Graft-Versus-Host-Disease News

Graft-Versus-Host-Disease News

Several forms of cancer are treated with blood stem cell transplants. When the donor is unrelated to the patient, the patient frequently develops graft-versus-host-disease (GVHD), in which the stem cells attack healthy cells as well as cancerous ones. Researchers have shown that removing the immune cells (T-cells) from the stem cell transplant reduces the risk of acute GVHD, though it does not reduce the incidence of chronic GVHD. The study is reported on the Cancer Consultants website.

So here we see a situation where the body’s immune system response makes the use of adult stem cells problematic. Removing the T-cells helped with the worst forms of the GVHD, but not overall with the condition. This suggests that adult stem cell transplants from genetically dissimilar individuals are not going to be a problem-free cure to caner anytime soon, and research needs to continue on several fronts. Embryonic stem cells seem promising, but I do wonder if cells cloned from the individual with cancer would be cells likely to develop into cancers themselves; the etiology of the cancer is a key component to effective stem cell treatment.

Bone Marrow Stem Cells Heal Hearts

Bone Marrow Stem Cells Heal Hearts

Researchers in Düsseldorf, Germany have shown that bone marrow stem cells transplanted into 18 patients with prior heart attacks had improvement in ventricular function and exercise capacity, and the heart muscle damage shrank. The study will appear in the November 1 issue of the Journal of the American College of Cardiology. A release is available from EurekAlert.

In the study, the scientists extracted bone marrow from the patients’ own hip bones and infused them into the coronary artery months or years after the heart attack occurred. Prior studies have shown that injection of stem cells into the heart shortly after a heart attack improves healing, but this was the first to try the procedure after large amounts of time had elapsed. Global left ventricular function increased by 15%, infarction wall movement velocity rose 57% (that essentially means that the heart was able to function better as a muscle), and the infarct size, or damaged area, decreased 30%.

With stem cells derived from the patients’ own hip bones, there is no risk of rejection by the body.

The study was a small group of only 18 patients with no control group or double-blinds, so it is not entirely conclusive. However, larger and more controlled trials are underway. Other physicians who were not involved in the study looked on the results as promising.

The more I hear about bone marrow stem cells and heart attacks, the better the news looks for people who have had heart attacks. The results of this study suggest that patients whose health is too poor to undergo a bone marrow harvesting and injection at the time of the cardiac arrest could still benefit from the procedure when they are healthier.

More Signaling Molecule Info

More Signaling Molecule Info

Yesterday I reported on the study showing how the Smoothened protein molecule worked with Hedgehog molecules to provide instructions to embryonic cells. Now scientists at the Salk Institute for Biological Studies have isolated a molecule which controls adult stem cells in mouse brains.

The Newswise press release says that researchers have identified the molecule, Wnt3, which tells stem cells to become nerve cells—neurons—rather than other types of brain cells known as astrocytes or oligodendrocytes. The astrocytes around the stem cells secrete Wnt3 to instruct the stem cells to differentiate into neurons. When the scientist blocked the production of Wnt3, the amount of new neural cells decreased significantly, and when they added it, the number of neurons increased. The cues which tell the astrocytes to secrete Wnt3 are still unknown.

According to the press release,

Many investigators have begun to explore the potential use of neuronal stem cells for the repair of circuits damaged by traumatic injury or degenerative disease, such as Parkinson’s, stroke, epilepsy and Alzheimer’s disease and well as depression. Identifying the molecular instructions that push neuronal stem cells down a certain path of specialization is a first step towards generating exactly the cell types needed to replace lost brain cells.

A short UPI version of the story is available on the Monsters And Critics website. The original article appears in the journal Nature. Again, this does not lead to any new treatment options, but the more known, the better.