Monthly Archives: October 2012

THE Nobel Prize-winning discovery of how to reprogram ordinary cells to behave like embryonic stem cells offers a way to skirt around ethical problems with human embryos, but safety concerns make their future use in treating disease uncertain.

While researchers have already applied the scientific breakthroughs of Britain's John Gurdon and Japan's Shinya Yamanaka to study how diseases develop, making such cells into new treatments will involve a lot more checks.

Stem cells act as the articlebody's master cells, providing the source material for all other cells. They could transform medicine by regenerating tissue for diseases ranging from blindness to Parkinson's disease.

Creating embryo-like stem cells without destroying embryos gets round a key controversy by avoiding the need to process embryos left over at fertility clinics a system that has led to political objections in the United States and elsewhere. Reprogrammed cells known as induced pluripotent stem cells, or iPS cells offer an ethically neutral alternative. They have been a source of intense research since Yamanaka discovered their potential in 2006, building on work that Gurdon did in frogs and tadpoles 40 years earlier.

Recently, however, different research groups have noticed problems with iPS cells, suggesting they may not be as good as embryonic ones. In one study, iPS cells died more quickly and another found multiple genetic mutations, raising concerns that they could cause tumours.

Despite this, Japanese researchers hope to test iPS cells in clinical trials for a form of blindness as early as next year - catching up with recent successful eye trials using embryonic stem cells.

Researchers in the West are generally more wary.

There is a bit of a divergence between Japan and the rest of the world on this, Chris Mason, professor of regenerative medicine at University College London, told Reuters.

Scientists in Japan are trying to move very rapidly towards clinical trials of iPS cells, whereas many of us still feel there are a lot of issues to overcome, especially in terms of safety.

The future potential for reprogrammed cells is that they could be taken from sick people who could have their own "person specific cell replacement" to mend damaged organs or tissues.

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Stem cell breakthrough opens new medical window

Thomas Perlmann of Karolinska Institute presents Sir John B. Gurdon of Britain and Shinya Yamanaka of Japan as winners of the 2012 Nobel Prize in medicine or physiology. The prize committee at Stockholms Karonlinska institute said the discovery has revolutionized our understanding of how cells and organisms develop. Photograph by Bertil Enevag Ericson/Scanpix/AP Photo

Stem cells derived from a mouses skin won Shinya Yamanaka the Nobel Prize yesterday. Now researchers in Japan are seeking to use his pioneering technology for an even greater prize: restoring sight.

Scientists at the Riken Center for Developmental Biology in Kobe plan to use so-called induced pluripotent stem cells in a trial among patients with macular degeneration, a disease in which the retina becomes damaged, resulting in loss of vision, Yamanaka told reporters in San Francisco yesterday.

Companies including Pfizer Inc. (PFE) are already planning trials of stem cells derived from human embryos. The Japanese study will be the first to use a technology that mimics the power of embryonic cells while avoiding the ethical controversy that accompanies them.

The work in that area looks very encouraging, John B. Gurdon, 79, a professor at the University of Cambridge who shared the Nobel with Yamanaka yesterday, said in an interview in London.

Yamanaka and Gurdon shared the 8 million Swedish kronor ($1.2 million) award for experiments 50 years apart that showed that mature cells retain in latent form all the DNA they had as immature stem cells, and that they can be returned to that potent state, offering the potential for a new generation of therapies against hard-to-treat diseases such as macular degeneration.

In a study published in 1962, Gurdon took a cell from a tadpoles gut, extracted the nucleus, and inserted it into the egg cell of an adult frog whose own nucleus had been removed. That reprogrammed egg cell developed into a tadpole with the genetic characteristics of the original tadpole, and subsequent trials yielded adult frogs.

Yamanaka, 50, a professor at Kyoto University, built on Gurdons work by adding four genes to a mouse skin cell, returning it to its immature state as a stem cell with the potential to become any cell in the body. He dubbed them induced pluripotent stem cells.

There are few moments in science that are undisputed as genuine elegant creativity and simplicity, Alan Trounson, the president of the California Institute for Regenerative Medicine in San Francisco, said in an e-mail. Shinya Yamanaka is responsible for one of those. An extraordinary accomplishment by a genuinely modest and brilliant scientist.

The technology may lead to new treatments against diseases such as Parkinsons by providing replacement cells.

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Nobel Winner’s Stem Cells to Be Tested in Eye Disease Next Year

Imagine the horror of a soldier losing a limb on the battlefield, or a loved one having a body part amputated due to diabetes. But, what if they could restore their limbs by activating their stem cells?

New Mexico State University biologist Graciela Unguez and a team of researchers found that electric fish, a vertebrate animal just like humans, can regenerate their tails following amputation after activating their stem cells. The findings were published in the May 2012 edition of the scientific journal, PLOS One.

"What's surprising is that as humans, we're one of the few animal species that do not readily regenerate limbs, organs or most tissues," Unguez said. "So, there's a lot of interest in how these fish do it, and what's preventing us from doing it."

Regeneration is the process of restoring lost cells, tissues or organs. According to Unguez, most animals have the ability to regenerate eyes and tails and some animals may be able to regenerate up to half of their bodies.

The researchers discovered that when they cut off up to one third of an electric fish's tail, including the spinal cord, vertebrae, muscles, skin, connective tissues and nerves, the fish would regenerate it. Unguez said the more tissue cut off, the longer the regeneration takes, but for the purpose of her study, it takes about three weeks.

"It's really exciting to us because, here's an example of an animal that can regenerate a lot of tissue types that are also found in humans," Unguez said. "So it puts into question this previous idea that those animals that can regenerate losses of many tissues do it because they do it differently than humans."

Unguez has used the electric fish as a model system to investigate the role that the nervous system plays in the fate of electrically excitable cells like muscle cells for 15 years. She noted that for many years, scientists have thought that highly regenerative animals use a mechanism of regeneration that does not involve stem cells, and this stem cell-based mechanism is well known in humans. In contrast, the stem cell-independent mechanism found in highly regenerative animals is not normally active in humans.

Unguez explained that stem cells are a small population of cells that do not mature and stay with us throughout our life, and then when called upon, they reenter the cell cycle to become muscle cells, neurons, skill cells and such.

But, what Unguez and her collaborators discovered was the opposite. The electric fish actually activated its own muscle and electric organ stem cells to regenerate. She said the adult fish regenerated unendingly with the activation of their stem cells.

"It does not negate other mechanisms, but it definitely showed that it was largely due to an activation of stem cells, just like humans have," Unguez said. "So maybe it's not as far apart, maybe some of the mechanisms involved or the events that need to be activated are more closely related than we thought."

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Electric fish at NMSU activate stem cells for regeneration

NEW YORK (AP) Two scientists from different generations won the Nobel Prize in medicine Monday for the groundbreaking discovery that cells in the body can be reprogrammed into completely different kinds, work that reflects the mechanism behind cloning and offers an alternative to using embryonic stem cells.

The work of British researcher John Gurdon and Japanese scientist Shinya Yamanaka who was born the year Gurdon made his discovery holds hope for treating diseases like Parkinson's and diabetes by growing customized tissue for transplant.

And it has spurred a new generation of laboratory studies into other illnesses, including schizophrenia, which may lead to new treatments.

Basically, Gurdon, 79, and Yamanaka, 50, showed how to make the equivalent of embryonic stem cells without the ethical questions those very versatile cells pose, a promise scientists are now scrambling to fulfill.

Once created, these "blank slate" cells can be nudged toward developing into other cell types. Skin cells can ultimately be transformed into brain cells, for example.

Just last week, scientists reported turning skin cells from mice into eggs that produced baby mice, a possible step toward new fertility treatments.

Gurdon and Yamanaka performed "courageous experiments" that challenged scientific opinion, said Doug Melton, co-director of the Harvard Stem Cell Institute.

"Their work shows ... that while cells might be specialized to do one thing, they have the potential to do something else," Melton said. It "really lays the groundwork for all the excitement about stem cell biology."

Another Harvard stem cell researcher, Dr. George Daley said, "I don't think anybody is surprised" by the award announcement. "The fact that these two share it together is inspired."

In announcing the $1.2 million award, the Nobel committee at Stockholm's Karolinska Institute said the work has "revolutionized our understanding of how cells and organisms develop."

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Nobel awarded for stem cell, early cloning work

8 October 2012 Last updated at 22:25 ET By Regan Morris BBC News, Los Angeles

US researchers say they will redouble their efforts to create human sperm from stem cells following the success of a Japanese study involving mice.

A Kyoto University team used mice stem cells to create eggs, which were fertilised to produce baby mice.

Dr Renee Pera, of Stanford University in California, aims to create human sperm to use for reproduction within two years, and eggs within five years.

Infertility affects up to 15% of reproductive-aged couples worldwide.

"I know people think it's Frankenstein medicine, but I think it's not an imagined or lessened health problem - infertility affects your whole life," Dr Pera says.

"To have sex and have a baby would be a super simple decision, but not everybody can do it."

But using embryonic stem cells for research - as Dr Pera's lab at the Institute for Stem Cell Biology and Regenerative Medicine does - is controversial because the embryos are destroyed in order to use them.

Dr Pera's lab uses embryos left over from IVF treatments.

Stem cells have the potential to grow into any cell in the body. Creating eggs in a lab could become mainstream, much like IVF is viewed today.

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US team aim to make human sperm