New Post (71) : Science and Ethics of HESC and iPSC research.
Human embryonic stem cell (HESC) research offers much hope for alleviating the human suffering brought on by the ravages of disease and injury. HESCs are characterized by their capacity for self-renewal and their ability to differentiate into all types of cells of the body. The main goal of HESC research is to identify the mechanisms that govern cell differentiation and to turn HESCs into specific cell types that can be used for treating debilitating and life-threatening diseases and injuries. Despite the tremendous therapeutic promise of HESC research, the research has met with heated opposition because the harvesting of HESCs involves the destruction of the human embryo.
((( HESCs are derived in vitro around the fifth day of the embryo's development (Thomson et al. 1998). A typical day-5 human embryo consists of 200-250 cells, most of which comprise the trophoblast, which is the outermost layer of the blastocyst. HESCs are harvested from the inner cell mass of the blastocyst, which consists of 30-34 cells. The derivation of HESC cultures requires the removal of the trophoblast. This process of disaggregating the blastocyst's cells eliminates its potential for further development. )))
Opponents of HESC research argue that the research is morally impermissible because it involves the unjust killing of innocent human beings.
Scientists recently succeeded in converting adult human skin cells into cells that appear to have the properties of HESCs by activating four genes in the adult cells (Takahashi et al. 2007; Yu et al. 2007). The reprogrammed cells — “induced pluripotent stem cells” (iPSCs) — could ultimately eliminate the need for HESCs.
However, at present, the consensus in the scientific community is that both HESC and iPSC research should be pursued, as we do not yet know whether iPSCs have the same potential as HESCs or whether it is safe to transplant them into humans.
Thus, the controversies around HESC research will continue, at least in the near-term.
Charlie Brown
