Back to the Archives—Stem Cells and Tumors

Back to the Archives—Stem Cells and Tumors

A year ago is old news in science these days, but sometimes even if it’s not “news,” it’s still interesting. An example of this is an AP article published nearly a year ago on Wired News about using stem cells to treat cancerous tumors in mice. A longer report on the study can also be found on Medical News Today.

In the research, which appeared in the Journal of the National Cancer Institute, scientists used a stem cell to encode the interferon beta gene. Interferon beta therapy can kill cancer cells but is highly toxic to the patient. When the stem cells were engineered to carry the interferon beta gene, they targeted the tumors directly and produced therapeutic proteins.

The stem cells in this case were mesenchymal stem cells, which are produced in the bone marrow and already work at healing wounds and forming scar tissue. Since tumors are made up in part of stomal cells, which are cells around a body opening, the stem cells “see” them as a wound and go directly there. In the study, mice treated with interferon beta stem cells lived 60 days, compared to 37 days for untreated mice and 41 days for mice treated with injections of interferon beta. No stem cells went to healthy organs.

At the time this study was published, the lead author, Michael Andreeff of the M.D. Anderson Cancer Center in Houston was hoping to get FDA approval for human clinical trials within a year. I was not able to find any more information on the current status of this, but there are 4 clinical trials currently recruiting for treatment with MSCs for other conditions. They can be found at Clinicaltrials.gov, a service of the NIH.

Bone Marrow Stem Cells Help Treat Liver Failure

Bone Marrow Stem Cells Help Treat Liver Failure

In a small study, three of 5 patients who received injections of stem cells from their own bone marrow had improved liver function and general health, according to physicians at the Imperial College London. The two patients who did not improve had no adverse reactions. The research was reported in New Scientist Magazine but is only available by subscription. A UPI story on the subject can be found at Monsters and Critics.

My conclusion—promising potential, but too small a sample for great excitement yet. Also, the liver is known to be able to regenerate much more successfully than other organs in the body (liver transplants can be done with a portion of a liver and not a whole liver), so I would be interested in knowing how much of the action of the stem cells was in differention to repair and replace damaged tissue, and how much of it might have been an effect of the cells secreting hormones and chemicals that aid in healing.

A few more details on hair stem cells

A few more details on hair stem cells

An article appearing in Pharmaceutical Business Review on-line gives a few more details on the rat hair study than I previously reported. The cells were injected into the skin of newborn mice, which was then grafted onto nude mice (mice which are genetically born without hair and are unable to mount most immune system responses). The stem cells formed 8 different kinds of other cells, including those of the outer root sheath, inner root sheath, the hair shaft, the sebaceous gland and the epidermis. 125 days later, a biopsy was taken from the graft and the process of cloning and culturing was repeated with the stem cells from that sample. Those cells also formed the various portions of hair cells.

Since the mice did not have an immune system response to the skin graft from the baby normal mice or to the presence of cells from another species, the issues of what sort of immune response a human body would mount remain unanswered.

Differentiated Neural Cells Have Long Life

Differentiated Neural Cells Have Long Life

Researchers at New York University’s Howard Hughes Institute of Medicine have shown that stem cells which differentiated into brain tissue in mice were still living at least a year later. In the study, the researchers examined how neural stem cells that had proliferated interacted with a protein called Shh (Sonic hedgehog). The Shh protein is a regulatory protein which controls gene activity during brain development and also plays a role in stem-cell self-renewal.

The mechanism of Shh’s action upon stem cells was unknown. The researchers labeled the neural stem cells in the adult mice so that they could tell which ones were responding to Shh at what time. They did not know whether the cells that responded were ones which were rapidly dividing or those which were in a quiescent stage, so they used a chemical to kill the quickly dividing cells. When the quiescent cells continued to respond to Shh signaling, it became clear that stem cells were still capable of self-renewal even after a year.

The study also showed that the neural stem cells differentiated to form neural cell types in addition to neurons. The research appears in this week’s journal Nature. Short articles on the study can be found on Physorg.com (a UPI story) and News-Medical.Net.