Stem cell research is another polarizing topic of late. I definitely think that people are intentionally under-informed on this subject. Perhaps if the details about stem cell research, including embryonic stem cell research are more clear, those supporting this area would not be instantly vilified. I will first say that all life must be treated with respect, whether it be human, canine, porcine, or a single cell.
As always, we have to start by introducing some terminology.
Multipotent progenitor cells - Cells that have the ability to develop into several other cell types, all of which are closely related. A good example is the blood stem cell that can develop into cells like red blood cells, platelets, T-cells, B-cells, etc.
Pluripotent progenitor cells - Cells that have the ability to differentiate into a large range of cell types. It is now commonly accepted that pluripotent cells can develop into any cell that is included as part of the embryo, i.e. organ tissue, bones, nervous system.
Totipotent progenitor cells - A cell that can produce all cell types needed to develop a fetus, including extra-embryonic tissue like the placenta.
The hope of stem cell research, is to take a multipotent or pluripotent stem cell and guide it to develop into a desired cell type. These cells can then be used to replace or repair damaged cells in the body. For example, a person with Type I diabetes might benefit from having stem cells developed into new, functioning pancreatic cells that can be placed to compensate for these patient's lack of insulin production. Amazing! One current limitation is that we can not take a multipotent stem cell, like a blood stem cell, and make it develop into a non-blood cell tissue like pancreatic tissue. Only a pluripotent stem gives us that power.
Where can we get multipotent stem cells? Some can be harvested from the umbilical chord, some from bone marrow, and some from fat. There is even a small amount of pluripotent stem cells available from these tissues.
If we can obtain pluripotent stem cells from adults, or non-embryonic sources, then why would we want to use embryonic stem cells? First off, the potency of non-embryonic is often limited, second, cells differentiated form adult stem cells often have shorter life times, or fail in transplantation. Embryonic stem cells (ESC) are truly pluripotent, and cells derived from ESC progenitors currently display superior performance at their relative function. That doesn't mean we abandon adult stem cells, it only means that we must continue to compare the function and potency of cells from all sources. In fact there is research currently investigating the potential of turning multipotent stem cell into a pluripotent one.
The controversy of ESC research I believe is mainly a result of false links to abortion. I do not know of ANY embryonic stem cell line that has come from an aborted fetus. The vast majority of ESC lines are the result of in-vitro fertilization. That is, the combination of sperm and egg outside the body, and chemical stimuli to induce proliferation. Despite all of the scientific advances, this cluster of cells will not, can not, develop into a human being.
The essential missing component of life is the womb. From a biochemical standpoint, the womb is a complex relationship between mother and fetus that can not be replicated in the lab. From a religious standpoint, the womb is the vessel of mankind. I find it very significant that Heavenly Father would so choose to introduce his Only Begotten into the world after being harbored in this consecrated manner.
As the cells for embryonic stem cell research have never been introduced into the womb, I must maintain that it is not parallel to abortion. If the manipulation or destruction of cell clusters from in-vitro fertilization is murder, then how should we feel about any other tissue that is of human origin? Should we preserve fat after liposuction? Should we protect the rights of an appendix? I am not devaluing life. I am just pointing out that a group of cells should be treated as such. The benefits and promise of stem cell research are magnificent, and I support the harvasting and culture of cells from all sources, save aborted children. Do not confuse embryonic stem cell research with abortion, the two could not be more different.
Simply put, stem cell research seeks to improve and preserve life.