In the Know: Stem cells

Stem cells are the foundation of every organ, tissue and cell in the human body that do not yet have a specific physiological function but have the potential to develop into many different cell types.

They are also distinguished from other cells by their ability to self-

renew. Stem cells divide and give rise to more stem cells. When a stem cell divides, each new cell has the potential to either remain as a stem cell or become another type of cell with a more specialized function, such as a muscle cell, red blood cell or brain cell.

According to the National Institutes of Health’s Center for Regenerative Medicine, scientists primarily work with two kinds of stem cells—embryonic stem cells and nonembryonic “somatic” or “adult” stem cells.

Embryonic stem cells are obtained from the inner cell mass of a blastocyst, the ball of cells formed when the fertilized egg or zygote divides and forms two cells (then again to form four and so on). It can divide almost indefinitely and can give rise to every cell type in the body.

Adult stem cells, on the other hand, are found in differentiated tissues and organs throughout the body and contribute to the maintenance and repair of organs.

Stem cells offer the possibility of replacement cells to treat a wide variety of diseases and disabilities, including diabetes, neurological disease, cardiovascular disease, blood disease and many other conditions.

According to the Harvard Stem Cell Institute (HSCI), embryonic stem cells have not yet been used to treat diseases in humans, “but progress has been made in the introduction of the first clinical trial using embryonic stem cells in the area of treating spinal cord injury.”

Adult stem cell-based therapies have been used to treat diseases in humans for over 40 years in the form of bone marrow transplants, according to HSCI. These are used to treat leukemia, lymphoma and inherited blood disorders.

In March, the Department of Health released implementing rules and regulations that cover stem cell and cell-based therapy to prevent abuses and dubious practices.

Health Secretary Enrique Ona said the rules restricted the use of genetically altered stem cells and tissues of human adults and the umbilical cord, fat-derived human stem cells and live animal stem cells.

The rules also prohibit the creation of human embryos and their derivatives, the use of aborted human fetal stem cells and their derivatives, and plant parts labeled as stem cells for human treatment and research, Ona said.

A number of politicians have been reported to have used stem cell therapy, including former President Joseph Estrada, Sen. Juan Ponce Enrile and former Sen. Ernesto Maceda.

In April, during the election campaign, Maceda credited his good health to stem cell therapy.

“I am now convinced that my stem cell therapy is effective and that’s the reason why I’ve been able to keep up with the rigorous campaign schedule,” he said. “I feel 20 years younger.”—Inquirer Research

Sources: hsci.harvard.edu, crm.nih.gov, Inquirer Archives