embryonic stem cells.

“Although these findings need to be replicated in other research laboratories to show that the new STAP (Stimulus-Triggered Acquisition of Pluripotency) cells can be successfully generated from human adult cells, their remarkable research findings offer the exciting prospect of generating pluripotent, patient-specific STAP cells, without the risks of genetic manipulation, using a relatively simple and inexpensive technique.

Significant implications

“Their findings also suggest that mammalian cells potentially adapt to a “stressful” environment by reverting into a cell type akin to pluripotent stem cells.

“This idea will feed into our current research at the MRC Centre for Drug Safety Science in understanding the limiting factors in generating functional liver cells from pluripotent stem cells, mechanisms involved in liver regeneration, and also aspects that cause the loss of human primary liver cell function.

“If these findings can indeed be replicated in human cells, they will also have significant implications for our work on the safety of regenerative medicines in the new UK Regenerative Medicine Hub, led by the University of Liverpool.”