Archive by category | Reprogramming/Pluripotency

Human iPS cells without genetic integration: Six reprogramming factors, a plasmid, and a holy grail

For the first time, human skin cells have been reprogrammed to pluripotency without requiring genetic elements to insert themselves into the reprogrammed cells. Though so-called induced pluripotent stem cells promise to be as powerful as embryonic stem cells in their ability to differentiate into all cell types, standard techniques use viruses to insert multiple copies of reprogramming genes into the cells; this makes the cells less predictable, and it creates a higher risk of a cancerous growth. As a result, many laboratories have been racing to publish techniques to reprogram cells without permanent genetic modification.  Read more

What a week for iPS! Human cells reprogrammed with genes that can take their leave

The bogey of making cells that behave like embryonic stem cells has been genetic engineering: so far, reprogramming human cells has required permanent genetic modification, a fact that raises worries of increased cancer risk and unpredictability.  Read more

Reprogramming with all but Oct4

There’s a paper just out in Cell today moving researchers closer to reprogramming without adding oncogenes. Sure, it starts with a cell type that’s not readily accessed in humans, but it does indicate that the cell type could matter. Also of interest should be a paper that was published in Cell last week, which compared where the four Yamanaka factors are binding in fully reprogrammed cells, partially reprogrammed cells, and fibroblasts. (See how the four factors reprogram)  … Read more

Double-locking against gene expression in embryonic stem cells

Here’s a research highlight that will appear soon on Nature Reports Stem Cells. This version has the addition of outside comment. It came in too late to be incorporated into the highlight, but I’m putting it here because I think it’s interesting.  Read more

Pluripotency without viruses or embryos

Ever since human cells were reprogrammed to behave like embryonic stem cells, a large group of scientists have said confidently that the feat can be accomplished without modifying the genome. Just this week, there has been a flurry of papers showing advances. Perhaps getting the most press are reports that biopsies from testes can be reprogrammed to pluripotency without any genetic modification at all.  Read more

Ian Wilmut’s move from cloning: getting practical with iPS

The scientist that helped clone Dolly the sheep has moved away from cloning and toward making embryonic-like stem cells without eggs. The shift is described in an article and interview in Scientific American. Wilmut (and others) think that iPS cells might one day replace ES cells for clinical applications and drug-testing applications, but no one thinks that day is now here. Bits of the SciAm articles are floating around the blogosphere, but these (willfully?) strip away some of the nuances, so it’s worth reading the full articles from the source. I also think that the article conflated and neglected a few ideas, which I’ll outline below.  Read more

Old stem cells made young; more maps of pluripotency

Once again, there are more great papers out there than I can write about. Below are two that will show up on the site in a few days. (Nature Reports web production schedule requires a week). Also check out Tom Zwaka’s paper that finds another, powerful control over Nanog; Sheng Ding shows that small molecules can substitute for two of the four Yamanaka factors, inching closer to reprogramming without viruses; in a high-throughput screen, Lorenz Studer shows us how known drugs affect human embryonic stem cells, a technique that might reveal unwanted side effects. (Those are all in the most recent Cell Stem Cell; see our Q&A with Sheng Ding on the potential of small molecules.)  … Read more