Tag Archives: biology

‘Undruggable’ cancer may be druggable after all: New target identified

The gene, SALL4, gives stem cells their ability to continue dividing as stem cells rather than becoming mature cells. Typically, cells only express SALL4 during embryonic development, but the gene is re-expressed in nearly all cases of acute myeloid leukemia and 10 to 30 percent of liver, lung, gastric, ovarian, endometrial, and breast cancers, strongly suggesting it plays a role in tumor formation. In work published in the New England Journal of Medicine, two HSCI-affiliated labs — one in Singapore and the other in Boston — show that knocking out the SALL4 gene in mouse liver tumors, or interfering with the activity of its protein product with a small inhibitor, treats the cancer. "Our paper is about liver cancer, but it is likely true about lung cancer, breast cancer, ovarian cancer, many, many cancers," said HSCI Blood Diseases Program leader Daniel Tenen, who also heads a laboratory at the Cancer Science Institute of Singapore (CSI Singapore)…

Cells play ‘tag’ to determine direction of movement

Scientists from Barcelona and London, looked at cells in the neural crest, a very mobile embryonic structure in vertebrates that gives rise to most of the peripheral nervous system and to other cell types in the cardiovascular system, pigment cells in the skin, and some bones, cartilage, and connective tissue in the head. Researchers saw that, during development, these neural crest cells ‘chase’ other types of cells — so-called placodal cells that give rise to the sensory organs — which dash away when approached, thus propelling the cell sheet in a certain direction. "The effect can also be likened to a donkey and carrot effect, with the neural crest cells — the donkey — chasing but never quite reaching the carrot, the placodal cells," explains Xavier Trepat, ICREA Research Professor of the UB and leader of the Research Group on Integrative Cell and Tissue Dynamics of IBEC…

Using math to kill cancer cells

"Oncolytic viruses are special in that they specifically target cancer cells," explains Dr. Bell, a senior scientist at the Ottawa Hospital Research Institute and professor at the University of Ottawa’s Faculty of Medicine. "Unfortunately, cancer is a very complicated and diverse disease, and some viruses work well in some circumstances and not well in others. As a result, there has been a lot of effort in trying to modify the viruses to make them safe, so they don’t target healthy tissue and yet are more efficient in eliminating cancer cells." Dr. …

New liver cell for cellular therapy to aid in liver regeneration

"The discovery of the novel progenitor represents a fundamental advance in this field and potentially to the liver regeneration field using cell therapy," said the study’s senior author, Valerie Gouon-Evans, PharmD, PhD, Assistant Professor, in the Department of Developmental and Regenerative Biology, Black Family Stem Cell Institute, at the Icahn School of Medicine at Mount Sinai. "Until now, liver transplantation has been the most successful treatment for people with liver failure, but we have a drastic shortage of organs…

Study: Cannabis may prevent brain damage

Marijuana continues to be a paradox as it makes its way from illicit drug to wonder medicine being used to treat a number of symptoms and disorders more safely than traditional pharmaceuticals. In the latest news, cannabis, which has been associated with long-term cognitive deficits in chronic users, is now being tested as a treatment to preserve brain function after traumatic injury. Amidst the many “it-damages-your-brain” studies, some reports have shown that cannabis has neuroprotective effects. Studies have suggested that it has protective effects in neurodegenerative diseases like multiple sclerosis, Alzheimer’s, Huntington’s and Parkinson’s diseases. The author of the new study, Dr. Yosef Sarne of Tel Aviv University's Adelson Center for the Biology of Addictive Diseases, theorized that ultra-low doses of tetrahydrocannabinol (THC), the main psychoactive component of marijuana, induces minor damage to the brain, which may actually “precondition” the brain to protect it against more severe damage from injuries such as lack of oxygen, seizures or toxic drug exposure. In other words, it may act as a sort of vaccine against more traumatic harm. In Dr. Sarne's animal study, published in the journals Behavioural Brain Research and Experimental Brain Research, researchers injected mice with a single, very low dose of THC — around 1,000 to 10,000 times less than what is found in a conventional “joint” — either several days before or after exposing the mice to a brain trauma. They found that the treated mice had enhanced biochemical processes, which protected brain cells and preserved cognitive function over time, compared to control mice that were not treated with THC. Specifically, when the mice were examined three to seven weeks after the brain injury, those in the THC group performed better in learning and memory tests. They also showed increased amounts of neuroprotective chemicals compared to the control group. In past laboratory experiments, Sarne’s group found that ultra-low doses of THC affected cell signaling, preventing cell death and promoting certain growth factors.   The researchers concluded that the use of low doses of THC can prevent long-term cognitive damage that results from brain injury in mice, but the drug needs to be tested in human trials. “Since we deal, in this case, in a basic process (THC is protective against a variety of insults, not just a specific condition), I personally believe it will go beyond rodents,” Sarne wrote in an email. Aside from treating patients with traumatic injury to the brain, Sarne suggested several ways of using THC preventively, before an injury occurs. One use could be for patients on cardiopulmonary heart-lung machines used in open heart surgery. These come with a risk of interrupting the blood supply to the brain. Sarne said that THC could be injected beforehand as a preventive measure in case the brain is deprived of oxygen. It could also be tested for use in patients such as those with epilepsy, who are at constant risk of brain injury, or those with a high risk of heart attack. Sarne is currently testing the ability of low doses of THC to prevent heart damage during a heart attack, to prevent the death of heart muscle cells that are deprived of oxygen.Laurie Tarkan is an award-winning health journalist whose work appears in the New York Times, among other national magazines and websites. She has authored several health books, including “Perfect Hormone Balance for Fertility.” Follow her on Twitter and Facebook.source : http://www.foxnews.com/health/2013/06/06/study-cannabis-may-prevent-brain-damage/

Evolutionary history of a cancer-related gene

A study published today by scientists from the Spanish National Cancer Research Centre (CNIO) describes how a genetic duplication that took place in the vertebrate ancestor some 500 million years ago encouraged the evolution of the ASF1b gene; a gene essential for proper cell division and related to some types of cancer such as breast cancer. The results of the study are published in Molecular Biology and Evolution. The conclusions of the study are the result of collaboration between the team led by Alfonso Valencia, Vice-Director of Basic Research and Director of CNIO’s Structural Biology & Biocomputing Programme, and the team led by Genevieve Almouzni, a member of CNIO’s Scientific Advisory Committee, at the Institut Curie in Paris, France. Valencia says that: "When proteins have such a close similarity as the one that exists between the two human copies of the ASF1 gene — ASF1a and ASF1b — it is commonly assumed that they have similar functions in cells; in this case related to fundamental processes such as DNA remodelling and repair, cell division, cell proliferation and genetic transcription or activation." The Genomic Environment, Key to Success in Separating Functions Almouzni’s team discovered several years ago that, despite the similarity in structure, the two copies of ASF1 were not redundant, but rather had divided up their ancestral functions…

First dual-action compound kills cancer cells, stops them from spreading

Nathan Luedtke and colleagues explain that the spread of melanoma and other forms of cancer beyond the original location — a process called metastasis — makes cancer such a serious disease. Photodynamic therapy (PDT), which involves administering a drug that kills cancer cells when exposed to light, already is available. But PDT works only on the main tumor and has other drawbacks. …

Scientists unexpectedly discover stress-resistant stem cells in fat tissue removed during liposuction

The cells, called Multi-lineage Stress-Enduring (Muse-AT) stem cells from fat, or adipose, tissue, were discovered by "scientific accident" when a piece of equipment failed in the lab, killing all the stem cells in the experiment except for the Muse-AT cells. The research team further discovered that not only are Muse-AT cells able to survive severe stress, they may even be activated by it, said study senior author Gregorio Chazenbalk, an associate researcher with UCLA Obstetrics and Gynecology…

Stench of human feet may lead to better malaria traps

For decades, health officials have battled malaria with insecticides, bed nets and drugs. Now, scientists say there might be a potent new tool to fight the deadly mosquito-borne disease: the stench of human feet. In a laboratory study, researchers found that mosquitoes infected with the tropical disease were more attracted to human odors from a dirty sock than those that didn't carry malaria. Insects carrying malaria parasites were three times more likely to be drawn to the stinky stockings. The new finding may help create traps that target only malaria-carrying mosquitoes, researchers say. “Smelly feet have a use after all,” said Dr. James Logan, who headed the research at the London School of Hygiene and Tropical Medicine. “Every time we identify a new part of how the malaria mosquito interacts with us, we're one step closer to controlling it better.” The sock findings were published last month in the journal, PLoS One. Malaria is estimated to kill more than 600,000 people every year, mostly children in Africa. Experts have long known that mosquitoes are drawn to human odors, but it was unclear if being infected with malaria made them even more attracted to us. Infected mosquitoes are believed to make up about 1 percent of the mosquito population. Using traps that only target malaria mosquitoes could result in fewer mosquitoes becoming resistant to the insecticides used to kill them. And it would likely be difficult for the insects to evade traps based on their sense of smell, scientists say. “The only way mosquitoes could (develop resistance) is if they were less attracted to human odors,” said Andrew Read, a professor of biology and entomology at the University of Pennsylvania, who was not part of Logan's research. “And if they did that and started feeding on something else - like cows - that would be fine.” Read said the same strategy might also work to target insects that carry other diseases such as dengue and Japanese encephalitis. In a related study, Logan and colleagues also sealed human volunteers into a foil bag to collect their body odor as they grew hot and sweaty. The odors were then piped into a tube next door, alongside another tube untainted by human odor. Afterwards, mosquitoes were released and had the option of flying into either tube. The insects buzzed in droves into the smelly tube. Logan said the next step is to identify the chemicals in human foot odor so that it can be made synthetically for mosquito traps. But given mosquitoes' highly developed sense of smell, getting that formula right will be challenging. Some smelly cheeses have the same odor as feet, Logan noted. “But mosquitoes aren't attracted to cheese because they've evolved to know the difference,” he said. “You have to get the mixture, ratios and concentrations of those chemicals exactly right otherwise the mosquito won't think it's a human.” Scientists said it's crucial to understand the subtleties of mosquito behavior. Other studies have shown mosquitoes don't become attracted to humans for about two weeks - the time it takes for the malaria parasites to become infectious for humans. “At the moment, we only have these glimpses of how parasites are manipulating the mosquitoes,” said George Christophides, chair of infectious disease and immunity at Imperial College London. “We need to exploit that information to help us control malaria.”source : http://www.foxnews.com/health/2013/06/04/stench-human-feet-may-lead-to-better-malaria-traps/