(Press-News.org) A new drug called pyrvinium pamoate inhibits aggressive forms of prostate cancer that are resistant to standard drugs, according to a study conducted in an animal model. The results will be presented Monday at The Endocrine Society's 95th Annual Meeting in San Francisco.
"Our novel prostate cancer drug works by a unique mechanism of action," said study lead author Jeremy Jones, PhD, assistant professor of molecular pharmacology at City of Hope, Beckman Research Institute, in Duarte, CA. "Thus, it has the potential to treat cancers resistant to currently approved therapies."
Prostate cancer is the second-leading cause of cancer death, after lung cancer, among men in the United States, according to the American Cancer Society. The disease affects about one out of every six men, and more than 29,000 will die of prostate cancer this year alone.
An age-related disease, prostate cancer usually affects men who are 65 or older. In addition to advanced age, genes and certain environmental factors influence the development of prostate cancer, although the exact causes remain unknown.
In a healthy prostate gland, cells express a protein called androgen-receptor, or AR, which is activated by male sex hormones, or androgens, including the primary male hormone testosterone. These same receptors also play a role in promoting the growth of the abnormal cells of prostate cancer.
The drugs that are currently available to treat prostate cancer work by preventing androgen from binding to the AR. Specifically, the drugs block androgen from attaching to a certain part of the AR known as the ligand-binding domain. This domain is the part of the receptor that hormones bind to when they activate the receptor. By blocking all androgen activity, these drugs induce chemical castration.
The problem is that prostate-cancer cells usually become resistant to androgen blockage. After initially responding, these aggressive cancers develop mutations that enable them to spread, or metastasize, without the influence of androgens. For this reason, these aggressive prostate cancers are called castration-resistant.
In contrast, the study drug binds to a different part of the AR that does not require androgen, according to Jones. "Our new lead compound, pyrvinium pamoate, works by a unique mechanism that involves binding to a different site on the AR and inhibiting its activity without preventing androgen binding," he said. "We are hopeful that an optimized derivative of pyrvinium will be able to inhibit all AR activity and inhibit the growth of human prostate cancers that become resistant to other AR-targeted therapies and perhaps result in a curative metastatic prostate cancer therapy."
Investigators conducted this pre-clinical study using prostate-cancer cells in an animal model.
The National Institutes of Health's National Cancer Institute supported part of this study.
###
New medication treats drug-resistant prostate cancer in the laboratory
2013-06-18
ELSE PRESS RELEASES FROM THIS DATE:
Obesity leads to brain inflammation, and low testosterone makes it worse
2013-06-18
Low testosterone worsens the harmful effects of obesity in the nervous system, a new study in mice finds. The results will be presented Monday at The Endocrine Society's 95th Annual Meeting in San Francisco.
"Low testosterone and obesity are common in aging men, and each is associated with type 2 diabetes and Alzheimer's disease," said the study's lead investigator, Anusha Jayaraman, PhD, of the University of Southern California in Los Angeles. "Our new findings demonstrate that obesity and low testosterone combine to not only increase the risk of diabetes but also damage ...
Directed in vitro technique may increase insulin resistance among offspring
2013-06-18
A special type of in vitro fertilization, or IVF, may increase the risk for insulin resistance among children conceived in this way, according to a new study from Greece. The results will be presented Monday at The Endocrine Society's 95th Annual Meeting in San Francisco.
During natural fertilization, as well as other IVF treatments, the egg is exposed to many sperm. In both of these cases, the strongest, healthiest sperm has the best chance of reaching and fertilizing the egg.
In contrast, the type of assisted reproductive technology, or ART, examined in this study ...
Missing enzyme linked to drug addiction
2013-06-18
A missing brain enzyme increases concentrations of a protein related to pain-killer addiction, according to an animal study. The results will be presented Monday at The Endocrine Society's 95th Annual Meeting in San Francisco.
Opioids are pain-killing drugs, derived from the opium plant, which block signals of pain between nerves in the body. They are manufactured in prescription medications like morphine and codeine, and also are found in some illegal drugs, like heroin. Both legal and illegal opioids can be highly addictive.
In addition to the synthetic opioids, natural ...
New study shows predators affect the carbon cycle
2013-06-18
A new study shows that the predator-prey relationship can affect the flow of carbon through an ecosystem. This previously unmeasured influence on the environment may offer a new way of looking at biodiversity management and carbon storage for climate change.
The study, conducted by researchers at the Yale School of Forestry & Environmental Studies, comes out this week in the Proceedings of the National Academy of Sciences. It looks at the relationship between grasshoppers and spiders—herbivores and predators in the study's food chain—and how it affects the movement of ...
Preventing eggs' death from chemotherapy
2013-06-18
CHICAGO --- Young women who have cancer treatment often lose their fertility because chemotherapy and radiation can damage or kill their immature ovarian eggs, called oocytes. Now, Northwestern Medicine® scientists have found the molecular pathway that can prevent the death of immature ovarian eggs due to chemotherapy, potentially preserving fertility and endocrine function.
Scientists achieved this in female mice by adding a currently approved chemotherapy drug, imatinib mesylate, to another chemotherapy drug cisplatin.
The results will be presented Monday, June 17, ...
Observation is safe, cost-saving in low-risk prostate cancer
2013-06-18
BOSTON -- Many men with low-risk, localized prostate cancers can safely choose active surveillance or "watchful waiting" instead of undergoing immediate treatment and have better quality of life while reducing health care costs, according to a study by researchers at Dana-Farber Cancer Institute and Massachusetts General Hospital.
Writing in the June 18 issue of the Annals of Internal Medicine, the authors said their statistical models showed that "observation is a reasonable and, in some situations, cost-saving alternative to initial treatment" for the estimated 70 percent ...
Animal thyroid extract as effective as T4 in treating hypothyroidism
2013-06-18
San Francisco, CA— Desiccated thyroid extract (DTE), derived from crushed preparations of animal thyroid glands, is a safe and effective alternative to standard T4 therapy in hypothyroid patients, a new study finds. The results will be presented Monday at The Endocrine Society's 95th Annual Meeting in San Francisco.
In adults, untreated hypothyroidism leads to poor mental and physical performance. It also can cause high blood cholesterol levels that can lead to heart disease. The condition is treated with Levothyroxine, a synthetic (laboratory-made) form of T4 that is ...
Mayo Clinic: Rotavirus vaccine given to newborns in Africa is effective
2013-06-18
ROCHESTER, Minn. -- Mayo Clinic and other researchers have shown that a vaccine given to newborns is at least 60 percent effective against rotavirus in Ghana. Rotavirus causes fever, vomiting and diarrhea, which in infants can cause severe dehydration. In developed nations, the condition often results in an emergency room visit or an occasional hospitalization, but is rarely fatal. In developing countries, however, rotavirus-related illness causes approximately 500,000 deaths per year. The findings appear this week in the Journal of Infectious Diseases.
Currently, there ...
Saint Louis University researchers discover a way to detect new viruses
2013-06-18
ST. LOUIS -- In research published in Biochemical and Biophysical Research Communications, Saint Louis University researchers describe a technology that can detect new, previously unknown viruses. The technique offers the potential to screen patients for viruses even when doctors have not identified a particular virus as the likely source of an infection.
In the new approach, scientists use blood serum as a biological source to categorize and discover viruses.
Taking advantage of the complete deciphering of the human genome, SLU researchers used a next-generation ...
Multidisciplinary initiative reduces airway infection in pediatric intensive care patients
2013-06-18
An initiative that combines a multidisciplinary health care approach with a range of preventive measures could cut the rate of a common airway infection among children in intensive care by more than half, a new study suggests. The research, led by a team at Nationwide Children's Hospital, appears in the June issue of the journal Pediatric Critical Care Medicine.
Ventilator-associated tracheobronchitis—VAT for short—is a lower respiratory infection caused by a buildup of bacteria in the airway. Ordinarily, these small organisms are easily cleared, but being on a ventilator ...