A novel method which can aid in the multiplication of adult stem cells, yielding a 30 fold enhanced harvest has been discovered. This finding could eventually pave way for the development of refinement in bone transplantation and gene therapy techniques.
The use of adult stem cells is encouraged to a great extent as it is associated with less ethical concerns and surpasses the utilization of human embryos, generated for reproductive purposes. However, a number of scientific challenges have to be overcome before these cells can be maximally exploited.
Technical aspects related to the isolation and in-vivo culture of adult stem cells is still in its infancy. Signals that induce the differentiation of adult stem cells into are poorly understood. The limited availability of adult stem cells in human tissues is also a major limiting factor.
The researchers of the present study were determined to develop an effective mechanism to accelerate the multiplication process following isolation from tissue. Hematopoietic stem cells (derived from fetal tissue of mice), capable of giving rise to blood cell components and cells of the immune system were taken up for the study.
The researchers were able to identify a specialized group of cells (different from stem cells) from the isolate. The stem cells were found to be dependent on the newly discovered cells for their growth and multiplication. The stem cells died when they were placed in an environment devoid of these cells. Based on this striking observation, the researchers began to look for specific gene expressions that were active in the new cell population.
It was hypothesized that such genes could code for growth factors or other similar substances, critical for stem cell growth and multiplication. The researchers employed microarray technique to locate such genes. One such identified component was Insulin like growth factor (IGF-2). A 8-fold increase in the stem cell population was observed when the hematopoietic cells were mixed with purified IGF-2.
Abundant expression of two other factors called Angiopoietin-like 2 (angpt12) and Angiopoietin-like -3 (angpt13) were also found. When these components were mixed with IGF-2, a 30-fold increase in the stem cell multiplication could be seen.
Stem cell therapy in the form of bone marrow transplantation remains a viable, life-saving option for patients with hematological malignancies. The stem cells can either be obtained from the bone marrow or even cord blood, though the latter is most commonly used. If this finding can be applied to the isolate, then perhaps, we could have adequate stem cells to treat a particular patient.
Gene therapy is yet another area, where the above finding can be useful. Issues related to the possibility of carcinogenesis as a consequence of gene therapy has to a large extent restricted the approval of any gene-therapy clinical trials.
The study has led to an improved understanding of the stem cell biology, stem cell therapy and research. The researchers are further interested in knowing whether similar results can be obtained for human cord blood as well.