U-M researchers link pathway to breast cancer stem cellsJune 02, 2009ANN ARBOR, Mich. - A gene well known to stop or suppress cancer plays a role in cancer stem cells, according to a new study from the University of Michigan Comprehensive Cancer Center. The researchers found that several pathways linked to the gene, called PTEN, also affected the growth of breast cancer stem cells. Further, by using a drug that interferes with that pathway, the researchers produced an up to 90 percent decrease in the number of cancer stem cells within a tumor. The study appears in the June issue of PLoS Biology, a journal from the Public Library of Science. PTEN is the most frequently inactivated tumor suppressor gene in several cancers, including breast cancer, where it is inactivated in about 40 percent of patients. PTEN is linked to poor outcomes and is associated with aggressive cancers resistant to chemotherapy and current targeted therapies. The U-M researchers deleted PTEN in tumors grown in cell cultures and in mice, and found an increase in the number of stem cells. They also looked at pathways associated with PTEN and reported that a pathway called PI3-K/Akt regulated the cancer stem cell population by activating another stem cell pathway, Wnt, which is also implicated in multiple cancer types. "Although there has been considerable progress in identifying cancer stem cells in a variety of tumor types, the pathways that drive the transformation of these cells are not well understood," says lead study author Hasan Korkaya, D.V.M., Ph.D., research investigator in internal medicine at the U-M Medical School. Researchers at U-M were the first to identify stem cells in breast cancer. These cells represent fewer than 5 percent of the cells in a tumor but are believed to be responsible for fueling a tumor's growth and spread. Researchers believe that the ultimate cure of cancer will require killing these cancer stem cells. In the current study, researchers looked at a drug called perifosine, which inhibits the Akt pathway. Tumors in mice were treated with perifosine or docetaxel, a standard chemotherapy drug. The docetaxel alone showed no effect on the number of cancer stem cells in the tumor. But adding perifosine reduced the cancer stem cell population by up to 90 percent. What's more, the cells treated with perifosine - either with or without docetaxel - were less likely to grow a secondary tumor, compared to the cells treated with just docetaxel. "This is most exciting since perifosine and other drugs that target this pathway are currently in clinical development. If cancer stem cells do contribute to tumor relapse, then adding drugs that target these cells may help to make our current therapies more effective," says study senior author Max S. Wicha, M.D., Distinguished Professor of Oncology and director of the U-M Comprehensive Cancer Center. The University of Michigan Health System |
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| Related Stem Cells Current Events and Stem Cells News Articles First reconstitution of an epidermis from human embryonic stem cells Stem cell research is making great strides. This is yet again illustrated by a study carried out by the I-STEM* Institute (I-STEM/ Inserm UEVE U861/AFM), published in the Lancet on 21 November 2009. The I-STEM team, directed by Marc Peschanski has just succeeded in recreating a whole epidermis from human embryonic stem cells. Bone Implant Offers Hope for Skull Deformities A synthetic bone matrix offers hope for babies born with craniosynostosis, a condition that causes the plates in the skull to fuse too soon. Your Own Stem Cells Can Treat Heart Disease The largest national stem cell study for heart disease showed the first evidence that transplanting a potent form of adult stem cells into the heart muscle of subjects with severe angina results in less pain and an improved ability to walk. The transplant subjects also experienced fewer deaths than those who didn't receive stem cells. Is hepatic differentiation of embryonic stem cells induced by valproic acid and cytokines? Embryonic stem (ES) cells, known for their capacity to proliferate indefinitely and differentiate into almost all types of cells including hepatocytes, have raised the hope of cellular replacement therapy for liver failure. Paradoxical protein might prevent cancer One difficulty with fighting cancer cells is that they are similar in many respects to the body's stem cells. By focusing on the differences, researchers at Karolinska Institutet have found a new way of tackling colon cancer. The study is presented in the prestigious journal Cell. U of M researchers find 2 units of umbilical cord blood reduce risk of leukemia recurrence A new study from the Masonic Cancer Center, University of Minnesota shows that patients who have acute leukemia and are transplanted with two units of umbilical cord blood (UCB) have significantly reduced risk of the disease returning. The use of stem cells in regenerative medicine may also be detrimental for health The use of stem cells in regenerative medicine is not always beneficial for human health, it may even be harmful according to a work done by the University of Granada and University of León. Scientists have demonstrated that transplantation of human mononuclear cells isolated from umbilical cord blood exerted a deleterious effect in rats with liver cirrhosis. Penn Study Provides First Clear Idea of How Rare Bone Disease Progresses An international team of scientists, led by researchers at the University of Pennsylvania School of Medicine, is taking the first step in developing a treatment for a rare genetic disorder called fibrodysplasia ossificans progressiva (FOP), in which the body's skeletal muscles and soft connective tissue turns to bone, immobilizing patients over a lifetime with a second skeleton. Iowa State University researcher discovers key to vital DNA, protein interaction A researcher at Iowa State University has discovered how a group of proteins from plant pathogenic bacteria interact with DNA in the plant cell, opening up the possibility for what the scientist calls a "cascade of advances." Scientists successfully reprogram blood cells Researchers have transplanted genetically modified hematopoietic stem cells into mice so that their developing red blood cells produce a critical lysosomal enzyme -preventing or reducing organ and central nervous system damage from the often-fatal genetic disorder Hurler's syndrome. More Stem Cells Current Events and Stem Cells News Articles |
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