Rodent studies are likely inadequate for testing many human therapies—including pharmaceuticals—since 50 percent of all chemicals test positive as carcinogens in rodents regardless of their source or identity, according to Thomas Hartung, a professor in the Bloomsburg College of Public Health at Johns Hopkins University. He suggests these rodent studies may be no better than a coin toss. For example, some components in coffee appear to be carcinogenic in rodents, but in humans moderate coffee consumption may reduce the risk of cancer.
In 2010, UGA faculty Steve Stice and Franklin West introduced 13 pigs that have shown promise in unlocking the path to new therapies. The pigs recently produced another positive finding: These adult-cell-sourced stem cells don't form tumors in pigs.
"Pluripotent stem cells have significant potential for stem cell therapies," said West, an animal science researcher and assistant professor in the UGA College of Agricultural and Environmental Sciences. "However, tests in mice often resulted in tumor formation that frequently led to death."
The formation of tumors has raised concerns about the safety of induced pluripotent stem cells, or iPSCs, and cells derived from these stem cells. Until now, all iPSC safety studies have been performed in rodent models.
"To address the concern, our research team studied tumor formation in pigs generated from pig iPSCs," West said. "Brain, skin, liver, pancreas, stomach, intestine, lung, heart, kidney, muscle, spleen and gonad tissues from all 11 pigs tested showed no evidence of tumors."
The absence of tumor formation in these pigs suggests that iPSCs can safely incorporate into tissues without tumor formation.
"Being able to safely use iPSCs without the potential of causing tumors is essential for this promising stem cell therapy to become a viable treatment option," said Stice, a Georgia Research Alliance Eminent Scholar in the College of Agricultural and Environmental Sciences. "We now have graduate students working on making neural cells from the human and pig stem cells to help further the studies. The human stem cells were effective in a rodent model for stroke, but rodent studies are not rigorous enough to start human clinical trials."
West agrees. "Over 700 drug treatments have gone to human clinical trials for stroke alone based on findings in rodents and have turned out not to be viable in humans," he said. "The pigs are much more human like, and they are going to be a much better model to study strokes."
West is leading a cooperative project between the UGA Regenerative Bioscience Center and stroke researchers at Georgia Health Sciences University. "This project will improve the speed and efficiency of treatment development for stroke and many other conditions and potentially reduce the number of nonhuman primates used in research," he said.
Additionally, Stice and West have now bred the pigs produced from iPSCs and have proven the stem cells did pass to the offspring. This finding opens the door for better animal-sourced tissue for human regenerative medicine such as islet cells that produce insulin for diabetic patients.
Using iPSC technology, the UGA Regenerative Bioscience Center is working with researchers at Emory University to make pigs whose cells from the pancreas would demonstrate decreased rejection in human treatments.
"The next step would be to put these pig insulin-producing cells into other animals, potentially dogs or cats suffering from diabetes—to see if it will produce insulin for them without being rejected," Stice said. "So, it's moving forward. Never as fast as we like, but it's moving."
Their research results were published in the October issue of Stem Cells. For an abstract of the study, see http://www.ncbi.nlm.nih.gov/pubmed/22039609
Franklin West | EurekAlert!
Molecular Force Sensors
20.09.2017 | Max-Planck-Institut für Biochemie
Foster tadpoles trigger parental instinct in poison frogs
20.09.2017 | Veterinärmedizinische Universität Wien
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...
Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
20.09.2017 | Life Sciences
20.09.2017 | Power and Electrical Engineering
20.09.2017 | Physics and Astronomy