A decade of embryonic stem cell research

Published in The Hindu on November 13, 2008

Stem cell research
The U.K. has been a trend-setter as far as research on human embryonic stem cells is concerned. — Photo: NIH

Medical science got a big boost when James Thomson of the University of Wisconsin-Madison announced on Nov 6, 1998 that he had successfully derived and sustained the culturing of human embryonic stem cells.

There was hope of using the technique to treat/cure certain diseases in about ten years’ time. That did not happen, though.

Though embryonic stem cells have not reached a stage where they can be used for clinical applications, there is optimism that they will be used sooner than later.

Much has been learnt about how human embryonic stem cells become any of the specialised human cells. But there is much more to be understood. Unfortunately, the immediate association with and apprehension of many Hitlers being cloned using the technique was the first challenge that this field had to tackle. Then came the issue of embryo destruction.

The obstacles

Harvesting human embryonic stem cells (hESC) from embryos destroys the embryos. This was a no-no for pro-life activists.

Saving a bunch of cells that people considered as representing life seemed more important than using them to treat/save people living with certain diseases.

It is another matter that many of the nearly 4 lakh embryos stored in infertility clinics in the U.S alone will be ultimately destroyed.

George Bush, dictated solely by his right-wing ideology, and not science, put the biggest spanner in the development of this nascent science.

If there was ever a single policy decision that has stifled science so much, then this is it — the decision to provide federal funding only to cell lines created from human embryos before August 9, 2001.

Two attempts to pass a legislation to expand federal funding were fruitless. He vetoed them on both occasions.

Trend-setter

The U.K. has been a trend-setter as far as research on hESC is concerned. It has a tightly regulated environment and has issued licences for every kind of research.

The licence to create embryonic stem cells through somatic cell nuclear transfer (also called parthenogenesis) in 2004 speaks for itself. The latest has been its approval of using animal eggs to produce hybrid embryos.

Using animal eggs sidestepped the issue of procuring human eggs and the criticism associated with it.

With embryonic stem cell research stifled, scientists in the U.S. had to turn their attention to adult stem cells. They have achieved a lot in this area, though. But adult stem cells have a limitation.

They cannot become any of the 250-odd cells like in the case of the embryonic stem cells. But scientists appear to have overcome this limitation. A new technique — induced Pluripotent Stem Cell (iPSC) — can reprogramme adult cells to make them as versatile as embryonic stem cells.

Recent development

And very recently, researchers at Kyoto University have improved the iPSC technique by not using viral vectors to introduce the four genes into cells.

These two techniques, along with the usage of adult stem cells, will go a long way in our understanding of how diseases set in, how they progress and how they can be treated. It will be a long while before complete organs can be grown using stem cells.

The good news is that new discoveries are coming in thick and fast. For instance, research has shown that mouse embryonic stem cells can be used to predict human breast cancer risk.

In May this year, American scientists have been able to induce hESCs to become human heart progenitor cells. These progenitor cells can produce all the three main heart cell types. Early this year, scientists developed a cell culture method to make sure that hESC that became neurons did not turn cancerous when transplanted.

Though adult stem cells are producing equally promising results, they should not be at the expense of ESC research. It is for the President-elect Barack Obama to correct this.