A preeminent figure in adult stem cell research is leaving the state of Michigan to continue his ground breaking Cancer Research in Texas.

Sean Morrison, director of the Center for Stem Cell Biology at the University of Michigan, isn’t mincing words on his way out the door.  Read More

“Hopes for treating life-threatening diseases with cells taken from patients’ own bodies have suffered a setback after research showed they might trigger severe immune reactions.

The surprise finding will be a hurdle for scientists working on induced pluripotent stem (iPS) cells, a variety of cell that holds promise for treating conditions as diverse as muscular dystrophy, Parkinson’s and heart disease.“  Read More

Just four years ago, scientists developed a method to convert adult cells of the body into cells that exhibit all the essential properties of early embryonic cells. This discovery created both excitement and hope that there will soon be new and effective therapies for treating a wide range of debilitating human conditions, including diabetes, Parkinson’s disease and spinal cord injuries.
The process of converting adult cells into an embryonic stem cell-like state is referred to as reprogramming, and the cells that are generated by this process are referred to as induced pluripotent stem (iPS) cells. The ability to produce human iPS cells has been hailed as a true breakthrough, because it offers hope that the cells needed for future cell-based therapies will be genetically matched to the patient undergoing treatment. As a consequence, there should be no need for drugs to suppress the immune system, which would be needed to prevent rejection if the cells are not genetically matched to the patient. Achieving the goal of producing patient-matched cells for cell-based therapies would be a major advance in regenerative medicine. However, much more work needs to be conducted before this goal becomes a reality.

The discovery of human iPS cells has led some to argue forcefully that there is no longer a need to study human embryonic stem (ES) cells, which are produced from early stage human embryos well before they form any fetal or adult cells. (In fact, once the embryo begins to form cells found in the human fetus, they can no longer give rise to human ES cells.) On the surface, the argument that we no longer need to work with human ES cells may sound reasonable, but this is a fallacious argument. Researchers who produce and study iPS cells know that we need to learn far more about iPS cells before we will be able to consistently produce and properly maintain high quality human iPS cells. The following discussion helps illustrate some of the reasons why it is essential to continue to work with and study human ES cells.

First, it is abundantly clear to stem cell researchers that human iPS cells produced in different laboratories around the world are not identical. Fortunately, stem cell biologists have been able to use human ES cells as the “gold standard” to judge the quality of human iPS cells. This would not have been possible without the intensive study and characterization of human ES cells over the past 12 years. In fact, it is important to recognize that if the study of human ES cells had been banned, we would not know how to produce human iPS cells or what properties human iPS cells should possess. In this regard, recent studies have identified some important difference between ES cells and iPS cells.

Second, continued progress in the study of human iPS cells is also tied to continued progress in our understanding of human ES cells. Although we know that human ES cells possess the ability to give rise to virtually any cell type in the body through differentiation (a property known as pluripotency), we still need to know more about the molecular properties of human ES cells. Knowing more about the molecular properties of human ES cells will enable us to determine with greater precision the quality and the true clinical potential of human iPS cells.

Third, and equally important, we still need to determine the best laboratory practices required to maintain the pluripotency of human ES cells during prolonged periods of study. This information is needed not only for working with human ES cells, it provides essential information needed for working with their reprogrammed counterparts, human iPS cells. For practical reasons, the best laboratory practices are more readily developed in the course of studying human ES cells.

There has been substantial progress made during the past decade in the field of regenerative medicine when viewed in the larger context. However, progress in this important area of biomedical research would have been far slower if we had not undertaken the isolation and study of human ES cells, which provided the critical groundwork for knowing how to produce human iPS cells. The future for regenerative medicine indeed appears to be very bright. Progress in regenerative medicine is not only likely to help alleviate acute pain and suffering, it is also likely to eventually provide new treatment strategies for chronic diseases that are very costly and which worsen with time. Compassion for those in need compel me to argue for continued study of all types of stem cells, including human ES cells. 

Dr. Rizzino is a stem cell biologist who was recruited to the University of Nebraska Medical Center in December of 1983. Prior to joining the University, he was an investigator at the National Cancer Institute. He has worked in the field of stem cell biology for over 30 years. He has been continuously funded by the National Institutes of Health since the mid 1980s.