Scientists at Harvard Medical School have developed an even better way of producing alternatives to human embryonic stem cells (hESCs). The new technique, which appears to be a huge improvement over induced pluripotent stem (iPS) cells, is being described as a major advance.

While iPS cells are very promising, they have significant drawbacks. The process for generating them is very inefficient and they can cause cancer. The new method, developed by a team headed by Derrick Rossi and published in the journal Cell Stem Cell, does not require risky genetic modification and holds great promise for making the reprogramming process more therapeutically relevant. Synthetic modified messenger RNA molecules encode the appropriate proteins but without integrating into the cell's DNA.

"All I can say is 'wow' - this is a game changer," said Robert Lanza, a stem cell researcher at Advanced Cell Technology told the Washington Post. "It would solve some of the most important problems in the field."

"Our technology represents a safe, efficient strategy for somatic cell reprogramming and directing cell fate that has wide ranging applicability for basic research, disease modeling and regenerative medicine," says Dr Rossi. "We believe that our approach has the potential to become a major and perhaps even central enabling technology for cell-based therapies."

What are the ethical implications?

Richard M. Doerflinger of the US Conference of Catholic Bishops told the Post: "With each new study it becomes more and more implausible to claim that scientists must rely on destruction of human embryos to achieve rapid progress in regenerative medicine."

However, the director of the National Institutes of Health, Francis S. Collins, insisted that research on hESCs must continue as they are a gold standard. “Previous research has shown that iPS cells retain some memory of their tissue of origin, which may have important implications for their use in therapeutics,” he said. “To explore these important potential differences, iPS research must continue to be conducted side by side with human embryonic cell research."  ~ Eurekalert, Sept 30, Harvard, Sept 30