Local
Breakthrough at St. Elizabeth’s weakens case for embryonic stem cells

By Donis Tracy
Posted: 2/11/2005

BRIGHTON — Researchers at Caritas St. Elizabeth’s Medical Center have identified adult stem cells that may have the capacity to repair and regenerate all tissue types in the body, further weakening the case for the necessity of embryonic stem-cell research.

 “This discovery represents a major breakthrough in stem-cell therapy,” said Dr. Douglas Losordo, chief of cardiovascular research at St. Elizabeth’s. “Based on our findings, we believe these newly discovered stem cells may have the capacity to generate into most tissue types in the human body. This is a very unique property that, until this time, has only been found in embryonic stem cells.”

Losordo together with Dr. Young-sup Yoon, led the team of researchers whose findings demonstrating the unique properties of these cells were published in the Feb. 1 issue of the Journal of Clinical Investigation.

Caritas St. Elizabeth’s Medical Center is the flagship hospital of the Caritas Christi Health Care System and a teaching hospital of the Tufts University School of Medicine.

Reviewing the study for The Pilot, Father Tadeusz Pacholczyk, director of education at the National Catholic Bioethics Center in Philadelphia, characterized the researchers’ findings as “very exciting.”

“It shows that there is a higher degree of flexibility in adult stem cells than many have thought in the past,” he said.

According to Father Pacholczyk, supporters of embryonic stem-cell research have long argued that adult stem cells were not as flexible as embryonic stem cells, thus making them less useful in repairing or healing damaged tissues and cells in the body.

“What appears novel about this report is that they have carefully derived a single cell type from the bone marrow, which can be expanded and used to flexibly generate a number of tissues,” explained Father Pacholczyk.

“Adult stem cells are incredibly powerful,” he added.

Stem cells have a number of unique properties not found in other cells types. They can divide and renew themselves over a long period of time and, while they are unspecialized in their structure, they have the ability to generate into specialized cells for specific tissues.

Currently, there are two different types of stem-cell research taking place — using embryonic and adult stem cells.

Adult stem cells can be found within tissues and organs, including bone marrow, the brain, blood vessels, peripheral blood, skin and the liver. Embryonic stem cells are found only in embryos. In order to harvest these stem cells, a human embryo must be destroyed.

“Adult stem cells have already been successfully used in human therapies for many years,” Father Pacholczyk stressed. “To date, no therapies in humans have ever been successfully carried out using embryonic stem cells.”

“The findings reported in Dr. Losordo’s study is but another affirmation that we don’t have to invest hundreds of thousands on dollars on something that is purely speculative, not to mention morally questionable,” he added.

Losordo and Yoon led the pre-clinical study in which researchers extracted stem cells from human bone marrow and transplanted them into the damaged hearts of rats. The stem cells induced cardiac regeneration, including the growth of new muscle and blood vessels in the heart. In addition, the researchers demonstrated that this specific subpopulation of stem cells has the capacity to develop into all types of cells, including those that make up the glands, digestive tract, hair, skin, nails, brain, nervous system and muscle.

While previous research has been conducted with rat or mouse bone marrow stem cells, this is the first study to show how human bone marrow stem cells can be used in the generation of various tissue types. Losordo and his team at Caritas St. Elizabeth’s are planning to conduct further pre-clinical research with this subpopulation of stem cells. If the findings confirm their hypothesis, they will seek to begin Phase I clinical trials with human patients.

 “In the future, we may be able to extract stem cells from a patient’s bone marrow to repair a wide variety of damaged tissue in his or her body. Furthermore, by growing tissue from a patient’s own stem cells, we could overcome issues related to cell therapy, such as tissue rejection,” said Losordo.