Japan’s leading genetics researcher could be “a matter of months” from reaching the Holy Grail of biotechnology – producing an “ethical” human stem cell without using a human embryo, he has said.

But in an exclusive interview with The Times, Shinya Yamanaka urged the scientific community: “Do not stop stem-cell research with human embryos, because patients will die if you do stop.” Although his work could transform the stem-cell field, speaking on the eve of his arrival in Britain to present research to geneticists, Professor Yamanaka emphasised that “right now, embryonic stem cells are vital to medical research”.

The potential of Professor Yamanaka’s breakthrough work – in which the skin cells of laboratory mice were genetically manipulated back to their embryonic state – has been hailed as the equivalent of “transforming lead into gold”. If the research develops in the way he hopes, runs the excited logic, the ethical problems that have swirled around embryonic stem-cell research would disappear.

No longer would the field, which experts believe could unlock cures for diseases such as diabetes and Parkinson’s, be hampered by controversy arising from the use of human embryos.

The concept of artificially inducing adult cells to return to a stem-cell state raises equally attractive possibilities for organ transplantation. If, for example, a patient’s skin cell could be reverted to stem-cell form and thence converted back into any other form of tissue – such as nerve, heart or other organs – it could then be transplanted without risk of rejection by the patient.

Professor Yamanaka, who himself expresses strong distaste for using human embryos as a source of stem cells, firmly believes that the interests of patients come first. “It is hard to predict how the science will develop, but I think we could produce a basic prototype-induced stem cell made from a human adult cell within six months to a year,” he said. “Within two to three years we may be able to create a stem cell that is indistinguishable from one taken from an embryo. What we cannot do, though, is to let the optimism over my science hold us back from conducting research on embryonic stem cells while we are waiting for the alternative.”

Stem cells are regarded as the “building blocks” of life because of their ability to grow into different types of tissue or organs. Those derived from embryos are the most versatile.

Professor Yamanaka explained that his technique for inducing stem cells – itself a pronounced departure from the research routes being pursued by rivals in the US and Britain – raises safety problems that need to be eradicated before the “ethical stem cell” is fit for use in humans. The four genes that he manipulates to create the transformation include one that acts as a “cancer switch” for healthy cells.

Although Professor Yamanaka’s work was welcomed by the opponents of the use of human embryos in stem-cell research, answering their objections was not his main motive.

Professor Yamanaka believes that his laboratory explains a lot. Small, cramped and on the second floor of a decrepit university building, the lab contrasts with the modern, better-funded ones he sees on visits overseas. It would, he says. surprise people who think of Japan as a high-tech paradise.

He hopes that his work might hasten Japan’s return to the top ranks of serious players in genetics technology.

Professor Yamanaka also sharply criticised the timid and “stupid” Japanese Government, which, he said, has no feel for the importance of science and imposes “terrible regulations and crazy policies that crush any long-term projects”. Hampered by mountains of bureaucratic paperwork and complex restrictions, Japanese stem-cell research has dwindled to virtually nothing. Britain, the US and South Korea have surged ahead.

The creation of an “ethical stem cell” usable by Japanese researchers without expensive licensing or onerous regulation would, he said, “give competitiveness back to his country”.

How countries regulate embryo research

— Somatic cell nuclear transfer (SCNT) involves the insertion of a somatic cell’s nucleus into an egg whose nucleus has been removed. It creates an embryonic clone of an animal harvested for stem cells

— Countries allowing this include the UK, China, India, Australia, Belgium, Japan, South Korea and Sweden

— In other countries, including France, Spain and Canada, genetic material must be derived from donations to fertility clinics

— Countries that prohibit stem-cell research or allow it only on cells obtained from abroad or those predating the legislation include the US, although California has its own rules allowing SCNT

Source: University of Minnesota Medical School