Well, I had no intent to write this infrequently but time sure slips away. I spent a lot of time studying for the LSAT (took it last week), which means that I got behind in all my work, and so it goes. So here are some very short synopses of research developments over the last few weeks.
Researchers at the University of Missouri have been able to derive five different types of cells from adult stem cells in pig blood, bone, blood vessel and nerve cells. The adult cells gave no indication of tumor formation. The technique involved isolating the stem cells and exposing them to different chemicals. The study also made use of a fluorescent gene marker to track the cells as they developed when they were re-inserted into a pig’s body. Press Release. In another study, researchers at Northwestern University were able to make a new cell from human blood stem cells: “human megakaryocytes (bone marrow cells that produce blood platelets that are responsible for blood clotting) derived from adult hematopoietic stem cells were, for the first time, reprogrammed into neutrophil-like cells similar to the white blood cells that are responsible for fighting infections.” Press Release.
The small heart stem cell trial taking place in Australia is showing success. Researchers said that patient have had improvement ranging from 10-60% in their heart functioning. The stem cells were separated from the patients’ blood and reinjected. Very short article on ABC. There were similar studies in Europe with different results, according to Forbes: a German team showed that patients who received the injections had 5.5% increase in function, compared to 3% for those who did not, and that they suffered fewer second heart attacks. Another German study had similar results. Both are notably less than what the Australians are claiming. Further, a Norwegian trial of 100 patients did not give any evidence of improvement. Researchers quoted said that research must go on, but this is not a therapy yet. See also the Mercury News.
Researchers have used human embryonic stem cells to slow vision loss in rats with a disease similar to of macular degeneration; the stem cells took the place of failing retinal cells, and the rats that received the stem cells had twice the visual acuity of the control group 40 days later. 18 different stem cell lines, including the federally approved ones and private ones, were used, with identical effects. This is good news for rats—it is less certain if this would work in people, since macular degeneration is a uniquely human disease. Washington Post.
The Batten Disease trial is about to get started, with one patient receiving treatment and the others receiving it thirty days later if there are no safety issues. This is a rare but horrible disease which slowly deprives children of motor function, speech, sight, communicative ability, and then they die. I really hope this works. Forbes.
You’ve probably already heard about this one, but researchers have been able to obtain stem cells from non-viable human embryos. Press release. This has of course not solved any ethical controversy—how do you know an embryo is dead? And even if it is, do you want to get cells from it? The chance of abnormality or genetic mutation is probably higher in an embryo that does not sustain itself. Seems to me that this might be useful for studying specific diseases but does not offer much that is not otherwise available. Houston Chronicle (Washington Post story).
Canadian researchers have used a monoclonal antibody developed in France to halt or cure acute myeloid leukemia in mice. The drug blocks a particular protein on the surface of a cancerous stem cell, thus preventing the cell from moving around and achoring itself anywhere in the body. Nowhere to settle, no more cancer cells to spawn. The researchers estimate it is at least 5-10 years before a trial could even be considered in humans. CBC. One should remember that the drug that caused the nearly fatal reaction in six British men last spring was also a monoclonal antibody.
Researchers at the Universities of Connecticut and of Pittsburgh have successfully cloned mice from a differentiated cell, using a type of specialized white blood cell called a granulocyte:
Surprisingly, the granulocytes were the most efficient donor cells for nuclear transfer among the different lineage cells, with 35 to 39 percent becoming a blastocyst, an early embryo consisting of about 100 to 150 cells, compared to 11 percent for the progenitor cells and only 4 percent for the stem cells. Only the granulocytes were able to produce two live cloned pups, although both died within a few hours of birth. As a control, the researchers performed nuclear transfer using embryonic stem cells; 49 percent developed to the blastocyst stage and 18 cloned pups were born.
Prior attempts to used different types of regular cells in cloning have failed. Any resulting blastocyst from a mature cell has had to be combined with a fertilized embryo. (Is any embryo unfertilized?) This research implies that the animal clones that have succeeded may be due to adult cells in the tissue environment. This is a pretty significant development, and obviously a lot more research is needed. It does confirm that the standard nuclear transfer procedure from ESCs is still more successful than any alternatives. The fact that the two mice that were cloned to birth died almost immediately suggests that something in the cloning process from regular cells is inhospitable to mammals. Press release. There has been a lot of media play on this one—the BBC has a decent article.
Researchers at the Howard Hughes Medical Institute have found an off-switch for skin stem cells; turning on the transcription factor gene Tcf3 blocked the differentiation of all three types of mature cells that a skin stem cell can develop into. The primary use for this knowledge will probably be in research, since it has been hard to keep stem cells from differentiating.
Possible bad news for breast cancer victims; researchers at the University of Southern California have found that almost all tumor cells in the bone marrow of women who have breast cancer are stem cells. This suggests that the likelihood of metastasis for women who have differentiated breast cancer—tumors in the bone marrow, not just the breast tissue—lasts longer than previously thought, perhaps for the rest of a lifetime. A lot more research still has to be done, and I expect will with this kind of finding.
Finally, this is not research, but it is important—the WARF will not collect royalties on any stem cell research done (by universities or non-profits) with its cells in the state of Wisconsin. Because of the way the WARF works, that’s a pretty strong incentive. Companies that relocate will also be eligible for grant money from the state. Governor Jim Doyle is working hard to make the state a desirable place for stem cell researchers. Milwaukee Business Journal. And the US Patent and Trademark Office has decided to review the WARF patents. This is no big surprise—they review about 90% of the patents requested. The executive director of a patent foundation said that 70% of the reviewed patents are revoked or modified. Mercury News (AP Wire).
And there you have it. I don’t see any particular theme to this research except that so much is still unknown.