New progress in U.S. skin stem cell research

November, Professor Yamanaka, a scientist at Kyoto University in Japan, made "induced pluripotent stem cells" (iPS) from human skin cells, an achievement that many industry experts called the greatest medical achievement of 2007In a December 23 paper published in the journal Nature, U.Sscientists said they took the results one step closer by using the same four genes as Professor Yamanaka to directly extract fetal lung and skin cells, newborn skin cells andhealthyskin cells from volunteersAs an early cell, stem cells can differentiate 220 different cells in adultsMedical researchers hope to one day grow these cells into tissues in laboratory dishes to replace organs damaged bydiseasesor accidentsProfessor Yamanaka's team used the retrovirus to import four genes into skin cells in mice and adults, causing them to lose their differentiation characteristics and become "induced pluripotent stem cells."The team, led by George Daley of the children'sHospital
in Boston, Massachusetts, used a similar approach to obtain stem cells from more types of skin cells, using gene reprogramming techniques to implant a set of four genes into skin cells that would enable them to function as embryonic stem cellsIn addition, the researchers found that the cancer gene called C-Myc was not used in the manufacture of stem cells, in line with Professor Yamanaka's December studyDaley said they used skin cells extracted directly from volunteers to conduct the study, compared with two previous research teams that used specialized human skin cells cultured in the labDaley says that while it may seem like a small difference, their latest results suggest that it is possible to extract skin cells from anyone for "skin stem cell" research The researchers say the results are important and mark another step toward "individualized" stem cells, in which the stem cells transplanted to patients are identical to their own genetic code, so they do not trigger a rejection by the body's immune system But the researchers stress that before induced pluripotent stem cells are proven to be safe and effective and can be used to grow supplementary tissue, their research faces many obstacles, so a way to avoid potentially harmful genetic modifications will be needed before the clinical application of pluripotent stem cells can begin One of the goals worth trying is to find a biochemical agent to replace gene penetration in the process of inducing pluripotent stem cells (Xu Wei)