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Showing posts with label Important. Show all posts
Showing posts with label Important. Show all posts

Friday, July 12, 2013

New Study Reveals Important Mechanism For Tumorigenesis

Main Category: Cancer / Oncology
Article Date: 08 May 2013 - 1:00 PDT Current ratings for:
New Study Reveals Important Mechanism For Tumorigenesis
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Cancer is a complex disease, in which cells undergo a series of alterations, including changes in their architecture; an increase in their ability to divide, to survive and to invade new tissues or metastasis. A category of genes, called oncogenes, is critical during cancer progression, as they codify proteins whose activity favours the development of cancer. One of these molecules, Src, is implicated in a large number of human cancers. However, it is still not clear how healthy cells constrain its activity not to become tumorous. In the latest issue of the journal Oncogene*, Florence Janody and her team at the Instituto Gulbenkian de Ciencia (IGC, Portugal), identified a novel mechanism by which the activity of Src is limited by the cell's skeleton (named cytoskeleton) limiting the development of tumours.

Using the fruit fly, Drosophila melanogaster, as a model, Florence Janody and her team were able to stop the tumour development induced by the high activity of Src through the genetic manipulation of the cytoskeleton in fly tissues. A major component of the cytoskeleton, the actin protein, form cables that crisscross the cell, creating a network, where molecules can move, inside the cell. These cables are constantly being elongated and shortened at their ends in a process tuned by molecules called actin-Capping Proteins. Florence Janody’s team showed that the development of tumours is stopped in the presence of high levels of the actin Capping Protein. This "tuner" restrains the activity of proteins that are usually activated by high levels of Src. Although the precise molecular mechanism is still unknown, the hypothesis raised by these scientists is that the "tuner" creates a tension in the cables of the cytoskeleton that impedes the action of these proteins. Conversely, the activity of Src is higher when the levels of the actin Capping Protein are lower, as the proteins activated by Src are able to escape the blocking effect of the network and act in the cell, resulting in the development of tumours. Thus, when the cytoskeleton network is not tightly regulated, the activity of oncogenes such as Src is not trapped and tumour development is observed.

Florence Janody says: "The cytoskeleton works as a "barbwire" network. The winner of the competition between molecules of the "barbwire" network and the Src oncogene, which fights against it, will determine whether the cell will stay healthy or become a cancer cell.

Beatriz Garcia Fernandez and Barbara Jezowska, first authors of this work added: "Our work suggests that the appearance of mutations in molecules that regulate the skeleton may play a significant role in inducing cancer development during the early stages of the disease by releasing the activity of oncogenes."

Src was the first oncogene described in the 1950s as capable to induce cancer. This discovery was awarded with the Nobel Prize in Physiology and Medicine in 1989.

Article adapted by Medical News Today from original press release. Click 'references' tab above for source.
Visit our cancer / oncology section for the latest news on this subject. This study was carried out at the IGC and was funded by Fundacao para a Ciencia e a Tecnologia (Portugal).

*Garcia Fernandez, B., Jezowska, B., and Janody, F. (2013) Drosophila actin-Capping Protein limits JNK activation by the Src proto-oncogene, Oncogene, May 6, doi:10.1038/onc.2013.155

Instituto Gulbenkian de Ciencia

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13 May. 2013. APA

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Wednesday, June 26, 2013

Three Important Studies Published In The June Issue Of Neurosurgery

Main Category: Neurology / Neuroscience
Also Included In: Cancer / Oncology
Article Date: 24 Jun 2013 - 0:00 PDT Current ratings for:
Three Important Studies Published In The June Issue Of Neurosurgery
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The results of three important studies have been published in the June issue of Neurosurgery, official journal of the Congress of Neurological Surgeons. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

One study indicates that continuous "machine learning" using artificial neural networks (ANNs) may improve the ability to predict survival in patients with advanced brain cancers. Another study in the June Neurosurgery supports increased use of stereotactic biopsy for obtaining samples of brainstem tumors; while another calls for medical professionals and specialty societies to play an increased role in evaluating "off label" uses of medications.

Artificial Neural Networks Predict Brain Cancer Prognosis

Dr. Matthew Ewend of University of North Carolina and colleagues evaluated the use of ANNs to predict the chances of survival for patients with brain cancer. Based on the biological functioning of brain cells, ANNs are computer programs designed "to learn patterns within a data set and then apply that learning for recognition and prediction."

The researchers performed a pilot study of ANNs using data on patients treated for advanced brain cancer at several hospitals. The results showed that ANNs beat standard prediction models for predicting patient survival. "Pooled voting" of five ANNs correctly predicted the risk of death within one year in 84 percent of patients, compared to 78 percent with a single ANN and 74 percent using standard statistical techniques.

The predictive power of ANNs would likely increase over time, providing a "facile and powerful means or predicting survival" in patients with brain cancers or other conditions. The researchers conclude, "With the explosion in clinical data over the past few years....we anticipate a growing need for modern machine learning techniques such as ANNs to properly make use of the information at our disposal and realize its full benefit for clinical care."

New Proposal for Evaluating 'Off Label' Uses of Medications

An improved process for evaluating "off label" use of drugs - using medications for purposes other than those for which they were approved - is described by Donlin Long, MD, PhD, of Johns Hopkins School of Medicine and Clark Watts, MD, JD, of University of Texas School of Law. They cite the example of bone morphogenetic protein-2 (BMP-2), a product approved to promote bone growth in one specific type of spinal fusion surgery.

After approval, surgeons started using BMP-2 for various other types of spinal surgery - leading to complications in some cases. The authors believe that problems resulting from "uncontrolled" off-label use have had a chilling effect, leading to missed opportunities to develop effective uses of BMP-2.

In the proposed approach, medical specialty societies such as the Congress of Neurological Surgeons would play a leading role in setting parameters for off-label use of new products, and in systematically gathering evidence of effectiveness. Drs. Long and Watts write, "Our goal is to challenge our professional societies to take a leadership role in the study of valid uses of new drugs and devices in a cooperative, constructive relationship with government regulators and industry."

Stereotactic Biopsy for Brainstem Tumors

Dr. Philipp Kickingereder of University Hospital of Cologne and colleagues present a review of research evidence on stereotactic biopsy - using triangulation techniques to precisely localize tumors - to obtain samples of uncommon brainstem cancers. While stereotactic biopsy is not a new technique, surgeons may hesitate to use it for brainstem tumors because of the perceived risks of the procedure.

But the available data show a diagnostic success rate of 96 percent, with a relatively low complication rates. Dr. Kickingereder and coauthors conclude that stereotactic biopsy is a safe and valuable procedure that provides samples for simultaneous tissue and genetic analysis - which may allow more individualized treatment. They recommend its use in all adult patients with brainstem cancers, as well as in certain groups of children.

Article adapted by Medical News Today from original press release. Click 'references' tab above for source.
Visit our neurology / neuroscience section for the latest news on this subject. Please use one of the following formats to cite this article in your essay, paper or report:

MLA

Health, Wolters Kluwer. "Three Important Studies Published In The June Issue Of Neurosurgery." Medical News Today. MediLexicon, Intl., 24 Jun. 2013. Web.
24 Jun. 2013. APA

Please note: If no author information is provided, the source is cited instead.


'Three Important Studies Published In The June Issue Of Neurosurgery'

Please note that we publish your name, but we do not publish your email address. It is only used to let you know when your message is published. We do not use it for any other purpose. Please see our privacy policy for more information.

If you write about specific medications or operations, please do not name health care professionals by name.

All opinions are moderated before being included (to stop spam)

Contact Our News Editors

For any corrections of factual information, or to contact the editors please use our feedback form.

Please send any medical news or health news press releases to:

Note: Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional. For more information, please read our terms and conditions.



View the original article here