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One logical outgrowth of the quest to control cell state as a part of regenerative medicine is an initiative to control the state of cancerous cells. From EurekAlert!: researchers "discovered that aggressive melanoma cells (but not normal skin cells nor less aggressive melanoma cells) contain specific proteins similar to those found in embryonic stem cells. This groundbreaking work led to the first molecular classification of malignant melanoma and may help to explain how, by becoming more like unspecialized stem cells, the aggressive melanoma cell gained enhanced abilities to migrate, invade and metastasize while virtually undetected by the immune system. ... Embryonic stem cells are pluripotent, meaning they are able to differentiate into any of the more than 200 cell types in the adult body. Which type of cell they become depends on the signals they receive from their microenvironment. Similarly, during cancer progression, malignant cells receive and release signals from their own microenvironment, cues that promote tumor growth and metastasis. ... scientists can change human metastatic melanoma cells back to normal-like skin cells - by exposing the tumor cells to the embryonic microenvironment of human embryonic stem cells."
View the Article Under Discussion: http://www.eurekalert.org/pub_releases/2007-04/nu-rcc042507.php
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WebMD gives an overview of some of the latest research into cancer stem cells: "Are most current cancer treatments -- as well as many in development -- aimed at eradicating the wrong cancer cells? That's the position of some leading researchers, who say that cancer is, fundamentally, a stem cell problem -- and that therapy should be targeted at so-called cancer stem cells. ... In the stem cell hypothesis, cancer is driven by specific cells that contain stem cell properties ... These cells then reproduce and replenish malignant tumors. Currently, most treatments target cancer cells, but not necessarily cancer stem cells ... While the treatment may shrink the tumor and keep it in check for a while, eventually, the untreated cancer stem cells proliferate into cancer cells, leading to a return of the tumor and death ... If the treatments targeted the cancer stem cells, however, the tumor would lose the ability to generate new cancer cells, eventually resulting in a cure." The article goes on to look at some specific demonstrations of errant stem cells and stem-like cells from recent months.
View the Article Under Discussion: http://www.webmd.com/cancer/news/20070420/stem-cells-may-be-at-root-of-cancer?print=true
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From Ouroboros, a look at where evolution has left us in the aging and longevity stakes: "An emerging theme in biogerontology is the idea that lifespan may be determined by the balance between regeneration and tumor suppression. Long-term tissue health demands that damaged and dead cells be replaced, but unlimited replicative potential poses the risk of cancer. Therefore, to prevent tumors, organisms must accept a decrease in regenerative capacity. ... How direct is this connection? In an indirect model, differentiated cells are the initiatiors of tumor growth. p53 limits stem cell proliferation, which in turn decreases the rate of production of new differentiated cells. Fewer cells available to undergo neoplastic transformation means fewer cells available to initiate tumors, with the unfortunate consequence that tissues requiring new cells to maintain homeostasis must go begging. In a direct model, tumor suppressor activity decreases the number of stem cells that might become dysregulated and transformed into cancer stem cells, a relatively new concept in cancer biology." Evolution got us this far, and now its up to us to carry the ball forward to greater longevity through advanced biotechnology.
View the Article Under Discussion: http://ouroboros.wordpress.com/2007/02/06/devils-bargain-tradeoffs-between-stem-cell-maintenance-and-tumor-suppression/
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EurekAlert! brings news of more cancer stem cells: "The cells we isolated are quite different from 99 percent of the millions of other cells in a human pancreatic tumor, and we think that, based on some preliminary research, standard treatments like chemotherapy and radiation may not be touching these cells. If that is why pancreatic cancer is so hard to treat, a new approach might be to design a drug that specifically targets pancreatic cancer stem cells without interfering with normal stem cell function ... theory suggests that only cells that have the properties of 'stemness' - that is, cells that can self-renew and differentiate into other types of cells - are the only ones capable of producing tumors. These 'cancer stem cells,' could derive from normal adult stem cells in organs that have mutated, or from a differentiated cell that has devolved to take on the qualities of stem cells. They are resistant to traditional therapy designed for cells that rapidly turn over because stem cells don't, according to some researchers. Thus, they remain after tumors shrink and may be responsible for cancer recurrence and metastasis."
View the Article Under Discussion: http://www.eurekalert.org/pub_releases/2007-02/aafc-sip013007.php
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A comparatively simple approach to tackling cancer stem cells is reported in Science: "Cancer stem cells are the ultimate source of the tumor, consistently supplying it with new cells. ... Killing these stem cells should allow researchers to hit a tumor where it hurts, yet chemotherapy has proven ineffective as it tends to kill only rapidly dividing cells. ... [researchers] started by comparing cancer stem cells to noncancerous neural stem cells. These neural tissue precursors are concentrated in regions rich in blood vessels. The vessels are lined with endothelial cells, which secrete chemical signals that help stem cell survive. ... after examining over 70 human brain tumors, the researchers found that cancer stem cells were frequently located close to tiny vessels called capillaries. ... Drugs that shrunk the capillaries also caused a significant drop in cancer stem cells and consequently put a damper on tumor growth." Comparatively simple it may be, but this new understanding required the tools of modern biotechnology; as is often the case, greater knowledge leads to better use of older medical technologies.
View the Article Under Discussion: http://sciencenow.sciencemag.org/cgi/content/full/2007/116/2
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University of Southern California researchers have found that cancer is rooted in stem cells. They found that cancer arises in cells that have already undergone epigenetic (heritable factors not associated with DNA) alterations, which points to ep... Read more 
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(From ScienceDaily). The best advances in science are those that make progress look easy and obvious - always anything but in practice. Simple steps forward in the knowledge and capabilities of biotechnology can often be combined to form tools far more effective than previously existed, as demonstrated here: "bone marrow stem cells stick to adhesive proteins called selectins more strongly than other cells ... selectins grab onto a specific carbohydrate on the surfaces of white blood cells, stem cells, and cancer cells. ... King's group coated a slender plastic tube with selectin. They then did a series of lab experiments, both in vitro and in vivo using rats, with this selectin-coated tube to filter the bloodstream for stem cells. It worked ... Another exciting application of King's invention is filtering the blood for cancer cells ... As a cancer cell flows along the implanted surface, King's device captures it and delivers an apoptosis signal, a biochemical way of telling the cancer cell to kill itself. Within two days, that cancer cell is dead. Normal cells are left totally unharmed because the device selectively targets cancer cells."
View the Article Under Discussion: http://www.sciencedaily.com/releases/2007/01/070104144824.htm
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If you like to see how the sausage is made, Seeking Alpha takes a look inside Geron, a company representative of the messy business of developing the latest regenerative medicine and cancer therapies: "Geron has two telomerase-based cancer drugs in human trials, though both are early stage. For metastatic prostate cancer, the company is injecting telomerase into patients, hoping to provoke a more aggressive immune response - a therapeutic vaccine. ... On the stem cell front, Geron is testing GRNOPC1 to treat spinal cord injuries. The drug was given to rats with injuries that prevented them from using their legs, and GRNOPC1 helped them regain control of their legs. ... A second drug, GRNIC1, uses embryonic stem cell-derived islet clusters treatment to treat diabetes. ... Geron plans to begin its initial human testing of the drug in 2007 ... GRNCM1, the third stem cell based drug candidate, is a potential treatment for myocardial infarction."
View the Article Under Discussion: http://biotech.seekingalpha.com/article/23090
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Now that scientists are getting a handle on cancer stem cells, it comes time to develop the means to precisely attack these cells, and thereby strike at the root of cancer. EurekAlert! outlines one of many early attempts: "The most common type of brain cancer - glioblastoma - is marked by the presence of these stem-cell-like brain cells, which, instead of triggering the replacement of damaged cells, form cancer tissue. Stem cells, unlike all other cells in the body, are capable of forming almost any kind of cell when the right 'signals' trigger their development. For their treatment experiment, the researchers relied on a class of proteins, bone morphogenic proteins, that cause neural stem-cell-like clusters to lose their stem cell properties, which in turn stops their ability to divide." The first step to working the machine is understanding what the levers do; our understanding at this level is still very crude, but even this is sometimes enough to get the job done.
View the Article Under Discussion: http://www.eurekalert.org/pub_releases/2006-12/jhmi-nps120706.php
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The Globe and Mail looks back at the history of cancer stem cell research, a most promising development in the quest to cure cancer: "Dr. Dick's discovery of the first cancer stem cell that year has led to the flurry of recent breakthroughs redefining cancer biology. Scientists once believed all cancer cells could sprout and sustain a tumour. But proof is growing that this deadly power belongs only to a tiny subset of abnormal stem cells that had previously gone undetected. These bad seeds have now been identified as the source of cancers of the blood, breast, bone, prostate, and this week, in another finding from Dr. Dick, the colon. The implications are staggering. Billions of dollars and decades of research may have targeted the wrong cells to cure the disease. No current treatment has been designed to kill them and they appear to be naturally resistant to the gold-standard therapies." Fortunately, the next generation of precisely targeted therapies are the right tools for the job.
View the Article Under Discussion: http://www.theglobeandmail.com/servlet/story/RTGAM.20061125.wxstem25/BNStory/Science/home?pageRequested=all&print=true
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