Scientists have proven that a functional prostate gland can be grown from a single adult stem cell. The glands were grown in mice but the research, by scientists at Genentech in San Francisco, may aid the diagnosis and treatment of prostate cancer in humans. It is the second instance of an entire organ being grown from a single stem cell; the first came in 2006, when scientists grew mammary glands in mice.
The team first found a marker, a protein, that would differentiate prostate stem cells from other cells in the prostate. This marker, C-117, can also be found in the human prostate, they said [Reuters]. Using the new C-117 marker and three previously known markers, the scientists identified stem cells in the prostate of baby mice and transplanted them onto the kidneys of adult mice. Three months later, the researchers removed the kidneys and analyzed the fate of the grafted cells. Of the 97 single-cell transplants, 14 had grown into fully functioning prostates–complete with multiple cell types, characteristic branching structures, and prostate-specific proteins [Technology Review].
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A preliminary study has shown that large doses of vitamin C may decrease the effectiveness of chemotherapy drugs, bringing new confusion into the debate over whether vitamin C supplements can help or harm cancer patients. In the study, researchers treated cancer cells with very high doses of vitamin C and then tried to kill the cells with various cancer drugs; they found that all the drugs were less effective on the pretreated cancer cells than on cells that had received no vitamin dose.
While the effect was only tested in cancer cells and mice, researchers say further studies should look for a parallel effect in humans. “There’s a possibility that taking supplemental vitamin C could have a detrimental effect on cancer treatment,” said study author Dr. Mark L. Heaney…. However, there’s no indication that smaller doses of vitamin C, such as those found in food and ordinary multivitamins, might be a problem, he said [HealthDay News].
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Researchers have found a way to create stem cells from adult liver cells without triggering DNA changes that have caused mutations and tumors in previous studies. Though demonstrated only in mice so far, the result marks another key achievement in the fledgling science of cellular reprogramming. The hope is to create human, embryonic-like stem cells — which can be turned into all the other tissue types of the body — without using eggs or destroying embryos. That freshly derived tissue could then be transplanted into patients to treat various diseases [The Wall Street Journal].
A method of using adult cells to create stem cells was debuted by Japanese researchers in 2006. By using viruses to insert key developmental genes, researchers coaxed human skin cells into an embryonic state, capable of growing into almost any other type of tissue…. But there was a catch: Viruses used to reset the cells tended to fuse with their DNA, leading to unpredictable mutations and cancer. The cells were promising in principle, but couldn’t be used medically [Wired News]. In the new breakthrough, researchers used a different kind of virus to introduce the genes, and found that it didn’t leave behind any damaging genetic code.
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Researchers have found that several moisturizers are linked to an increased skin cancer risk in hairless mice, but caution that there’s no reason for people to panic. Mouse skin is very different from human skin, they say, and the mice also developed a very curable type of cancer called squamous cell carcinoma, not the more lethal melanoma.
Lead researcher Allan Conney says the team discovered the risk while testing a theory that caffeine could prevent skin cancer. “We sort of got into this by accident,” Conney said in a telephone interview. “We wanted a safe cream that we could put the caffeine into” [Reuters].
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In patients with non-Hodgkin’s lymphoma, researchers have found a way to turn cells in the patients’ own immune system into cancer-fighting machines. In a new study, researchers injected patients with a drug that helped immune cells attach themselves to tumor cells. The study saw considerable improvement in only 11 of the 38 patients in this preliminary trial, but researchers say the results are significant because all seven of the patients who received the highest dose of medication saw their tumors shrink. In four cases, the tumors completely vanished.
The new results are the latest promising finding in the developing field of immunotherapy, in which the body’s own defenses are augmented and then unleashed to fight back disease. Researchers are also investigating ways to train the immune system to attack brain cancer tumors, and in June doctors announced that a patient with advanced skin cancer was free of the disease two years after they injected him with billions of his own immune cells [Telegraph].
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At the age of 75, men should stop getting screened for prostate cancer, according to new recommendations from a government task force. The group reported finding evidence that the benefits of treatment based on routine screening of this age group “are small to none” [AP]. Those potential benefits are far outweighed by the possible anxiety, unnecessary surgery, and harmful side effects that elderly men can experience if the screening finds early-stage prostate cancer and the patient chooses to treat it.
Most oncologists already argue against treating most men in that age group for prostate cancer because they are more likely to die from some other cause than from their tumor [Los Angeles Times]. Prostate cancer often progresses slowly, and doctors say it can take 10 years before a patient begins to show symptoms. Many doctors now advocate a “watchful waiting” approach when prostate cancer is detected, instead of aggressive treatment that can cause impotence, incontinence, and bowel problems.
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Injections of high doses of vitamin C slowed the growth of tumors in mice by 50 percent, and also prevented the cancers from metastasizing to other parts of the body. Researchers say the findings form a “firm basis” for trials in humans, with a view to using vitamin C injections alongside conventional drugs, particularly for some of the most lethal tumours, such as pancreatic, ovarian and brain cancer [The Guardian].
But some cancer specialists are sceptical, and fear that desperate patients will be prompted to start taking large doses of the vitamin. That may be dangerous, because antioxidants such as vitamin C could undermine the effectiveness of standard cancer drugs and radiation therapy [New Scientist]. Researchers point out that they were only able to deliver a higher dose of the vitamin through intravenous injection and that patients couldn’t get a similar dose through diet or vitamin supplements, because the digestive system can absorb a limited amount of the vitamin.
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The director of a cancer research center in Pittsburgh issued a surprising warning to his staff yesterday, advising them to avoid using cell phones as much as possible, because of the possible risk of brain cancer. The memo was promptly leaked to the media, igniting a firestorm of debate over whether the ubiquitous devices are dangerous.
The claim from the Pittsburgh researcher, Ronald Herberman, was particularly unexpected because numerous academic studies have found no connection between cell phone use and the risk of brain tumors. But Herberman says he’s basing his alarm on early unpublished data. He says it takes too long to get answers from science and he believes people should take action now — especially when it comes to children. “Really at the heart of my concern is that we shouldn’t wait for a definitive study to come out, but err on the side of being safe rather than sorry later,” Herberman said [AP].
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A study of an experimental prostate cancer drug showed dramatic results that have thrilled researchers: The drug shrank prostate tumors and doubled survival rates in more than 70 percent of patients with an aggressive form of prostate cancer. The test subjects were men whose cancer had not responded to other treatments, and who had a life expectancy of about a year.
Although the study, which was published in the Journal of Clinical Oncology [subscription required], covered only 21 patients, the drug is now being tested in more than 250 men with what appears to be similar results, experts said. “There is a general sense in the prostate cancer community that this agent is extremely promising and is very likely to have an important role in the management of prostate cancer patients,” said Dr. Howard M. Sandler [Los Angeles Times]. Experts say the drug could reach the doctors’ offices by 2011.
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Researchers say they have turned a tobacco plant into a living factory that can produce individualized vaccines to fight a type of cancer known as follicular lymphoma. While similar vaccines have been grown inside animal cells, researchers say this new process is quicker and less expensive, and could carry less risk to the patient, as animal cells might hold unknown viruses [BBC News].
In the new technique, researchers took biopsies from each lymphoma patient and isolated the gene that produces tumor-fighting antibodies, which is slightly different in each person. In each case, they then used a genetically engineered tobacco virus to bring the gene into a tobacco plant, where the plant responded by turning out antibodies. One week later the tobacco leaves were picked and ground into pulp, and the antibodies were extracted. These antibodies are put into a patient newly-diagnosed with the disease, to “prime” the body’s immune system to attack any cell carrying them. If successful, this would mean the body would then recognise and destroy the lymphoma cells [BBC News].
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A microbe that has caused trouble in human stomachs for around 60,000 years may also play a role in preventing children from developing asthma and other allergies. In a new study, researchers say that a current campaign to wipe out the bacterium, Helicobacter pylori, may be having the unintended consequence of boosting asthma rates in kids.
A longtime resident of the human stomach, H. pylori went largely undetected until Australian scientists discovered it in 1979 and went on to show that it can cause stomach ulcers. Further work has linked it to stomach cancer. It’s now treated with antibiotics whenever detected [Science News]. But researchers say that when they studied health records of over 7,000 kids between the ages of 3 and 13, they found that children with H. pylori in their stomachs were less than half as likely to develop asthma. Those children were also less likely to suffer from eczema and hay fever.
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Australia’s Tasmanian devils are breeding at younger ages in response to a strange form of infectious cancer that is spreading rapidly through devil populations. The feisty marsupials are now reproducing before the lethal cancer strikes them down—a response that may be the species’ only chance to avoid extinction.
Researcher Shelly Lachish explains: “In a normal, healthy devil population the females would rarely breed before the age of two, but now 60 per cent of one-year-olds in diseased populations have produced young…. They are teenagers in human terms. It’s a remarkable change given early breeding was once very, very rare” [Sydney Morning Herald]. While some researchers believe this to be an example of rapid evolution, skeptics say the case is not yet closed.
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A hormone therapy sometimes called “medical castration” that’s used to treat prostate cancer is of no help to patients in the early stages of the disease, according to a new study. What’s more, the treatment’s side effects far outweigh any potential benefit for most patients [Los Angeles Times].
The treatment, which cuts off the production of male hormones, has been found to be effective in treating aggressive prostate cancer that is spreading through the body; this prompted doctors to begin prescribing the hormone therapy to patients with early stage, localized tumors as well. But the results of this new study are likely to reverse that trend. Hormone therapy’s most obvious side effect is sexual dysfunction. Of greater concern are several recent studies linking [these] therapies to diabetes, heart disease, bone fractures, and reduced muscle mass [WebMD].
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Sometimes good things come in small packages. Researchers say they’ve developed a nanoparticle that can deliver cancer-fighting drugs to a tumor’s blood vessels with laser-like precision, and that studies in mice show that this system could stop tumors from metastasizing, or spreading through the body.
Researchers say that packaging a toxic chemotherapy drug in nanoparticles for specific delivery to cancer cells, rather than a larger, wide-acting dose, could make for safer and more potent cancer treatments. “There are many drugs that companies have made that have fallen by the wayside or been shelved due to toxicity,” says [study author] David Cheresh [New Scientist].
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Researchers have developed a test that may soon allow doctors to track the progress of lung cancer tumors in “real time.” A sophisticated device allows doctors to detect and isolate the few circulating tumor cells that travel through the blood stream, which can then provide information about the main tumor’s growth and its response to medication.
As tumors grow, a handful of cancer cells may peel away and slip into the blood, [study author Daniel] Haber says. While few in number — with about one cancer cell for every 1 billion blood cells — these cells can be deadly if they settle in other parts of the body and form new tumors, a process called metastasis. Until now, doctors have never been able to easily analyze them [USA Today]. Now doctors will be able to conduct a genetic analysis of the free-floating tumor cells, allowing doctors to tailor their treatment to the individual patient and taking an important step towards “personalized medicine.”
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