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The regrowth of cancer stem cells is responsible for the drug resistance that develops in many breast tumors and the reason that for many patients, the benefits of chemo are short-lived. Cancer recurrence after chemotherapy is frequently fatal. "Breast cancer stem cells pose a serious problem for therapy," says lead study investigator Gregg Semenza, M.D., Ph.D., the C. Michael Armstrong Professor of Medicine, director of the Vascular Biology Program at the Johns Hopkins Institute for Cell Engineering and a member of the Johns Hopkins Kimmel Cancer Center. "These are the cells that can break away from a tumor and metastasize; these are the cells you most want to kill with chemotherapy. Paradoxically, though, cancer stem cells are quite resistant to chemotherapy." Semenza says previous studies have shown that resistance to chemotherapy arises from the hardy nature of cancer stem cells, which are often found in the centers of tumors, where oxygen levels are quite...

In a new study, doctoral student Cajsa Davegårdh has studied so-called DNA methylation in muscle stem cells in both obese and non-obese individuals. DNA methylation is an epigenetic process in which small molecules -- methyl groups -are added to genes and fine-tune the gene's activity, like a dimmer switch. By comparing the DNA methylation in immature and mature muscle cells from healthy individuals, Cajsa Davegårdh discovered that the actual degree of methylation had a major impact on the maturation process. "Many genes that had changed their genetic expression also changed their degree of methylation during the development to mature muscle cells, which indicates a connection," she says. A pro-inflammatory gene, IL-32, turned out to be particularly important with regard to the maturation process and the insulin sensitivity of the fully developed muscle cell. Impaired insulin sensitivity is common in obesity and is a risk factor for type 2 diabetes. "By red...

Illinois professor Brendan Harley and postdoctoral researcher Ji Solar Choi discovered that biomaterials that mimic bone marrow can alter blood cell growth. Credit score: L. Brian Stauffer Researchers on the College of Illinois report they will alter blood cell growth by means of the usage of biomaterials designed to imitate traits of the bone marrow. The findings, reported within the journal  Science Advances , are a primary step towards growing simpler bone marrow therapies for ailments like leukemia and lymphoma. Blood cells move all through the physique delivering life-supporting oxygen and vitamins. As these cells are used and recycled they're regenerated by bone marrow, the delicate tissue contained in the physique's lengthy and hole bones. Sure areas of bone marrow comprise hematopoietic stem cells, the precursors of all blood and immune cells, mentioned College of Illinois chemical and biomolecular engineering professor Bren...

Earlier this month, Sanford began enrolling participants in the Safety and Efficacy of Adult Adipose-Derived Stem Cell Injections into Partial Thickness Rotator Cuff Tears clinical trial. The trial uses stromal vascular fraction, a mixture of cells and nutrients isolated from a patient's own body that contain adipose-derived stem cells, as a potential therapy for partial-thickness rotator cuff tears. Sanford scientists and clinicians are exploring the application of this type of stem cells for other conditions. The team put together the review after recognizing that the medical and general communities have limited knowledge about the various types of stem cells and how they could be used in medicine. The article, "Fat and Furious: Harnessing the Full Potential of Adipose-Derived Stromal Vascular Fraction," is a review of the various types of stem cells found in humans and how they can be used in medical applications. The researchers emphasized the difference between...

With this new perspective, they began to consider innovative ways to use specialized cells in the eye, like retinal pigment epithelial cells and ganglion cells. Today researchers continue to follow that path, knowing that each small step they take may lead to future glaucoma treatments. What Are Retinal Pigment Epithelium (RPE) Cells? Most people know at least a little about the retina. The retina is a thin tissue that's about an inch in diameter , yet it contains all the photoreceptor cells responsible for beginning vision and their circuits that produce signals that become vision. If you could look beneath the retina, you'd find a sheet of black cells called the retinal pigment epithelium, (RPE). The easiest way to describe the RPE is to say it supports the retina, but that doesn't begin describe its value. These cells help by renewing the light-absorbing pigments contained in the rod and cone photoreceptors on a daily basis. They also enhance vision by absorbing ...

When we are young, our blood stem cells produce an even and well-balanced number of red and white blood cells according to need. As we age, however, the capacity of the blood stem cells to produce the number of blood cells we need declines. "This type of age-related change can have major consequences as it can lead to an imbalance in stem cell production. For example, a reduced production of immune cells or excessive production of other types of cells can be a precursor to leukemia," explains David Bryder, who headed the study at Lund University. Tracking old stem cells A fundamental question was whether blood stem cells age differently within a single individual or whether all blood stem cells are equally affected by advancing  age. In an initial stage, it was therefore important to genetically mark old blood stem cells, to enable the identification and tracking of those most affected by age. In the next step, these traceable cells were reprogrammed to another type ...