Continued Improvement in iPS Cells
Researchers continue to rapidly improve the technology of production for induced pluripotent stem (iPS) cells: a "research team has discovered a more efficient way to create [iPS] cells, derived from mouse fibroblasts, by using a single virus vector instead of multiple viruses in the reprogramming process. The result is a powerful laboratory tool and a significant step toward the application of embryonic stem cell-like cells for clinical purposes such as the regeneration of organs damaged by inherited or degenerative diseases ... Prior research studies have required multiple retroviral vectors for reprogramming - steps that depended on four different viruses to transfer genes into the cells' DNA - essentially a separate virus for each reprogramming gene ... Upon activation these genes convert the cells from their adult, differentiated status to what amounts to an embryonic-like state. However, the high number of genomic integrations - 15 to 20 - that typically occurs when multiple viruses are used for reprogramming, poses a safety risk in humans, as some of these genes [can] cause cancer. ... The major milestone [was] combining the four vectors into a single 'stem cell cassette' containing all four genes. The cassette (named STEMCCA) [was] able to generate iPS cells more efficiently - 10 times higher than previously reported studies."
Link: http://www.eurekalert.org/pub_releases/2009-01/bu-cas010709.php