Thought this was interesting in view of the many dogs we hear of having “scratching” issues.  I wonder if the unnaturally sterile environments we provide them is actually harmful (plus, Frontline, heartworm meds, shampoos, etc).?  These ongoing studies are targeted for humans who have increasing issues with allergies and asthma.  If it is environmentally caused, why wouldn’t our pets, who share our homes, not have similar issues cropping up?   I think I’ve done everyone a favor here by never washing the floors… -Andrea

Lice can be nice to us

PA 111/09

Parasite infestations might have a good side. Wild mice from a Nottinghamshire forest have given experts at The University of Nottingham clues as to the importance of some parasites, such as lice, for the conditioning of a “natural” immune system.

Jan Bradley, Professor of Parasitology, said: “Our understanding of mammalian immunology is largely based on rodents reared under highly unnatural pathogen and stress-free conditions. Analysing the immune response in wild populations can give crucial insights into how the immune system functions in its natural context.”

Many health problems in modern humans are caused by over-active immune responses. The immune system should be able to tell the difference between foreign invaders and its own body cells. But sometimes it can mistake self proteins for non self proteins triggering an attack on its own body and causing an autoimmune disease such as arthritis, asthma, diabetes or multiple sclerosis. Or the body can mistake a harmless substance as a threat causing an allergic response.

The authors say some parasites may exert a moderating effect on the function of a key component of the immune system, which could help reduce overall immune reactivity and the risk of developing immune dysfunctions.

Their research, published in the open access journal BMC Biology, links the louse Polyplax serrata to a strong dampening of certain immune responses in wild wood mice. This implies that other mammals, such as modern humans, that develop in artificial environments may have less regulated, overactive immune systems precisely because they are not exposed to parasites throughout their lives.  

The researchers speculate that the louse is able to exert some kind of immuno-suppressive effect, possibly directly by secreting some substance into the mice from its saliva, or indirectly by transmitting bacteria or other pathogens.

Professor Bradley said: “Much like laboratory mice, people in developed countries are currently exposed to a very different profile of infections to that encountered by their ancestors. It is possible that the immune dysfunctions we see today are the result of immune systems moulded by evolution for a set of challenges completely different to those encountered in modern times.”

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Notes to editors: The University of Nottingham is ranked in the UK’s Top 10 and the World’s Top 100 universities by the Shanghai Jiao Tong (SJTU) and Times Higher (THE) World University Rankings.

UVA Researchers Advise Caution in Use of SRC Inhibitors to Treat Bladder Cancer

CHARLOTTESVILLE, Va., March 25, 2009 – Researchers at the University of Virginia Health System have found that one of the genes commonly thought to promote the growth and spread of some types of cancers is in fact beneficial in bladder cancer – a major discovery that could significantly alter the way bladder cancers are treated in the future. 

Bladder cancer is the fifth most common cancer in the United States, resulting in an estimated 14,000 deaths a year.  A majority of these deaths are due to the cancer spreading, or metastasizing, to other areas of the body such as the lung and liver.

The study, published in the April issue of Proceedings of the National Academy of Sciences, shows that in bladder cancer the SRC gene may help rather than hinder the natural ability of cells to suppress aggressive tumor growth.  

“We found that SRC modifies a recently discovered metastasis suppressor gene called RhoGDI2 making it more potent at slowing bladder cancer’s ability to metastasize,” says lead author Dan Theodorescu, MD, PhD, professor of urologic oncology and molecular physiology at the UVA School of Medicine. 

SRC is a type of oncogene — genes that are known to trigger cancer.  In most cancers SRC has been shown to promote tumor development and contribute to the spread of cancer.  Other genes, called metastasis suppressor genes, block this activity, and only when their levels are reduced is cancer able to spread.

In the study, researchers analyzed human bladder cancer and discovered that SRC levels diminish as bladder cancer progresses.  Furthermore, they found that reduced SRC levels and significant levels of the metastasis suppressor gene, RhoGD12, appear mutually exclusive in individual tumors – providing evidence that both genes are likely involved in the process leading to suppression of bladder cancer metastases.

“Our findings have important implications for the use of targeted therapeutic agents that inhibit SRC in bladder cancer and highlight the general importance of personalizing therapy in cancer,” says Theodorescu.  “Our data suggest using caution for their use in treating bladder cancer until more studies are carried out to define the implications of this form of therapy in bladder cancer.”