New horizon in stem-cell research

A team of scientists led by a 30-year-old Japanese woman has discovered a simple method to produce stem cells — immature cells that can develop into all types of tissues in the body. The team headed by Dr. Haruko Obokata has found that body cells taken from mice can be reprogrammed into stem cells by simply exposing them to low-PH acid liquids.

The discovery, made public in the Jan. 29 issue of Nature magazine, is an epoch-making discovery that defies common knowledge and breaks new ground in life science.

It is hoped that more efforts will be made so that the discovery will lead to the advancement of regenerative medicine. It is also important to recognize that the discovery will have a great impact on biological studies of cells in a larger sense. It is hoped that the discovery will stimulate a wide range of research on cells, irrespective of whether they are from animals or from plants.

Scientists at Harvard University and the government-backed Riken’s Center for Developmental Biology in Kobe soaked lymph corpuscle taken from 7-day-old mice in mildly acidic liquids for about 30 minutes, cultured a few cells that survived and transplanted them into mice. They found that the cells developed into nerve and muscle tissues.

They named this new way of reprogramming adult cells into pluripotent cells that can grow into any types of mature tissues in the body “stimulus-triggered acquisition of pluripotency” or STAP. This method has broken the established theory in biology that without tampering with cell nuclei, it is impossible to reprogram specialized cells to become stem cells. The method used in producing STAP cells is easier than the method used by Dr. Shinya Yamanaka of Kyoto University, who received the Nobel Prize in Physiology or Medicine in 2012. Yamanaka and his team succeeded in 2006 in creating pluripotent stem cells by introducing only four genes into mature cells from the skin of a mouse. In 2007, they succeeded in creating similar induced pluripotent stem (iPS) cells by using cells from the skin of a human.

STAP cells can be produced in a much shorter period of time and are expected to have a lower risk of developing cancer than iPS cells. They can also become tissues that form the placenta, which is not possible with iPS cells. STAP cells can be made not only from blood cells but also from skin and muscle cells.

Other methods in addition to soaking in a mildly acidic solution, such as the passage of cells through glass tubes and exposure to a mildly toxic substance, can also produce STAP cells. Although it has not yet been known whether the same results will be obtained when human cells are used, the STAP cell discovery raises the hope of its application for medical treatment.

Obokata’s perseverance and efforts to make this indisputable discovery should be praised. The first thesis she sent to Nature magazine was rejected as ridiculing hundred years of history of cell biology. She spent some five more years after the first experiment and eventually succeeded in having her second thesis accepted by the science magazine.

She not only has shown flexibility in thinking but also has made strenuous efforts to advance her research. It is also significant that many other scientists helped her in her research.

It is hoped that her story will not only encourage young scientists — especially women — but also provide indications of what research environment and support are needed to achieve high quality scientific research.