A description of the findings appears in the online early May edition of theProceedings of the National Academy of Sciences. “Blocking one of these cell-recruiting signals in a mouse’s tumor made it much less likely to metastasize or spread.If a drug can be found that safely blocks the same signal in humans, it could be a very useful addition to current breast cancer treatment — particularly for patients with chemotherapy-resistant tumors.” said Gregg Semenza, M.D., Ph.D., a professor and director of the Vascular Biology Program in theJohns Hopkins University School of Medicine’s Institute for Cell Engineering. Semenza’s research group studies a chemical signal called hypoxia-inducible factor 1 (HIF-1), which cells release to help them cope with low-oxygen conditions. Earlier, the group determined that HIF-1 helps breast tumor cells survive the low-oxygen conditions in which they often live, and spread to other parts of the body such as the lungs. “In breast cancer, it’s not the original tumor that kills patients, but the metastases.” said Semenza. Also in a previous study, Semenza’s group found that HIF-1 induced adult stem cells called mesenchymal stem cells release a signal to nearby breast cancer cells, which made them more likely to spread. The researchers suspected this communication might run both ways and that the stem cells’ presence might also help the cancer to recruit the host animal’s white blood cells. Breast cancers need the support of several types of host cells in order to metastasize, including mesenchymal stem cells and one type of white blood cell, Semenza notes. Studying tumor cells grown in a dish, Semenza’s team used chemicals that blocked the functions of various proteins to map a web of signals flying among breast cancer cells, menenchymal stem cells and white blood cells. One positive feedback loop brought mesenchymal stem cells close in to the breast cancer cells. A separate loop of signals between the stem cells and cancer cells caused the cancer cells to release a chemical “beacon” that drew in white blood cells. The concentrations of all the signals in the web were increased by the presence of HIF-1 — and ultimately, by low-oxygen conditions. The team then used genetic engineering to reduce the levels of the cell-recruiting signals in breast cancer cells and implanted those cells into female mice. Compared with unaltered breast cancer cells, those with reduced recruiting power grew into similar-sized tumors, Semenza says, but were much less likely to spread. All of the breast cancer cells used in the study were so-called triple-negative, meaning they lack receptors for estrogen, progesterone and human epidermal growth factor receptor 2, so they do not respond to therapies that target those receptors. In people, triple-negative breast cancers also tend to be more deadly than other breast cancers because they contain more HIF-1, Semenza says. “This study adds to the evidence that a HIF-1 inhibitor drug could be an effective addition to chemotherapy regimens, especially for triple-negative breast cancers.” he said. Several potential drugs of this kind are now in the early stages of development, he notes. References
For the original version including any supplementary images or video, visit http://www.stemcellsfreak.com/2014/05/signals-found-that-recruit-host-animals.html
Some, such as kidney damage thought to be caused by powerful poisons released by the bugs and arthritis triggered by a faulty immune response, occur within weeks. Others, such as high blood pressure, take years to appear. Long-term: Salmonella, E coli and other types of food poisoning may have lifelong consequences Experts say the chance that the link is coincidental is remote – and are calling for more to be done to identify victims of food poisoning and monitor their long-term health. Others say that prevention is key – and better hand and food hygiene would cut the number of cases of food poisoning and so the number of people left with lifelong complications. Why are so many seriously ill women misdiagnosed with IBS? GPs mix it with endometriosis, Crohn’s and even cancer… Almost 90,000 cases of food poisoning are recorded each year in England and Wales. However, the true number is likely to be closer to one million, as only a minority of victims will visit their doctor and give a sample that will be logged in the official statistics. Common bugs are E coli, usually caught from eating undercooked beef including mince and burgers; campylobacter, found in raw and undercooked meat, especially chicken; and salmonella, which is found in eggs, meat and milk. Studies have linked E coli (pictured) to kidney failure and diabetes While they can be fatal, most people recover after a few days. But this months issue of Scientific American warns that even a short bout of sickness or diarrhoea could have long-term consequences. Studies have linked E coli to kidney failure and diabetes and campylobacter to bowel problems and Guillain-Barre syndrome, a potentially fatal condition in which the immune system attacks the nerves, causing muscle weakness and paralysis. Salmonella has been blamed for a form of arthritis. Scientific American says: It is a scary idea that food poisoning – which we think of as lasting just a few days – could instead have lifelong after-effects. The incidence of such sequelae, in medical parlance, has been thought to be low, but not many researchers studied the problem until recently. New findings by several scientific teams suggest the phenomenon is more common than anyone thought. Figures are still relatively scarce. But one of the most stunning and persuasive studies was carried out on Canada after thousands of men and women became ill from drinking water contaminated with manure. A government-funded study found that, eight years later, those who suffered severe diarrhoea due to the dirty water were more than twice as likely to have had a heart attack or stroke than those who were unaffected or only mildly ill. Their risk of kidney problems was more than three times as high. They also had greater than normal odds of high blood pressure.
For the original version including any supplementary images or video, visit http://www.dailymail.co.uk/health/article-2117948/Food-poisoning-lifelong-consequences-bugs-linked-host-illnesses.html