06 October 2010

Allergy to cancer

Anastasia Reznichenko, the magazine "Results" No. 40-2010

Allergies and cancer are diseases that doctors are increasingly diagnosing today. About 8 million people die from cancer every year on the planet and 11 million new cases of tumors are registered. Moreover, according to the calculations of the World Health Organization, this figure will grow. At the same time, according to scientists, every second inhabitant of the Earth will be among the allergy sufferers in a few years. And this is the scope of the epidemic, which needs to be done something.
In modern research papers, paradoxical at first glance hypotheses are increasingly found, as if allergy sufferers are less likely than others to be included in the lists of cancer patients. Scientists have a new strategic goal – to understand the reasons for such a strange addiction in order to find the connecting thread between cancer and allergies. It is possible that, having discovered it, it will be possible to create an ideal weapon against two enemies of humanity at once.

Dry figuresBack in 2005, specialists from the Epidemiology Department of the American Cancer Society, together with colleagues from the Medical Faculty of the University of Ottawa (Canada), published the results of a large-scale study conducted from 1982 to 2000.

All this time, scientists have been following the medical histories of about a million Americans. At the time of the beginning of the experiment, the participants of the study had no manifestations of any malignant formations. At the same time, 14 percent of the subjects had asthma or hay fever in their medical history. By 2000, a little more than 80 thousand people died of cancer in the study group. Moreover, it turned out that allergy sufferers died of cancer ten percent less often than people who did not suffer from allergies. This gave rise to further research. Recently, a number of epidemiological studies have been completed in the USA and Canada, which partially confirmed that allergy sufferers are less likely to be among cancer patients. So, experts from the University of Texas found that patients with asthma have a 30 percent lower risk of ovarian cancer than women who are not allergic. According to another study, allergic children are 40 percent less likely to suffer from leukemia. According to epidemiologists from Cornell University in the USA, children with hypersensitivity to allergens have a lower risk of getting throat, skin or lung cancer in the future.

These studies have prompted scientists to think that allergies and cancer may be somehow related to each other. But how? It is known that tumors are formed from the body's own cells, in which, for one reason or another, genetic disorders have occurred. In this case, the human immune system does not resist and ignores neoplasms, since they do not seem alien to it. With the development of allergies in the body, the opposite happens – the immune system reacts aggressively to seemingly innocent substances, and then, as a result of complex biochemical processes, new biologically active substances are formed that trigger the pathological process. But why in one case does the body react to external aggressive interventions in the same way, and in the other – in a completely different way?

"Both asthma and cancer are multifactorial diseases, they arise when the genetic characteristics of an individual interact with the external environment in which he is located and the factors of which affect him," says Nadezhda Cherdyntseva, Deputy Director for Science of the Research Institute of Oncology of the Siberian Branch of the Russian Academy of Medical Sciences, Doctor of Biological Sciences. – The response of different people to the same damaging environmental factors may vary, and this ultimately determines the development of a particular disease. In conditions of adverse effects, the key role is played by genes that neutralize aggressive substances that can damage the genetic material of cells and lead to the development of cancer or cause a pathological response of the immune system in the form of allergies. The immune system exercises extracellular control over the genetic constancy of the organism."

Dr. Judith Schwarzbaum of the Ohio State University College of Public Health explains this using the example of glioma, the most common primary brain tumor: "In brain cancer, the immune system is suppressed, which leads to tumor growth. At the same time, the inadequate behavior of the immune system in case of allergies does not allow malignant cells to suppress immunity so easily, which means that the development of the tumor will be at least inhibited. But inflammation associated with allergies can also have a negative effect. It all depends on which tissues of the body are affected and whether there are cancer cells in the human body." What triggers these processes?

by the way
The vaccine has almost doubled the survival rate for brain cancerCopper news

An experimental vaccine has almost doubled the survival rates of patients with brain cancer, reports MSNBC (Brain cancer vaccine doubles survival). Clinical trials of the drug were conducted by a group of specialists led by John Sampson from Duke University in North Carolina, USA. A report on their work is published in the Journal of Clinical Oncology (John H. Sampson et al., Immunological Escape After Prolonged Progression-Free Survival With Epidermal Growth Factor ReceptorVariant III Peptide Vaccination in Patients With NewlyDiagnosed Glioblastoma).
35 patients with the most common and aggressive brain tumor, glioblastoma multiforme, were selected to participate in the study. All patients underwent radiation therapy and received the antitumor drug Temodar (temozolomide).
Injections of an experimental drug that prevents the formation of transmembrane receptors of epidermal growth factor type III (EGFRvIII), causing rapid growth of glioblastoma, were received by 18 study participants. The remaining patients were included in the control group.
According to the results of clinical trials, 82 percent of patients who were vaccinated stopped the formation of new EGFRvIII. At the same time, the average life expectancy of vaccinated patients was 26 months, while in the control group this indicator did not exceed 15 months.
The authors of the study noted that the new vaccine only affects the receptors of cancer cells, which makes its use safer compared to other drugs. EGFRVIII are found in cells not only of glioblastomas, but also of other malignant neoplasms, in connection with which scientists hope to use the drug to treat other types of cancer.

At the cellular levelIn search of the culprit, specialists from the Research Institute of Oncology of the Siberian Branch of the Russian Academy of Medical Sciences analyzed data on the possible role of so-called T-cells–regulators that monitor the activities of key actors of the immune system - T-lymphocytes.

T-lymphocytes-helpers (helpers, from English help) are divided into two types, each of which performs its own function. T-helpers 1 mostly contribute to the development of cellular immune response by activating T-killers that destroy the "enemy" – be it a microbe, a virus or genetically modified (malignant) own cells. T-helper 2 activates B-lymphocytes, contributing to the development of a humoral immune response (the development of special antibodies) – protecting the body from bacteria in the extracellular space and blood. They also trigger the development of allergies.

T regulatory cells that protect against pathological changes in the immune system maintain a balance between the activity of type 1 and type 2 T helper cells. By examining the content of T-cells of different types in the body of people suffering from allergies and those with malignant tumors, scientists have identified one very interesting pattern. Thus, with atopic disorders, T-regulators did not fully perform their function, as a result of which an imbalance of T-helpers in favor of type 2 was outlined. On the other hand, patients suffering from lung cancer had an accumulation of T-regulators, which was associated with a poor prognosis. The study of the mechanisms of regulatory cells in atopy and oncological pathology will allow in the future to create fundamentally new approaches for the treatment and prevention of diseases.

In turn, researchers from the Center for Physiology, Pathophysiology and Immunology of the Medical University of Vienna, led by Dr. Erica Jansen-Jarolim, focused on the effect of immunoglobulin E on cancer cells. Immunoglobulin E, for the production of which T-helpers of the second type are responsible, is considered the main mediator of allergic reactions. The experiment showed the suppressive effect of this immunoglobulin on some types of tumors with the development of hypersensitivity to allergens. Scientists managed to create a kind of vaccine, which was tested on rodents, and get a positive effect. In practice, it has been demonstrated that by provoking an allergy, it is possible to stop the development of a tumor. However, the researchers themselves note that this result is preliminary. In order to create a truly effective drug that will not give a side effect in the form of an acute allergic reaction, it is planned to influence T-cells involved in the allergic process in further studies. For today, this is perhaps the main task that immunologists have to solve.

Although researchers agree that there is a link between allergies and cancer and that this relationship is reversed, they are in no hurry to declare allergies a kind of panacea for cancer. The mechanisms that trigger both pathological processes are much more complicated than it seems. "Using the methods of molecular epidemiology," says Nadezhda Cherdyntseva, "we have shown that predisposition to lung cancer and asthma is associated with a change in the function of different genes. Previously, when comparing patients with glioma and asthma, such results were obtained by Dr. Schwarzbaum with respect to other genes." Since not one, but many different genes are responsible for allergic reactions of one type or another, there is still a lot of research to identify them. In fact, scientists have at their disposal an intricate DNA puzzle, in which many parts are currently missing. However, by putting it together, science can get the answer to how cancer can be overcome – and without a single sneeze.

Portal "Eternal youth" http://vechnayamolodost.ru06.10.2010

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