Stem Cells can Reduce the Side Effects of Radiation Therapy
Researchers have announced that a treatment with adult stem cells can reduce the side effects of radiation therapy in mice and rats.
Numerous presentations at the 25th Annual Congress of the European Society for Therapeutic Radiology and Oncology (ESTRO) show that tissue damaged by radiation heals faster after stem cell therapy.
"Stem cell research will have many consequences for various fields of medicine", predicts Catherine Verfaillie, Director of the Stem Cell Institute of the University Leuven (Belgium), in a review lecture during the Presidential Symposium of the ESTRO conference on October 9.
For example, stem cells that settle in the organ systems could be stimulated and then repair tissue damage.
Radiation therapists have been following this track for some time in various projects that are presented at the ESTRO conference.
Rob Coppes of the University Groningen (The Netherlands) presents an EU-sponsored international undertaking at the conference, which is called the "FIRST Project" for short. (FIRST stands for "further improvement of radiotherapy through side effect reduction by stem cell transplantation").
The researchers have discovered that the side effects of a radiation therapy on various healthy tissues, such as skin and mucosa, can be reduced by treatment with adult stem cells.
The stem cells migrate to the radiated tissue and support its regeneration. If studies confirm that this stem cell effect also occurs in humans, this would expand the treatment options for tumours because currently valid radiation dosage limits could be surpassed.
For instance, a radiation-biological research team led by Wolfgang Dorr of the Clinic for Radiation Therapy and Radiooncology at the Technical University Dresden reports that adult stem cells can reduce the side effects of radiation therapy on the mouth mucosa in mice.
The scientists observed that the radiation tolerance of the mucosa was clearly increased if the animals received a bone marrow transplant prior to or during a fractionated radiation - during which adult stem cells are also transferred practically automatically.
A comparable effect was also observed by the scientists when they lured the stem cells from the bone marrow of the radiated animals into the blood circulation by injecting a growth factor, called G-CSF for short.
Mesenchymal Stem Cells Protect:
A team led by Dr. Michèle Martin of the Service de Génomique Fonctionnelle from Evry (France) also reports on studies in mice.
The researchers had treated the animals with a radiation dose that led to tissue damage of the skin within three weeks.
Without treatment, it took eight weeks until this damage had healed. Part of the mice was injected by the researchers with human mesenchymal stem cells 20 hours after the radiation exposure.
The stem cells were adult stem cells from, e.g., the bone marrow that can differentiate into fat, cartilage, tendon, skin or muscle cells.
The scientists noted that the skin damage in the treated animals healed faster and better than in the untreated animals.
In addition, the scientists examined tissue samples from the damaged skin areas.
The stem cells - so the result - had indeed migrated to the radiated skin regions. As Martin reports, their morphology was similar to that of the epithelium.