In experiments that could open a new era in stem cell
biology, scientists have found a simple way to reprogramme
mature animal cells back into an embryonic-like state that
allows them to generate many types of tissue.
The research, described as game-changing by experts in the
field, suggests human cells could in future be reprogrammed
by the same technique, offering a simpler way to replace
damaged cells or grow new organs for sick and injured people.
Chris Mason, chair of regenerative medicine bioprocessing at
University College London, who was not involved in the work,
said its approach in mice was "the most simple, lowest-cost
and quickest method" to generate so-called pluripotent cells
- able to develop into many different cell types - from
"If it works in man, this could be the game changer that
ultimately makes a wide range of cell therapies available
using the patient's own cells as starting material - the age
of personalised medicine would have finally arrived," he
The experiments, reported in two papers in the journal Nature
on Wednesday, involved scientists from the RIKEN Center for
Developmental Biology in Japan and Brigham and Women's
Hospital and Harvard Medical School in the United States.
The researchers took skin and blood cells, let them multiply,
then subjected them to stress "almost to the point of death",
they explained, by exposing them to various events including
trauma, low oxygen levels and acidic environments.
One of these "stressful" situations was simply to bathe the
cells in a weak acid solution for around 30 minutes.
Within days, the scientists found that the cells had not only
survived but had also recovered by naturally reverting into a
state similar to that of an embryonic stem cell.
These stem cells - dubbed Stimulus-Triggered Acquisition of
Pluripotency, or STAP, cells by the researchers - were then
able to differentiate and mature into different types of
cells and tissue, depending on the environments they were put
"If we can work out the mechanisms by which differentiation
states are maintained and lost, it could open up a wide range
of possibilities for new research and applications using
living cells," said Haruko Obokata, who lead the work at
Stem cells are the body's master cells and are able to
differentiate into all other types of cells. Scientists say
that by helping to regenerate tissue and potentially grow new
organs, they could offer ways of tackling diseases for which
there are currently only limited treatments.
Recent experimental research has seen stem cells used to to
create a functional human liver and to create beating heart
There are two main types of stem cells: embryonic ones,
harvested from embryos, and adult or iPS cells, which are
taken from skin or blood and reprogrammed back into stem
Because the harvesting of embryonic stem cells requires the
destruction of a human embryo, the technique has been the
subject of ethical concerns and protests from pro-life
Dusko Ilic, a reader in stem cell science at Kings College
London, said the Nature studies described "a major scientific
discovery" and predicted their findings would open "a new era
in stem cell biology".
"Whether human cells would respond in a similar way to
comparable environmental cues ... remains to be shown," he
said in an emailed comment. "I am sure that the group is
working on this and I would not be surprised if they succeed
even within this calendar year."
Robin Lovell-Badge, a stem cell expert at Britain's National
Institute for Medical Research, said it would be some time
before the exact nature and capabilities of the STAP cells
would be fully understood by scientists - and only then would
their full potential in medicine become clearer.
"But the really intriguing thing to discover will be the
mechanism underlying how a low pH shock triggers
reprogramming," he said. "And why does it not happen when we
eat lemon or vinegar, or drink cola?"