Stem cells are very important subjects of research in 21st century medicine and biotechnology. Of all types of stem cells, embryonic stem cells (ESC), because of their strong ability at self-renewal and differentiation, are expected by international scientific circles to develop into various kinds of terminal products. Research evidences indicate that most cells types in the human body, including cardiomyocytes, pancreatic cells, neuronal cells, and germ cells can be derived from the differentiation of human embryonic stem cells. Therefore, ESC plays an important role in biology, toxicology, pharmacology, and the implantation of human organs. Especially in cell-based therapies, ESC can be an important source of cell supply.
Up to the end of 2006, reports about human embryonic stem cells developing into germ cells were few and far between. The only exception was a report by Clark et al in 2004. Clark and his team proved that through the formation of embryoid bodies hESC could express germ cell markers. Clark and his team, however, did not actually observe the formation of oocyte or sperm.
The National Taiwan University Hospital research team, on the other hand, utilized their self-cultivated hESC lines (NTU1 and NTU2) and observed the differentiation of these hESC cells into cells expressing germ cell specific markers. Most interestingly, follicle-like structures could also be observed in some of these cells. It is expected that continuous study by the NTU team will likely provide further useful information and techniques into future application in the treatment of infertility and habitual abortion.
In addition, if functional eggs can be produced, they can also become ovum donors for somatic cell nuclear transfer. Dr, Hsin-fu Chen, Assistant Professor at NTU's Graduate Institute of Clinical Medicine, and his team members are committed to the reproducibility of experiment with a view toward increasing the efficiency of the growth of the oocyte, confirming its biological function and its degree of meiosis, and follow-up animal transplantation studies to see whether human embryonic stem cells can help ovarian regeneration.
NTU's research group include members from the Obstetrics Department, the Pathology Department, the Institute of Clinical Medicine, and the Institute of Anatomy and Cell Biology. Academia Sinica's Institute of Cellular Biology also participated in the research process and offered tremendous help. In addition to the glorious achievements mentioned in preceding paragraphs, this research team has recently been able to cultivate hESC cells into heart cells. This type of newly developed heart cells have a more concerted ability at beating and contraction, and a better rate of growth.
The achievements of NTU's research team won the honor of becoming the cover story of the February issue of the internationally acclaimed medical journal "Human Reproduction".
Dr. Hsin-fu Chen, Assistant Professor of NTU's Institute of Clinical Medicine
hESC developing into a follicular structure