“Latest Stem Cells News”

About five years ago, Professor Janet Sawicki at the Lankenau Institute in Pennsylvania read an article about nanoparticles developed by MIT’s Daniel Anderson and Robert Langer for gene therapy, the insertion of genes into living cells for the treatment of disease. Sawicki was working on treating ovarian cancer by delivering — through viruses — the gene for the diphtheria toxin, which kills tumor cells (…)

Gregg Semenza, M.D., Ph.D.

Blood vessel blockage, a common condition in old age or diabetes, leads to low blood flow and results in low oxygen, which can kill cells and tissues. Such blockages can require amputation resulting in loss of limbs. Now, using mice as their model, researchers at Johns Hopkins have developed therapies that increase blood flow, improve movement and decrease tissue death and the need for amputation. The findings, published online last week in the early edition of the Proceedings of the National Academy of Sciences, hold promise for developing clinical therapies.

“In a young, healthy individual, hypoxia — low oxygen levels — triggers the body to make factors that help coordinate the growth of new blood vessels but this process doesn’t work as well as we age,” says Gregg Semenza, M.D., Ph.D., professor of pediatrics and genetic medicine and director of the vascular biology program at the Johns Hopkins Institute for Cell Engineering. “Now, with the help of gene therapy and stem cells we can help reactivate the body’s response to hypoxia and save limbs.”

Previously, Semenza’s team generated a virus that carries the gene encoding an active form of the HIF-1 protein, which turns on genes necessary for building new blood vessels. When injected into the hind legs of otherwise healthy mice and rabbits that had been treated to reduce blood flow, the HIF-1 virus treatment partially restored blood flow.

People with diabetes have a 40 times higher risk of losing a limb to amputation, says Semenza. To find out if HIF-1 gene therapy could improve blood flow in a diabetic animal, the team then tested the same virus in diabetic and non-diabetic mice that had blood flow cut off to one hind leg. Twenty-one days after treatment, the HIF-1 virus-treated mice had 85 percent recovery of blood flow compared with 24 percent in the mock-treated mice. And, treated, diabetic mice had much less tissue damage compared to the untreated diabetic mice. These results were reported in the Nov. 3 issue of the Proceedings of the National Academy of Sciences.

Scientists are one step closer to creating a gene therapy/stem cell combination to combat genetic diseases. With work, this research may lead to not only curing the disease, but also repairing the damage left behind.

While gene therapy is a burgeoning field that has shown great results in treating genetic disorders, many of those diseases leave behind heavily damaged tissue that the body is unable to repair. So even if the disease is completely eradicated, quality of life may not necessarily improve, and without help, health can still continue to deteriorate.

Since stem cell research began, there has been a hope that use of those cells may help alleviate some of the trauma left behind by genetic diseases. While the theory has been shown to work in mice, this is the first time a human cell line has confirmed that it is possible the therapy will work for humans as well.

Researchers at the Salk Institute for Biological Studies in La Jolla, California, chose to focus on Fanconi anemia (FA), a genetic disorder that is characterized by short stature, bone marrow failure, irregularities in blood cells that can lead to clotting, and an increased risk of leukemia. Even after gene therapy and “bone marrow transplants to correct the hematological [blood] problems, patients remain at high risk of developing cancer and other serious health conditions.”

The Nature-published technique employed by Juan-Carlos Izpisúa Belmonte’s team was two-fold. First, they collected hair and skin cells from those suffering from FA. These types of cells are known as somatic cells, and can be used to create induced pluripotent stem (iPS) cells. Once a hair cell has been transformed into an iPS cell, it can be coaxed to differentiate into virtually any cell in the human body.

Maria Grazia Roncarolo

It was stunning to see them closed inside of those plastic bubbles, kept far from all external contact because their immune system does not react against any foreign antigens. Today scientists can say that ADA-SCID (adenosine deaminase deficiency), a serious combined immunodeficiency caused due to a lack of the adenosine deaminase enzyme, has been definitively defeated by gene therapy developed at San Raffaele of Milan.

The final study, which combined the conclusions of clinical studies, which began in 2000 on strategic therapies developed by the HSR-TIGET (San Raffaele Telethon Institute for Gene Therapy) group, led by Maria Grazia Roncarolo and Alessandro Aiuti, and was published in the New England Journal of Medicine.

It was stunning to see them closed inside of those plastic bubbles, kept far from all external contact because their immune system does not react against any foreign antigens. Today scientists can say that ADA-SCID (adenosine deaminase deficiency), a serious combined immunodeficiency caused due to a lack of the adenosine deaminase enzyme, has been definitively defeated by gene therapy developed at San Raffaele of Milan.

The final study, which combined the conclusions of clinical studies, which began in 2000 on strategic therapies developed by the HSR-TIGET (San Raffaele Telethon Institute for Gene Therapy) group, led by Maria Grazia Roncarolo and Alessandro Aiuti, and was published in the New England Journal of Medicine.

It has been about 8 years since Salsabil, the first Palestinia baby suffering congenital immunodeficiency (Ada-Scid), has been healed using gene therapy. And it has been about 7 years since her story to Abdul Rahim’s one, a Pakistani baby born in the end of 2006 in Qatar.
His parents did lose 3 children because of Ada-Scid, and Abdul’s case is one of the most symbolic.
Just after his birth doctors did diagnose his illness and succeeded to healt his pneumonia during his first days of life.
So Abdul’s parents and doctors who were follow him contacted the San Raffaele Telethon Institute for Gene Therapy (Hsr-Tiget), starting files to bring him in Italy.