Untreatable conditions can be helped with reprogrammed adult stem cells

In just two years, the celebrated adult stem cell researcher Shinya Yamanaka hopes that clinical trials will begin on curing the once-untreatable spinal injuries with the help of “reprogrammed” adult cells or ‘induced pluripotent stem' (iPS) cells.

Animal trials have shown promising results of transplanting iPS cells to treat paralytic spinal injury, said Professor Yamanaka, delivering a lecture on “New Era of Medicine with iPS Cells” here on Monday.

The lecture was organised as part of the Cell Press-TNQ India Distinguished Lectureship Series.

Prof. Yamanaka, who started his career as a physician 25 years ago and “tried to be an orthopaedic surgeon”, said: “I soon realised I was not so good at surgery. I also realised that even a good surgeon can't help many patients suffering from untreatable diseases and injuries.”

This inspired him to change his career and get back to studying “basic medicine”.

That's where he “met” the iPS cell, which led him to his major scientific breakthrough in 2007 allowing him to “reprogramme” adult human skin cells into embryonic-like stem cells.

The iPS cells have revolutionised research on regenerative medicine: they are free from debates over ethics — often raised in the use of human embryos — and reduce the risk of tissue rejection after transplant. Once established, these cells can be used to elucidate disease mechanisms and to screen drugs.

But creating these cells is both time and money-consuming, he said.

It costs as much as U.S. $ 1 million to treat just one patient, and takes six to eight months to generate, expand and induce differentiation in iPS cells.

“In the case of spinal injuries, we have to transplant the cells within a month after the injury.

“To overcome this, we think it makes sense to create and maintain an iPS cell bank from healthy individuals,” he said.

The risk of rejection by an individual's immune system can be minimised by matching donors with HLA (human leucocyte antigen), a form of “blood type” for human cells.

In Japan, for instance, just 75 unique HLA homozygotes would match 80 per cent of the population, he explained.

Prof. Yamanaka, who was awarded the Albert Lasker Prize in 2009 and the Wolf Prize in 2011, later answered questions from budding biologists and veteran scientists in the audience.

He will speak next in Chennai on February 1 and New Delhi on February 3 as part of the lectureship series.