Scientists have generated human stem cells that in some respects mimic mouse naïve cells, but their dependence on the addition of several extrinsic agents, and their propensity to develop abnormal karyotype calls into question their resemblance to a naturally occurring "naïve" state in humans. Here, we report that a recombinant, truncated human NME7, referred to as NME7AB here, induces a stable naïve-like state in human embryonic stem cells and induced pluripotent stem cells without the use of inhibitors, transgenes, leukemia inhibitory factor (LIF), fibroblast growth factor 2 (FGF2), feeder cells, or their conditioned media. Evidence of a naïve state includes reactivation of the second X chromosome in female source cells, increased expression of naïve markers and decreased expression of primed state markers, ability to be clonally expanded and increased differentiation potential.
View Article and Find Full Text PDFWe report that a single growth factor, NM23-H1, enables serial passaging of both human ES and iPS cells in the absence of feeder cells, their conditioned media or bFGF in a fully defined xeno-free media on a novel defined, xeno-free surface. Stem cells cultured in this system show a gene expression pattern indicative of a more "naïve" state than stem cells grown in bFGF-based media. NM23-H1 and MUC1* growth factor receptor cooperate to control stem cell self-replication.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2011
Gold nanoparticles hold great promise for studying protein-protein interactions because of their intrinsic optical properties. Pink when in a homogeneous suspension, the solution turns blue-gray when particles are drawn close together, for example, when immobilized proteins specifically interact with each other. However, the nanoparticle stability, size, and method of protein attachment contribute to the unreliable outcome of current assays.
View Article and Find Full Text PDFBreast Cancer Res Treat
November 2009
In the United States, 211,000 women are diagnosed each year with breast cancer. Of the 42,000 breast cancer patients who overexpress the HER2 growth factor receptor, <35% are responsive to treatment with the HER2-disabling antibody, called trastuzumab (Herceptin). Despite those statistics, women diagnosed with breast cancer are now tested to determine how much of this important growth factor receptor is present in their tumor because patients whose treatment includes trastuzumab are three-times more likely to survive for at least 5 years and are two-times more likely to survive without a cancer recurrence.
View Article and Find Full Text PDFThe MUC1 protein is aberrantly expressed on an estimated 75% of all human solid tumor cancers. We recently reported that a transmembrane cleavage product, MUC1*, is the predominant form of the protein on cancer cells [1]. Further, our evidence indicated that MUC1* functions as a growth factor receptor on tumor cells, while the full-length protein appeared to have no growth promoting activity.
View Article and Find Full Text PDFThe MUC1 protein is aberrantly expressed on many solid tumor cancers. In contrast to its apical clustering on healthy epithelial cells, it is uniformly distributed over cancer cells. However, a mechanistic link between aberrant expression and cancer has remained elusive.
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