CLONING USED TO MAKE STEM CELLS
For the first time, cloning technologies have been used to generate stem cells that are genetically matched to adult patients.
Fear not: No legitimate scientist is in the business of cloning humans. But cloned embryos can be used as a source for stem cells that match a patient and can produce any cell type in that person (…)
“This is a dream that we’ve had for 15 years or so in the stem cell field,” said John Gearhart, director of the Institute for Regenerative Medicine at the University of Pennsylvania. Gearhart first proposed this approach for patient-specific stem cell generation in the 1990s but was not involved in the recent studies.
Stem cells have the potential to develop into any kind of tissue in the human body. From growing organs to treating diabetes, many future medical advances are hoped to arise from stem cells.
Scientists wrote in the journal Cell Stem Cell this month that they used skin cells from a man, 35, and another man, 75, to create stem cells from cloned embryos (…)
“We reaffirmed that it is possible to produce patient-specific stem cells using a nuclear transfer technology regardless of the patient’s age,” said co-lead author Young Gie Chung at the CHA Stem Cell Institute in Seoul, South Korea.
On Monday, an independent group led by scientists at the New York Stem Cell Foundation Research Institute published results in Nature using a similar approach. They used skin cells from a 32-year-old woman with Type 1 diabetes to generate stem cells matched to her.
Both new reports follow the groundbreaking research published last year by Shoukhrat Mitalipov and colleagues at Oregon Health & Science University in the journal Cell. In that study, researchers produced cloned embryos and stem cells using skin cells from a fetus and an 8-month-old baby.
“It’s a remarkable process that gives us these master cells, these stems cells that are essentially the seeds for all of the tissues in our bodies,” said George Daley, director of the Stem Cell Transplantation Program at Boston Children’s Hospital, who was not involved in the recent studies. “That’s why it’s so important for medical research” (…)
Chung’s group — which led the Cell Stem Cell study — used this cloning method that Mitalipov had pioneered to get two stem cell lines out of 77 eggs. “It seems that the quality of oocyte (egg) plays a pivotal role,” Chung said.
Egli and colleagues had their own spin on the cloning process, amending it so that it happens in a more controlled way. Their study in Nature used electricity in combination with chemicals, and manipulating the calcium concentration, to improve the procedure. They generated stem cells specific to the diabetic patient who had donated skin cells; the eggs came from donors.
This group got four cell lines from 71 eggs, said research assistant Lydia Mailander. The average egg donation is 14 to 15 oocytes. Researchers estimate it would take two such donations to get one stem cell line.
In mice, Egli and colleagues showed in a separate study that the cloned stem cells from the diabetic patient mature into glucose-responsive beta cells, which secrete insulin into the bloodstream of the animals (…)