Stem Cell Research

Stem cells have great potential in basic research and are being slowly integrated into toxicological research. This symposium provided an overview of the state of the field, stem cell models, described allogenic stem cell treatments and issues of immu- nogenicity associated with protein therapeutics, and tehn concentrated on stem cell uses in regenerative medicine focusing on lung and testing strategies on engineered tissues from a pathologist's perspective. There are numerous potential benefits of stem cells for the treatment of human disease, and these range from oncologic therapeutics to manipulation of the immune system response, the ability to individually tailor treatments to the specific per- son's genetic haplotype, and the possibility of replacing dis- eased organs and tissue with genetically engineered materials. Such therapeutic promises demonstrate the importance of this relatively new area of investigation. Stem cells are also being used to study the underlying pathophysiological mechanisms of various diseases, the differences in disease manifestation between individuals, and the replacement of some animal testing by in vitro assays. This symposium highlighted areas where stem cell research could advance the understanding of human health issues and addressed some of the issues that pathologists face when trying to evaluate the use of stem cells in animals and devices. An overview of the state of regenerative medicine was offered by Alan Trounson, past President of Californian Insti- tute of Regenerative Medicine. The talk entitled ''Where is the Field of Regenerative Medicine Going?'' stated that stem cell research has changed the landscape for regenerative medicine by showing that stem cell assays and directed differentiation protocols can derive cells that are capable of repair of damaged and diseased tissues. The assays facilitate identification of can- cer stem cells that are now enabling new drugs, monoclonal antibodies, and engineered cell therapies that can search and destroy dangerous metastasizing cancer stem cells. Develop- ments in stem cell engineering also enables cure of genetic diseases by introducing true copies of genes to replace mutated gene sequences causing disease. The stem cell engineering also enables the manipulation of the immune system and the donor cells, removing alloreactive antigens and the elimination of reactive T cells. Furthermore, mutation or knockdown of key viral receptor genes will prevent blood cell infection with HIV. Such technologies are now undergoing trials as a cure for HIV/ AIDS. Embryonic stem cell derivatives are also entering trials for reversing blindness and type 1 diabetes and it is expected that induced pluripotent stem cells (iPSCs) will enter clinical trials for eye disease. Fetal and embryonic stem cells are being